--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/runtime/thread.cpp Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,4864 @@
+/*
+ * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#include "precompiled.hpp"
+#include "classfile/classLoader.hpp"
+#include "classfile/javaClasses.hpp"
+#include "classfile/moduleEntry.hpp"
+#include "classfile/systemDictionary.hpp"
+#include "classfile/vmSymbols.hpp"
+#include "code/codeCache.hpp"
+#include "code/scopeDesc.hpp"
+#include "compiler/compileBroker.hpp"
+#include "compiler/compileTask.hpp"
+#include "gc/shared/gcId.hpp"
+#include "gc/shared/gcLocker.inline.hpp"
+#include "gc/shared/workgroup.hpp"
+#include "interpreter/interpreter.hpp"
+#include "interpreter/linkResolver.hpp"
+#include "interpreter/oopMapCache.hpp"
+#include "jvmtifiles/jvmtiEnv.hpp"
+#include "logging/log.hpp"
+#include "logging/logConfiguration.hpp"
+#include "logging/logStream.hpp"
+#include "memory/metaspaceShared.hpp"
+#include "memory/oopFactory.hpp"
+#include "memory/resourceArea.hpp"
+#include "memory/universe.inline.hpp"
+#include "oops/instanceKlass.hpp"
+#include "oops/objArrayOop.hpp"
+#include "oops/oop.inline.hpp"
+#include "oops/symbol.hpp"
+#include "oops/verifyOopClosure.hpp"
+#include "prims/jvm.h"
+#include "prims/jvm_misc.hpp"
+#include "prims/jvmtiExport.hpp"
+#include "prims/jvmtiThreadState.hpp"
+#include "prims/privilegedStack.hpp"
+#include "runtime/arguments.hpp"
+#include "runtime/atomic.hpp"
+#include "runtime/biasedLocking.hpp"
+#include "runtime/commandLineFlagConstraintList.hpp"
+#include "runtime/commandLineFlagWriteableList.hpp"
+#include "runtime/commandLineFlagRangeList.hpp"
+#include "runtime/deoptimization.hpp"
+#include "runtime/frame.inline.hpp"
+#include "runtime/globals.hpp"
+#include "runtime/init.hpp"
+#include "runtime/interfaceSupport.hpp"
+#include "runtime/java.hpp"
+#include "runtime/javaCalls.hpp"
+#include "runtime/jniPeriodicChecker.hpp"
+#include "runtime/timerTrace.hpp"
+#include "runtime/memprofiler.hpp"
+#include "runtime/mutexLocker.hpp"
+#include "runtime/objectMonitor.hpp"
+#include "runtime/orderAccess.inline.hpp"
+#include "runtime/osThread.hpp"
+#include "runtime/safepoint.hpp"
+#include "runtime/sharedRuntime.hpp"
+#include "runtime/statSampler.hpp"
+#include "runtime/stubRoutines.hpp"
+#include "runtime/sweeper.hpp"
+#include "runtime/task.hpp"
+#include "runtime/thread.inline.hpp"
+#include "runtime/threadCritical.hpp"
+#include "runtime/vframe.hpp"
+#include "runtime/vframeArray.hpp"
+#include "runtime/vframe_hp.hpp"
+#include "runtime/vmThread.hpp"
+#include "runtime/vm_operations.hpp"
+#include "runtime/vm_version.hpp"
+#include "services/attachListener.hpp"
+#include "services/management.hpp"
+#include "services/memTracker.hpp"
+#include "services/threadService.hpp"
+#include "trace/traceMacros.hpp"
+#include "trace/tracing.hpp"
+#include "utilities/align.hpp"
+#include "utilities/defaultStream.hpp"
+#include "utilities/dtrace.hpp"
+#include "utilities/events.hpp"
+#include "utilities/macros.hpp"
+#include "utilities/preserveException.hpp"
+#include "utilities/vmError.hpp"
+#if INCLUDE_ALL_GCS
+#include "gc/cms/concurrentMarkSweepThread.hpp"
+#include "gc/g1/concurrentMarkThread.inline.hpp"
+#include "gc/parallel/pcTasks.hpp"
+#endif // INCLUDE_ALL_GCS
+#if INCLUDE_JVMCI
+#include "jvmci/jvmciCompiler.hpp"
+#include "jvmci/jvmciRuntime.hpp"
+#include "logging/logHandle.hpp"
+#endif
+#ifdef COMPILER1
+#include "c1/c1_Compiler.hpp"
+#endif
+#ifdef COMPILER2
+#include "opto/c2compiler.hpp"
+#include "opto/idealGraphPrinter.hpp"
+#endif
+#if INCLUDE_RTM_OPT
+#include "runtime/rtmLocking.hpp"
+#endif
+
+// Initialization after module runtime initialization
+void universe_post_module_init(); // must happen after call_initPhase2
+
+#ifdef DTRACE_ENABLED
+
+// Only bother with this argument setup if dtrace is available
+
+ #define HOTSPOT_THREAD_PROBE_start HOTSPOT_THREAD_START
+ #define HOTSPOT_THREAD_PROBE_stop HOTSPOT_THREAD_STOP
+
+ #define DTRACE_THREAD_PROBE(probe, javathread) \
+ { \
+ ResourceMark rm(this); \
+ int len = 0; \
+ const char* name = (javathread)->get_thread_name(); \
+ len = strlen(name); \
+ HOTSPOT_THREAD_PROBE_##probe(/* probe = start, stop */ \
+ (char *) name, len, \
+ java_lang_Thread::thread_id((javathread)->threadObj()), \
+ (uintptr_t) (javathread)->osthread()->thread_id(), \
+ java_lang_Thread::is_daemon((javathread)->threadObj())); \
+ }
+
+#else // ndef DTRACE_ENABLED
+
+ #define DTRACE_THREAD_PROBE(probe, javathread)
+
+#endif // ndef DTRACE_ENABLED
+
+#ifndef USE_LIBRARY_BASED_TLS_ONLY
+// Current thread is maintained as a thread-local variable
+THREAD_LOCAL_DECL Thread* Thread::_thr_current = NULL;
+#endif
+// Class hierarchy
+// - Thread
+// - VMThread
+// - WatcherThread
+// - ConcurrentMarkSweepThread
+// - JavaThread
+// - CompilerThread
+
+// ======= Thread ========
+// Support for forcing alignment of thread objects for biased locking
+void* Thread::allocate(size_t size, bool throw_excpt, MEMFLAGS flags) {
+ if (UseBiasedLocking) {
+ const int alignment = markOopDesc::biased_lock_alignment;
+ size_t aligned_size = size + (alignment - sizeof(intptr_t));
+ void* real_malloc_addr = throw_excpt? AllocateHeap(aligned_size, flags, CURRENT_PC)
+ : AllocateHeap(aligned_size, flags, CURRENT_PC,
+ AllocFailStrategy::RETURN_NULL);
+ void* aligned_addr = align_up(real_malloc_addr, alignment);
+ assert(((uintptr_t) aligned_addr + (uintptr_t) size) <=
+ ((uintptr_t) real_malloc_addr + (uintptr_t) aligned_size),
+ "JavaThread alignment code overflowed allocated storage");
+ if (aligned_addr != real_malloc_addr) {
+ log_info(biasedlocking)("Aligned thread " INTPTR_FORMAT " to " INTPTR_FORMAT,
+ p2i(real_malloc_addr),
+ p2i(aligned_addr));
+ }
+ ((Thread*) aligned_addr)->_real_malloc_address = real_malloc_addr;
+ return aligned_addr;
+ } else {
+ return throw_excpt? AllocateHeap(size, flags, CURRENT_PC)
+ : AllocateHeap(size, flags, CURRENT_PC, AllocFailStrategy::RETURN_NULL);
+ }
+}
+
+void Thread::operator delete(void* p) {
+ if (UseBiasedLocking) {
+ void* real_malloc_addr = ((Thread*) p)->_real_malloc_address;
+ FreeHeap(real_malloc_addr);
+ } else {
+ FreeHeap(p);
+ }
+}
+
+
+// Base class for all threads: VMThread, WatcherThread, ConcurrentMarkSweepThread,
+// JavaThread
+
+
+Thread::Thread() {
+ // stack and get_thread
+ set_stack_base(NULL);
+ set_stack_size(0);
+ set_self_raw_id(0);
+ set_lgrp_id(-1);
+ DEBUG_ONLY(clear_suspendible_thread();)
+
+ // allocated data structures
+ set_osthread(NULL);
+ set_resource_area(new (mtThread)ResourceArea());
+ DEBUG_ONLY(_current_resource_mark = NULL;)
+ set_handle_area(new (mtThread) HandleArea(NULL));
+ set_metadata_handles(new (ResourceObj::C_HEAP, mtClass) GrowableArray<Metadata*>(30, true));
+ set_active_handles(NULL);
+ set_free_handle_block(NULL);
+ set_last_handle_mark(NULL);
+
+ // This initial value ==> never claimed.
+ _oops_do_parity = 0;
+
+ // the handle mark links itself to last_handle_mark
+ new HandleMark(this);
+
+ // plain initialization
+ debug_only(_owned_locks = NULL;)
+ debug_only(_allow_allocation_count = 0;)
+ NOT_PRODUCT(_allow_safepoint_count = 0;)
+ NOT_PRODUCT(_skip_gcalot = false;)
+ _jvmti_env_iteration_count = 0;
+ set_allocated_bytes(0);
+ _vm_operation_started_count = 0;
+ _vm_operation_completed_count = 0;
+ _current_pending_monitor = NULL;
+ _current_pending_monitor_is_from_java = true;
+ _current_waiting_monitor = NULL;
+ _num_nested_signal = 0;
+ omFreeList = NULL;
+ omFreeCount = 0;
+ omFreeProvision = 32;
+ omInUseList = NULL;
+ omInUseCount = 0;
+
+#ifdef ASSERT
+ _visited_for_critical_count = false;
+#endif
+
+ _SR_lock = new Monitor(Mutex::suspend_resume, "SR_lock", true,
+ Monitor::_safepoint_check_sometimes);
+ _suspend_flags = 0;
+
+ // thread-specific hashCode stream generator state - Marsaglia shift-xor form
+ _hashStateX = os::random();
+ _hashStateY = 842502087;
+ _hashStateZ = 0x8767; // (int)(3579807591LL & 0xffff) ;
+ _hashStateW = 273326509;
+
+ _OnTrap = 0;
+ _schedctl = NULL;
+ _Stalled = 0;
+ _TypeTag = 0x2BAD;
+
+ // Many of the following fields are effectively final - immutable
+ // Note that nascent threads can't use the Native Monitor-Mutex
+ // construct until the _MutexEvent is initialized ...
+ // CONSIDER: instead of using a fixed set of purpose-dedicated ParkEvents
+ // we might instead use a stack of ParkEvents that we could provision on-demand.
+ // The stack would act as a cache to avoid calls to ParkEvent::Allocate()
+ // and ::Release()
+ _ParkEvent = ParkEvent::Allocate(this);
+ _SleepEvent = ParkEvent::Allocate(this);
+ _MutexEvent = ParkEvent::Allocate(this);
+ _MuxEvent = ParkEvent::Allocate(this);
+
+#ifdef CHECK_UNHANDLED_OOPS
+ if (CheckUnhandledOops) {
+ _unhandled_oops = new UnhandledOops(this);
+ }
+#endif // CHECK_UNHANDLED_OOPS
+#ifdef ASSERT
+ if (UseBiasedLocking) {
+ assert((((uintptr_t) this) & (markOopDesc::biased_lock_alignment - 1)) == 0, "forced alignment of thread object failed");
+ assert(this == _real_malloc_address ||
+ this == align_up(_real_malloc_address, (int)markOopDesc::biased_lock_alignment),
+ "bug in forced alignment of thread objects");
+ }
+#endif // ASSERT
+}
+
+void Thread::initialize_thread_current() {
+#ifndef USE_LIBRARY_BASED_TLS_ONLY
+ assert(_thr_current == NULL, "Thread::current already initialized");
+ _thr_current = this;
+#endif
+ assert(ThreadLocalStorage::thread() == NULL, "ThreadLocalStorage::thread already initialized");
+ ThreadLocalStorage::set_thread(this);
+ assert(Thread::current() == ThreadLocalStorage::thread(), "TLS mismatch!");
+}
+
+void Thread::clear_thread_current() {
+ assert(Thread::current() == ThreadLocalStorage::thread(), "TLS mismatch!");
+#ifndef USE_LIBRARY_BASED_TLS_ONLY
+ _thr_current = NULL;
+#endif
+ ThreadLocalStorage::set_thread(NULL);
+}
+
+void Thread::record_stack_base_and_size() {
+ set_stack_base(os::current_stack_base());
+ set_stack_size(os::current_stack_size());
+ // CR 7190089: on Solaris, primordial thread's stack is adjusted
+ // in initialize_thread(). Without the adjustment, stack size is
+ // incorrect if stack is set to unlimited (ulimit -s unlimited).
+ // So far, only Solaris has real implementation of initialize_thread().
+ //
+ // set up any platform-specific state.
+ os::initialize_thread(this);
+
+ // Set stack limits after thread is initialized.
+ if (is_Java_thread()) {
+ ((JavaThread*) this)->set_stack_overflow_limit();
+ ((JavaThread*) this)->set_reserved_stack_activation(stack_base());
+ }
+#if INCLUDE_NMT
+ // record thread's native stack, stack grows downward
+ MemTracker::record_thread_stack(stack_end(), stack_size());
+#endif // INCLUDE_NMT
+ log_debug(os, thread)("Thread " UINTX_FORMAT " stack dimensions: "
+ PTR_FORMAT "-" PTR_FORMAT " (" SIZE_FORMAT "k).",
+ os::current_thread_id(), p2i(stack_base() - stack_size()),
+ p2i(stack_base()), stack_size()/1024);
+}
+
+
+Thread::~Thread() {
+ EVENT_THREAD_DESTRUCT(this);
+
+ // stack_base can be NULL if the thread is never started or exited before
+ // record_stack_base_and_size called. Although, we would like to ensure
+ // that all started threads do call record_stack_base_and_size(), there is
+ // not proper way to enforce that.
+#if INCLUDE_NMT
+ if (_stack_base != NULL) {
+ MemTracker::release_thread_stack(stack_end(), stack_size());
+#ifdef ASSERT
+ set_stack_base(NULL);
+#endif
+ }
+#endif // INCLUDE_NMT
+
+ // deallocate data structures
+ delete resource_area();
+ // since the handle marks are using the handle area, we have to deallocated the root
+ // handle mark before deallocating the thread's handle area,
+ assert(last_handle_mark() != NULL, "check we have an element");
+ delete last_handle_mark();
+ assert(last_handle_mark() == NULL, "check we have reached the end");
+
+ // It's possible we can encounter a null _ParkEvent, etc., in stillborn threads.
+ // We NULL out the fields for good hygiene.
+ ParkEvent::Release(_ParkEvent); _ParkEvent = NULL;
+ ParkEvent::Release(_SleepEvent); _SleepEvent = NULL;
+ ParkEvent::Release(_MutexEvent); _MutexEvent = NULL;
+ ParkEvent::Release(_MuxEvent); _MuxEvent = NULL;
+
+ delete handle_area();
+ delete metadata_handles();
+
+ // SR_handler uses this as a termination indicator -
+ // needs to happen before os::free_thread()
+ delete _SR_lock;
+ _SR_lock = NULL;
+
+ // osthread() can be NULL, if creation of thread failed.
+ if (osthread() != NULL) os::free_thread(osthread());
+
+ // clear Thread::current if thread is deleting itself.
+ // Needed to ensure JNI correctly detects non-attached threads.
+ if (this == Thread::current()) {
+ clear_thread_current();
+ }
+
+ CHECK_UNHANDLED_OOPS_ONLY(if (CheckUnhandledOops) delete unhandled_oops();)
+}
+
+// NOTE: dummy function for assertion purpose.
+void Thread::run() {
+ ShouldNotReachHere();
+}
+
+#ifdef ASSERT
+// Private method to check for dangling thread pointer
+void check_for_dangling_thread_pointer(Thread *thread) {
+ assert(!thread->is_Java_thread() || Thread::current() == thread || Threads_lock->owned_by_self(),
+ "possibility of dangling Thread pointer");
+}
+#endif
+
+ThreadPriority Thread::get_priority(const Thread* const thread) {
+ ThreadPriority priority;
+ // Can return an error!
+ (void)os::get_priority(thread, priority);
+ assert(MinPriority <= priority && priority <= MaxPriority, "non-Java priority found");
+ return priority;
+}
+
+void Thread::set_priority(Thread* thread, ThreadPriority priority) {
+ debug_only(check_for_dangling_thread_pointer(thread);)
+ // Can return an error!
+ (void)os::set_priority(thread, priority);
+}
+
+
+void Thread::start(Thread* thread) {
+ // Start is different from resume in that its safety is guaranteed by context or
+ // being called from a Java method synchronized on the Thread object.
+ if (!DisableStartThread) {
+ if (thread->is_Java_thread()) {
+ // Initialize the thread state to RUNNABLE before starting this thread.
+ // Can not set it after the thread started because we do not know the
+ // exact thread state at that time. It could be in MONITOR_WAIT or
+ // in SLEEPING or some other state.
+ java_lang_Thread::set_thread_status(((JavaThread*)thread)->threadObj(),
+ java_lang_Thread::RUNNABLE);
+ }
+ os::start_thread(thread);
+ }
+}
+
+// Enqueue a VM_Operation to do the job for us - sometime later
+void Thread::send_async_exception(oop java_thread, oop java_throwable) {
+ VM_ThreadStop* vm_stop = new VM_ThreadStop(java_thread, java_throwable);
+ VMThread::execute(vm_stop);
+}
+
+
+// Check if an external suspend request has completed (or has been
+// cancelled). Returns true if the thread is externally suspended and
+// false otherwise.
+//
+// The bits parameter returns information about the code path through
+// the routine. Useful for debugging:
+//
+// set in is_ext_suspend_completed():
+// 0x00000001 - routine was entered
+// 0x00000010 - routine return false at end
+// 0x00000100 - thread exited (return false)
+// 0x00000200 - suspend request cancelled (return false)
+// 0x00000400 - thread suspended (return true)
+// 0x00001000 - thread is in a suspend equivalent state (return true)
+// 0x00002000 - thread is native and walkable (return true)
+// 0x00004000 - thread is native_trans and walkable (needed retry)
+//
+// set in wait_for_ext_suspend_completion():
+// 0x00010000 - routine was entered
+// 0x00020000 - suspend request cancelled before loop (return false)
+// 0x00040000 - thread suspended before loop (return true)
+// 0x00080000 - suspend request cancelled in loop (return false)
+// 0x00100000 - thread suspended in loop (return true)
+// 0x00200000 - suspend not completed during retry loop (return false)
+
+// Helper class for tracing suspend wait debug bits.
+//
+// 0x00000100 indicates that the target thread exited before it could
+// self-suspend which is not a wait failure. 0x00000200, 0x00020000 and
+// 0x00080000 each indicate a cancelled suspend request so they don't
+// count as wait failures either.
+#define DEBUG_FALSE_BITS (0x00000010 | 0x00200000)
+
+class TraceSuspendDebugBits : public StackObj {
+ private:
+ JavaThread * jt;
+ bool is_wait;
+ bool called_by_wait; // meaningful when !is_wait
+ uint32_t * bits;
+
+ public:
+ TraceSuspendDebugBits(JavaThread *_jt, bool _is_wait, bool _called_by_wait,
+ uint32_t *_bits) {
+ jt = _jt;
+ is_wait = _is_wait;
+ called_by_wait = _called_by_wait;
+ bits = _bits;
+ }
+
+ ~TraceSuspendDebugBits() {
+ if (!is_wait) {
+#if 1
+ // By default, don't trace bits for is_ext_suspend_completed() calls.
+ // That trace is very chatty.
+ return;
+#else
+ if (!called_by_wait) {
+ // If tracing for is_ext_suspend_completed() is enabled, then only
+ // trace calls to it from wait_for_ext_suspend_completion()
+ return;
+ }
+#endif
+ }
+
+ if (AssertOnSuspendWaitFailure || TraceSuspendWaitFailures) {
+ if (bits != NULL && (*bits & DEBUG_FALSE_BITS) != 0) {
+ MutexLocker ml(Threads_lock); // needed for get_thread_name()
+ ResourceMark rm;
+
+ tty->print_cr(
+ "Failed wait_for_ext_suspend_completion(thread=%s, debug_bits=%x)",
+ jt->get_thread_name(), *bits);
+
+ guarantee(!AssertOnSuspendWaitFailure, "external suspend wait failed");
+ }
+ }
+ }
+};
+#undef DEBUG_FALSE_BITS
+
+
+bool JavaThread::is_ext_suspend_completed(bool called_by_wait, int delay,
+ uint32_t *bits) {
+ TraceSuspendDebugBits tsdb(this, false /* !is_wait */, called_by_wait, bits);
+
+ bool did_trans_retry = false; // only do thread_in_native_trans retry once
+ bool do_trans_retry; // flag to force the retry
+
+ *bits |= 0x00000001;
+
+ do {
+ do_trans_retry = false;
+
+ if (is_exiting()) {
+ // Thread is in the process of exiting. This is always checked
+ // first to reduce the risk of dereferencing a freed JavaThread.
+ *bits |= 0x00000100;
+ return false;
+ }
+
+ if (!is_external_suspend()) {
+ // Suspend request is cancelled. This is always checked before
+ // is_ext_suspended() to reduce the risk of a rogue resume
+ // confusing the thread that made the suspend request.
+ *bits |= 0x00000200;
+ return false;
+ }
+
+ if (is_ext_suspended()) {
+ // thread is suspended
+ *bits |= 0x00000400;
+ return true;
+ }
+
+ // Now that we no longer do hard suspends of threads running
+ // native code, the target thread can be changing thread state
+ // while we are in this routine:
+ //
+ // _thread_in_native -> _thread_in_native_trans -> _thread_blocked
+ //
+ // We save a copy of the thread state as observed at this moment
+ // and make our decision about suspend completeness based on the
+ // copy. This closes the race where the thread state is seen as
+ // _thread_in_native_trans in the if-thread_blocked check, but is
+ // seen as _thread_blocked in if-thread_in_native_trans check.
+ JavaThreadState save_state = thread_state();
+
+ if (save_state == _thread_blocked && is_suspend_equivalent()) {
+ // If the thread's state is _thread_blocked and this blocking
+ // condition is known to be equivalent to a suspend, then we can
+ // consider the thread to be externally suspended. This means that
+ // the code that sets _thread_blocked has been modified to do
+ // self-suspension if the blocking condition releases. We also
+ // used to check for CONDVAR_WAIT here, but that is now covered by
+ // the _thread_blocked with self-suspension check.
+ //
+ // Return true since we wouldn't be here unless there was still an
+ // external suspend request.
+ *bits |= 0x00001000;
+ return true;
+ } else if (save_state == _thread_in_native && frame_anchor()->walkable()) {
+ // Threads running native code will self-suspend on native==>VM/Java
+ // transitions. If its stack is walkable (should always be the case
+ // unless this function is called before the actual java_suspend()
+ // call), then the wait is done.
+ *bits |= 0x00002000;
+ return true;
+ } else if (!called_by_wait && !did_trans_retry &&
+ save_state == _thread_in_native_trans &&
+ frame_anchor()->walkable()) {
+ // The thread is transitioning from thread_in_native to another
+ // thread state. check_safepoint_and_suspend_for_native_trans()
+ // will force the thread to self-suspend. If it hasn't gotten
+ // there yet we may have caught the thread in-between the native
+ // code check above and the self-suspend. Lucky us. If we were
+ // called by wait_for_ext_suspend_completion(), then it
+ // will be doing the retries so we don't have to.
+ //
+ // Since we use the saved thread state in the if-statement above,
+ // there is a chance that the thread has already transitioned to
+ // _thread_blocked by the time we get here. In that case, we will
+ // make a single unnecessary pass through the logic below. This
+ // doesn't hurt anything since we still do the trans retry.
+
+ *bits |= 0x00004000;
+
+ // Once the thread leaves thread_in_native_trans for another
+ // thread state, we break out of this retry loop. We shouldn't
+ // need this flag to prevent us from getting back here, but
+ // sometimes paranoia is good.
+ did_trans_retry = true;
+
+ // We wait for the thread to transition to a more usable state.
+ for (int i = 1; i <= SuspendRetryCount; i++) {
+ // We used to do an "os::yield_all(i)" call here with the intention
+ // that yielding would increase on each retry. However, the parameter
+ // is ignored on Linux which means the yield didn't scale up. Waiting
+ // on the SR_lock below provides a much more predictable scale up for
+ // the delay. It also provides a simple/direct point to check for any
+ // safepoint requests from the VMThread
+
+ // temporarily drops SR_lock while doing wait with safepoint check
+ // (if we're a JavaThread - the WatcherThread can also call this)
+ // and increase delay with each retry
+ SR_lock()->wait(!Thread::current()->is_Java_thread(), i * delay);
+
+ // check the actual thread state instead of what we saved above
+ if (thread_state() != _thread_in_native_trans) {
+ // the thread has transitioned to another thread state so
+ // try all the checks (except this one) one more time.
+ do_trans_retry = true;
+ break;
+ }
+ } // end retry loop
+
+
+ }
+ } while (do_trans_retry);
+
+ *bits |= 0x00000010;
+ return false;
+}
+
+// Wait for an external suspend request to complete (or be cancelled).
+// Returns true if the thread is externally suspended and false otherwise.
+//
+bool JavaThread::wait_for_ext_suspend_completion(int retries, int delay,
+ uint32_t *bits) {
+ TraceSuspendDebugBits tsdb(this, true /* is_wait */,
+ false /* !called_by_wait */, bits);
+
+ // local flag copies to minimize SR_lock hold time
+ bool is_suspended;
+ bool pending;
+ uint32_t reset_bits;
+
+ // set a marker so is_ext_suspend_completed() knows we are the caller
+ *bits |= 0x00010000;
+
+ // We use reset_bits to reinitialize the bits value at the top of
+ // each retry loop. This allows the caller to make use of any
+ // unused bits for their own marking purposes.
+ reset_bits = *bits;
+
+ {
+ MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
+ is_suspended = is_ext_suspend_completed(true /* called_by_wait */,
+ delay, bits);
+ pending = is_external_suspend();
+ }
+ // must release SR_lock to allow suspension to complete
+
+ if (!pending) {
+ // A cancelled suspend request is the only false return from
+ // is_ext_suspend_completed() that keeps us from entering the
+ // retry loop.
+ *bits |= 0x00020000;
+ return false;
+ }
+
+ if (is_suspended) {
+ *bits |= 0x00040000;
+ return true;
+ }
+
+ for (int i = 1; i <= retries; i++) {
+ *bits = reset_bits; // reinit to only track last retry
+
+ // We used to do an "os::yield_all(i)" call here with the intention
+ // that yielding would increase on each retry. However, the parameter
+ // is ignored on Linux which means the yield didn't scale up. Waiting
+ // on the SR_lock below provides a much more predictable scale up for
+ // the delay. It also provides a simple/direct point to check for any
+ // safepoint requests from the VMThread
+
+ {
+ MutexLocker ml(SR_lock());
+ // wait with safepoint check (if we're a JavaThread - the WatcherThread
+ // can also call this) and increase delay with each retry
+ SR_lock()->wait(!Thread::current()->is_Java_thread(), i * delay);
+
+ is_suspended = is_ext_suspend_completed(true /* called_by_wait */,
+ delay, bits);
+
+ // It is possible for the external suspend request to be cancelled
+ // (by a resume) before the actual suspend operation is completed.
+ // Refresh our local copy to see if we still need to wait.
+ pending = is_external_suspend();
+ }
+
+ if (!pending) {
+ // A cancelled suspend request is the only false return from
+ // is_ext_suspend_completed() that keeps us from staying in the
+ // retry loop.
+ *bits |= 0x00080000;
+ return false;
+ }
+
+ if (is_suspended) {
+ *bits |= 0x00100000;
+ return true;
+ }
+ } // end retry loop
+
+ // thread did not suspend after all our retries
+ *bits |= 0x00200000;
+ return false;
+}
+
+#ifndef PRODUCT
+void JavaThread::record_jump(address target, address instr, const char* file,
+ int line) {
+
+ // This should not need to be atomic as the only way for simultaneous
+ // updates is via interrupts. Even then this should be rare or non-existent
+ // and we don't care that much anyway.
+
+ int index = _jmp_ring_index;
+ _jmp_ring_index = (index + 1) & (jump_ring_buffer_size - 1);
+ _jmp_ring[index]._target = (intptr_t) target;
+ _jmp_ring[index]._instruction = (intptr_t) instr;
+ _jmp_ring[index]._file = file;
+ _jmp_ring[index]._line = line;
+}
+#endif // PRODUCT
+
+void Thread::interrupt(Thread* thread) {
+ debug_only(check_for_dangling_thread_pointer(thread);)
+ os::interrupt(thread);
+}
+
+bool Thread::is_interrupted(Thread* thread, bool clear_interrupted) {
+ debug_only(check_for_dangling_thread_pointer(thread);)
+ // Note: If clear_interrupted==false, this simply fetches and
+ // returns the value of the field osthread()->interrupted().
+ return os::is_interrupted(thread, clear_interrupted);
+}
+
+
+// GC Support
+bool Thread::claim_oops_do_par_case(int strong_roots_parity) {
+ jint thread_parity = _oops_do_parity;
+ if (thread_parity != strong_roots_parity) {
+ jint res = Atomic::cmpxchg(strong_roots_parity, &_oops_do_parity, thread_parity);
+ if (res == thread_parity) {
+ return true;
+ } else {
+ guarantee(res == strong_roots_parity, "Or else what?");
+ return false;
+ }
+ }
+ return false;
+}
+
+void Thread::oops_do(OopClosure* f, CodeBlobClosure* cf) {
+ active_handles()->oops_do(f);
+ // Do oop for ThreadShadow
+ f->do_oop((oop*)&_pending_exception);
+ handle_area()->oops_do(f);
+
+ if (MonitorInUseLists) {
+ // When using thread local monitor lists, we scan them here,
+ // and the remaining global monitors in ObjectSynchronizer::oops_do().
+ ObjectSynchronizer::thread_local_used_oops_do(this, f);
+ }
+}
+
+void Thread::metadata_handles_do(void f(Metadata*)) {
+ // Only walk the Handles in Thread.
+ if (metadata_handles() != NULL) {
+ for (int i = 0; i< metadata_handles()->length(); i++) {
+ f(metadata_handles()->at(i));
+ }
+ }
+}
+
+void Thread::print_on(outputStream* st) const {
+ // get_priority assumes osthread initialized
+ if (osthread() != NULL) {
+ int os_prio;
+ if (os::get_native_priority(this, &os_prio) == OS_OK) {
+ st->print("os_prio=%d ", os_prio);
+ }
+ st->print("tid=" INTPTR_FORMAT " ", p2i(this));
+ ext().print_on(st);
+ osthread()->print_on(st);
+ }
+ debug_only(if (WizardMode) print_owned_locks_on(st);)
+}
+
+// Thread::print_on_error() is called by fatal error handler. Don't use
+// any lock or allocate memory.
+void Thread::print_on_error(outputStream* st, char* buf, int buflen) const {
+ assert(!(is_Compiler_thread() || is_Java_thread()), "Can't call name() here if it allocates");
+
+ if (is_VM_thread()) { st->print("VMThread"); }
+ else if (is_GC_task_thread()) { st->print("GCTaskThread"); }
+ else if (is_Watcher_thread()) { st->print("WatcherThread"); }
+ else if (is_ConcurrentGC_thread()) { st->print("ConcurrentGCThread"); }
+ else { st->print("Thread"); }
+
+ if (is_Named_thread()) {
+ st->print(" \"%s\"", name());
+ }
+
+ st->print(" [stack: " PTR_FORMAT "," PTR_FORMAT "]",
+ p2i(stack_end()), p2i(stack_base()));
+
+ if (osthread()) {
+ st->print(" [id=%d]", osthread()->thread_id());
+ }
+}
+
+void Thread::print_value_on(outputStream* st) const {
+ if (is_Named_thread()) {
+ st->print(" \"%s\" ", name());
+ }
+ st->print(INTPTR_FORMAT, p2i(this)); // print address
+}
+
+#ifdef ASSERT
+void Thread::print_owned_locks_on(outputStream* st) const {
+ Monitor *cur = _owned_locks;
+ if (cur == NULL) {
+ st->print(" (no locks) ");
+ } else {
+ st->print_cr(" Locks owned:");
+ while (cur) {
+ cur->print_on(st);
+ cur = cur->next();
+ }
+ }
+}
+
+static int ref_use_count = 0;
+
+bool Thread::owns_locks_but_compiled_lock() const {
+ for (Monitor *cur = _owned_locks; cur; cur = cur->next()) {
+ if (cur != Compile_lock) return true;
+ }
+ return false;
+}
+
+
+#endif
+
+#ifndef PRODUCT
+
+// The flag: potential_vm_operation notifies if this particular safepoint state could potential
+// invoke the vm-thread (i.e., and oop allocation). In that case, we also have to make sure that
+// no threads which allow_vm_block's are held
+void Thread::check_for_valid_safepoint_state(bool potential_vm_operation) {
+ // Check if current thread is allowed to block at a safepoint
+ if (!(_allow_safepoint_count == 0)) {
+ fatal("Possible safepoint reached by thread that does not allow it");
+ }
+ if (is_Java_thread() && ((JavaThread*)this)->thread_state() != _thread_in_vm) {
+ fatal("LEAF method calling lock?");
+ }
+
+#ifdef ASSERT
+ if (potential_vm_operation && is_Java_thread()
+ && !Universe::is_bootstrapping()) {
+ // Make sure we do not hold any locks that the VM thread also uses.
+ // This could potentially lead to deadlocks
+ for (Monitor *cur = _owned_locks; cur; cur = cur->next()) {
+ // Threads_lock is special, since the safepoint synchronization will not start before this is
+ // acquired. Hence, a JavaThread cannot be holding it at a safepoint. So is VMOperationRequest_lock,
+ // since it is used to transfer control between JavaThreads and the VMThread
+ // Do not *exclude* any locks unless you are absolutely sure it is correct. Ask someone else first!
+ if ((cur->allow_vm_block() &&
+ cur != Threads_lock &&
+ cur != Compile_lock && // Temporary: should not be necessary when we get separate compilation
+ cur != VMOperationRequest_lock &&
+ cur != VMOperationQueue_lock) ||
+ cur->rank() == Mutex::special) {
+ fatal("Thread holding lock at safepoint that vm can block on: %s", cur->name());
+ }
+ }
+ }
+
+ if (GCALotAtAllSafepoints) {
+ // We could enter a safepoint here and thus have a gc
+ InterfaceSupport::check_gc_alot();
+ }
+#endif
+}
+#endif
+
+bool Thread::is_in_stack(address adr) const {
+ assert(Thread::current() == this, "is_in_stack can only be called from current thread");
+ address end = os::current_stack_pointer();
+ // Allow non Java threads to call this without stack_base
+ if (_stack_base == NULL) return true;
+ if (stack_base() >= adr && adr >= end) return true;
+
+ return false;
+}
+
+bool Thread::is_in_usable_stack(address adr) const {
+ size_t stack_guard_size = os::uses_stack_guard_pages() ? JavaThread::stack_guard_zone_size() : 0;
+ size_t usable_stack_size = _stack_size - stack_guard_size;
+
+ return ((adr < stack_base()) && (adr >= stack_base() - usable_stack_size));
+}
+
+
+// We had to move these methods here, because vm threads get into ObjectSynchronizer::enter
+// However, there is a note in JavaThread::is_lock_owned() about the VM threads not being
+// used for compilation in the future. If that change is made, the need for these methods
+// should be revisited, and they should be removed if possible.
+
+bool Thread::is_lock_owned(address adr) const {
+ return on_local_stack(adr);
+}
+
+bool Thread::set_as_starting_thread() {
+ // NOTE: this must be called inside the main thread.
+ return os::create_main_thread((JavaThread*)this);
+}
+
+static void initialize_class(Symbol* class_name, TRAPS) {
+ Klass* klass = SystemDictionary::resolve_or_fail(class_name, true, CHECK);
+ InstanceKlass::cast(klass)->initialize(CHECK);
+}
+
+
+// Creates the initial ThreadGroup
+static Handle create_initial_thread_group(TRAPS) {
+ Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_ThreadGroup(), true, CHECK_NH);
+ InstanceKlass* ik = InstanceKlass::cast(k);
+
+ Handle system_instance = ik->allocate_instance_handle(CHECK_NH);
+ {
+ JavaValue result(T_VOID);
+ JavaCalls::call_special(&result,
+ system_instance,
+ ik,
+ vmSymbols::object_initializer_name(),
+ vmSymbols::void_method_signature(),
+ CHECK_NH);
+ }
+ Universe::set_system_thread_group(system_instance());
+
+ Handle main_instance = ik->allocate_instance_handle(CHECK_NH);
+ {
+ JavaValue result(T_VOID);
+ Handle string = java_lang_String::create_from_str("main", CHECK_NH);
+ JavaCalls::call_special(&result,
+ main_instance,
+ ik,
+ vmSymbols::object_initializer_name(),
+ vmSymbols::threadgroup_string_void_signature(),
+ system_instance,
+ string,
+ CHECK_NH);
+ }
+ return main_instance;
+}
+
+// Creates the initial Thread
+static oop create_initial_thread(Handle thread_group, JavaThread* thread,
+ TRAPS) {
+ Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(), true, CHECK_NULL);
+ InstanceKlass* ik = InstanceKlass::cast(k);
+ instanceHandle thread_oop = ik->allocate_instance_handle(CHECK_NULL);
+
+ java_lang_Thread::set_thread(thread_oop(), thread);
+ java_lang_Thread::set_priority(thread_oop(), NormPriority);
+ thread->set_threadObj(thread_oop());
+
+ Handle string = java_lang_String::create_from_str("main", CHECK_NULL);
+
+ JavaValue result(T_VOID);
+ JavaCalls::call_special(&result, thread_oop,
+ ik,
+ vmSymbols::object_initializer_name(),
+ vmSymbols::threadgroup_string_void_signature(),
+ thread_group,
+ string,
+ CHECK_NULL);
+ return thread_oop();
+}
+
+char java_runtime_name[128] = "";
+char java_runtime_version[128] = "";
+
+// extract the JRE name from java.lang.VersionProps.java_runtime_name
+static const char* get_java_runtime_name(TRAPS) {
+ Klass* k = SystemDictionary::find(vmSymbols::java_lang_VersionProps(),
+ Handle(), Handle(), CHECK_AND_CLEAR_NULL);
+ fieldDescriptor fd;
+ bool found = k != NULL &&
+ InstanceKlass::cast(k)->find_local_field(vmSymbols::java_runtime_name_name(),
+ vmSymbols::string_signature(), &fd);
+ if (found) {
+ oop name_oop = k->java_mirror()->obj_field(fd.offset());
+ if (name_oop == NULL) {
+ return NULL;
+ }
+ const char* name = java_lang_String::as_utf8_string(name_oop,
+ java_runtime_name,
+ sizeof(java_runtime_name));
+ return name;
+ } else {
+ return NULL;
+ }
+}
+
+// extract the JRE version from java.lang.VersionProps.java_runtime_version
+static const char* get_java_runtime_version(TRAPS) {
+ Klass* k = SystemDictionary::find(vmSymbols::java_lang_VersionProps(),
+ Handle(), Handle(), CHECK_AND_CLEAR_NULL);
+ fieldDescriptor fd;
+ bool found = k != NULL &&
+ InstanceKlass::cast(k)->find_local_field(vmSymbols::java_runtime_version_name(),
+ vmSymbols::string_signature(), &fd);
+ if (found) {
+ oop name_oop = k->java_mirror()->obj_field(fd.offset());
+ if (name_oop == NULL) {
+ return NULL;
+ }
+ const char* name = java_lang_String::as_utf8_string(name_oop,
+ java_runtime_version,
+ sizeof(java_runtime_version));
+ return name;
+ } else {
+ return NULL;
+ }
+}
+
+// General purpose hook into Java code, run once when the VM is initialized.
+// The Java library method itself may be changed independently from the VM.
+static void call_postVMInitHook(TRAPS) {
+ Klass* klass = SystemDictionary::resolve_or_null(vmSymbols::jdk_internal_vm_PostVMInitHook(), THREAD);
+ if (klass != NULL) {
+ JavaValue result(T_VOID);
+ JavaCalls::call_static(&result, klass, vmSymbols::run_method_name(),
+ vmSymbols::void_method_signature(),
+ CHECK);
+ }
+}
+
+static void reset_vm_info_property(TRAPS) {
+ // the vm info string
+ ResourceMark rm(THREAD);
+ const char *vm_info = VM_Version::vm_info_string();
+
+ // java.lang.System class
+ Klass* klass = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_System(), true, CHECK);
+
+ // setProperty arguments
+ Handle key_str = java_lang_String::create_from_str("java.vm.info", CHECK);
+ Handle value_str = java_lang_String::create_from_str(vm_info, CHECK);
+
+ // return value
+ JavaValue r(T_OBJECT);
+
+ // public static String setProperty(String key, String value);
+ JavaCalls::call_static(&r,
+ klass,
+ vmSymbols::setProperty_name(),
+ vmSymbols::string_string_string_signature(),
+ key_str,
+ value_str,
+ CHECK);
+}
+
+
+void JavaThread::allocate_threadObj(Handle thread_group, const char* thread_name,
+ bool daemon, TRAPS) {
+ assert(thread_group.not_null(), "thread group should be specified");
+ assert(threadObj() == NULL, "should only create Java thread object once");
+
+ Klass* k = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_Thread(), true, CHECK);
+ InstanceKlass* ik = InstanceKlass::cast(k);
+ instanceHandle thread_oop = ik->allocate_instance_handle(CHECK);
+
+ java_lang_Thread::set_thread(thread_oop(), this);
+ java_lang_Thread::set_priority(thread_oop(), NormPriority);
+ set_threadObj(thread_oop());
+
+ JavaValue result(T_VOID);
+ if (thread_name != NULL) {
+ Handle name = java_lang_String::create_from_str(thread_name, CHECK);
+ // Thread gets assigned specified name and null target
+ JavaCalls::call_special(&result,
+ thread_oop,
+ ik,
+ vmSymbols::object_initializer_name(),
+ vmSymbols::threadgroup_string_void_signature(),
+ thread_group, // Argument 1
+ name, // Argument 2
+ THREAD);
+ } else {
+ // Thread gets assigned name "Thread-nnn" and null target
+ // (java.lang.Thread doesn't have a constructor taking only a ThreadGroup argument)
+ JavaCalls::call_special(&result,
+ thread_oop,
+ ik,
+ vmSymbols::object_initializer_name(),
+ vmSymbols::threadgroup_runnable_void_signature(),
+ thread_group, // Argument 1
+ Handle(), // Argument 2
+ THREAD);
+ }
+
+
+ if (daemon) {
+ java_lang_Thread::set_daemon(thread_oop());
+ }
+
+ if (HAS_PENDING_EXCEPTION) {
+ return;
+ }
+
+ Klass* group = SystemDictionary::ThreadGroup_klass();
+ Handle threadObj(THREAD, this->threadObj());
+
+ JavaCalls::call_special(&result,
+ thread_group,
+ group,
+ vmSymbols::add_method_name(),
+ vmSymbols::thread_void_signature(),
+ threadObj, // Arg 1
+ THREAD);
+}
+
+// NamedThread -- non-JavaThread subclasses with multiple
+// uniquely named instances should derive from this.
+NamedThread::NamedThread() : Thread() {
+ _name = NULL;
+ _processed_thread = NULL;
+ _gc_id = GCId::undefined();
+}
+
+NamedThread::~NamedThread() {
+ if (_name != NULL) {
+ FREE_C_HEAP_ARRAY(char, _name);
+ _name = NULL;
+ }
+}
+
+void NamedThread::set_name(const char* format, ...) {
+ guarantee(_name == NULL, "Only get to set name once.");
+ _name = NEW_C_HEAP_ARRAY(char, max_name_len, mtThread);
+ guarantee(_name != NULL, "alloc failure");
+ va_list ap;
+ va_start(ap, format);
+ jio_vsnprintf(_name, max_name_len, format, ap);
+ va_end(ap);
+}
+
+void NamedThread::initialize_named_thread() {
+ set_native_thread_name(name());
+}
+
+void NamedThread::print_on(outputStream* st) const {
+ st->print("\"%s\" ", name());
+ Thread::print_on(st);
+ st->cr();
+}
+
+
+// ======= WatcherThread ========
+
+// The watcher thread exists to simulate timer interrupts. It should
+// be replaced by an abstraction over whatever native support for
+// timer interrupts exists on the platform.
+
+WatcherThread* WatcherThread::_watcher_thread = NULL;
+bool WatcherThread::_startable = false;
+volatile bool WatcherThread::_should_terminate = false;
+
+WatcherThread::WatcherThread() : Thread() {
+ assert(watcher_thread() == NULL, "we can only allocate one WatcherThread");
+ if (os::create_thread(this, os::watcher_thread)) {
+ _watcher_thread = this;
+
+ // Set the watcher thread to the highest OS priority which should not be
+ // used, unless a Java thread with priority java.lang.Thread.MAX_PRIORITY
+ // is created. The only normal thread using this priority is the reference
+ // handler thread, which runs for very short intervals only.
+ // If the VMThread's priority is not lower than the WatcherThread profiling
+ // will be inaccurate.
+ os::set_priority(this, MaxPriority);
+ if (!DisableStartThread) {
+ os::start_thread(this);
+ }
+ }
+}
+
+int WatcherThread::sleep() const {
+ // The WatcherThread does not participate in the safepoint protocol
+ // for the PeriodicTask_lock because it is not a JavaThread.
+ MutexLockerEx ml(PeriodicTask_lock, Mutex::_no_safepoint_check_flag);
+
+ if (_should_terminate) {
+ // check for termination before we do any housekeeping or wait
+ return 0; // we did not sleep.
+ }
+
+ // remaining will be zero if there are no tasks,
+ // causing the WatcherThread to sleep until a task is
+ // enrolled
+ int remaining = PeriodicTask::time_to_wait();
+ int time_slept = 0;
+
+ // we expect this to timeout - we only ever get unparked when
+ // we should terminate or when a new task has been enrolled
+ OSThreadWaitState osts(this->osthread(), false /* not Object.wait() */);
+
+ jlong time_before_loop = os::javaTimeNanos();
+
+ while (true) {
+ bool timedout = PeriodicTask_lock->wait(Mutex::_no_safepoint_check_flag,
+ remaining);
+ jlong now = os::javaTimeNanos();
+
+ if (remaining == 0) {
+ // if we didn't have any tasks we could have waited for a long time
+ // consider the time_slept zero and reset time_before_loop
+ time_slept = 0;
+ time_before_loop = now;
+ } else {
+ // need to recalculate since we might have new tasks in _tasks
+ time_slept = (int) ((now - time_before_loop) / 1000000);
+ }
+
+ // Change to task list or spurious wakeup of some kind
+ if (timedout || _should_terminate) {
+ break;
+ }
+
+ remaining = PeriodicTask::time_to_wait();
+ if (remaining == 0) {
+ // Last task was just disenrolled so loop around and wait until
+ // another task gets enrolled
+ continue;
+ }
+
+ remaining -= time_slept;
+ if (remaining <= 0) {
+ break;
+ }
+ }
+
+ return time_slept;
+}
+
+void WatcherThread::run() {
+ assert(this == watcher_thread(), "just checking");
+
+ this->record_stack_base_and_size();
+ this->set_native_thread_name(this->name());
+ this->set_active_handles(JNIHandleBlock::allocate_block());
+ while (true) {
+ assert(watcher_thread() == Thread::current(), "thread consistency check");
+ assert(watcher_thread() == this, "thread consistency check");
+
+ // Calculate how long it'll be until the next PeriodicTask work
+ // should be done, and sleep that amount of time.
+ int time_waited = sleep();
+
+ if (VMError::is_error_reported()) {
+ // A fatal error has happened, the error handler(VMError::report_and_die)
+ // should abort JVM after creating an error log file. However in some
+ // rare cases, the error handler itself might deadlock. Here periodically
+ // check for error reporting timeouts, and if it happens, just proceed to
+ // abort the VM.
+
+ // This code is in WatcherThread because WatcherThread wakes up
+ // periodically so the fatal error handler doesn't need to do anything;
+ // also because the WatcherThread is less likely to crash than other
+ // threads.
+
+ for (;;) {
+ // Note: we use naked sleep in this loop because we want to avoid using
+ // any kind of VM infrastructure which may be broken at this point.
+ if (VMError::check_timeout()) {
+ // We hit error reporting timeout. Error reporting was interrupted and
+ // will be wrapping things up now (closing files etc). Give it some more
+ // time, then quit the VM.
+ os::naked_short_sleep(200);
+ // Print a message to stderr.
+ fdStream err(defaultStream::output_fd());
+ err.print_raw_cr("# [ timer expired, abort... ]");
+ // skip atexit/vm_exit/vm_abort hooks
+ os::die();
+ }
+
+ // Wait a second, then recheck for timeout.
+ os::naked_short_sleep(999);
+ }
+ }
+
+ if (_should_terminate) {
+ // check for termination before posting the next tick
+ break;
+ }
+
+ PeriodicTask::real_time_tick(time_waited);
+ }
+
+ // Signal that it is terminated
+ {
+ MutexLockerEx mu(Terminator_lock, Mutex::_no_safepoint_check_flag);
+ _watcher_thread = NULL;
+ Terminator_lock->notify();
+ }
+}
+
+void WatcherThread::start() {
+ assert(PeriodicTask_lock->owned_by_self(), "PeriodicTask_lock required");
+
+ if (watcher_thread() == NULL && _startable) {
+ _should_terminate = false;
+ // Create the single instance of WatcherThread
+ new WatcherThread();
+ }
+}
+
+void WatcherThread::make_startable() {
+ assert(PeriodicTask_lock->owned_by_self(), "PeriodicTask_lock required");
+ _startable = true;
+}
+
+void WatcherThread::stop() {
+ {
+ // Follow normal safepoint aware lock enter protocol since the
+ // WatcherThread is stopped by another JavaThread.
+ MutexLocker ml(PeriodicTask_lock);
+ _should_terminate = true;
+
+ WatcherThread* watcher = watcher_thread();
+ if (watcher != NULL) {
+ // unpark the WatcherThread so it can see that it should terminate
+ watcher->unpark();
+ }
+ }
+
+ MutexLocker mu(Terminator_lock);
+
+ while (watcher_thread() != NULL) {
+ // This wait should make safepoint checks, wait without a timeout,
+ // and wait as a suspend-equivalent condition.
+ Terminator_lock->wait(!Mutex::_no_safepoint_check_flag, 0,
+ Mutex::_as_suspend_equivalent_flag);
+ }
+}
+
+void WatcherThread::unpark() {
+ assert(PeriodicTask_lock->owned_by_self(), "PeriodicTask_lock required");
+ PeriodicTask_lock->notify();
+}
+
+void WatcherThread::print_on(outputStream* st) const {
+ st->print("\"%s\" ", name());
+ Thread::print_on(st);
+ st->cr();
+}
+
+// ======= JavaThread ========
+
+#if INCLUDE_JVMCI
+
+jlong* JavaThread::_jvmci_old_thread_counters;
+
+bool jvmci_counters_include(JavaThread* thread) {
+ oop threadObj = thread->threadObj();
+ return !JVMCICountersExcludeCompiler || !thread->is_Compiler_thread();
+}
+
+void JavaThread::collect_counters(typeArrayOop array) {
+ if (JVMCICounterSize > 0) {
+ MutexLocker tl(Threads_lock);
+ for (int i = 0; i < array->length(); i++) {
+ array->long_at_put(i, _jvmci_old_thread_counters[i]);
+ }
+ for (JavaThread* tp = Threads::first(); tp != NULL; tp = tp->next()) {
+ if (jvmci_counters_include(tp)) {
+ for (int i = 0; i < array->length(); i++) {
+ array->long_at_put(i, array->long_at(i) + tp->_jvmci_counters[i]);
+ }
+ }
+ }
+ }
+}
+
+#endif // INCLUDE_JVMCI
+
+// A JavaThread is a normal Java thread
+
+void JavaThread::initialize() {
+ // Initialize fields
+
+ set_saved_exception_pc(NULL);
+ set_threadObj(NULL);
+ _anchor.clear();
+ set_entry_point(NULL);
+ set_jni_functions(jni_functions());
+ set_callee_target(NULL);
+ set_vm_result(NULL);
+ set_vm_result_2(NULL);
+ set_vframe_array_head(NULL);
+ set_vframe_array_last(NULL);
+ set_deferred_locals(NULL);
+ set_deopt_mark(NULL);
+ set_deopt_compiled_method(NULL);
+ clear_must_deopt_id();
+ set_monitor_chunks(NULL);
+ set_next(NULL);
+ set_thread_state(_thread_new);
+ _terminated = _not_terminated;
+ _privileged_stack_top = NULL;
+ _array_for_gc = NULL;
+ _suspend_equivalent = false;
+ _in_deopt_handler = 0;
+ _doing_unsafe_access = false;
+ _stack_guard_state = stack_guard_unused;
+#if INCLUDE_JVMCI
+ _pending_monitorenter = false;
+ _pending_deoptimization = -1;
+ _pending_failed_speculation = NULL;
+ _pending_transfer_to_interpreter = false;
+ _adjusting_comp_level = false;
+ _jvmci._alternate_call_target = NULL;
+ assert(_jvmci._implicit_exception_pc == NULL, "must be");
+ if (JVMCICounterSize > 0) {
+ _jvmci_counters = NEW_C_HEAP_ARRAY(jlong, JVMCICounterSize, mtInternal);
+ memset(_jvmci_counters, 0, sizeof(jlong) * JVMCICounterSize);
+ } else {
+ _jvmci_counters = NULL;
+ }
+#endif // INCLUDE_JVMCI
+ _reserved_stack_activation = NULL; // stack base not known yet
+ (void)const_cast<oop&>(_exception_oop = oop(NULL));
+ _exception_pc = 0;
+ _exception_handler_pc = 0;
+ _is_method_handle_return = 0;
+ _jvmti_thread_state= NULL;
+ _should_post_on_exceptions_flag = JNI_FALSE;
+ _jvmti_get_loaded_classes_closure = NULL;
+ _interp_only_mode = 0;
+ _special_runtime_exit_condition = _no_async_condition;
+ _pending_async_exception = NULL;
+ _thread_stat = NULL;
+ _thread_stat = new ThreadStatistics();
+ _blocked_on_compilation = false;
+ _jni_active_critical = 0;
+ _pending_jni_exception_check_fn = NULL;
+ _do_not_unlock_if_synchronized = false;
+ _cached_monitor_info = NULL;
+ _parker = Parker::Allocate(this);
+
+#ifndef PRODUCT
+ _jmp_ring_index = 0;
+ for (int ji = 0; ji < jump_ring_buffer_size; ji++) {
+ record_jump(NULL, NULL, NULL, 0);
+ }
+#endif // PRODUCT
+
+ // Setup safepoint state info for this thread
+ ThreadSafepointState::create(this);
+
+ debug_only(_java_call_counter = 0);
+
+ // JVMTI PopFrame support
+ _popframe_condition = popframe_inactive;
+ _popframe_preserved_args = NULL;
+ _popframe_preserved_args_size = 0;
+ _frames_to_pop_failed_realloc = 0;
+
+ pd_initialize();
+}
+
+#if INCLUDE_ALL_GCS
+SATBMarkQueueSet JavaThread::_satb_mark_queue_set;
+DirtyCardQueueSet JavaThread::_dirty_card_queue_set;
+#endif // INCLUDE_ALL_GCS
+
+JavaThread::JavaThread(bool is_attaching_via_jni) :
+ Thread()
+#if INCLUDE_ALL_GCS
+ , _satb_mark_queue(&_satb_mark_queue_set),
+ _dirty_card_queue(&_dirty_card_queue_set)
+#endif // INCLUDE_ALL_GCS
+{
+ initialize();
+ if (is_attaching_via_jni) {
+ _jni_attach_state = _attaching_via_jni;
+ } else {
+ _jni_attach_state = _not_attaching_via_jni;
+ }
+ assert(deferred_card_mark().is_empty(), "Default MemRegion ctor");
+}
+
+bool JavaThread::reguard_stack(address cur_sp) {
+ if (_stack_guard_state != stack_guard_yellow_reserved_disabled
+ && _stack_guard_state != stack_guard_reserved_disabled) {
+ return true; // Stack already guarded or guard pages not needed.
+ }
+
+ if (register_stack_overflow()) {
+ // For those architectures which have separate register and
+ // memory stacks, we must check the register stack to see if
+ // it has overflowed.
+ return false;
+ }
+
+ // Java code never executes within the yellow zone: the latter is only
+ // there to provoke an exception during stack banging. If java code
+ // is executing there, either StackShadowPages should be larger, or
+ // some exception code in c1, c2 or the interpreter isn't unwinding
+ // when it should.
+ guarantee(cur_sp > stack_reserved_zone_base(),
+ "not enough space to reguard - increase StackShadowPages");
+ if (_stack_guard_state == stack_guard_yellow_reserved_disabled) {
+ enable_stack_yellow_reserved_zone();
+ if (reserved_stack_activation() != stack_base()) {
+ set_reserved_stack_activation(stack_base());
+ }
+ } else if (_stack_guard_state == stack_guard_reserved_disabled) {
+ set_reserved_stack_activation(stack_base());
+ enable_stack_reserved_zone();
+ }
+ return true;
+}
+
+bool JavaThread::reguard_stack(void) {
+ return reguard_stack(os::current_stack_pointer());
+}
+
+
+void JavaThread::block_if_vm_exited() {
+ if (_terminated == _vm_exited) {
+ // _vm_exited is set at safepoint, and Threads_lock is never released
+ // we will block here forever
+ Threads_lock->lock_without_safepoint_check();
+ ShouldNotReachHere();
+ }
+}
+
+
+// Remove this ifdef when C1 is ported to the compiler interface.
+static void compiler_thread_entry(JavaThread* thread, TRAPS);
+static void sweeper_thread_entry(JavaThread* thread, TRAPS);
+
+JavaThread::JavaThread(ThreadFunction entry_point, size_t stack_sz) :
+ Thread()
+#if INCLUDE_ALL_GCS
+ , _satb_mark_queue(&_satb_mark_queue_set),
+ _dirty_card_queue(&_dirty_card_queue_set)
+#endif // INCLUDE_ALL_GCS
+{
+ initialize();
+ _jni_attach_state = _not_attaching_via_jni;
+ set_entry_point(entry_point);
+ // Create the native thread itself.
+ // %note runtime_23
+ os::ThreadType thr_type = os::java_thread;
+ thr_type = entry_point == &compiler_thread_entry ? os::compiler_thread :
+ os::java_thread;
+ os::create_thread(this, thr_type, stack_sz);
+ // The _osthread may be NULL here because we ran out of memory (too many threads active).
+ // We need to throw and OutOfMemoryError - however we cannot do this here because the caller
+ // may hold a lock and all locks must be unlocked before throwing the exception (throwing
+ // the exception consists of creating the exception object & initializing it, initialization
+ // will leave the VM via a JavaCall and then all locks must be unlocked).
+ //
+ // The thread is still suspended when we reach here. Thread must be explicit started
+ // by creator! Furthermore, the thread must also explicitly be added to the Threads list
+ // by calling Threads:add. The reason why this is not done here, is because the thread
+ // object must be fully initialized (take a look at JVM_Start)
+}
+
+JavaThread::~JavaThread() {
+
+ // JSR166 -- return the parker to the free list
+ Parker::Release(_parker);
+ _parker = NULL;
+
+ // Free any remaining previous UnrollBlock
+ vframeArray* old_array = vframe_array_last();
+
+ if (old_array != NULL) {
+ Deoptimization::UnrollBlock* old_info = old_array->unroll_block();
+ old_array->set_unroll_block(NULL);
+ delete old_info;
+ delete old_array;
+ }
+
+ GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred = deferred_locals();
+ if (deferred != NULL) {
+ // This can only happen if thread is destroyed before deoptimization occurs.
+ assert(deferred->length() != 0, "empty array!");
+ do {
+ jvmtiDeferredLocalVariableSet* dlv = deferred->at(0);
+ deferred->remove_at(0);
+ // individual jvmtiDeferredLocalVariableSet are CHeapObj's
+ delete dlv;
+ } while (deferred->length() != 0);
+ delete deferred;
+ }
+
+ // All Java related clean up happens in exit
+ ThreadSafepointState::destroy(this);
+ if (_thread_stat != NULL) delete _thread_stat;
+
+#if INCLUDE_JVMCI
+ if (JVMCICounterSize > 0) {
+ if (jvmci_counters_include(this)) {
+ for (int i = 0; i < JVMCICounterSize; i++) {
+ _jvmci_old_thread_counters[i] += _jvmci_counters[i];
+ }
+ }
+ FREE_C_HEAP_ARRAY(jlong, _jvmci_counters);
+ }
+#endif // INCLUDE_JVMCI
+}
+
+
+// The first routine called by a new Java thread
+void JavaThread::run() {
+ // initialize thread-local alloc buffer related fields
+ this->initialize_tlab();
+
+ // used to test validity of stack trace backs
+ this->record_base_of_stack_pointer();
+
+ // Record real stack base and size.
+ this->record_stack_base_and_size();
+
+ this->create_stack_guard_pages();
+
+ this->cache_global_variables();
+
+ // Thread is now sufficient initialized to be handled by the safepoint code as being
+ // in the VM. Change thread state from _thread_new to _thread_in_vm
+ ThreadStateTransition::transition_and_fence(this, _thread_new, _thread_in_vm);
+
+ assert(JavaThread::current() == this, "sanity check");
+ assert(!Thread::current()->owns_locks(), "sanity check");
+
+ DTRACE_THREAD_PROBE(start, this);
+
+ // This operation might block. We call that after all safepoint checks for a new thread has
+ // been completed.
+ this->set_active_handles(JNIHandleBlock::allocate_block());
+
+ if (JvmtiExport::should_post_thread_life()) {
+ JvmtiExport::post_thread_start(this);
+ }
+
+ EventThreadStart event;
+ if (event.should_commit()) {
+ event.set_thread(THREAD_TRACE_ID(this));
+ event.commit();
+ }
+
+ // We call another function to do the rest so we are sure that the stack addresses used
+ // from there will be lower than the stack base just computed
+ thread_main_inner();
+
+ // Note, thread is no longer valid at this point!
+}
+
+
+void JavaThread::thread_main_inner() {
+ assert(JavaThread::current() == this, "sanity check");
+ assert(this->threadObj() != NULL, "just checking");
+
+ // Execute thread entry point unless this thread has a pending exception
+ // or has been stopped before starting.
+ // Note: Due to JVM_StopThread we can have pending exceptions already!
+ if (!this->has_pending_exception() &&
+ !java_lang_Thread::is_stillborn(this->threadObj())) {
+ {
+ ResourceMark rm(this);
+ this->set_native_thread_name(this->get_thread_name());
+ }
+ HandleMark hm(this);
+ this->entry_point()(this, this);
+ }
+
+ DTRACE_THREAD_PROBE(stop, this);
+
+ this->exit(false);
+ delete this;
+}
+
+
+static void ensure_join(JavaThread* thread) {
+ // We do not need to grap the Threads_lock, since we are operating on ourself.
+ Handle threadObj(thread, thread->threadObj());
+ assert(threadObj.not_null(), "java thread object must exist");
+ ObjectLocker lock(threadObj, thread);
+ // Ignore pending exception (ThreadDeath), since we are exiting anyway
+ thread->clear_pending_exception();
+ // Thread is exiting. So set thread_status field in java.lang.Thread class to TERMINATED.
+ java_lang_Thread::set_thread_status(threadObj(), java_lang_Thread::TERMINATED);
+ // Clear the native thread instance - this makes isAlive return false and allows the join()
+ // to complete once we've done the notify_all below
+ java_lang_Thread::set_thread(threadObj(), NULL);
+ lock.notify_all(thread);
+ // Ignore pending exception (ThreadDeath), since we are exiting anyway
+ thread->clear_pending_exception();
+}
+
+
+// For any new cleanup additions, please check to see if they need to be applied to
+// cleanup_failed_attach_current_thread as well.
+void JavaThread::exit(bool destroy_vm, ExitType exit_type) {
+ assert(this == JavaThread::current(), "thread consistency check");
+
+ HandleMark hm(this);
+ Handle uncaught_exception(this, this->pending_exception());
+ this->clear_pending_exception();
+ Handle threadObj(this, this->threadObj());
+ assert(threadObj.not_null(), "Java thread object should be created");
+
+ // FIXIT: This code should be moved into else part, when reliable 1.2/1.3 check is in place
+ {
+ EXCEPTION_MARK;
+
+ CLEAR_PENDING_EXCEPTION;
+ }
+ if (!destroy_vm) {
+ if (uncaught_exception.not_null()) {
+ EXCEPTION_MARK;
+ // Call method Thread.dispatchUncaughtException().
+ Klass* thread_klass = SystemDictionary::Thread_klass();
+ JavaValue result(T_VOID);
+ JavaCalls::call_virtual(&result,
+ threadObj, thread_klass,
+ vmSymbols::dispatchUncaughtException_name(),
+ vmSymbols::throwable_void_signature(),
+ uncaught_exception,
+ THREAD);
+ if (HAS_PENDING_EXCEPTION) {
+ ResourceMark rm(this);
+ jio_fprintf(defaultStream::error_stream(),
+ "\nException: %s thrown from the UncaughtExceptionHandler"
+ " in thread \"%s\"\n",
+ pending_exception()->klass()->external_name(),
+ get_thread_name());
+ CLEAR_PENDING_EXCEPTION;
+ }
+ }
+
+ // Called before the java thread exit since we want to read info
+ // from java_lang_Thread object
+ EventThreadEnd event;
+ if (event.should_commit()) {
+ event.set_thread(THREAD_TRACE_ID(this));
+ event.commit();
+ }
+
+ // Call after last event on thread
+ EVENT_THREAD_EXIT(this);
+
+ // Call Thread.exit(). We try 3 times in case we got another Thread.stop during
+ // the execution of the method. If that is not enough, then we don't really care. Thread.stop
+ // is deprecated anyhow.
+ if (!is_Compiler_thread()) {
+ int count = 3;
+ while (java_lang_Thread::threadGroup(threadObj()) != NULL && (count-- > 0)) {
+ EXCEPTION_MARK;
+ JavaValue result(T_VOID);
+ Klass* thread_klass = SystemDictionary::Thread_klass();
+ JavaCalls::call_virtual(&result,
+ threadObj, thread_klass,
+ vmSymbols::exit_method_name(),
+ vmSymbols::void_method_signature(),
+ THREAD);
+ CLEAR_PENDING_EXCEPTION;
+ }
+ }
+ // notify JVMTI
+ if (JvmtiExport::should_post_thread_life()) {
+ JvmtiExport::post_thread_end(this);
+ }
+
+ // We have notified the agents that we are exiting, before we go on,
+ // we must check for a pending external suspend request and honor it
+ // in order to not surprise the thread that made the suspend request.
+ while (true) {
+ {
+ MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
+ if (!is_external_suspend()) {
+ set_terminated(_thread_exiting);
+ ThreadService::current_thread_exiting(this);
+ break;
+ }
+ // Implied else:
+ // Things get a little tricky here. We have a pending external
+ // suspend request, but we are holding the SR_lock so we
+ // can't just self-suspend. So we temporarily drop the lock
+ // and then self-suspend.
+ }
+
+ ThreadBlockInVM tbivm(this);
+ java_suspend_self();
+
+ // We're done with this suspend request, but we have to loop around
+ // and check again. Eventually we will get SR_lock without a pending
+ // external suspend request and will be able to mark ourselves as
+ // exiting.
+ }
+ // no more external suspends are allowed at this point
+ } else {
+ // before_exit() has already posted JVMTI THREAD_END events
+ }
+
+ // Notify waiters on thread object. This has to be done after exit() is called
+ // on the thread (if the thread is the last thread in a daemon ThreadGroup the
+ // group should have the destroyed bit set before waiters are notified).
+ ensure_join(this);
+ assert(!this->has_pending_exception(), "ensure_join should have cleared");
+
+ // 6282335 JNI DetachCurrentThread spec states that all Java monitors
+ // held by this thread must be released. The spec does not distinguish
+ // between JNI-acquired and regular Java monitors. We can only see
+ // regular Java monitors here if monitor enter-exit matching is broken.
+ //
+ // Optionally release any monitors for regular JavaThread exits. This
+ // is provided as a work around for any bugs in monitor enter-exit
+ // matching. This can be expensive so it is not enabled by default.
+ //
+ // ensure_join() ignores IllegalThreadStateExceptions, and so does
+ // ObjectSynchronizer::release_monitors_owned_by_thread().
+ if (exit_type == jni_detach || ObjectMonitor::Knob_ExitRelease) {
+ // Sanity check even though JNI DetachCurrentThread() would have
+ // returned JNI_ERR if there was a Java frame. JavaThread exit
+ // should be done executing Java code by the time we get here.
+ assert(!this->has_last_Java_frame(),
+ "should not have a Java frame when detaching or exiting");
+ ObjectSynchronizer::release_monitors_owned_by_thread(this);
+ assert(!this->has_pending_exception(), "release_monitors should have cleared");
+ }
+
+ // These things needs to be done while we are still a Java Thread. Make sure that thread
+ // is in a consistent state, in case GC happens
+ assert(_privileged_stack_top == NULL, "must be NULL when we get here");
+
+ if (active_handles() != NULL) {
+ JNIHandleBlock* block = active_handles();
+ set_active_handles(NULL);
+ JNIHandleBlock::release_block(block);
+ }
+
+ if (free_handle_block() != NULL) {
+ JNIHandleBlock* block = free_handle_block();
+ set_free_handle_block(NULL);
+ JNIHandleBlock::release_block(block);
+ }
+
+ // These have to be removed while this is still a valid thread.
+ remove_stack_guard_pages();
+
+ if (UseTLAB) {
+ tlab().make_parsable(true); // retire TLAB
+ }
+
+ if (JvmtiEnv::environments_might_exist()) {
+ JvmtiExport::cleanup_thread(this);
+ }
+
+ // We must flush any deferred card marks before removing a thread from
+ // the list of active threads.
+ Universe::heap()->flush_deferred_store_barrier(this);
+ assert(deferred_card_mark().is_empty(), "Should have been flushed");
+
+#if INCLUDE_ALL_GCS
+ // We must flush the G1-related buffers before removing a thread
+ // from the list of active threads. We must do this after any deferred
+ // card marks have been flushed (above) so that any entries that are
+ // added to the thread's dirty card queue as a result are not lost.
+ if (UseG1GC) {
+ flush_barrier_queues();
+ }
+#endif // INCLUDE_ALL_GCS
+
+ log_info(os, thread)("JavaThread %s (tid: " UINTX_FORMAT ").",
+ exit_type == JavaThread::normal_exit ? "exiting" : "detaching",
+ os::current_thread_id());
+
+ // Remove from list of active threads list, and notify VM thread if we are the last non-daemon thread
+ Threads::remove(this);
+}
+
+#if INCLUDE_ALL_GCS
+// Flush G1-related queues.
+void JavaThread::flush_barrier_queues() {
+ satb_mark_queue().flush();
+ dirty_card_queue().flush();
+}
+
+void JavaThread::initialize_queues() {
+ assert(!SafepointSynchronize::is_at_safepoint(),
+ "we should not be at a safepoint");
+
+ SATBMarkQueue& satb_queue = satb_mark_queue();
+ SATBMarkQueueSet& satb_queue_set = satb_mark_queue_set();
+ // The SATB queue should have been constructed with its active
+ // field set to false.
+ assert(!satb_queue.is_active(), "SATB queue should not be active");
+ assert(satb_queue.is_empty(), "SATB queue should be empty");
+ // If we are creating the thread during a marking cycle, we should
+ // set the active field of the SATB queue to true.
+ if (satb_queue_set.is_active()) {
+ satb_queue.set_active(true);
+ }
+
+ DirtyCardQueue& dirty_queue = dirty_card_queue();
+ // The dirty card queue should have been constructed with its
+ // active field set to true.
+ assert(dirty_queue.is_active(), "dirty card queue should be active");
+}
+#endif // INCLUDE_ALL_GCS
+
+void JavaThread::cleanup_failed_attach_current_thread() {
+ if (active_handles() != NULL) {
+ JNIHandleBlock* block = active_handles();
+ set_active_handles(NULL);
+ JNIHandleBlock::release_block(block);
+ }
+
+ if (free_handle_block() != NULL) {
+ JNIHandleBlock* block = free_handle_block();
+ set_free_handle_block(NULL);
+ JNIHandleBlock::release_block(block);
+ }
+
+ // These have to be removed while this is still a valid thread.
+ remove_stack_guard_pages();
+
+ if (UseTLAB) {
+ tlab().make_parsable(true); // retire TLAB, if any
+ }
+
+#if INCLUDE_ALL_GCS
+ if (UseG1GC) {
+ flush_barrier_queues();
+ }
+#endif // INCLUDE_ALL_GCS
+
+ Threads::remove(this);
+ delete this;
+}
+
+
+
+
+JavaThread* JavaThread::active() {
+ Thread* thread = Thread::current();
+ if (thread->is_Java_thread()) {
+ return (JavaThread*) thread;
+ } else {
+ assert(thread->is_VM_thread(), "this must be a vm thread");
+ VM_Operation* op = ((VMThread*) thread)->vm_operation();
+ JavaThread *ret=op == NULL ? NULL : (JavaThread *)op->calling_thread();
+ assert(ret->is_Java_thread(), "must be a Java thread");
+ return ret;
+ }
+}
+
+bool JavaThread::is_lock_owned(address adr) const {
+ if (Thread::is_lock_owned(adr)) return true;
+
+ for (MonitorChunk* chunk = monitor_chunks(); chunk != NULL; chunk = chunk->next()) {
+ if (chunk->contains(adr)) return true;
+ }
+
+ return false;
+}
+
+
+void JavaThread::add_monitor_chunk(MonitorChunk* chunk) {
+ chunk->set_next(monitor_chunks());
+ set_monitor_chunks(chunk);
+}
+
+void JavaThread::remove_monitor_chunk(MonitorChunk* chunk) {
+ guarantee(monitor_chunks() != NULL, "must be non empty");
+ if (monitor_chunks() == chunk) {
+ set_monitor_chunks(chunk->next());
+ } else {
+ MonitorChunk* prev = monitor_chunks();
+ while (prev->next() != chunk) prev = prev->next();
+ prev->set_next(chunk->next());
+ }
+}
+
+// JVM support.
+
+// Note: this function shouldn't block if it's called in
+// _thread_in_native_trans state (such as from
+// check_special_condition_for_native_trans()).
+void JavaThread::check_and_handle_async_exceptions(bool check_unsafe_error) {
+
+ if (has_last_Java_frame() && has_async_condition()) {
+ // If we are at a polling page safepoint (not a poll return)
+ // then we must defer async exception because live registers
+ // will be clobbered by the exception path. Poll return is
+ // ok because the call we a returning from already collides
+ // with exception handling registers and so there is no issue.
+ // (The exception handling path kills call result registers but
+ // this is ok since the exception kills the result anyway).
+
+ if (is_at_poll_safepoint()) {
+ // if the code we are returning to has deoptimized we must defer
+ // the exception otherwise live registers get clobbered on the
+ // exception path before deoptimization is able to retrieve them.
+ //
+ RegisterMap map(this, false);
+ frame caller_fr = last_frame().sender(&map);
+ assert(caller_fr.is_compiled_frame(), "what?");
+ if (caller_fr.is_deoptimized_frame()) {
+ log_info(exceptions)("deferred async exception at compiled safepoint");
+ return;
+ }
+ }
+ }
+
+ JavaThread::AsyncRequests condition = clear_special_runtime_exit_condition();
+ if (condition == _no_async_condition) {
+ // Conditions have changed since has_special_runtime_exit_condition()
+ // was called:
+ // - if we were here only because of an external suspend request,
+ // then that was taken care of above (or cancelled) so we are done
+ // - if we were here because of another async request, then it has
+ // been cleared between the has_special_runtime_exit_condition()
+ // and now so again we are done
+ return;
+ }
+
+ // Check for pending async. exception
+ if (_pending_async_exception != NULL) {
+ // Only overwrite an already pending exception, if it is not a threadDeath.
+ if (!has_pending_exception() || !pending_exception()->is_a(SystemDictionary::ThreadDeath_klass())) {
+
+ // We cannot call Exceptions::_throw(...) here because we cannot block
+ set_pending_exception(_pending_async_exception, __FILE__, __LINE__);
+
+ LogTarget(Info, exceptions) lt;
+ if (lt.is_enabled()) {
+ ResourceMark rm;
+ LogStream ls(lt);
+ ls.print("Async. exception installed at runtime exit (" INTPTR_FORMAT ")", p2i(this));
+ if (has_last_Java_frame()) {
+ frame f = last_frame();
+ ls.print(" (pc: " INTPTR_FORMAT " sp: " INTPTR_FORMAT " )", p2i(f.pc()), p2i(f.sp()));
+ }
+ ls.print_cr(" of type: %s", _pending_async_exception->klass()->external_name());
+ }
+ _pending_async_exception = NULL;
+ clear_has_async_exception();
+ }
+ }
+
+ if (check_unsafe_error &&
+ condition == _async_unsafe_access_error && !has_pending_exception()) {
+ condition = _no_async_condition; // done
+ switch (thread_state()) {
+ case _thread_in_vm: {
+ JavaThread* THREAD = this;
+ THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in an unsafe memory access operation");
+ }
+ case _thread_in_native: {
+ ThreadInVMfromNative tiv(this);
+ JavaThread* THREAD = this;
+ THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in an unsafe memory access operation");
+ }
+ case _thread_in_Java: {
+ ThreadInVMfromJava tiv(this);
+ JavaThread* THREAD = this;
+ THROW_MSG(vmSymbols::java_lang_InternalError(), "a fault occurred in a recent unsafe memory access operation in compiled Java code");
+ }
+ default:
+ ShouldNotReachHere();
+ }
+ }
+
+ assert(condition == _no_async_condition || has_pending_exception() ||
+ (!check_unsafe_error && condition == _async_unsafe_access_error),
+ "must have handled the async condition, if no exception");
+}
+
+void JavaThread::handle_special_runtime_exit_condition(bool check_asyncs) {
+ //
+ // Check for pending external suspend. Internal suspend requests do
+ // not use handle_special_runtime_exit_condition().
+ // If JNIEnv proxies are allowed, don't self-suspend if the target
+ // thread is not the current thread. In older versions of jdbx, jdbx
+ // threads could call into the VM with another thread's JNIEnv so we
+ // can be here operating on behalf of a suspended thread (4432884).
+ bool do_self_suspend = is_external_suspend_with_lock();
+ if (do_self_suspend && (!AllowJNIEnvProxy || this == JavaThread::current())) {
+ //
+ // Because thread is external suspended the safepoint code will count
+ // thread as at a safepoint. This can be odd because we can be here
+ // as _thread_in_Java which would normally transition to _thread_blocked
+ // at a safepoint. We would like to mark the thread as _thread_blocked
+ // before calling java_suspend_self like all other callers of it but
+ // we must then observe proper safepoint protocol. (We can't leave
+ // _thread_blocked with a safepoint in progress). However we can be
+ // here as _thread_in_native_trans so we can't use a normal transition
+ // constructor/destructor pair because they assert on that type of
+ // transition. We could do something like:
+ //
+ // JavaThreadState state = thread_state();
+ // set_thread_state(_thread_in_vm);
+ // {
+ // ThreadBlockInVM tbivm(this);
+ // java_suspend_self()
+ // }
+ // set_thread_state(_thread_in_vm_trans);
+ // if (safepoint) block;
+ // set_thread_state(state);
+ //
+ // but that is pretty messy. Instead we just go with the way the
+ // code has worked before and note that this is the only path to
+ // java_suspend_self that doesn't put the thread in _thread_blocked
+ // mode.
+
+ frame_anchor()->make_walkable(this);
+ java_suspend_self();
+
+ // We might be here for reasons in addition to the self-suspend request
+ // so check for other async requests.
+ }
+
+ if (check_asyncs) {
+ check_and_handle_async_exceptions();
+ }
+#if INCLUDE_TRACE
+ if (is_trace_suspend()) {
+ TRACE_SUSPEND_THREAD(this);
+ }
+#endif
+}
+
+void JavaThread::send_thread_stop(oop java_throwable) {
+ assert(Thread::current()->is_VM_thread(), "should be in the vm thread");
+ assert(Threads_lock->is_locked(), "Threads_lock should be locked by safepoint code");
+ assert(SafepointSynchronize::is_at_safepoint(), "all threads are stopped");
+
+ // Do not throw asynchronous exceptions against the compiler thread
+ // (the compiler thread should not be a Java thread -- fix in 1.4.2)
+ if (!can_call_java()) return;
+
+ {
+ // Actually throw the Throwable against the target Thread - however
+ // only if there is no thread death exception installed already.
+ if (_pending_async_exception == NULL || !_pending_async_exception->is_a(SystemDictionary::ThreadDeath_klass())) {
+ // If the topmost frame is a runtime stub, then we are calling into
+ // OptoRuntime from compiled code. Some runtime stubs (new, monitor_exit..)
+ // must deoptimize the caller before continuing, as the compiled exception handler table
+ // may not be valid
+ if (has_last_Java_frame()) {
+ frame f = last_frame();
+ if (f.is_runtime_frame() || f.is_safepoint_blob_frame()) {
+ // BiasedLocking needs an updated RegisterMap for the revoke monitors pass
+ RegisterMap reg_map(this, UseBiasedLocking);
+ frame compiled_frame = f.sender(®_map);
+ if (!StressCompiledExceptionHandlers && compiled_frame.can_be_deoptimized()) {
+ Deoptimization::deoptimize(this, compiled_frame, ®_map);
+ }
+ }
+ }
+
+ // Set async. pending exception in thread.
+ set_pending_async_exception(java_throwable);
+
+ if (log_is_enabled(Info, exceptions)) {
+ ResourceMark rm;
+ log_info(exceptions)("Pending Async. exception installed of type: %s",
+ InstanceKlass::cast(_pending_async_exception->klass())->external_name());
+ }
+ // for AbortVMOnException flag
+ Exceptions::debug_check_abort(_pending_async_exception->klass()->external_name());
+ }
+ }
+
+
+ // Interrupt thread so it will wake up from a potential wait()
+ Thread::interrupt(this);
+}
+
+// External suspension mechanism.
+//
+// Tell the VM to suspend a thread when ever it knows that it does not hold on
+// to any VM_locks and it is at a transition
+// Self-suspension will happen on the transition out of the vm.
+// Catch "this" coming in from JNIEnv pointers when the thread has been freed
+//
+// Guarantees on return:
+// + Target thread will not execute any new bytecode (that's why we need to
+// force a safepoint)
+// + Target thread will not enter any new monitors
+//
+void JavaThread::java_suspend() {
+ { MutexLocker mu(Threads_lock);
+ if (!Threads::includes(this) || is_exiting() || this->threadObj() == NULL) {
+ return;
+ }
+ }
+
+ { MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
+ if (!is_external_suspend()) {
+ // a racing resume has cancelled us; bail out now
+ return;
+ }
+
+ // suspend is done
+ uint32_t debug_bits = 0;
+ // Warning: is_ext_suspend_completed() may temporarily drop the
+ // SR_lock to allow the thread to reach a stable thread state if
+ // it is currently in a transient thread state.
+ if (is_ext_suspend_completed(false /* !called_by_wait */,
+ SuspendRetryDelay, &debug_bits)) {
+ return;
+ }
+ }
+
+ VM_ThreadSuspend vm_suspend;
+ VMThread::execute(&vm_suspend);
+}
+
+// Part II of external suspension.
+// A JavaThread self suspends when it detects a pending external suspend
+// request. This is usually on transitions. It is also done in places
+// where continuing to the next transition would surprise the caller,
+// e.g., monitor entry.
+//
+// Returns the number of times that the thread self-suspended.
+//
+// Note: DO NOT call java_suspend_self() when you just want to block current
+// thread. java_suspend_self() is the second stage of cooperative
+// suspension for external suspend requests and should only be used
+// to complete an external suspend request.
+//
+int JavaThread::java_suspend_self() {
+ int ret = 0;
+
+ // we are in the process of exiting so don't suspend
+ if (is_exiting()) {
+ clear_external_suspend();
+ return ret;
+ }
+
+ assert(_anchor.walkable() ||
+ (is_Java_thread() && !((JavaThread*)this)->has_last_Java_frame()),
+ "must have walkable stack");
+
+ MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
+
+ assert(!this->is_ext_suspended(),
+ "a thread trying to self-suspend should not already be suspended");
+
+ if (this->is_suspend_equivalent()) {
+ // If we are self-suspending as a result of the lifting of a
+ // suspend equivalent condition, then the suspend_equivalent
+ // flag is not cleared until we set the ext_suspended flag so
+ // that wait_for_ext_suspend_completion() returns consistent
+ // results.
+ this->clear_suspend_equivalent();
+ }
+
+ // A racing resume may have cancelled us before we grabbed SR_lock
+ // above. Or another external suspend request could be waiting for us
+ // by the time we return from SR_lock()->wait(). The thread
+ // that requested the suspension may already be trying to walk our
+ // stack and if we return now, we can change the stack out from under
+ // it. This would be a "bad thing (TM)" and cause the stack walker
+ // to crash. We stay self-suspended until there are no more pending
+ // external suspend requests.
+ while (is_external_suspend()) {
+ ret++;
+ this->set_ext_suspended();
+
+ // _ext_suspended flag is cleared by java_resume()
+ while (is_ext_suspended()) {
+ this->SR_lock()->wait(Mutex::_no_safepoint_check_flag);
+ }
+ }
+
+ return ret;
+}
+
+#ifdef ASSERT
+// verify the JavaThread has not yet been published in the Threads::list, and
+// hence doesn't need protection from concurrent access at this stage
+void JavaThread::verify_not_published() {
+ if (!Threads_lock->owned_by_self()) {
+ MutexLockerEx ml(Threads_lock, Mutex::_no_safepoint_check_flag);
+ assert(!Threads::includes(this),
+ "java thread shouldn't have been published yet!");
+ } else {
+ assert(!Threads::includes(this),
+ "java thread shouldn't have been published yet!");
+ }
+}
+#endif
+
+// Slow path when the native==>VM/Java barriers detect a safepoint is in
+// progress or when _suspend_flags is non-zero.
+// Current thread needs to self-suspend if there is a suspend request and/or
+// block if a safepoint is in progress.
+// Async exception ISN'T checked.
+// Note only the ThreadInVMfromNative transition can call this function
+// directly and when thread state is _thread_in_native_trans
+void JavaThread::check_safepoint_and_suspend_for_native_trans(JavaThread *thread) {
+ assert(thread->thread_state() == _thread_in_native_trans, "wrong state");
+
+ JavaThread *curJT = JavaThread::current();
+ bool do_self_suspend = thread->is_external_suspend();
+
+ assert(!curJT->has_last_Java_frame() || curJT->frame_anchor()->walkable(), "Unwalkable stack in native->vm transition");
+
+ // If JNIEnv proxies are allowed, don't self-suspend if the target
+ // thread is not the current thread. In older versions of jdbx, jdbx
+ // threads could call into the VM with another thread's JNIEnv so we
+ // can be here operating on behalf of a suspended thread (4432884).
+ if (do_self_suspend && (!AllowJNIEnvProxy || curJT == thread)) {
+ JavaThreadState state = thread->thread_state();
+
+ // We mark this thread_blocked state as a suspend-equivalent so
+ // that a caller to is_ext_suspend_completed() won't be confused.
+ // The suspend-equivalent state is cleared by java_suspend_self().
+ thread->set_suspend_equivalent();
+
+ // If the safepoint code sees the _thread_in_native_trans state, it will
+ // wait until the thread changes to other thread state. There is no
+ // guarantee on how soon we can obtain the SR_lock and complete the
+ // self-suspend request. It would be a bad idea to let safepoint wait for
+ // too long. Temporarily change the state to _thread_blocked to
+ // let the VM thread know that this thread is ready for GC. The problem
+ // of changing thread state is that safepoint could happen just after
+ // java_suspend_self() returns after being resumed, and VM thread will
+ // see the _thread_blocked state. We must check for safepoint
+ // after restoring the state and make sure we won't leave while a safepoint
+ // is in progress.
+ thread->set_thread_state(_thread_blocked);
+ thread->java_suspend_self();
+ thread->set_thread_state(state);
+
+ InterfaceSupport::serialize_thread_state_with_handler(thread);
+ }
+
+ if (SafepointSynchronize::do_call_back()) {
+ // If we are safepointing, then block the caller which may not be
+ // the same as the target thread (see above).
+ SafepointSynchronize::block(curJT);
+ }
+
+ if (thread->is_deopt_suspend()) {
+ thread->clear_deopt_suspend();
+ RegisterMap map(thread, false);
+ frame f = thread->last_frame();
+ while (f.id() != thread->must_deopt_id() && ! f.is_first_frame()) {
+ f = f.sender(&map);
+ }
+ if (f.id() == thread->must_deopt_id()) {
+ thread->clear_must_deopt_id();
+ f.deoptimize(thread);
+ } else {
+ fatal("missed deoptimization!");
+ }
+ }
+#if INCLUDE_TRACE
+ if (thread->is_trace_suspend()) {
+ TRACE_SUSPEND_THREAD(thread);
+ }
+#endif
+}
+
+// Slow path when the native==>VM/Java barriers detect a safepoint is in
+// progress or when _suspend_flags is non-zero.
+// Current thread needs to self-suspend if there is a suspend request and/or
+// block if a safepoint is in progress.
+// Also check for pending async exception (not including unsafe access error).
+// Note only the native==>VM/Java barriers can call this function and when
+// thread state is _thread_in_native_trans.
+void JavaThread::check_special_condition_for_native_trans(JavaThread *thread) {
+ check_safepoint_and_suspend_for_native_trans(thread);
+
+ if (thread->has_async_exception()) {
+ // We are in _thread_in_native_trans state, don't handle unsafe
+ // access error since that may block.
+ thread->check_and_handle_async_exceptions(false);
+ }
+}
+
+// This is a variant of the normal
+// check_special_condition_for_native_trans with slightly different
+// semantics for use by critical native wrappers. It does all the
+// normal checks but also performs the transition back into
+// thread_in_Java state. This is required so that critical natives
+// can potentially block and perform a GC if they are the last thread
+// exiting the GCLocker.
+void JavaThread::check_special_condition_for_native_trans_and_transition(JavaThread *thread) {
+ check_special_condition_for_native_trans(thread);
+
+ // Finish the transition
+ thread->set_thread_state(_thread_in_Java);
+
+ if (thread->do_critical_native_unlock()) {
+ ThreadInVMfromJavaNoAsyncException tiv(thread);
+ GCLocker::unlock_critical(thread);
+ thread->clear_critical_native_unlock();
+ }
+}
+
+// We need to guarantee the Threads_lock here, since resumes are not
+// allowed during safepoint synchronization
+// Can only resume from an external suspension
+void JavaThread::java_resume() {
+ assert_locked_or_safepoint(Threads_lock);
+
+ // Sanity check: thread is gone, has started exiting or the thread
+ // was not externally suspended.
+ if (!Threads::includes(this) || is_exiting() || !is_external_suspend()) {
+ return;
+ }
+
+ MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
+
+ clear_external_suspend();
+
+ if (is_ext_suspended()) {
+ clear_ext_suspended();
+ SR_lock()->notify_all();
+ }
+}
+
+size_t JavaThread::_stack_red_zone_size = 0;
+size_t JavaThread::_stack_yellow_zone_size = 0;
+size_t JavaThread::_stack_reserved_zone_size = 0;
+size_t JavaThread::_stack_shadow_zone_size = 0;
+
+void JavaThread::create_stack_guard_pages() {
+ if (!os::uses_stack_guard_pages() || _stack_guard_state != stack_guard_unused) { return; }
+ address low_addr = stack_end();
+ size_t len = stack_guard_zone_size();
+
+ assert(is_aligned(low_addr, os::vm_page_size()), "Stack base should be the start of a page");
+ assert(is_aligned(len, os::vm_page_size()), "Stack size should be a multiple of page size");
+
+ int must_commit = os::must_commit_stack_guard_pages();
+ // warning("Guarding at " PTR_FORMAT " for len " SIZE_FORMAT "\n", low_addr, len);
+
+ if (must_commit && !os::create_stack_guard_pages((char *) low_addr, len)) {
+ log_warning(os, thread)("Attempt to allocate stack guard pages failed.");
+ return;
+ }
+
+ if (os::guard_memory((char *) low_addr, len)) {
+ _stack_guard_state = stack_guard_enabled;
+ } else {
+ log_warning(os, thread)("Attempt to protect stack guard pages failed ("
+ PTR_FORMAT "-" PTR_FORMAT ").", p2i(low_addr), p2i(low_addr + len));
+ if (os::uncommit_memory((char *) low_addr, len)) {
+ log_warning(os, thread)("Attempt to deallocate stack guard pages failed.");
+ }
+ return;
+ }
+
+ log_debug(os, thread)("Thread " UINTX_FORMAT " stack guard pages activated: "
+ PTR_FORMAT "-" PTR_FORMAT ".",
+ os::current_thread_id(), p2i(low_addr), p2i(low_addr + len));
+}
+
+void JavaThread::remove_stack_guard_pages() {
+ assert(Thread::current() == this, "from different thread");
+ if (_stack_guard_state == stack_guard_unused) return;
+ address low_addr = stack_end();
+ size_t len = stack_guard_zone_size();
+
+ if (os::must_commit_stack_guard_pages()) {
+ if (os::remove_stack_guard_pages((char *) low_addr, len)) {
+ _stack_guard_state = stack_guard_unused;
+ } else {
+ log_warning(os, thread)("Attempt to deallocate stack guard pages failed ("
+ PTR_FORMAT "-" PTR_FORMAT ").", p2i(low_addr), p2i(low_addr + len));
+ return;
+ }
+ } else {
+ if (_stack_guard_state == stack_guard_unused) return;
+ if (os::unguard_memory((char *) low_addr, len)) {
+ _stack_guard_state = stack_guard_unused;
+ } else {
+ log_warning(os, thread)("Attempt to unprotect stack guard pages failed ("
+ PTR_FORMAT "-" PTR_FORMAT ").", p2i(low_addr), p2i(low_addr + len));
+ return;
+ }
+ }
+
+ log_debug(os, thread)("Thread " UINTX_FORMAT " stack guard pages removed: "
+ PTR_FORMAT "-" PTR_FORMAT ".",
+ os::current_thread_id(), p2i(low_addr), p2i(low_addr + len));
+}
+
+void JavaThread::enable_stack_reserved_zone() {
+ assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
+ assert(_stack_guard_state != stack_guard_enabled, "already enabled");
+
+ // The base notation is from the stack's point of view, growing downward.
+ // We need to adjust it to work correctly with guard_memory()
+ address base = stack_reserved_zone_base() - stack_reserved_zone_size();
+
+ guarantee(base < stack_base(),"Error calculating stack reserved zone");
+ guarantee(base < os::current_stack_pointer(),"Error calculating stack reserved zone");
+
+ if (os::guard_memory((char *) base, stack_reserved_zone_size())) {
+ _stack_guard_state = stack_guard_enabled;
+ } else {
+ warning("Attempt to guard stack reserved zone failed.");
+ }
+ enable_register_stack_guard();
+}
+
+void JavaThread::disable_stack_reserved_zone() {
+ assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
+ assert(_stack_guard_state != stack_guard_reserved_disabled, "already disabled");
+
+ // Simply return if called for a thread that does not use guard pages.
+ if (_stack_guard_state == stack_guard_unused) return;
+
+ // The base notation is from the stack's point of view, growing downward.
+ // We need to adjust it to work correctly with guard_memory()
+ address base = stack_reserved_zone_base() - stack_reserved_zone_size();
+
+ if (os::unguard_memory((char *)base, stack_reserved_zone_size())) {
+ _stack_guard_state = stack_guard_reserved_disabled;
+ } else {
+ warning("Attempt to unguard stack reserved zone failed.");
+ }
+ disable_register_stack_guard();
+}
+
+void JavaThread::enable_stack_yellow_reserved_zone() {
+ assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
+ assert(_stack_guard_state != stack_guard_enabled, "already enabled");
+
+ // The base notation is from the stacks point of view, growing downward.
+ // We need to adjust it to work correctly with guard_memory()
+ address base = stack_red_zone_base();
+
+ guarantee(base < stack_base(), "Error calculating stack yellow zone");
+ guarantee(base < os::current_stack_pointer(), "Error calculating stack yellow zone");
+
+ if (os::guard_memory((char *) base, stack_yellow_reserved_zone_size())) {
+ _stack_guard_state = stack_guard_enabled;
+ } else {
+ warning("Attempt to guard stack yellow zone failed.");
+ }
+ enable_register_stack_guard();
+}
+
+void JavaThread::disable_stack_yellow_reserved_zone() {
+ assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
+ assert(_stack_guard_state != stack_guard_yellow_reserved_disabled, "already disabled");
+
+ // Simply return if called for a thread that does not use guard pages.
+ if (_stack_guard_state == stack_guard_unused) return;
+
+ // The base notation is from the stacks point of view, growing downward.
+ // We need to adjust it to work correctly with guard_memory()
+ address base = stack_red_zone_base();
+
+ if (os::unguard_memory((char *)base, stack_yellow_reserved_zone_size())) {
+ _stack_guard_state = stack_guard_yellow_reserved_disabled;
+ } else {
+ warning("Attempt to unguard stack yellow zone failed.");
+ }
+ disable_register_stack_guard();
+}
+
+void JavaThread::enable_stack_red_zone() {
+ // The base notation is from the stacks point of view, growing downward.
+ // We need to adjust it to work correctly with guard_memory()
+ assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
+ address base = stack_red_zone_base() - stack_red_zone_size();
+
+ guarantee(base < stack_base(), "Error calculating stack red zone");
+ guarantee(base < os::current_stack_pointer(), "Error calculating stack red zone");
+
+ if (!os::guard_memory((char *) base, stack_red_zone_size())) {
+ warning("Attempt to guard stack red zone failed.");
+ }
+}
+
+void JavaThread::disable_stack_red_zone() {
+ // The base notation is from the stacks point of view, growing downward.
+ // We need to adjust it to work correctly with guard_memory()
+ assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
+ address base = stack_red_zone_base() - stack_red_zone_size();
+ if (!os::unguard_memory((char *)base, stack_red_zone_size())) {
+ warning("Attempt to unguard stack red zone failed.");
+ }
+}
+
+void JavaThread::frames_do(void f(frame*, const RegisterMap* map)) {
+ // ignore is there is no stack
+ if (!has_last_Java_frame()) return;
+ // traverse the stack frames. Starts from top frame.
+ for (StackFrameStream fst(this); !fst.is_done(); fst.next()) {
+ frame* fr = fst.current();
+ f(fr, fst.register_map());
+ }
+}
+
+
+#ifndef PRODUCT
+// Deoptimization
+// Function for testing deoptimization
+void JavaThread::deoptimize() {
+ // BiasedLocking needs an updated RegisterMap for the revoke monitors pass
+ StackFrameStream fst(this, UseBiasedLocking);
+ bool deopt = false; // Dump stack only if a deopt actually happens.
+ bool only_at = strlen(DeoptimizeOnlyAt) > 0;
+ // Iterate over all frames in the thread and deoptimize
+ for (; !fst.is_done(); fst.next()) {
+ if (fst.current()->can_be_deoptimized()) {
+
+ if (only_at) {
+ // Deoptimize only at particular bcis. DeoptimizeOnlyAt
+ // consists of comma or carriage return separated numbers so
+ // search for the current bci in that string.
+ address pc = fst.current()->pc();
+ nmethod* nm = (nmethod*) fst.current()->cb();
+ ScopeDesc* sd = nm->scope_desc_at(pc);
+ char buffer[8];
+ jio_snprintf(buffer, sizeof(buffer), "%d", sd->bci());
+ size_t len = strlen(buffer);
+ const char * found = strstr(DeoptimizeOnlyAt, buffer);
+ while (found != NULL) {
+ if ((found[len] == ',' || found[len] == '\n' || found[len] == '\0') &&
+ (found == DeoptimizeOnlyAt || found[-1] == ',' || found[-1] == '\n')) {
+ // Check that the bci found is bracketed by terminators.
+ break;
+ }
+ found = strstr(found + 1, buffer);
+ }
+ if (!found) {
+ continue;
+ }
+ }
+
+ if (DebugDeoptimization && !deopt) {
+ deopt = true; // One-time only print before deopt
+ tty->print_cr("[BEFORE Deoptimization]");
+ trace_frames();
+ trace_stack();
+ }
+ Deoptimization::deoptimize(this, *fst.current(), fst.register_map());
+ }
+ }
+
+ if (DebugDeoptimization && deopt) {
+ tty->print_cr("[AFTER Deoptimization]");
+ trace_frames();
+ }
+}
+
+
+// Make zombies
+void JavaThread::make_zombies() {
+ for (StackFrameStream fst(this); !fst.is_done(); fst.next()) {
+ if (fst.current()->can_be_deoptimized()) {
+ // it is a Java nmethod
+ nmethod* nm = CodeCache::find_nmethod(fst.current()->pc());
+ nm->make_not_entrant();
+ }
+ }
+}
+#endif // PRODUCT
+
+
+void JavaThread::deoptimized_wrt_marked_nmethods() {
+ if (!has_last_Java_frame()) return;
+ // BiasedLocking needs an updated RegisterMap for the revoke monitors pass
+ StackFrameStream fst(this, UseBiasedLocking);
+ for (; !fst.is_done(); fst.next()) {
+ if (fst.current()->should_be_deoptimized()) {
+ Deoptimization::deoptimize(this, *fst.current(), fst.register_map());
+ }
+ }
+}
+
+
+// If the caller is a NamedThread, then remember, in the current scope,
+// the given JavaThread in its _processed_thread field.
+class RememberProcessedThread: public StackObj {
+ NamedThread* _cur_thr;
+ public:
+ RememberProcessedThread(JavaThread* jthr) {
+ Thread* thread = Thread::current();
+ if (thread->is_Named_thread()) {
+ _cur_thr = (NamedThread *)thread;
+ _cur_thr->set_processed_thread(jthr);
+ } else {
+ _cur_thr = NULL;
+ }
+ }
+
+ ~RememberProcessedThread() {
+ if (_cur_thr) {
+ _cur_thr->set_processed_thread(NULL);
+ }
+ }
+};
+
+void JavaThread::oops_do(OopClosure* f, CodeBlobClosure* cf) {
+ // Verify that the deferred card marks have been flushed.
+ assert(deferred_card_mark().is_empty(), "Should be empty during GC");
+
+ // Traverse the GCHandles
+ Thread::oops_do(f, cf);
+
+ JVMCI_ONLY(f->do_oop((oop*)&_pending_failed_speculation);)
+
+ assert((!has_last_Java_frame() && java_call_counter() == 0) ||
+ (has_last_Java_frame() && java_call_counter() > 0), "wrong java_sp info!");
+
+ if (has_last_Java_frame()) {
+ // Record JavaThread to GC thread
+ RememberProcessedThread rpt(this);
+
+ // Traverse the privileged stack
+ if (_privileged_stack_top != NULL) {
+ _privileged_stack_top->oops_do(f);
+ }
+
+ // traverse the registered growable array
+ if (_array_for_gc != NULL) {
+ for (int index = 0; index < _array_for_gc->length(); index++) {
+ f->do_oop(_array_for_gc->adr_at(index));
+ }
+ }
+
+ // Traverse the monitor chunks
+ for (MonitorChunk* chunk = monitor_chunks(); chunk != NULL; chunk = chunk->next()) {
+ chunk->oops_do(f);
+ }
+
+ // Traverse the execution stack
+ for (StackFrameStream fst(this); !fst.is_done(); fst.next()) {
+ fst.current()->oops_do(f, cf, fst.register_map());
+ }
+ }
+
+ // callee_target is never live across a gc point so NULL it here should
+ // it still contain a methdOop.
+
+ set_callee_target(NULL);
+
+ assert(vframe_array_head() == NULL, "deopt in progress at a safepoint!");
+ // If we have deferred set_locals there might be oops waiting to be
+ // written
+ GrowableArray<jvmtiDeferredLocalVariableSet*>* list = deferred_locals();
+ if (list != NULL) {
+ for (int i = 0; i < list->length(); i++) {
+ list->at(i)->oops_do(f);
+ }
+ }
+
+ // Traverse instance variables at the end since the GC may be moving things
+ // around using this function
+ f->do_oop((oop*) &_threadObj);
+ f->do_oop((oop*) &_vm_result);
+ f->do_oop((oop*) &_exception_oop);
+ f->do_oop((oop*) &_pending_async_exception);
+
+ if (jvmti_thread_state() != NULL) {
+ jvmti_thread_state()->oops_do(f);
+ }
+}
+
+void JavaThread::nmethods_do(CodeBlobClosure* cf) {
+ assert((!has_last_Java_frame() && java_call_counter() == 0) ||
+ (has_last_Java_frame() && java_call_counter() > 0), "wrong java_sp info!");
+
+ if (has_last_Java_frame()) {
+ // Traverse the execution stack
+ for (StackFrameStream fst(this); !fst.is_done(); fst.next()) {
+ fst.current()->nmethods_do(cf);
+ }
+ }
+}
+
+void JavaThread::metadata_do(void f(Metadata*)) {
+ if (has_last_Java_frame()) {
+ // Traverse the execution stack to call f() on the methods in the stack
+ for (StackFrameStream fst(this); !fst.is_done(); fst.next()) {
+ fst.current()->metadata_do(f);
+ }
+ } else if (is_Compiler_thread()) {
+ // need to walk ciMetadata in current compile tasks to keep alive.
+ CompilerThread* ct = (CompilerThread*)this;
+ if (ct->env() != NULL) {
+ ct->env()->metadata_do(f);
+ }
+ if (ct->task() != NULL) {
+ ct->task()->metadata_do(f);
+ }
+ }
+}
+
+// Printing
+const char* _get_thread_state_name(JavaThreadState _thread_state) {
+ switch (_thread_state) {
+ case _thread_uninitialized: return "_thread_uninitialized";
+ case _thread_new: return "_thread_new";
+ case _thread_new_trans: return "_thread_new_trans";
+ case _thread_in_native: return "_thread_in_native";
+ case _thread_in_native_trans: return "_thread_in_native_trans";
+ case _thread_in_vm: return "_thread_in_vm";
+ case _thread_in_vm_trans: return "_thread_in_vm_trans";
+ case _thread_in_Java: return "_thread_in_Java";
+ case _thread_in_Java_trans: return "_thread_in_Java_trans";
+ case _thread_blocked: return "_thread_blocked";
+ case _thread_blocked_trans: return "_thread_blocked_trans";
+ default: return "unknown thread state";
+ }
+}
+
+#ifndef PRODUCT
+void JavaThread::print_thread_state_on(outputStream *st) const {
+ st->print_cr(" JavaThread state: %s", _get_thread_state_name(_thread_state));
+};
+void JavaThread::print_thread_state() const {
+ print_thread_state_on(tty);
+}
+#endif // PRODUCT
+
+// Called by Threads::print() for VM_PrintThreads operation
+void JavaThread::print_on(outputStream *st) const {
+ st->print_raw("\"");
+ st->print_raw(get_thread_name());
+ st->print_raw("\" ");
+ oop thread_oop = threadObj();
+ if (thread_oop != NULL) {
+ st->print("#" INT64_FORMAT " ", (int64_t)java_lang_Thread::thread_id(thread_oop));
+ if (java_lang_Thread::is_daemon(thread_oop)) st->print("daemon ");
+ st->print("prio=%d ", java_lang_Thread::priority(thread_oop));
+ }
+ Thread::print_on(st);
+ // print guess for valid stack memory region (assume 4K pages); helps lock debugging
+ st->print_cr("[" INTPTR_FORMAT "]", (intptr_t)last_Java_sp() & ~right_n_bits(12));
+ if (thread_oop != NULL) {
+ st->print_cr(" java.lang.Thread.State: %s", java_lang_Thread::thread_status_name(thread_oop));
+ }
+#ifndef PRODUCT
+ print_thread_state_on(st);
+ _safepoint_state->print_on(st);
+#endif // PRODUCT
+ if (is_Compiler_thread()) {
+ CompilerThread* ct = (CompilerThread*)this;
+ if (ct->task() != NULL) {
+ st->print(" Compiling: ");
+ ct->task()->print(st, NULL, true, false);
+ } else {
+ st->print(" No compile task");
+ }
+ st->cr();
+ }
+}
+
+void JavaThread::print_name_on_error(outputStream* st, char *buf, int buflen) const {
+ st->print("%s", get_thread_name_string(buf, buflen));
+}
+
+// Called by fatal error handler. The difference between this and
+// JavaThread::print() is that we can't grab lock or allocate memory.
+void JavaThread::print_on_error(outputStream* st, char *buf, int buflen) const {
+ st->print("JavaThread \"%s\"", get_thread_name_string(buf, buflen));
+ oop thread_obj = threadObj();
+ if (thread_obj != NULL) {
+ if (java_lang_Thread::is_daemon(thread_obj)) st->print(" daemon");
+ }
+ st->print(" [");
+ st->print("%s", _get_thread_state_name(_thread_state));
+ if (osthread()) {
+ st->print(", id=%d", osthread()->thread_id());
+ }
+ st->print(", stack(" PTR_FORMAT "," PTR_FORMAT ")",
+ p2i(stack_end()), p2i(stack_base()));
+ st->print("]");
+ return;
+}
+
+// Verification
+
+static void frame_verify(frame* f, const RegisterMap *map) { f->verify(map); }
+
+void JavaThread::verify() {
+ // Verify oops in the thread.
+ oops_do(&VerifyOopClosure::verify_oop, NULL);
+
+ // Verify the stack frames.
+ frames_do(frame_verify);
+}
+
+// CR 6300358 (sub-CR 2137150)
+// Most callers of this method assume that it can't return NULL but a
+// thread may not have a name whilst it is in the process of attaching to
+// the VM - see CR 6412693, and there are places where a JavaThread can be
+// seen prior to having it's threadObj set (eg JNI attaching threads and
+// if vm exit occurs during initialization). These cases can all be accounted
+// for such that this method never returns NULL.
+const char* JavaThread::get_thread_name() const {
+#ifdef ASSERT
+ // early safepoints can hit while current thread does not yet have TLS
+ if (!SafepointSynchronize::is_at_safepoint()) {
+ Thread *cur = Thread::current();
+ if (!(cur->is_Java_thread() && cur == this)) {
+ // Current JavaThreads are allowed to get their own name without
+ // the Threads_lock.
+ assert_locked_or_safepoint(Threads_lock);
+ }
+ }
+#endif // ASSERT
+ return get_thread_name_string();
+}
+
+// Returns a non-NULL representation of this thread's name, or a suitable
+// descriptive string if there is no set name
+const char* JavaThread::get_thread_name_string(char* buf, int buflen) const {
+ const char* name_str;
+ oop thread_obj = threadObj();
+ if (thread_obj != NULL) {
+ oop name = java_lang_Thread::name(thread_obj);
+ if (name != NULL) {
+ if (buf == NULL) {
+ name_str = java_lang_String::as_utf8_string(name);
+ } else {
+ name_str = java_lang_String::as_utf8_string(name, buf, buflen);
+ }
+ } else if (is_attaching_via_jni()) { // workaround for 6412693 - see 6404306
+ name_str = "<no-name - thread is attaching>";
+ } else {
+ name_str = Thread::name();
+ }
+ } else {
+ name_str = Thread::name();
+ }
+ assert(name_str != NULL, "unexpected NULL thread name");
+ return name_str;
+}
+
+
+const char* JavaThread::get_threadgroup_name() const {
+ debug_only(if (JavaThread::current() != this) assert_locked_or_safepoint(Threads_lock);)
+ oop thread_obj = threadObj();
+ if (thread_obj != NULL) {
+ oop thread_group = java_lang_Thread::threadGroup(thread_obj);
+ if (thread_group != NULL) {
+ // ThreadGroup.name can be null
+ return java_lang_ThreadGroup::name(thread_group);
+ }
+ }
+ return NULL;
+}
+
+const char* JavaThread::get_parent_name() const {
+ debug_only(if (JavaThread::current() != this) assert_locked_or_safepoint(Threads_lock);)
+ oop thread_obj = threadObj();
+ if (thread_obj != NULL) {
+ oop thread_group = java_lang_Thread::threadGroup(thread_obj);
+ if (thread_group != NULL) {
+ oop parent = java_lang_ThreadGroup::parent(thread_group);
+ if (parent != NULL) {
+ // ThreadGroup.name can be null
+ return java_lang_ThreadGroup::name(parent);
+ }
+ }
+ }
+ return NULL;
+}
+
+ThreadPriority JavaThread::java_priority() const {
+ oop thr_oop = threadObj();
+ if (thr_oop == NULL) return NormPriority; // Bootstrapping
+ ThreadPriority priority = java_lang_Thread::priority(thr_oop);
+ assert(MinPriority <= priority && priority <= MaxPriority, "sanity check");
+ return priority;
+}
+
+void JavaThread::prepare(jobject jni_thread, ThreadPriority prio) {
+
+ assert(Threads_lock->owner() == Thread::current(), "must have threads lock");
+ // Link Java Thread object <-> C++ Thread
+
+ // Get the C++ thread object (an oop) from the JNI handle (a jthread)
+ // and put it into a new Handle. The Handle "thread_oop" can then
+ // be used to pass the C++ thread object to other methods.
+
+ // Set the Java level thread object (jthread) field of the
+ // new thread (a JavaThread *) to C++ thread object using the
+ // "thread_oop" handle.
+
+ // Set the thread field (a JavaThread *) of the
+ // oop representing the java_lang_Thread to the new thread (a JavaThread *).
+
+ Handle thread_oop(Thread::current(),
+ JNIHandles::resolve_non_null(jni_thread));
+ assert(InstanceKlass::cast(thread_oop->klass())->is_linked(),
+ "must be initialized");
+ set_threadObj(thread_oop());
+ java_lang_Thread::set_thread(thread_oop(), this);
+
+ if (prio == NoPriority) {
+ prio = java_lang_Thread::priority(thread_oop());
+ assert(prio != NoPriority, "A valid priority should be present");
+ }
+
+ // Push the Java priority down to the native thread; needs Threads_lock
+ Thread::set_priority(this, prio);
+
+ prepare_ext();
+
+ // Add the new thread to the Threads list and set it in motion.
+ // We must have threads lock in order to call Threads::add.
+ // It is crucial that we do not block before the thread is
+ // added to the Threads list for if a GC happens, then the java_thread oop
+ // will not be visited by GC.
+ Threads::add(this);
+}
+
+oop JavaThread::current_park_blocker() {
+ // Support for JSR-166 locks
+ oop thread_oop = threadObj();
+ if (thread_oop != NULL &&
+ JDK_Version::current().supports_thread_park_blocker()) {
+ return java_lang_Thread::park_blocker(thread_oop);
+ }
+ return NULL;
+}
+
+
+void JavaThread::print_stack_on(outputStream* st) {
+ if (!has_last_Java_frame()) return;
+ ResourceMark rm;
+ HandleMark hm;
+
+ RegisterMap reg_map(this);
+ vframe* start_vf = last_java_vframe(®_map);
+ int count = 0;
+ for (vframe* f = start_vf; f; f = f->sender()) {
+ if (f->is_java_frame()) {
+ javaVFrame* jvf = javaVFrame::cast(f);
+ java_lang_Throwable::print_stack_element(st, jvf->method(), jvf->bci());
+
+ // Print out lock information
+ if (JavaMonitorsInStackTrace) {
+ jvf->print_lock_info_on(st, count);
+ }
+ } else {
+ // Ignore non-Java frames
+ }
+
+ // Bail-out case for too deep stacks
+ count++;
+ if (MaxJavaStackTraceDepth == count) return;
+ }
+}
+
+
+// JVMTI PopFrame support
+void JavaThread::popframe_preserve_args(ByteSize size_in_bytes, void* start) {
+ assert(_popframe_preserved_args == NULL, "should not wipe out old PopFrame preserved arguments");
+ if (in_bytes(size_in_bytes) != 0) {
+ _popframe_preserved_args = NEW_C_HEAP_ARRAY(char, in_bytes(size_in_bytes), mtThread);
+ _popframe_preserved_args_size = in_bytes(size_in_bytes);
+ Copy::conjoint_jbytes(start, _popframe_preserved_args, _popframe_preserved_args_size);
+ }
+}
+
+void* JavaThread::popframe_preserved_args() {
+ return _popframe_preserved_args;
+}
+
+ByteSize JavaThread::popframe_preserved_args_size() {
+ return in_ByteSize(_popframe_preserved_args_size);
+}
+
+WordSize JavaThread::popframe_preserved_args_size_in_words() {
+ int sz = in_bytes(popframe_preserved_args_size());
+ assert(sz % wordSize == 0, "argument size must be multiple of wordSize");
+ return in_WordSize(sz / wordSize);
+}
+
+void JavaThread::popframe_free_preserved_args() {
+ assert(_popframe_preserved_args != NULL, "should not free PopFrame preserved arguments twice");
+ FREE_C_HEAP_ARRAY(char, (char*) _popframe_preserved_args);
+ _popframe_preserved_args = NULL;
+ _popframe_preserved_args_size = 0;
+}
+
+#ifndef PRODUCT
+
+void JavaThread::trace_frames() {
+ tty->print_cr("[Describe stack]");
+ int frame_no = 1;
+ for (StackFrameStream fst(this); !fst.is_done(); fst.next()) {
+ tty->print(" %d. ", frame_no++);
+ fst.current()->print_value_on(tty, this);
+ tty->cr();
+ }
+}
+
+class PrintAndVerifyOopClosure: public OopClosure {
+ protected:
+ template <class T> inline void do_oop_work(T* p) {
+ oop obj = oopDesc::load_decode_heap_oop(p);
+ if (obj == NULL) return;
+ tty->print(INTPTR_FORMAT ": ", p2i(p));
+ if (oopDesc::is_oop_or_null(obj)) {
+ if (obj->is_objArray()) {
+ tty->print_cr("valid objArray: " INTPTR_FORMAT, p2i(obj));
+ } else {
+ obj->print();
+ }
+ } else {
+ tty->print_cr("invalid oop: " INTPTR_FORMAT, p2i(obj));
+ }
+ tty->cr();
+ }
+ public:
+ virtual void do_oop(oop* p) { do_oop_work(p); }
+ virtual void do_oop(narrowOop* p) { do_oop_work(p); }
+};
+
+
+static void oops_print(frame* f, const RegisterMap *map) {
+ PrintAndVerifyOopClosure print;
+ f->print_value();
+ f->oops_do(&print, NULL, (RegisterMap*)map);
+}
+
+// Print our all the locations that contain oops and whether they are
+// valid or not. This useful when trying to find the oldest frame
+// where an oop has gone bad since the frame walk is from youngest to
+// oldest.
+void JavaThread::trace_oops() {
+ tty->print_cr("[Trace oops]");
+ frames_do(oops_print);
+}
+
+
+#ifdef ASSERT
+// Print or validate the layout of stack frames
+void JavaThread::print_frame_layout(int depth, bool validate_only) {
+ ResourceMark rm;
+ PRESERVE_EXCEPTION_MARK;
+ FrameValues values;
+ int frame_no = 0;
+ for (StackFrameStream fst(this, false); !fst.is_done(); fst.next()) {
+ fst.current()->describe(values, ++frame_no);
+ if (depth == frame_no) break;
+ }
+ if (validate_only) {
+ values.validate();
+ } else {
+ tty->print_cr("[Describe stack layout]");
+ values.print(this);
+ }
+}
+#endif
+
+void JavaThread::trace_stack_from(vframe* start_vf) {
+ ResourceMark rm;
+ int vframe_no = 1;
+ for (vframe* f = start_vf; f; f = f->sender()) {
+ if (f->is_java_frame()) {
+ javaVFrame::cast(f)->print_activation(vframe_no++);
+ } else {
+ f->print();
+ }
+ if (vframe_no > StackPrintLimit) {
+ tty->print_cr("...<more frames>...");
+ return;
+ }
+ }
+}
+
+
+void JavaThread::trace_stack() {
+ if (!has_last_Java_frame()) return;
+ ResourceMark rm;
+ HandleMark hm;
+ RegisterMap reg_map(this);
+ trace_stack_from(last_java_vframe(®_map));
+}
+
+
+#endif // PRODUCT
+
+
+javaVFrame* JavaThread::last_java_vframe(RegisterMap *reg_map) {
+ assert(reg_map != NULL, "a map must be given");
+ frame f = last_frame();
+ for (vframe* vf = vframe::new_vframe(&f, reg_map, this); vf; vf = vf->sender()) {
+ if (vf->is_java_frame()) return javaVFrame::cast(vf);
+ }
+ return NULL;
+}
+
+
+Klass* JavaThread::security_get_caller_class(int depth) {
+ vframeStream vfst(this);
+ vfst.security_get_caller_frame(depth);
+ if (!vfst.at_end()) {
+ return vfst.method()->method_holder();
+ }
+ return NULL;
+}
+
+static void compiler_thread_entry(JavaThread* thread, TRAPS) {
+ assert(thread->is_Compiler_thread(), "must be compiler thread");
+ CompileBroker::compiler_thread_loop();
+}
+
+static void sweeper_thread_entry(JavaThread* thread, TRAPS) {
+ NMethodSweeper::sweeper_loop();
+}
+
+// Create a CompilerThread
+CompilerThread::CompilerThread(CompileQueue* queue,
+ CompilerCounters* counters)
+ : JavaThread(&compiler_thread_entry) {
+ _env = NULL;
+ _log = NULL;
+ _task = NULL;
+ _queue = queue;
+ _counters = counters;
+ _buffer_blob = NULL;
+ _compiler = NULL;
+
+#ifndef PRODUCT
+ _ideal_graph_printer = NULL;
+#endif
+}
+
+bool CompilerThread::can_call_java() const {
+ return _compiler != NULL && _compiler->is_jvmci();
+}
+
+// Create sweeper thread
+CodeCacheSweeperThread::CodeCacheSweeperThread()
+: JavaThread(&sweeper_thread_entry) {
+ _scanned_compiled_method = NULL;
+}
+
+void CodeCacheSweeperThread::oops_do(OopClosure* f, CodeBlobClosure* cf) {
+ JavaThread::oops_do(f, cf);
+ if (_scanned_compiled_method != NULL && cf != NULL) {
+ // Safepoints can occur when the sweeper is scanning an nmethod so
+ // process it here to make sure it isn't unloaded in the middle of
+ // a scan.
+ cf->do_code_blob(_scanned_compiled_method);
+ }
+}
+
+void CodeCacheSweeperThread::nmethods_do(CodeBlobClosure* cf) {
+ JavaThread::nmethods_do(cf);
+ if (_scanned_compiled_method != NULL && cf != NULL) {
+ // Safepoints can occur when the sweeper is scanning an nmethod so
+ // process it here to make sure it isn't unloaded in the middle of
+ // a scan.
+ cf->do_code_blob(_scanned_compiled_method);
+ }
+}
+
+
+// ======= Threads ========
+
+// The Threads class links together all active threads, and provides
+// operations over all threads. It is protected by its own Mutex
+// lock, which is also used in other contexts to protect thread
+// operations from having the thread being operated on from exiting
+// and going away unexpectedly (e.g., safepoint synchronization)
+
+JavaThread* Threads::_thread_list = NULL;
+int Threads::_number_of_threads = 0;
+int Threads::_number_of_non_daemon_threads = 0;
+int Threads::_return_code = 0;
+int Threads::_thread_claim_parity = 0;
+size_t JavaThread::_stack_size_at_create = 0;
+#ifdef ASSERT
+bool Threads::_vm_complete = false;
+#endif
+
+// All JavaThreads
+#define ALL_JAVA_THREADS(X) for (JavaThread* X = _thread_list; X; X = X->next())
+
+// All JavaThreads + all non-JavaThreads (i.e., every thread in the system)
+void Threads::threads_do(ThreadClosure* tc) {
+ assert_locked_or_safepoint(Threads_lock);
+ // ALL_JAVA_THREADS iterates through all JavaThreads
+ ALL_JAVA_THREADS(p) {
+ tc->do_thread(p);
+ }
+ // Someday we could have a table or list of all non-JavaThreads.
+ // For now, just manually iterate through them.
+ tc->do_thread(VMThread::vm_thread());
+ Universe::heap()->gc_threads_do(tc);
+ WatcherThread *wt = WatcherThread::watcher_thread();
+ // Strictly speaking, the following NULL check isn't sufficient to make sure
+ // the data for WatcherThread is still valid upon being examined. However,
+ // considering that WatchThread terminates when the VM is on the way to
+ // exit at safepoint, the chance of the above is extremely small. The right
+ // way to prevent termination of WatcherThread would be to acquire
+ // Terminator_lock, but we can't do that without violating the lock rank
+ // checking in some cases.
+ if (wt != NULL) {
+ tc->do_thread(wt);
+ }
+
+ // If CompilerThreads ever become non-JavaThreads, add them here
+}
+
+void Threads::parallel_java_threads_do(ThreadClosure* tc) {
+ int cp = Threads::thread_claim_parity();
+ ALL_JAVA_THREADS(p) {
+ if (p->claim_oops_do(true, cp)) {
+ tc->do_thread(p);
+ }
+ }
+ // Thread claiming protocol requires us to claim the same interesting
+ // threads on all paths. Notably, Threads::possibly_parallel_threads_do
+ // claims all Java threads *and* the VMThread. To avoid breaking the
+ // claiming protocol, we have to claim VMThread on this path too, even
+ // if we do not apply the closure to the VMThread.
+ VMThread* vmt = VMThread::vm_thread();
+ (void)vmt->claim_oops_do(true, cp);
+}
+
+// The system initialization in the library has three phases.
+//
+// Phase 1: java.lang.System class initialization
+// java.lang.System is a primordial class loaded and initialized
+// by the VM early during startup. java.lang.System.<clinit>
+// only does registerNatives and keeps the rest of the class
+// initialization work later until thread initialization completes.
+//
+// System.initPhase1 initializes the system properties, the static
+// fields in, out, and err. Set up java signal handlers, OS-specific
+// system settings, and thread group of the main thread.
+static void call_initPhase1(TRAPS) {
+ Klass* klass = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_System(), true, CHECK);
+ JavaValue result(T_VOID);
+ JavaCalls::call_static(&result, klass, vmSymbols::initPhase1_name(),
+ vmSymbols::void_method_signature(), CHECK);
+}
+
+// Phase 2. Module system initialization
+// This will initialize the module system. Only java.base classes
+// can be loaded until phase 2 completes.
+//
+// Call System.initPhase2 after the compiler initialization and jsr292
+// classes get initialized because module initialization runs a lot of java
+// code, that for performance reasons, should be compiled. Also, this will
+// enable the startup code to use lambda and other language features in this
+// phase and onward.
+//
+// After phase 2, The VM will begin search classes from -Xbootclasspath/a.
+static void call_initPhase2(TRAPS) {
+ TraceTime timer("Initialize module system", TRACETIME_LOG(Info, startuptime));
+
+ Klass* klass = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_System(), true, CHECK);
+
+ JavaValue result(T_INT);
+ JavaCallArguments args;
+ args.push_int(DisplayVMOutputToStderr);
+ args.push_int(log_is_enabled(Debug, init)); // print stack trace if exception thrown
+ JavaCalls::call_static(&result, klass, vmSymbols::initPhase2_name(),
+ vmSymbols::boolean_boolean_int_signature(), &args, CHECK);
+ if (result.get_jint() != JNI_OK) {
+ vm_exit_during_initialization(); // no message or exception
+ }
+
+ universe_post_module_init();
+}
+
+// Phase 3. final setup - set security manager, system class loader and TCCL
+//
+// This will instantiate and set the security manager, set the system class
+// loader as well as the thread context class loader. The security manager
+// and system class loader may be a custom class loaded from -Xbootclasspath/a,
+// other modules or the application's classpath.
+static void call_initPhase3(TRAPS) {
+ Klass* klass = SystemDictionary::resolve_or_fail(vmSymbols::java_lang_System(), true, CHECK);
+ JavaValue result(T_VOID);
+ JavaCalls::call_static(&result, klass, vmSymbols::initPhase3_name(),
+ vmSymbols::void_method_signature(), CHECK);
+}
+
+void Threads::initialize_java_lang_classes(JavaThread* main_thread, TRAPS) {
+ TraceTime timer("Initialize java.lang classes", TRACETIME_LOG(Info, startuptime));
+
+ if (EagerXrunInit && Arguments::init_libraries_at_startup()) {
+ create_vm_init_libraries();
+ }
+
+ initialize_class(vmSymbols::java_lang_String(), CHECK);
+
+ // Inject CompactStrings value after the static initializers for String ran.
+ java_lang_String::set_compact_strings(CompactStrings);
+
+ // Initialize java_lang.System (needed before creating the thread)
+ initialize_class(vmSymbols::java_lang_System(), CHECK);
+ // The VM creates & returns objects of this class. Make sure it's initialized.
+ initialize_class(vmSymbols::java_lang_Class(), CHECK);
+ initialize_class(vmSymbols::java_lang_ThreadGroup(), CHECK);
+ Handle thread_group = create_initial_thread_group(CHECK);
+ Universe::set_main_thread_group(thread_group());
+ initialize_class(vmSymbols::java_lang_Thread(), CHECK);
+ oop thread_object = create_initial_thread(thread_group, main_thread, CHECK);
+ main_thread->set_threadObj(thread_object);
+ // Set thread status to running since main thread has
+ // been started and running.
+ java_lang_Thread::set_thread_status(thread_object,
+ java_lang_Thread::RUNNABLE);
+
+ // The VM creates objects of this class.
+ initialize_class(vmSymbols::java_lang_Module(), CHECK);
+
+ // The VM preresolves methods to these classes. Make sure that they get initialized
+ initialize_class(vmSymbols::java_lang_reflect_Method(), CHECK);
+ initialize_class(vmSymbols::java_lang_ref_Finalizer(), CHECK);
+
+ // Phase 1 of the system initialization in the library, java.lang.System class initialization
+ call_initPhase1(CHECK);
+
+ // get the Java runtime name after java.lang.System is initialized
+ JDK_Version::set_runtime_name(get_java_runtime_name(THREAD));
+ JDK_Version::set_runtime_version(get_java_runtime_version(THREAD));
+
+ // an instance of OutOfMemory exception has been allocated earlier
+ initialize_class(vmSymbols::java_lang_OutOfMemoryError(), CHECK);
+ initialize_class(vmSymbols::java_lang_NullPointerException(), CHECK);
+ initialize_class(vmSymbols::java_lang_ClassCastException(), CHECK);
+ initialize_class(vmSymbols::java_lang_ArrayStoreException(), CHECK);
+ initialize_class(vmSymbols::java_lang_ArithmeticException(), CHECK);
+ initialize_class(vmSymbols::java_lang_StackOverflowError(), CHECK);
+ initialize_class(vmSymbols::java_lang_IllegalMonitorStateException(), CHECK);
+ initialize_class(vmSymbols::java_lang_IllegalArgumentException(), CHECK);
+}
+
+void Threads::initialize_jsr292_core_classes(TRAPS) {
+ TraceTime timer("Initialize java.lang.invoke classes", TRACETIME_LOG(Info, startuptime));
+
+ initialize_class(vmSymbols::java_lang_invoke_MethodHandle(), CHECK);
+ initialize_class(vmSymbols::java_lang_invoke_ResolvedMethodName(), CHECK);
+ initialize_class(vmSymbols::java_lang_invoke_MemberName(), CHECK);
+ initialize_class(vmSymbols::java_lang_invoke_MethodHandleNatives(), CHECK);
+}
+
+jint Threads::create_vm(JavaVMInitArgs* args, bool* canTryAgain) {
+ extern void JDK_Version_init();
+
+ // Preinitialize version info.
+ VM_Version::early_initialize();
+
+ // Check version
+ if (!is_supported_jni_version(args->version)) return JNI_EVERSION;
+
+ // Initialize library-based TLS
+ ThreadLocalStorage::init();
+
+ // Initialize the output stream module
+ ostream_init();
+
+ // Process java launcher properties.
+ Arguments::process_sun_java_launcher_properties(args);
+
+ // Initialize the os module
+ os::init();
+
+ // Record VM creation timing statistics
+ TraceVmCreationTime create_vm_timer;
+ create_vm_timer.start();
+
+ // Initialize system properties.
+ Arguments::init_system_properties();
+
+ // So that JDK version can be used as a discriminator when parsing arguments
+ JDK_Version_init();
+
+ // Update/Initialize System properties after JDK version number is known
+ Arguments::init_version_specific_system_properties();
+
+ // Make sure to initialize log configuration *before* parsing arguments
+ LogConfiguration::initialize(create_vm_timer.begin_time());
+
+ // Parse arguments
+ jint parse_result = Arguments::parse(args);
+ if (parse_result != JNI_OK) return parse_result;
+
+ os::init_before_ergo();
+
+ jint ergo_result = Arguments::apply_ergo();
+ if (ergo_result != JNI_OK) return ergo_result;
+
+ // Final check of all ranges after ergonomics which may change values.
+ if (!CommandLineFlagRangeList::check_ranges()) {
+ return JNI_EINVAL;
+ }
+
+ // Final check of all 'AfterErgo' constraints after ergonomics which may change values.
+ bool constraint_result = CommandLineFlagConstraintList::check_constraints(CommandLineFlagConstraint::AfterErgo);
+ if (!constraint_result) {
+ return JNI_EINVAL;
+ }
+
+ CommandLineFlagWriteableList::mark_startup();
+
+ if (PauseAtStartup) {
+ os::pause();
+ }
+
+ HOTSPOT_VM_INIT_BEGIN();
+
+ // Timing (must come after argument parsing)
+ TraceTime timer("Create VM", TRACETIME_LOG(Info, startuptime));
+
+ // Initialize the os module after parsing the args
+ jint os_init_2_result = os::init_2();
+ if (os_init_2_result != JNI_OK) return os_init_2_result;
+
+ jint adjust_after_os_result = Arguments::adjust_after_os();
+ if (adjust_after_os_result != JNI_OK) return adjust_after_os_result;
+
+ // Initialize output stream logging
+ ostream_init_log();
+
+ // Convert -Xrun to -agentlib: if there is no JVM_OnLoad
+ // Must be before create_vm_init_agents()
+ if (Arguments::init_libraries_at_startup()) {
+ convert_vm_init_libraries_to_agents();
+ }
+
+ // Launch -agentlib/-agentpath and converted -Xrun agents
+ if (Arguments::init_agents_at_startup()) {
+ create_vm_init_agents();
+ }
+
+ // Initialize Threads state
+ _thread_list = NULL;
+ _number_of_threads = 0;
+ _number_of_non_daemon_threads = 0;
+
+ // Initialize global data structures and create system classes in heap
+ vm_init_globals();
+
+#if INCLUDE_JVMCI
+ if (JVMCICounterSize > 0) {
+ JavaThread::_jvmci_old_thread_counters = NEW_C_HEAP_ARRAY(jlong, JVMCICounterSize, mtInternal);
+ memset(JavaThread::_jvmci_old_thread_counters, 0, sizeof(jlong) * JVMCICounterSize);
+ } else {
+ JavaThread::_jvmci_old_thread_counters = NULL;
+ }
+#endif // INCLUDE_JVMCI
+
+ // Attach the main thread to this os thread
+ JavaThread* main_thread = new JavaThread();
+ main_thread->set_thread_state(_thread_in_vm);
+ main_thread->initialize_thread_current();
+ // must do this before set_active_handles
+ main_thread->record_stack_base_and_size();
+ main_thread->set_active_handles(JNIHandleBlock::allocate_block());
+
+ if (!main_thread->set_as_starting_thread()) {
+ vm_shutdown_during_initialization(
+ "Failed necessary internal allocation. Out of swap space");
+ delete main_thread;
+ *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
+ return JNI_ENOMEM;
+ }
+
+ // Enable guard page *after* os::create_main_thread(), otherwise it would
+ // crash Linux VM, see notes in os_linux.cpp.
+ main_thread->create_stack_guard_pages();
+
+ // Initialize Java-Level synchronization subsystem
+ ObjectMonitor::Initialize();
+
+ // Initialize global modules
+ jint status = init_globals();
+ if (status != JNI_OK) {
+ delete main_thread;
+ *canTryAgain = false; // don't let caller call JNI_CreateJavaVM again
+ return status;
+ }
+
+ if (TRACE_INITIALIZE() != JNI_OK) {
+ vm_exit_during_initialization("Failed to initialize tracing backend");
+ }
+
+ // Should be done after the heap is fully created
+ main_thread->cache_global_variables();
+
+ HandleMark hm;
+
+ { MutexLocker mu(Threads_lock);
+ Threads::add(main_thread);
+ }
+
+ // Any JVMTI raw monitors entered in onload will transition into
+ // real raw monitor. VM is setup enough here for raw monitor enter.
+ JvmtiExport::transition_pending_onload_raw_monitors();
+
+ // Create the VMThread
+ { TraceTime timer("Start VMThread", TRACETIME_LOG(Info, startuptime));
+
+ VMThread::create();
+ Thread* vmthread = VMThread::vm_thread();
+
+ if (!os::create_thread(vmthread, os::vm_thread)) {
+ vm_exit_during_initialization("Cannot create VM thread. "
+ "Out of system resources.");
+ }
+
+ // Wait for the VM thread to become ready, and VMThread::run to initialize
+ // Monitors can have spurious returns, must always check another state flag
+ {
+ MutexLocker ml(Notify_lock);
+ os::start_thread(vmthread);
+ while (vmthread->active_handles() == NULL) {
+ Notify_lock->wait();
+ }
+ }
+ }
+
+ assert(Universe::is_fully_initialized(), "not initialized");
+ if (VerifyDuringStartup) {
+ // Make sure we're starting with a clean slate.
+ VM_Verify verify_op;
+ VMThread::execute(&verify_op);
+ }
+
+ Thread* THREAD = Thread::current();
+
+ // Always call even when there are not JVMTI environments yet, since environments
+ // may be attached late and JVMTI must track phases of VM execution
+ JvmtiExport::enter_early_start_phase();
+
+ // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
+ JvmtiExport::post_early_vm_start();
+
+ initialize_java_lang_classes(main_thread, CHECK_JNI_ERR);
+
+ // We need this for ClassDataSharing - the initial vm.info property is set
+ // with the default value of CDS "sharing" which may be reset through
+ // command line options.
+ reset_vm_info_property(CHECK_JNI_ERR);
+
+ quicken_jni_functions();
+
+ // No more stub generation allowed after that point.
+ StubCodeDesc::freeze();
+
+ // Set flag that basic initialization has completed. Used by exceptions and various
+ // debug stuff, that does not work until all basic classes have been initialized.
+ set_init_completed();
+
+ LogConfiguration::post_initialize();
+ Metaspace::post_initialize();
+
+ HOTSPOT_VM_INIT_END();
+
+ // record VM initialization completion time
+#if INCLUDE_MANAGEMENT
+ Management::record_vm_init_completed();
+#endif // INCLUDE_MANAGEMENT
+
+ // Signal Dispatcher needs to be started before VMInit event is posted
+ os::signal_init(CHECK_JNI_ERR);
+
+ // Start Attach Listener if +StartAttachListener or it can't be started lazily
+ if (!DisableAttachMechanism) {
+ AttachListener::vm_start();
+ if (StartAttachListener || AttachListener::init_at_startup()) {
+ AttachListener::init();
+ }
+ }
+
+ // Launch -Xrun agents
+ // Must be done in the JVMTI live phase so that for backward compatibility the JDWP
+ // back-end can launch with -Xdebug -Xrunjdwp.
+ if (!EagerXrunInit && Arguments::init_libraries_at_startup()) {
+ create_vm_init_libraries();
+ }
+
+ if (CleanChunkPoolAsync) {
+ Chunk::start_chunk_pool_cleaner_task();
+ }
+
+ // initialize compiler(s)
+#if defined(COMPILER1) || defined(COMPILER2) || defined(SHARK) || INCLUDE_JVMCI
+ CompileBroker::compilation_init(CHECK_JNI_ERR);
+#endif
+
+ // Pre-initialize some JSR292 core classes to avoid deadlock during class loading.
+ // It is done after compilers are initialized, because otherwise compilations of
+ // signature polymorphic MH intrinsics can be missed
+ // (see SystemDictionary::find_method_handle_intrinsic).
+ initialize_jsr292_core_classes(CHECK_JNI_ERR);
+
+ // This will initialize the module system. Only java.base classes can be
+ // loaded until phase 2 completes
+ call_initPhase2(CHECK_JNI_ERR);
+
+ // Always call even when there are not JVMTI environments yet, since environments
+ // may be attached late and JVMTI must track phases of VM execution
+ JvmtiExport::enter_start_phase();
+
+ // Notify JVMTI agents that VM has started (JNI is up) - nop if no agents.
+ JvmtiExport::post_vm_start();
+
+ // Final system initialization including security manager and system class loader
+ call_initPhase3(CHECK_JNI_ERR);
+
+ // cache the system class loader
+ SystemDictionary::compute_java_system_loader(CHECK_(JNI_ERR));
+
+#if INCLUDE_JVMCI
+ if (EnableJVMCI) {
+ // Initialize JVMCI eagerly if JVMCIPrintProperties is enabled.
+ // The JVMCI Java initialization code will read this flag and
+ // do the printing if it's set.
+ bool init = JVMCIPrintProperties;
+
+ if (!init) {
+ // 8145270: Force initialization of JVMCI runtime otherwise requests for blocking
+ // compilations via JVMCI will not actually block until JVMCI is initialized.
+ init = UseJVMCICompiler && (!UseInterpreter || !BackgroundCompilation);
+ }
+
+ if (init) {
+ JVMCIRuntime::force_initialization(CHECK_JNI_ERR);
+ }
+ }
+#endif
+
+ // Always call even when there are not JVMTI environments yet, since environments
+ // may be attached late and JVMTI must track phases of VM execution
+ JvmtiExport::enter_live_phase();
+
+ // Notify JVMTI agents that VM initialization is complete - nop if no agents.
+ JvmtiExport::post_vm_initialized();
+
+ if (TRACE_START() != JNI_OK) {
+ vm_exit_during_initialization("Failed to start tracing backend.");
+ }
+
+#if INCLUDE_MANAGEMENT
+ Management::initialize(THREAD);
+
+ if (HAS_PENDING_EXCEPTION) {
+ // management agent fails to start possibly due to
+ // configuration problem and is responsible for printing
+ // stack trace if appropriate. Simply exit VM.
+ vm_exit(1);
+ }
+#endif // INCLUDE_MANAGEMENT
+
+ if (MemProfiling) MemProfiler::engage();
+ StatSampler::engage();
+ if (CheckJNICalls) JniPeriodicChecker::engage();
+
+ BiasedLocking::init();
+
+#if INCLUDE_RTM_OPT
+ RTMLockingCounters::init();
+#endif
+
+ if (JDK_Version::current().post_vm_init_hook_enabled()) {
+ call_postVMInitHook(THREAD);
+ // The Java side of PostVMInitHook.run must deal with all
+ // exceptions and provide means of diagnosis.
+ if (HAS_PENDING_EXCEPTION) {
+ CLEAR_PENDING_EXCEPTION;
+ }
+ }
+
+ {
+ MutexLocker ml(PeriodicTask_lock);
+ // Make sure the WatcherThread can be started by WatcherThread::start()
+ // or by dynamic enrollment.
+ WatcherThread::make_startable();
+ // Start up the WatcherThread if there are any periodic tasks
+ // NOTE: All PeriodicTasks should be registered by now. If they
+ // aren't, late joiners might appear to start slowly (we might
+ // take a while to process their first tick).
+ if (PeriodicTask::num_tasks() > 0) {
+ WatcherThread::start();
+ }
+ }
+
+ create_vm_timer.end();
+#ifdef ASSERT
+ _vm_complete = true;
+#endif
+
+ if (DumpSharedSpaces) {
+ MetaspaceShared::preload_and_dump(CHECK_JNI_ERR);
+ ShouldNotReachHere();
+ }
+
+ return JNI_OK;
+}
+
+// type for the Agent_OnLoad and JVM_OnLoad entry points
+extern "C" {
+ typedef jint (JNICALL *OnLoadEntry_t)(JavaVM *, char *, void *);
+}
+// Find a command line agent library and return its entry point for
+// -agentlib: -agentpath: -Xrun
+// num_symbol_entries must be passed-in since only the caller knows the number of symbols in the array.
+static OnLoadEntry_t lookup_on_load(AgentLibrary* agent,
+ const char *on_load_symbols[],
+ size_t num_symbol_entries) {
+ OnLoadEntry_t on_load_entry = NULL;
+ void *library = NULL;
+
+ if (!agent->valid()) {
+ char buffer[JVM_MAXPATHLEN];
+ char ebuf[1024] = "";
+ const char *name = agent->name();
+ const char *msg = "Could not find agent library ";
+
+ // First check to see if agent is statically linked into executable
+ if (os::find_builtin_agent(agent, on_load_symbols, num_symbol_entries)) {
+ library = agent->os_lib();
+ } else if (agent->is_absolute_path()) {
+ library = os::dll_load(name, ebuf, sizeof ebuf);
+ if (library == NULL) {
+ const char *sub_msg = " in absolute path, with error: ";
+ size_t len = strlen(msg) + strlen(name) + strlen(sub_msg) + strlen(ebuf) + 1;
+ char *buf = NEW_C_HEAP_ARRAY(char, len, mtThread);
+ jio_snprintf(buf, len, "%s%s%s%s", msg, name, sub_msg, ebuf);
+ // If we can't find the agent, exit.
+ vm_exit_during_initialization(buf, NULL);
+ FREE_C_HEAP_ARRAY(char, buf);
+ }
+ } else {
+ // Try to load the agent from the standard dll directory
+ if (os::dll_locate_lib(buffer, sizeof(buffer), Arguments::get_dll_dir(),
+ name)) {
+ library = os::dll_load(buffer, ebuf, sizeof ebuf);
+ }
+ if (library == NULL) { // Try the library path directory.
+ if (os::dll_build_name(buffer, sizeof(buffer), name)) {
+ library = os::dll_load(buffer, ebuf, sizeof ebuf);
+ }
+ if (library == NULL) {
+ const char *sub_msg = " on the library path, with error: ";
+ size_t len = strlen(msg) + strlen(name) + strlen(sub_msg) + strlen(ebuf) + 1;
+ char *buf = NEW_C_HEAP_ARRAY(char, len, mtThread);
+ jio_snprintf(buf, len, "%s%s%s%s", msg, name, sub_msg, ebuf);
+ // If we can't find the agent, exit.
+ vm_exit_during_initialization(buf, NULL);
+ FREE_C_HEAP_ARRAY(char, buf);
+ }
+ }
+ }
+ agent->set_os_lib(library);
+ agent->set_valid();
+ }
+
+ // Find the OnLoad function.
+ on_load_entry =
+ CAST_TO_FN_PTR(OnLoadEntry_t, os::find_agent_function(agent,
+ false,
+ on_load_symbols,
+ num_symbol_entries));
+ return on_load_entry;
+}
+
+// Find the JVM_OnLoad entry point
+static OnLoadEntry_t lookup_jvm_on_load(AgentLibrary* agent) {
+ const char *on_load_symbols[] = JVM_ONLOAD_SYMBOLS;
+ return lookup_on_load(agent, on_load_symbols, sizeof(on_load_symbols) / sizeof(char*));
+}
+
+// Find the Agent_OnLoad entry point
+static OnLoadEntry_t lookup_agent_on_load(AgentLibrary* agent) {
+ const char *on_load_symbols[] = AGENT_ONLOAD_SYMBOLS;
+ return lookup_on_load(agent, on_load_symbols, sizeof(on_load_symbols) / sizeof(char*));
+}
+
+// For backwards compatibility with -Xrun
+// Convert libraries with no JVM_OnLoad, but which have Agent_OnLoad to be
+// treated like -agentpath:
+// Must be called before agent libraries are created
+void Threads::convert_vm_init_libraries_to_agents() {
+ AgentLibrary* agent;
+ AgentLibrary* next;
+
+ for (agent = Arguments::libraries(); agent != NULL; agent = next) {
+ next = agent->next(); // cache the next agent now as this agent may get moved off this list
+ OnLoadEntry_t on_load_entry = lookup_jvm_on_load(agent);
+
+ // If there is an JVM_OnLoad function it will get called later,
+ // otherwise see if there is an Agent_OnLoad
+ if (on_load_entry == NULL) {
+ on_load_entry = lookup_agent_on_load(agent);
+ if (on_load_entry != NULL) {
+ // switch it to the agent list -- so that Agent_OnLoad will be called,
+ // JVM_OnLoad won't be attempted and Agent_OnUnload will
+ Arguments::convert_library_to_agent(agent);
+ } else {
+ vm_exit_during_initialization("Could not find JVM_OnLoad or Agent_OnLoad function in the library", agent->name());
+ }
+ }
+ }
+}
+
+// Create agents for -agentlib: -agentpath: and converted -Xrun
+// Invokes Agent_OnLoad
+// Called very early -- before JavaThreads exist
+void Threads::create_vm_init_agents() {
+ extern struct JavaVM_ main_vm;
+ AgentLibrary* agent;
+
+ JvmtiExport::enter_onload_phase();
+
+ for (agent = Arguments::agents(); agent != NULL; agent = agent->next()) {
+ OnLoadEntry_t on_load_entry = lookup_agent_on_load(agent);
+
+ if (on_load_entry != NULL) {
+ // Invoke the Agent_OnLoad function
+ jint err = (*on_load_entry)(&main_vm, agent->options(), NULL);
+ if (err != JNI_OK) {
+ vm_exit_during_initialization("agent library failed to init", agent->name());
+ }
+ } else {
+ vm_exit_during_initialization("Could not find Agent_OnLoad function in the agent library", agent->name());
+ }
+ }
+ JvmtiExport::enter_primordial_phase();
+}
+
+extern "C" {
+ typedef void (JNICALL *Agent_OnUnload_t)(JavaVM *);
+}
+
+void Threads::shutdown_vm_agents() {
+ // Send any Agent_OnUnload notifications
+ const char *on_unload_symbols[] = AGENT_ONUNLOAD_SYMBOLS;
+ size_t num_symbol_entries = ARRAY_SIZE(on_unload_symbols);
+ extern struct JavaVM_ main_vm;
+ for (AgentLibrary* agent = Arguments::agents(); agent != NULL; agent = agent->next()) {
+
+ // Find the Agent_OnUnload function.
+ Agent_OnUnload_t unload_entry = CAST_TO_FN_PTR(Agent_OnUnload_t,
+ os::find_agent_function(agent,
+ false,
+ on_unload_symbols,
+ num_symbol_entries));
+
+ // Invoke the Agent_OnUnload function
+ if (unload_entry != NULL) {
+ JavaThread* thread = JavaThread::current();
+ ThreadToNativeFromVM ttn(thread);
+ HandleMark hm(thread);
+ (*unload_entry)(&main_vm);
+ }
+ }
+}
+
+// Called for after the VM is initialized for -Xrun libraries which have not been converted to agent libraries
+// Invokes JVM_OnLoad
+void Threads::create_vm_init_libraries() {
+ extern struct JavaVM_ main_vm;
+ AgentLibrary* agent;
+
+ for (agent = Arguments::libraries(); agent != NULL; agent = agent->next()) {
+ OnLoadEntry_t on_load_entry = lookup_jvm_on_load(agent);
+
+ if (on_load_entry != NULL) {
+ // Invoke the JVM_OnLoad function
+ JavaThread* thread = JavaThread::current();
+ ThreadToNativeFromVM ttn(thread);
+ HandleMark hm(thread);
+ jint err = (*on_load_entry)(&main_vm, agent->options(), NULL);
+ if (err != JNI_OK) {
+ vm_exit_during_initialization("-Xrun library failed to init", agent->name());
+ }
+ } else {
+ vm_exit_during_initialization("Could not find JVM_OnLoad function in -Xrun library", agent->name());
+ }
+ }
+}
+
+JavaThread* Threads::find_java_thread_from_java_tid(jlong java_tid) {
+ assert(Threads_lock->owned_by_self(), "Must hold Threads_lock");
+
+ JavaThread* java_thread = NULL;
+ // Sequential search for now. Need to do better optimization later.
+ for (JavaThread* thread = Threads::first(); thread != NULL; thread = thread->next()) {
+ oop tobj = thread->threadObj();
+ if (!thread->is_exiting() &&
+ tobj != NULL &&
+ java_tid == java_lang_Thread::thread_id(tobj)) {
+ java_thread = thread;
+ break;
+ }
+ }
+ return java_thread;
+}
+
+
+// Last thread running calls java.lang.Shutdown.shutdown()
+void JavaThread::invoke_shutdown_hooks() {
+ HandleMark hm(this);
+
+ // We could get here with a pending exception, if so clear it now.
+ if (this->has_pending_exception()) {
+ this->clear_pending_exception();
+ }
+
+ EXCEPTION_MARK;
+ Klass* shutdown_klass =
+ SystemDictionary::resolve_or_null(vmSymbols::java_lang_Shutdown(),
+ THREAD);
+ if (shutdown_klass != NULL) {
+ // SystemDictionary::resolve_or_null will return null if there was
+ // an exception. If we cannot load the Shutdown class, just don't
+ // call Shutdown.shutdown() at all. This will mean the shutdown hooks
+ // and finalizers (if runFinalizersOnExit is set) won't be run.
+ // Note that if a shutdown hook was registered or runFinalizersOnExit
+ // was called, the Shutdown class would have already been loaded
+ // (Runtime.addShutdownHook and runFinalizersOnExit will load it).
+ JavaValue result(T_VOID);
+ JavaCalls::call_static(&result,
+ shutdown_klass,
+ vmSymbols::shutdown_method_name(),
+ vmSymbols::void_method_signature(),
+ THREAD);
+ }
+ CLEAR_PENDING_EXCEPTION;
+}
+
+// Threads::destroy_vm() is normally called from jni_DestroyJavaVM() when
+// the program falls off the end of main(). Another VM exit path is through
+// vm_exit() when the program calls System.exit() to return a value or when
+// there is a serious error in VM. The two shutdown paths are not exactly
+// the same, but they share Shutdown.shutdown() at Java level and before_exit()
+// and VM_Exit op at VM level.
+//
+// Shutdown sequence:
+// + Shutdown native memory tracking if it is on
+// + Wait until we are the last non-daemon thread to execute
+// <-- every thing is still working at this moment -->
+// + Call java.lang.Shutdown.shutdown(), which will invoke Java level
+// shutdown hooks, run finalizers if finalization-on-exit
+// + Call before_exit(), prepare for VM exit
+// > run VM level shutdown hooks (they are registered through JVM_OnExit(),
+// currently the only user of this mechanism is File.deleteOnExit())
+// > stop StatSampler, watcher thread, CMS threads,
+// post thread end and vm death events to JVMTI,
+// stop signal thread
+// + Call JavaThread::exit(), it will:
+// > release JNI handle blocks, remove stack guard pages
+// > remove this thread from Threads list
+// <-- no more Java code from this thread after this point -->
+// + Stop VM thread, it will bring the remaining VM to a safepoint and stop
+// the compiler threads at safepoint
+// <-- do not use anything that could get blocked by Safepoint -->
+// + Disable tracing at JNI/JVM barriers
+// + Set _vm_exited flag for threads that are still running native code
+// + Delete this thread
+// + Call exit_globals()
+// > deletes tty
+// > deletes PerfMemory resources
+// + Return to caller
+
+bool Threads::destroy_vm() {
+ JavaThread* thread = JavaThread::current();
+
+#ifdef ASSERT
+ _vm_complete = false;
+#endif
+ // Wait until we are the last non-daemon thread to execute
+ { MutexLocker nu(Threads_lock);
+ while (Threads::number_of_non_daemon_threads() > 1)
+ // This wait should make safepoint checks, wait without a timeout,
+ // and wait as a suspend-equivalent condition.
+ Threads_lock->wait(!Mutex::_no_safepoint_check_flag, 0,
+ Mutex::_as_suspend_equivalent_flag);
+ }
+
+ // Hang forever on exit if we are reporting an error.
+ if (ShowMessageBoxOnError && VMError::is_error_reported()) {
+ os::infinite_sleep();
+ }
+ os::wait_for_keypress_at_exit();
+
+ // run Java level shutdown hooks
+ thread->invoke_shutdown_hooks();
+
+ before_exit(thread);
+
+ thread->exit(true);
+
+ // Stop VM thread.
+ {
+ // 4945125 The vm thread comes to a safepoint during exit.
+ // GC vm_operations can get caught at the safepoint, and the
+ // heap is unparseable if they are caught. Grab the Heap_lock
+ // to prevent this. The GC vm_operations will not be able to
+ // queue until after the vm thread is dead. After this point,
+ // we'll never emerge out of the safepoint before the VM exits.
+
+ MutexLocker ml(Heap_lock);
+
+ VMThread::wait_for_vm_thread_exit();
+ assert(SafepointSynchronize::is_at_safepoint(), "VM thread should exit at Safepoint");
+ VMThread::destroy();
+ }
+
+ // clean up ideal graph printers
+#if defined(COMPILER2) && !defined(PRODUCT)
+ IdealGraphPrinter::clean_up();
+#endif
+
+ // Now, all Java threads are gone except daemon threads. Daemon threads
+ // running Java code or in VM are stopped by the Safepoint. However,
+ // daemon threads executing native code are still running. But they
+ // will be stopped at native=>Java/VM barriers. Note that we can't
+ // simply kill or suspend them, as it is inherently deadlock-prone.
+
+ VM_Exit::set_vm_exited();
+
+ notify_vm_shutdown();
+
+ delete thread;
+
+#if INCLUDE_JVMCI
+ if (JVMCICounterSize > 0) {
+ FREE_C_HEAP_ARRAY(jlong, JavaThread::_jvmci_old_thread_counters);
+ }
+#endif
+
+ // exit_globals() will delete tty
+ exit_globals();
+
+ LogConfiguration::finalize();
+
+ return true;
+}
+
+
+jboolean Threads::is_supported_jni_version_including_1_1(jint version) {
+ if (version == JNI_VERSION_1_1) return JNI_TRUE;
+ return is_supported_jni_version(version);
+}
+
+
+jboolean Threads::is_supported_jni_version(jint version) {
+ if (version == JNI_VERSION_1_2) return JNI_TRUE;
+ if (version == JNI_VERSION_1_4) return JNI_TRUE;
+ if (version == JNI_VERSION_1_6) return JNI_TRUE;
+ if (version == JNI_VERSION_1_8) return JNI_TRUE;
+ if (version == JNI_VERSION_9) return JNI_TRUE;
+ return JNI_FALSE;
+}
+
+
+void Threads::add(JavaThread* p, bool force_daemon) {
+ // The threads lock must be owned at this point
+ assert_locked_or_safepoint(Threads_lock);
+
+ // See the comment for this method in thread.hpp for its purpose and
+ // why it is called here.
+ p->initialize_queues();
+ p->set_next(_thread_list);
+ _thread_list = p;
+ _number_of_threads++;
+ oop threadObj = p->threadObj();
+ bool daemon = true;
+ // Bootstrapping problem: threadObj can be null for initial
+ // JavaThread (or for threads attached via JNI)
+ if ((!force_daemon) && (threadObj == NULL || !java_lang_Thread::is_daemon(threadObj))) {
+ _number_of_non_daemon_threads++;
+ daemon = false;
+ }
+
+ ThreadService::add_thread(p, daemon);
+
+ // Possible GC point.
+ Events::log(p, "Thread added: " INTPTR_FORMAT, p2i(p));
+}
+
+void Threads::remove(JavaThread* p) {
+
+ // Reclaim the objectmonitors from the omInUseList and omFreeList of the moribund thread.
+ ObjectSynchronizer::omFlush(p);
+
+ // Extra scope needed for Thread_lock, so we can check
+ // that we do not remove thread without safepoint code notice
+ { MutexLocker ml(Threads_lock);
+
+ assert(includes(p), "p must be present");
+
+ JavaThread* current = _thread_list;
+ JavaThread* prev = NULL;
+
+ while (current != p) {
+ prev = current;
+ current = current->next();
+ }
+
+ if (prev) {
+ prev->set_next(current->next());
+ } else {
+ _thread_list = p->next();
+ }
+ _number_of_threads--;
+ oop threadObj = p->threadObj();
+ bool daemon = true;
+ if (threadObj == NULL || !java_lang_Thread::is_daemon(threadObj)) {
+ _number_of_non_daemon_threads--;
+ daemon = false;
+
+ // Only one thread left, do a notify on the Threads_lock so a thread waiting
+ // on destroy_vm will wake up.
+ if (number_of_non_daemon_threads() == 1) {
+ Threads_lock->notify_all();
+ }
+ }
+ ThreadService::remove_thread(p, daemon);
+
+ // Make sure that safepoint code disregard this thread. This is needed since
+ // the thread might mess around with locks after this point. This can cause it
+ // to do callbacks into the safepoint code. However, the safepoint code is not aware
+ // of this thread since it is removed from the queue.
+ p->set_terminated_value();
+ } // unlock Threads_lock
+
+ // Since Events::log uses a lock, we grab it outside the Threads_lock
+ Events::log(p, "Thread exited: " INTPTR_FORMAT, p2i(p));
+}
+
+// Threads_lock must be held when this is called (or must be called during a safepoint)
+bool Threads::includes(JavaThread* p) {
+ assert(Threads_lock->is_locked(), "sanity check");
+ ALL_JAVA_THREADS(q) {
+ if (q == p) {
+ return true;
+ }
+ }
+ return false;
+}
+
+// Operations on the Threads list for GC. These are not explicitly locked,
+// but the garbage collector must provide a safe context for them to run.
+// In particular, these things should never be called when the Threads_lock
+// is held by some other thread. (Note: the Safepoint abstraction also
+// uses the Threads_lock to guarantee this property. It also makes sure that
+// all threads gets blocked when exiting or starting).
+
+void Threads::oops_do(OopClosure* f, CodeBlobClosure* cf) {
+ ALL_JAVA_THREADS(p) {
+ p->oops_do(f, cf);
+ }
+ VMThread::vm_thread()->oops_do(f, cf);
+}
+
+void Threads::change_thread_claim_parity() {
+ // Set the new claim parity.
+ assert(_thread_claim_parity >= 0 && _thread_claim_parity <= 2,
+ "Not in range.");
+ _thread_claim_parity++;
+ if (_thread_claim_parity == 3) _thread_claim_parity = 1;
+ assert(_thread_claim_parity >= 1 && _thread_claim_parity <= 2,
+ "Not in range.");
+}
+
+#ifdef ASSERT
+void Threads::assert_all_threads_claimed() {
+ ALL_JAVA_THREADS(p) {
+ const int thread_parity = p->oops_do_parity();
+ assert((thread_parity == _thread_claim_parity),
+ "Thread " PTR_FORMAT " has incorrect parity %d != %d", p2i(p), thread_parity, _thread_claim_parity);
+ }
+ VMThread* vmt = VMThread::vm_thread();
+ const int thread_parity = vmt->oops_do_parity();
+ assert((thread_parity == _thread_claim_parity),
+ "VMThread " PTR_FORMAT " has incorrect parity %d != %d", p2i(vmt), thread_parity, _thread_claim_parity);
+}
+#endif // ASSERT
+
+void Threads::possibly_parallel_oops_do(bool is_par, OopClosure* f, CodeBlobClosure* cf) {
+ int cp = Threads::thread_claim_parity();
+ ALL_JAVA_THREADS(p) {
+ if (p->claim_oops_do(is_par, cp)) {
+ p->oops_do(f, cf);
+ }
+ }
+ VMThread* vmt = VMThread::vm_thread();
+ if (vmt->claim_oops_do(is_par, cp)) {
+ vmt->oops_do(f, cf);
+ }
+}
+
+#if INCLUDE_ALL_GCS
+// Used by ParallelScavenge
+void Threads::create_thread_roots_tasks(GCTaskQueue* q) {
+ ALL_JAVA_THREADS(p) {
+ q->enqueue(new ThreadRootsTask(p));
+ }
+ q->enqueue(new ThreadRootsTask(VMThread::vm_thread()));
+}
+
+// Used by Parallel Old
+void Threads::create_thread_roots_marking_tasks(GCTaskQueue* q) {
+ ALL_JAVA_THREADS(p) {
+ q->enqueue(new ThreadRootsMarkingTask(p));
+ }
+ q->enqueue(new ThreadRootsMarkingTask(VMThread::vm_thread()));
+}
+#endif // INCLUDE_ALL_GCS
+
+void Threads::nmethods_do(CodeBlobClosure* cf) {
+ ALL_JAVA_THREADS(p) {
+ // This is used by the code cache sweeper to mark nmethods that are active
+ // on the stack of a Java thread. Ignore the sweeper thread itself to avoid
+ // marking CodeCacheSweeperThread::_scanned_compiled_method as active.
+ if(!p->is_Code_cache_sweeper_thread()) {
+ p->nmethods_do(cf);
+ }
+ }
+}
+
+void Threads::metadata_do(void f(Metadata*)) {
+ ALL_JAVA_THREADS(p) {
+ p->metadata_do(f);
+ }
+}
+
+class ThreadHandlesClosure : public ThreadClosure {
+ void (*_f)(Metadata*);
+ public:
+ ThreadHandlesClosure(void f(Metadata*)) : _f(f) {}
+ virtual void do_thread(Thread* thread) {
+ thread->metadata_handles_do(_f);
+ }
+};
+
+void Threads::metadata_handles_do(void f(Metadata*)) {
+ // Only walk the Handles in Thread.
+ ThreadHandlesClosure handles_closure(f);
+ threads_do(&handles_closure);
+}
+
+void Threads::deoptimized_wrt_marked_nmethods() {
+ ALL_JAVA_THREADS(p) {
+ p->deoptimized_wrt_marked_nmethods();
+ }
+}
+
+
+// Get count Java threads that are waiting to enter the specified monitor.
+GrowableArray<JavaThread*>* Threads::get_pending_threads(int count,
+ address monitor,
+ bool doLock) {
+ assert(doLock || SafepointSynchronize::is_at_safepoint(),
+ "must grab Threads_lock or be at safepoint");
+ GrowableArray<JavaThread*>* result = new GrowableArray<JavaThread*>(count);
+
+ int i = 0;
+ {
+ MutexLockerEx ml(doLock ? Threads_lock : NULL);
+ ALL_JAVA_THREADS(p) {
+ if (!p->can_call_java()) continue;
+
+ address pending = (address)p->current_pending_monitor();
+ if (pending == monitor) { // found a match
+ if (i < count) result->append(p); // save the first count matches
+ i++;
+ }
+ }
+ }
+ return result;
+}
+
+
+JavaThread *Threads::owning_thread_from_monitor_owner(address owner,
+ bool doLock) {
+ assert(doLock ||
+ Threads_lock->owned_by_self() ||
+ SafepointSynchronize::is_at_safepoint(),
+ "must grab Threads_lock or be at safepoint");
+
+ // NULL owner means not locked so we can skip the search
+ if (owner == NULL) return NULL;
+
+ {
+ MutexLockerEx ml(doLock ? Threads_lock : NULL);
+ ALL_JAVA_THREADS(p) {
+ // first, see if owner is the address of a Java thread
+ if (owner == (address)p) return p;
+ }
+ }
+ // Cannot assert on lack of success here since this function may be
+ // used by code that is trying to report useful problem information
+ // like deadlock detection.
+ if (UseHeavyMonitors) return NULL;
+
+ // If we didn't find a matching Java thread and we didn't force use of
+ // heavyweight monitors, then the owner is the stack address of the
+ // Lock Word in the owning Java thread's stack.
+ //
+ JavaThread* the_owner = NULL;
+ {
+ MutexLockerEx ml(doLock ? Threads_lock : NULL);
+ ALL_JAVA_THREADS(q) {
+ if (q->is_lock_owned(owner)) {
+ the_owner = q;
+ break;
+ }
+ }
+ }
+ // cannot assert on lack of success here; see above comment
+ return the_owner;
+}
+
+// Threads::print_on() is called at safepoint by VM_PrintThreads operation.
+void Threads::print_on(outputStream* st, bool print_stacks,
+ bool internal_format, bool print_concurrent_locks) {
+ char buf[32];
+ st->print_raw_cr(os::local_time_string(buf, sizeof(buf)));
+
+ st->print_cr("Full thread dump %s (%s %s):",
+ Abstract_VM_Version::vm_name(),
+ Abstract_VM_Version::vm_release(),
+ Abstract_VM_Version::vm_info_string());
+ st->cr();
+
+#if INCLUDE_SERVICES
+ // Dump concurrent locks
+ ConcurrentLocksDump concurrent_locks;
+ if (print_concurrent_locks) {
+ concurrent_locks.dump_at_safepoint();
+ }
+#endif // INCLUDE_SERVICES
+
+ ALL_JAVA_THREADS(p) {
+ ResourceMark rm;
+ p->print_on(st);
+ if (print_stacks) {
+ if (internal_format) {
+ p->trace_stack();
+ } else {
+ p->print_stack_on(st);
+ }
+ }
+ st->cr();
+#if INCLUDE_SERVICES
+ if (print_concurrent_locks) {
+ concurrent_locks.print_locks_on(p, st);
+ }
+#endif // INCLUDE_SERVICES
+ }
+
+ VMThread::vm_thread()->print_on(st);
+ st->cr();
+ Universe::heap()->print_gc_threads_on(st);
+ WatcherThread* wt = WatcherThread::watcher_thread();
+ if (wt != NULL) {
+ wt->print_on(st);
+ st->cr();
+ }
+ st->flush();
+}
+
+void Threads::print_on_error(Thread* this_thread, outputStream* st, Thread* current, char* buf,
+ int buflen, bool* found_current) {
+ if (this_thread != NULL) {
+ bool is_current = (current == this_thread);
+ *found_current = *found_current || is_current;
+ st->print("%s", is_current ? "=>" : " ");
+
+ st->print(PTR_FORMAT, p2i(this_thread));
+ st->print(" ");
+ this_thread->print_on_error(st, buf, buflen);
+ st->cr();
+ }
+}
+
+class PrintOnErrorClosure : public ThreadClosure {
+ outputStream* _st;
+ Thread* _current;
+ char* _buf;
+ int _buflen;
+ bool* _found_current;
+ public:
+ PrintOnErrorClosure(outputStream* st, Thread* current, char* buf,
+ int buflen, bool* found_current) :
+ _st(st), _current(current), _buf(buf), _buflen(buflen), _found_current(found_current) {}
+
+ virtual void do_thread(Thread* thread) {
+ Threads::print_on_error(thread, _st, _current, _buf, _buflen, _found_current);
+ }
+};
+
+// Threads::print_on_error() is called by fatal error handler. It's possible
+// that VM is not at safepoint and/or current thread is inside signal handler.
+// Don't print stack trace, as the stack may not be walkable. Don't allocate
+// memory (even in resource area), it might deadlock the error handler.
+void Threads::print_on_error(outputStream* st, Thread* current, char* buf,
+ int buflen) {
+ bool found_current = false;
+ st->print_cr("Java Threads: ( => current thread )");
+ ALL_JAVA_THREADS(thread) {
+ print_on_error(thread, st, current, buf, buflen, &found_current);
+ }
+ st->cr();
+
+ st->print_cr("Other Threads:");
+ print_on_error(VMThread::vm_thread(), st, current, buf, buflen, &found_current);
+ print_on_error(WatcherThread::watcher_thread(), st, current, buf, buflen, &found_current);
+
+ PrintOnErrorClosure print_closure(st, current, buf, buflen, &found_current);
+ Universe::heap()->gc_threads_do(&print_closure);
+
+ if (!found_current) {
+ st->cr();
+ st->print("=>" PTR_FORMAT " (exited) ", p2i(current));
+ current->print_on_error(st, buf, buflen);
+ st->cr();
+ }
+ st->cr();
+ st->print_cr("Threads with active compile tasks:");
+ print_threads_compiling(st, buf, buflen);
+}
+
+void Threads::print_threads_compiling(outputStream* st, char* buf, int buflen) {
+ ALL_JAVA_THREADS(thread) {
+ if (thread->is_Compiler_thread()) {
+ CompilerThread* ct = (CompilerThread*) thread;
+ if (ct->task() != NULL) {
+ thread->print_name_on_error(st, buf, buflen);
+ ct->task()->print(st, NULL, true, true);
+ }
+ }
+ }
+}
+
+
+// Internal SpinLock and Mutex
+// Based on ParkEvent
+
+// Ad-hoc mutual exclusion primitives: SpinLock and Mux
+//
+// We employ SpinLocks _only for low-contention, fixed-length
+// short-duration critical sections where we're concerned
+// about native mutex_t or HotSpot Mutex:: latency.
+// The mux construct provides a spin-then-block mutual exclusion
+// mechanism.
+//
+// Testing has shown that contention on the ListLock guarding gFreeList
+// is common. If we implement ListLock as a simple SpinLock it's common
+// for the JVM to devolve to yielding with little progress. This is true
+// despite the fact that the critical sections protected by ListLock are
+// extremely short.
+//
+// TODO-FIXME: ListLock should be of type SpinLock.
+// We should make this a 1st-class type, integrated into the lock
+// hierarchy as leaf-locks. Critically, the SpinLock structure
+// should have sufficient padding to avoid false-sharing and excessive
+// cache-coherency traffic.
+
+
+typedef volatile int SpinLockT;
+
+void Thread::SpinAcquire(volatile int * adr, const char * LockName) {
+ if (Atomic::cmpxchg (1, adr, 0) == 0) {
+ return; // normal fast-path return
+ }
+
+ // Slow-path : We've encountered contention -- Spin/Yield/Block strategy.
+ TEVENT(SpinAcquire - ctx);
+ int ctr = 0;
+ int Yields = 0;
+ for (;;) {
+ while (*adr != 0) {
+ ++ctr;
+ if ((ctr & 0xFFF) == 0 || !os::is_MP()) {
+ if (Yields > 5) {
+ os::naked_short_sleep(1);
+ } else {
+ os::naked_yield();
+ ++Yields;
+ }
+ } else {
+ SpinPause();
+ }
+ }
+ if (Atomic::cmpxchg(1, adr, 0) == 0) return;
+ }
+}
+
+void Thread::SpinRelease(volatile int * adr) {
+ assert(*adr != 0, "invariant");
+ OrderAccess::fence(); // guarantee at least release consistency.
+ // Roach-motel semantics.
+ // It's safe if subsequent LDs and STs float "up" into the critical section,
+ // but prior LDs and STs within the critical section can't be allowed
+ // to reorder or float past the ST that releases the lock.
+ // Loads and stores in the critical section - which appear in program
+ // order before the store that releases the lock - must also appear
+ // before the store that releases the lock in memory visibility order.
+ // Conceptually we need a #loadstore|#storestore "release" MEMBAR before
+ // the ST of 0 into the lock-word which releases the lock, so fence
+ // more than covers this on all platforms.
+ *adr = 0;
+}
+
+// muxAcquire and muxRelease:
+//
+// * muxAcquire and muxRelease support a single-word lock-word construct.
+// The LSB of the word is set IFF the lock is held.
+// The remainder of the word points to the head of a singly-linked list
+// of threads blocked on the lock.
+//
+// * The current implementation of muxAcquire-muxRelease uses its own
+// dedicated Thread._MuxEvent instance. If we're interested in
+// minimizing the peak number of extant ParkEvent instances then
+// we could eliminate _MuxEvent and "borrow" _ParkEvent as long
+// as certain invariants were satisfied. Specifically, care would need
+// to be taken with regards to consuming unpark() "permits".
+// A safe rule of thumb is that a thread would never call muxAcquire()
+// if it's enqueued (cxq, EntryList, WaitList, etc) and will subsequently
+// park(). Otherwise the _ParkEvent park() operation in muxAcquire() could
+// consume an unpark() permit intended for monitorenter, for instance.
+// One way around this would be to widen the restricted-range semaphore
+// implemented in park(). Another alternative would be to provide
+// multiple instances of the PlatformEvent() for each thread. One
+// instance would be dedicated to muxAcquire-muxRelease, for instance.
+//
+// * Usage:
+// -- Only as leaf locks
+// -- for short-term locking only as muxAcquire does not perform
+// thread state transitions.
+//
+// Alternatives:
+// * We could implement muxAcquire and muxRelease with MCS or CLH locks
+// but with parking or spin-then-park instead of pure spinning.
+// * Use Taura-Oyama-Yonenzawa locks.
+// * It's possible to construct a 1-0 lock if we encode the lockword as
+// (List,LockByte). Acquire will CAS the full lockword while Release
+// will STB 0 into the LockByte. The 1-0 scheme admits stranding, so
+// acquiring threads use timers (ParkTimed) to detect and recover from
+// the stranding window. Thread/Node structures must be aligned on 256-byte
+// boundaries by using placement-new.
+// * Augment MCS with advisory back-link fields maintained with CAS().
+// Pictorially: LockWord -> T1 <-> T2 <-> T3 <-> ... <-> Tn <-> Owner.
+// The validity of the backlinks must be ratified before we trust the value.
+// If the backlinks are invalid the exiting thread must back-track through the
+// the forward links, which are always trustworthy.
+// * Add a successor indication. The LockWord is currently encoded as
+// (List, LOCKBIT:1). We could also add a SUCCBIT or an explicit _succ variable
+// to provide the usual futile-wakeup optimization.
+// See RTStt for details.
+// * Consider schedctl.sc_nopreempt to cover the critical section.
+//
+
+
+typedef volatile intptr_t MutexT; // Mux Lock-word
+enum MuxBits { LOCKBIT = 1 };
+
+void Thread::muxAcquire(volatile intptr_t * Lock, const char * LockName) {
+ intptr_t w = Atomic::cmpxchg_ptr(LOCKBIT, Lock, 0);
+ if (w == 0) return;
+ if ((w & LOCKBIT) == 0 && Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) {
+ return;
+ }
+
+ TEVENT(muxAcquire - Contention);
+ ParkEvent * const Self = Thread::current()->_MuxEvent;
+ assert((intptr_t(Self) & LOCKBIT) == 0, "invariant");
+ for (;;) {
+ int its = (os::is_MP() ? 100 : 0) + 1;
+
+ // Optional spin phase: spin-then-park strategy
+ while (--its >= 0) {
+ w = *Lock;
+ if ((w & LOCKBIT) == 0 && Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) {
+ return;
+ }
+ }
+
+ Self->reset();
+ Self->OnList = intptr_t(Lock);
+ // The following fence() isn't _strictly necessary as the subsequent
+ // CAS() both serializes execution and ratifies the fetched *Lock value.
+ OrderAccess::fence();
+ for (;;) {
+ w = *Lock;
+ if ((w & LOCKBIT) == 0) {
+ if (Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) {
+ Self->OnList = 0; // hygiene - allows stronger asserts
+ return;
+ }
+ continue; // Interference -- *Lock changed -- Just retry
+ }
+ assert(w & LOCKBIT, "invariant");
+ Self->ListNext = (ParkEvent *) (w & ~LOCKBIT);
+ if (Atomic::cmpxchg_ptr(intptr_t(Self)|LOCKBIT, Lock, w) == w) break;
+ }
+
+ while (Self->OnList != 0) {
+ Self->park();
+ }
+ }
+}
+
+void Thread::muxAcquireW(volatile intptr_t * Lock, ParkEvent * ev) {
+ intptr_t w = Atomic::cmpxchg_ptr(LOCKBIT, Lock, 0);
+ if (w == 0) return;
+ if ((w & LOCKBIT) == 0 && Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) {
+ return;
+ }
+
+ TEVENT(muxAcquire - Contention);
+ ParkEvent * ReleaseAfter = NULL;
+ if (ev == NULL) {
+ ev = ReleaseAfter = ParkEvent::Allocate(NULL);
+ }
+ assert((intptr_t(ev) & LOCKBIT) == 0, "invariant");
+ for (;;) {
+ guarantee(ev->OnList == 0, "invariant");
+ int its = (os::is_MP() ? 100 : 0) + 1;
+
+ // Optional spin phase: spin-then-park strategy
+ while (--its >= 0) {
+ w = *Lock;
+ if ((w & LOCKBIT) == 0 && Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) {
+ if (ReleaseAfter != NULL) {
+ ParkEvent::Release(ReleaseAfter);
+ }
+ return;
+ }
+ }
+
+ ev->reset();
+ ev->OnList = intptr_t(Lock);
+ // The following fence() isn't _strictly necessary as the subsequent
+ // CAS() both serializes execution and ratifies the fetched *Lock value.
+ OrderAccess::fence();
+ for (;;) {
+ w = *Lock;
+ if ((w & LOCKBIT) == 0) {
+ if (Atomic::cmpxchg_ptr (w|LOCKBIT, Lock, w) == w) {
+ ev->OnList = 0;
+ // We call ::Release while holding the outer lock, thus
+ // artificially lengthening the critical section.
+ // Consider deferring the ::Release() until the subsequent unlock(),
+ // after we've dropped the outer lock.
+ if (ReleaseAfter != NULL) {
+ ParkEvent::Release(ReleaseAfter);
+ }
+ return;
+ }
+ continue; // Interference -- *Lock changed -- Just retry
+ }
+ assert(w & LOCKBIT, "invariant");
+ ev->ListNext = (ParkEvent *) (w & ~LOCKBIT);
+ if (Atomic::cmpxchg_ptr(intptr_t(ev)|LOCKBIT, Lock, w) == w) break;
+ }
+
+ while (ev->OnList != 0) {
+ ev->park();
+ }
+ }
+}
+
+// Release() must extract a successor from the list and then wake that thread.
+// It can "pop" the front of the list or use a detach-modify-reattach (DMR) scheme
+// similar to that used by ParkEvent::Allocate() and ::Release(). DMR-based
+// Release() would :
+// (A) CAS() or swap() null to *Lock, releasing the lock and detaching the list.
+// (B) Extract a successor from the private list "in-hand"
+// (C) attempt to CAS() the residual back into *Lock over null.
+// If there were any newly arrived threads and the CAS() would fail.
+// In that case Release() would detach the RATs, re-merge the list in-hand
+// with the RATs and repeat as needed. Alternately, Release() might
+// detach and extract a successor, but then pass the residual list to the wakee.
+// The wakee would be responsible for reattaching and remerging before it
+// competed for the lock.
+//
+// Both "pop" and DMR are immune from ABA corruption -- there can be
+// multiple concurrent pushers, but only one popper or detacher.
+// This implementation pops from the head of the list. This is unfair,
+// but tends to provide excellent throughput as hot threads remain hot.
+// (We wake recently run threads first).
+//
+// All paths through muxRelease() will execute a CAS.
+// Release consistency -- We depend on the CAS in muxRelease() to provide full
+// bidirectional fence/MEMBAR semantics, ensuring that all prior memory operations
+// executed within the critical section are complete and globally visible before the
+// store (CAS) to the lock-word that releases the lock becomes globally visible.
+void Thread::muxRelease(volatile intptr_t * Lock) {
+ for (;;) {
+ const intptr_t w = Atomic::cmpxchg_ptr(0, Lock, LOCKBIT);
+ assert(w & LOCKBIT, "invariant");
+ if (w == LOCKBIT) return;
+ ParkEvent * const List = (ParkEvent *) (w & ~LOCKBIT);
+ assert(List != NULL, "invariant");
+ assert(List->OnList == intptr_t(Lock), "invariant");
+ ParkEvent * const nxt = List->ListNext;
+ guarantee((intptr_t(nxt) & LOCKBIT) == 0, "invariant");
+
+ // The following CAS() releases the lock and pops the head element.
+ // The CAS() also ratifies the previously fetched lock-word value.
+ if (Atomic::cmpxchg_ptr (intptr_t(nxt), Lock, w) != w) {
+ continue;
+ }
+ List->OnList = 0;
+ OrderAccess::fence();
+ List->unpark();
+ return;
+ }
+}
+
+
+void Threads::verify() {
+ ALL_JAVA_THREADS(p) {
+ p->verify();
+ }
+ VMThread* thread = VMThread::vm_thread();
+ if (thread != NULL) thread->verify();
+}