--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/runtime/thread.cpp Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,3972 @@
+/*
+ * Copyright 1997-2007 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+# include "incls/_precompiled.incl"
+# include "incls/_thread.cpp.incl"
+
+#ifdef DTRACE_ENABLED
+
+// Only bother with this argument setup if dtrace is available
+
+HS_DTRACE_PROBE_DECL(hotspot, vm__init__begin);
+HS_DTRACE_PROBE_DECL(hotspot, vm__init__end);
+HS_DTRACE_PROBE_DECL5(hotspot, thread__start, char*, intptr_t,
+ intptr_t, intptr_t, bool);
+HS_DTRACE_PROBE_DECL5(hotspot, thread__stop, char*, intptr_t,
+ intptr_t, intptr_t, bool);
+
+#define DTRACE_THREAD_PROBE(probe, javathread) \
+ { \
+ ResourceMark rm(this); \
+ int len = 0; \
+ const char* name = (javathread)->get_thread_name(); \
+ len = strlen(name); \
+ HS_DTRACE_PROBE5(hotspot, thread__##probe, \
+ name, len, \
+ java_lang_Thread::thread_id((javathread)->threadObj()), \
+ (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
+
+// Class hierarchy
+// - Thread
+// - VMThread
+// - WatcherThread
+// - ConcurrentMarkSweepThread
+// - JavaThread
+// - CompilerThread
+
+// ======= Thread ========
+
+// Support for forcing alignment of thread objects for biased locking
+void* Thread::operator new(size_t size) {
+ if (UseBiasedLocking) {
+ const int alignment = markOopDesc::biased_lock_alignment;
+ size_t aligned_size = size + (alignment - sizeof(intptr_t));
+ void* real_malloc_addr = CHeapObj::operator new(aligned_size);
+ void* aligned_addr = (void*) align_size_up((intptr_t) 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 (TraceBiasedLocking) {
+ if (aligned_addr != real_malloc_addr)
+ tty->print_cr("Aligned thread " INTPTR_FORMAT " to " INTPTR_FORMAT,
+ real_malloc_addr, aligned_addr);
+ }
+ ((Thread*) aligned_addr)->_real_malloc_address = real_malloc_addr;
+ return aligned_addr;
+ } else {
+ return CHeapObj::operator new(size);
+ }
+}
+
+void Thread::operator delete(void* p) {
+ if (UseBiasedLocking) {
+ void* real_malloc_addr = ((Thread*) p)->_real_malloc_address;
+ CHeapObj::operator delete(real_malloc_addr);
+ } else {
+ CHeapObj::operator delete(p);
+ }
+}
+
+
+// Base class for all threads: VMThread, WatcherThread, ConcurrentMarkSweepThread,
+// JavaThread
+
+
+Thread::Thread() {
+ // stack
+ _stack_base = NULL;
+ _stack_size = 0;
+ _self_raw_id = 0;
+ _lgrp_id = -1;
+ _osthread = NULL;
+
+ // allocated data structures
+ set_resource_area(new ResourceArea());
+ set_handle_area(new HandleArea(NULL));
+ set_active_handles(NULL);
+ set_free_handle_block(NULL);
+ set_last_handle_mark(NULL);
+ set_osthread(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;)
+ CHECK_UNHANDLED_OOPS_ONLY(_gc_locked_out_count = 0;)
+ _highest_lock = NULL;
+ _jvmti_env_iteration_count = 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 ;
+
+ _SR_lock = new Monitor(Mutex::suspend_resume, "SR_lock", true);
+ _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 == (void*) align_size_up((intptr_t) _real_malloc_address, markOopDesc::biased_lock_alignment),
+ "bug in forced alignment of thread objects");
+ }
+#endif /* ASSERT */
+}
+
+void Thread::initialize_thread_local_storage() {
+ // Note: Make sure this method only calls
+ // non-blocking operations. Otherwise, it might not work
+ // with the thread-startup/safepoint interaction.
+
+ // During Java thread startup, safepoint code should allow this
+ // method to complete because it may need to allocate memory to
+ // store information for the new thread.
+
+ // initialize structure dependent on thread local storage
+ ThreadLocalStorage::set_thread(this);
+
+ // set up any platform-specific state.
+ os::initialize_thread();
+
+}
+
+void Thread::record_stack_base_and_size() {
+ set_stack_base(os::current_stack_base());
+ set_stack_size(os::current_stack_size());
+}
+
+
+Thread::~Thread() {
+ // Reclaim the objectmonitors from the omFreeList of the moribund thread.
+ ObjectSynchronizer::omFlush (this) ;
+
+ // 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();
+
+ // osthread() can be NULL, if creation of thread failed.
+ if (osthread() != NULL) os::free_thread(osthread());
+
+ delete _SR_lock;
+
+ // clear thread local storage if the Thread is deleting itself
+ if (this == Thread::current()) {
+ ThreadLocalStorage::set_thread(NULL);
+ } else {
+ // In the case where we're not the current thread, invalidate all the
+ // caches in case some code tries to get the current thread or the
+ // thread that was destroyed, and gets stale information.
+ ThreadLocalStorage::invalidate_all();
+ }
+ 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
+
+
+#ifndef PRODUCT
+// Tracing method for basic thread operations
+void Thread::trace(const char* msg, const Thread* const thread) {
+ if (!TraceThreadEvents) return;
+ ResourceMark rm;
+ ThreadCritical tc;
+ const char *name = "non-Java thread";
+ int prio = -1;
+ if (thread->is_Java_thread()
+ && !thread->is_Compiler_thread()) {
+ // The Threads_lock must be held to get information about
+ // this thread but may not be in some situations when
+ // tracing thread events.
+ bool release_Threads_lock = false;
+ if (!Threads_lock->owned_by_self()) {
+ Threads_lock->lock();
+ release_Threads_lock = true;
+ }
+ JavaThread* jt = (JavaThread *)thread;
+ name = (char *)jt->get_thread_name();
+ oop thread_oop = jt->threadObj();
+ if (thread_oop != NULL) {
+ prio = java_lang_Thread::priority(thread_oop);
+ }
+ if (release_Threads_lock) {
+ Threads_lock->unlock();
+ }
+ }
+ tty->print_cr("Thread::%s " INTPTR_FORMAT " [%lx] %s (prio: %d)", msg, thread, thread->osthread()->thread_id(), name, prio);
+}
+#endif
+
+
+ThreadPriority Thread::get_priority(const Thread* const thread) {
+ trace("get priority", 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) {
+ trace("set priority", thread);
+ debug_only(check_for_dangling_thread_pointer(thread);)
+ // Can return an error!
+ (void)os::set_priority(thread, priority);
+}
+
+
+void Thread::start(Thread* thread) {
+ trace("start", 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-existant
+ // 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 */
+
+// Called by flat profiler
+// Callers have already called wait_for_ext_suspend_completion
+// The assertion for that is currently too complex to put here:
+bool JavaThread::profile_last_Java_frame(frame* _fr) {
+ bool gotframe = false;
+ // self suspension saves needed state.
+ if (has_last_Java_frame() && _anchor.walkable()) {
+ *_fr = pd_last_frame();
+ gotframe = true;
+ }
+ return gotframe;
+}
+
+void Thread::interrupt(Thread* thread) {
+ trace("interrupt", thread);
+ debug_only(check_for_dangling_thread_pointer(thread);)
+ os::interrupt(thread);
+}
+
+bool Thread::is_interrupted(Thread* thread, bool clear_interrupted) {
+ trace("is_interrupted", thread);
+ 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?");
+ assert(SharedHeap::heap()->n_par_threads() > 0,
+ "Should only fail when parallel.");
+ return false;
+ }
+ }
+ assert(SharedHeap::heap()->n_par_threads() > 0,
+ "Should only fail when parallel.");
+ return false;
+}
+
+void Thread::oops_do(OopClosure* f) {
+ active_handles()->oops_do(f);
+ // Do oop for ThreadShadow
+ f->do_oop((oop*)&_pending_exception);
+ handle_area()->oops_do(f);
+}
+
+void Thread::nmethods_do() {
+}
+
+void Thread::print_on(outputStream* st) const {
+ // get_priority assumes osthread initialized
+ if (osthread() != NULL) {
+ st->print("prio=%d tid=" INTPTR_FORMAT " ", get_priority(this), this);
+ 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 {
+ if (is_VM_thread()) st->print("VMThread");
+ else if (is_Compiler_thread()) st->print("CompilerThread");
+ else if (is_Java_thread()) st->print("JavaThread");
+ 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");
+
+ st->print(" [stack: " PTR_FORMAT "," PTR_FORMAT "]",
+ _stack_base - _stack_size, _stack_base);
+
+ if (osthread()) {
+ st->print(" [id=%d]", osthread()->thread_id());
+ }
+}
+
+#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 absolutly 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 spearate compilation
+ cur != VMOperationRequest_lock &&
+ cur != VMOperationQueue_lock) ||
+ cur->rank() == Mutex::special) {
+ warning("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::lock_is_in_stack(address adr) const {
+ assert(Thread::current() == this, "lock_is_in_stack can only be called from current thread");
+ // High limit: highest_lock is set during thread execution
+ // Low limit: address of the local variable dummy, rounded to 4K boundary.
+ // (The rounding helps finding threads in unsafe mode, even if the particular stack
+ // frame has been popped already. Correct as long as stacks are at least 4K long and aligned.)
+ address end = os::current_stack_pointer();
+ if (_highest_lock >= adr && adr >= end) return true;
+
+ return false;
+}
+
+
+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();
+ if (stack_base() >= adr && adr >= end) return true;
+
+ return false;
+}
+
+
+// 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 {
+ if (lock_is_in_stack(adr) ) return true;
+ return false;
+}
+
+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(symbolHandle class_name, TRAPS) {
+ klassOop 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) {
+ klassOop k = SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_ThreadGroup(), true, CHECK_NH);
+ instanceKlassHandle klass (THREAD, k);
+
+ Handle system_instance = klass->allocate_instance_handle(CHECK_NH);
+ {
+ JavaValue result(T_VOID);
+ JavaCalls::call_special(&result,
+ system_instance,
+ klass,
+ vmSymbolHandles::object_initializer_name(),
+ vmSymbolHandles::void_method_signature(),
+ CHECK_NH);
+ }
+ Universe::set_system_thread_group(system_instance());
+
+ Handle main_instance = klass->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,
+ klass,
+ vmSymbolHandles::object_initializer_name(),
+ vmSymbolHandles::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) {
+ klassOop k = SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_Thread(), true, CHECK_NULL);
+ instanceKlassHandle klass (THREAD, k);
+ instanceHandle thread_oop = klass->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,
+ klass,
+ vmSymbolHandles::object_initializer_name(),
+ vmSymbolHandles::threadgroup_string_void_signature(),
+ thread_group,
+ string,
+ CHECK_NULL);
+ return thread_oop();
+}
+
+static void call_initializeSystemClass(TRAPS) {
+ klassOop k = SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_System(), true, CHECK);
+ instanceKlassHandle klass (THREAD, k);
+
+ JavaValue result(T_VOID);
+ JavaCalls::call_static(&result, klass, vmSymbolHandles::initializeSystemClass_name(),
+ vmSymbolHandles::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
+ klassOop k = SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_System(), true, CHECK);
+ instanceKlassHandle klass (THREAD, k);
+
+ // 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,
+ vmSymbolHandles::setProperty_name(),
+ vmSymbolHandles::string_string_string_signature(),
+ key_str,
+ value_str,
+ CHECK);
+}
+
+
+void JavaThread::allocate_threadObj(Handle thread_group, 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");
+
+ klassOop k = SystemDictionary::resolve_or_fail(vmSymbolHandles::java_lang_Thread(), true, CHECK);
+ instanceKlassHandle klass (THREAD, k);
+ instanceHandle thread_oop = klass->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,
+ klass,
+ vmSymbolHandles::object_initializer_name(),
+ vmSymbolHandles::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,
+ klass,
+ vmSymbolHandles::object_initializer_name(),
+ vmSymbolHandles::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;
+ }
+
+ KlassHandle group(this, SystemDictionary::threadGroup_klass());
+ Handle threadObj(this, this->threadObj());
+
+ JavaCalls::call_special(&result,
+ thread_group,
+ group,
+ vmSymbolHandles::add_method_name(),
+ vmSymbolHandles::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;
+}
+
+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);
+ guarantee(_name != NULL, "alloc failure");
+ va_list ap;
+ va_start(ap, format);
+ jio_vsnprintf(_name, max_name_len, format, ap);
+ va_end(ap);
+}
+
+// ======= 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::_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);
+ }
+ }
+}
+
+void WatcherThread::run() {
+ assert(this == watcher_thread(), "just checking");
+
+ this->record_stack_base_and_size();
+ this->initialize_thread_local_storage();
+ this->set_active_handles(JNIHandleBlock::allocate_block());
+ while(!_should_terminate) {
+ 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.
+ const size_t time_to_wait = PeriodicTask::time_to_wait();
+ os::sleep(this, time_to_wait, false);
+
+ if (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 we try to
+ // kill JVM if the fatal error handler fails to abort in 2 minutes.
+ //
+ // 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 (;;) {
+ if (!ShowMessageBoxOnError
+ && (OnError == NULL || OnError[0] == '\0')
+ && Arguments::abort_hook() == NULL) {
+ os::sleep(this, 2 * 60 * 1000, false);
+ fdStream err(defaultStream::output_fd());
+ err.print_raw_cr("# [ timer expired, abort... ]");
+ // skip atexit/vm_exit/vm_abort hooks
+ os::die();
+ }
+
+ // Wake up 5 seconds later, the fatal handler may reset OnError or
+ // ShowMessageBoxOnError when it is ready to abort.
+ os::sleep(this, 5 * 1000, false);
+ }
+ }
+
+ PeriodicTask::real_time_tick(time_to_wait);
+
+ // If we have no more tasks left due to dynamic disenrollment,
+ // shut down the thread since we don't currently support dynamic enrollment
+ if (PeriodicTask::num_tasks() == 0) {
+ _should_terminate = true;
+ }
+ }
+
+ // Signal that it is terminated
+ {
+ MutexLockerEx mu(Terminator_lock, Mutex::_no_safepoint_check_flag);
+ _watcher_thread = NULL;
+ Terminator_lock->notify();
+ }
+
+ // Thread destructor usually does this..
+ ThreadLocalStorage::set_thread(NULL);
+}
+
+void WatcherThread::start() {
+ if (watcher_thread() == NULL) {
+ _should_terminate = false;
+ // Create the single instance of WatcherThread
+ new WatcherThread();
+ }
+}
+
+void WatcherThread::stop() {
+ // it is ok to take late safepoints here, if needed
+ MutexLocker mu(Terminator_lock);
+ _should_terminate = true;
+ while(watcher_thread() != NULL) {
+ // This wait should make safepoint checks, wait without a timeout,
+ // and wait as a suspend-equivalent condition.
+ //
+ // Note: If the FlatProfiler is running, then this thread is waiting
+ // for the WatcherThread to terminate and the WatcherThread, via the
+ // FlatProfiler task, is waiting for the external suspend request on
+ // this thread to complete. wait_for_ext_suspend_completion() will
+ // eventually timeout, but that takes time. Making this wait a
+ // suspend-equivalent condition solves that timeout problem.
+ //
+ Terminator_lock->wait(!Mutex::_no_safepoint_check_flag, 0,
+ Mutex::_as_suspend_equivalent_flag);
+ }
+}
+
+void WatcherThread::print_on(outputStream* st) const {
+ st->print("\"%s\" ", name());
+ Thread::print_on(st);
+ st->cr();
+}
+
+// ======= JavaThread ========
+
+// 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);
+ 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;
+ _exception_oop = NULL;
+ _exception_pc = 0;
+ _exception_handler_pc = 0;
+ _exception_stack_size = 0;
+ _jvmti_thread_state= NULL;
+ _jvmti_get_loaded_classes_closure = NULL;
+ _interp_only_mode = 0;
+ _special_runtime_exit_condition = _no_async_condition;
+ _pending_async_exception = NULL;
+ _is_compiling = false;
+ _thread_stat = NULL;
+ _thread_stat = new ThreadStatistics();
+ _blocked_on_compilation = false;
+ _jni_active_critical = 0;
+ _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 */
+
+ set_thread_profiler(NULL);
+ if (FlatProfiler::is_active()) {
+ // This is where we would decide to either give each thread it's own profiler
+ // or use one global one from FlatProfiler,
+ // or up to some count of the number of profiled threads, etc.
+ ThreadProfiler* pp = new ThreadProfiler();
+ pp->engage();
+ set_thread_profiler(pp);
+ }
+
+ // 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;
+
+ pd_initialize();
+}
+
+JavaThread::JavaThread(bool is_attaching) : Thread() {
+ initialize();
+ _is_attaching = is_attaching;
+}
+
+bool JavaThread::reguard_stack(address cur_sp) {
+ if (_stack_guard_state != stack_guard_yellow_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_yellow_zone_base(), "not enough space to reguard - increase StackShadowPages");
+
+ enable_stack_yellow_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);
+
+JavaThread::JavaThread(ThreadFunction entry_point, size_t stack_sz) : Thread() {
+ if (TraceThreadEvents) {
+ tty->print_cr("creating thread %p", this);
+ }
+ initialize();
+ _is_attaching = false;
+ 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() {
+ if (TraceThreadEvents) {
+ tty->print_cr("terminate thread %p", this);
+ }
+
+ // 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_profiler != NULL) delete _thread_profiler;
+ if (_thread_stat != NULL) delete _thread_stat;
+
+ if (jvmti_thread_state() != NULL) {
+ JvmtiExport::cleanup_thread(this);
+ }
+}
+
+
+// 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 validitity of stack trace backs
+ this->record_base_of_stack_pointer();
+
+ // Record real stack base and size.
+ this->record_stack_base_and_size();
+
+ // Initialize thread local storage; set before calling MutexLocker
+ this->initialize_thread_local_storage();
+
+ this->create_stack_guard_pages();
+
+ // 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);
+ }
+
+ // 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. If this thread is being asked to restart,
+ // or has been stopped before starting, do not reexecute entry point.
+ // Note: Due to JVM_StopThread we can have pending exceptions already!
+ if (!this->has_pending_exception() && !java_lang_Thread::is_stillborn(this->threadObj())) {
+ // enter the thread's entry point only if we have no pending exceptions
+ 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();
+ // It is of profound importance that we set the stillborn bit and reset the thread object,
+ // before we do the notify. Since, changing these two variable will make JVM_IsAlive return
+ // false. So in case another thread is doing a join on this thread , it will detect that the thread
+ // is dead when it gets notified.
+ java_lang_Thread::set_stillborn(threadObj());
+ // 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);
+ 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");
+ if (!InitializeJavaLangSystem) return;
+
+ 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");
+
+ if (get_thread_profiler() != NULL) {
+ get_thread_profiler()->disengage();
+ ResourceMark rm;
+ get_thread_profiler()->print(get_thread_name());
+ }
+
+
+ // FIXIT: This code should be moved into else part, when reliable 1.2/1.3 check is in place
+ {
+ EXCEPTION_MARK;
+
+ CLEAR_PENDING_EXCEPTION;
+ }
+ // FIXIT: The is_null check is only so it works better on JDK1.2 VM's. This
+ // has to be fixed by a runtime query method
+ if (!destroy_vm || JDK_Version::is_jdk12x_version()) {
+ // JSR-166: change call from from ThreadGroup.uncaughtException to
+ // java.lang.Thread.dispatchUncaughtException
+ if (uncaught_exception.not_null()) {
+ Handle group(this, java_lang_Thread::threadGroup(threadObj()));
+ Events::log("uncaught exception INTPTR_FORMAT " " INTPTR_FORMAT " " INTPTR_FORMAT",
+ (address)uncaught_exception(), (address)threadObj(), (address)group());
+ {
+ EXCEPTION_MARK;
+ // Check if the method Thread.dispatchUncaughtException() exists. If so
+ // call it. Otherwise we have an older library without the JSR-166 changes,
+ // so call ThreadGroup.uncaughtException()
+ KlassHandle recvrKlass(THREAD, threadObj->klass());
+ CallInfo callinfo;
+ KlassHandle thread_klass(THREAD, SystemDictionary::thread_klass());
+ LinkResolver::resolve_virtual_call(callinfo, threadObj, recvrKlass, thread_klass,
+ vmSymbolHandles::dispatchUncaughtException_name(),
+ vmSymbolHandles::throwable_void_signature(),
+ KlassHandle(), false, false, THREAD);
+ CLEAR_PENDING_EXCEPTION;
+ methodHandle method = callinfo.selected_method();
+ if (method.not_null()) {
+ JavaValue result(T_VOID);
+ JavaCalls::call_virtual(&result,
+ threadObj, thread_klass,
+ vmSymbolHandles::dispatchUncaughtException_name(),
+ vmSymbolHandles::throwable_void_signature(),
+ uncaught_exception,
+ THREAD);
+ } else {
+ KlassHandle thread_group(THREAD, SystemDictionary::threadGroup_klass());
+ JavaValue result(T_VOID);
+ JavaCalls::call_virtual(&result,
+ group, thread_group,
+ vmSymbolHandles::uncaughtException_name(),
+ vmSymbolHandles::thread_throwable_void_signature(),
+ threadObj, // Arg 1
+ uncaught_exception, // Arg 2
+ THREAD);
+ }
+ CLEAR_PENDING_EXCEPTION;
+ }
+ }
+
+ // 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.
+ { int count = 3;
+ while (java_lang_Thread::threadGroup(threadObj()) != NULL && (count-- > 0)) {
+ EXCEPTION_MARK;
+ JavaValue result(T_VOID);
+ KlassHandle thread_klass(THREAD, SystemDictionary::thread_klass());
+ JavaCalls::call_virtual(&result,
+ threadObj, thread_klass,
+ vmSymbolHandles::exit_method_name(),
+ vmSymbolHandles::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. A detach operation must only
+ // get here if there are no Java frames on the stack. Therefore, any
+ // owned monitors at this point MUST be JNI-acquired monitors which are
+ // pre-inflated and in the monitor cache.
+ //
+ // ensure_join() ignores IllegalThreadStateExceptions, and so does this.
+ if (exit_type == jni_detach && JNIDetachReleasesMonitors) {
+ assert(!this->has_last_Java_frame(), "detaching with Java frames?");
+ 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
+ }
+
+ // Remove from list of active threads list, and notify VM thread if we are the last non-daemon thread
+ Threads::remove(this);
+}
+
+void JavaThread::cleanup_failed_attach_current_thread() {
+
+ if (get_thread_profiler() != NULL) {
+ get_thread_profiler()->disengage();
+ ResourceMark rm;
+ get_thread_profiler()->print(get_thread_name());
+ }
+
+ 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);
+ }
+
+ if (UseTLAB) {
+ tlab().make_parsable(true); // retire TLAB, if any
+ }
+
+ Threads::remove(this);
+ delete this;
+}
+
+
+JavaThread* JavaThread::active() {
+ Thread* thread = ThreadLocalStorage::thread();
+ assert(thread != NULL, "just checking");
+ 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 (lock_is_in_stack(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()) {
+ if (TraceExceptions) {
+ ResourceMark rm;
+ tty->print_cr("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__);
+
+ if (TraceExceptions) {
+ ResourceMark rm;
+ tty->print("Async. exception installed at runtime exit (" INTPTR_FORMAT ")", this);
+ if (has_last_Java_frame() ) {
+ frame f = last_frame();
+ tty->print(" (pc: " INTPTR_FORMAT " sp: " INTPTR_FORMAT " )", f.pc(), f.sp());
+ }
+ tty->print_cr(" of type: %s", instanceKlass::cast(_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();
+ }
+}
+
+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 (is_Compiler_thread()) return;
+
+ // This is a change from JDK 1.1, but JDK 1.2 will also do it:
+ if (java_throwable->is_a(SystemDictionary::threaddeath_klass())) {
+ java_lang_Thread::set_stillborn(threadObj());
+ }
+
+ {
+ // 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 (compiled_frame.can_be_deoptimized()) {
+ Deoptimization::deoptimize(this, compiled_frame, ®_map);
+ }
+ }
+ }
+
+ // Set async. pending exception in thread.
+ set_pending_async_exception(java_throwable);
+
+ if (TraceExceptions) {
+ ResourceMark rm;
+ tty->print_cr("Pending Async. exception installed of type: %s", instanceKlass::cast(_pending_async_exception->klass())->external_name());
+ }
+ // for AbortVMOnException flag
+ NOT_PRODUCT(Exceptions::debug_check_abort(instanceKlass::cast(_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_ForceSafepoint 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_any_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);
+ // Make sure new state is seen by VM thread
+ if (os::is_MP()) {
+ if (UseMembar) {
+ // Force a fence between the write above and read below
+ OrderAccess::fence();
+ } else {
+ // Must use this rather than serialization page in particular on Windows
+ InterfaceSupport::serialize_memory(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();
+ // Since we know we're safe to deopt the current state is a safe state
+ f.deoptimize(thread, true);
+ } else {
+ fatal("missed deoptimization!");
+ }
+ }
+}
+
+// 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);
+ }
+}
+
+// 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();
+ }
+}
+
+void JavaThread::create_stack_guard_pages() {
+ if (! os::uses_stack_guard_pages() || _stack_guard_state != stack_guard_unused) return;
+ address low_addr = stack_base() - stack_size();
+ size_t len = (StackYellowPages + StackRedPages) * os::vm_page_size();
+
+ int allocate = os::allocate_stack_guard_pages();
+ // warning("Guarding at " PTR_FORMAT " for len " SIZE_FORMAT "\n", low_addr, len);
+
+ if (allocate && !os::commit_memory((char *) low_addr, len)) {
+ warning("Attempt to allocate stack guard pages failed.");
+ return;
+ }
+
+ if (os::guard_memory((char *) low_addr, len)) {
+ _stack_guard_state = stack_guard_enabled;
+ } else {
+ warning("Attempt to protect stack guard pages failed.");
+ if (os::uncommit_memory((char *) low_addr, len)) {
+ warning("Attempt to deallocate stack guard pages failed.");
+ }
+ }
+}
+
+void JavaThread::remove_stack_guard_pages() {
+ if (_stack_guard_state == stack_guard_unused) return;
+ address low_addr = stack_base() - stack_size();
+ size_t len = (StackYellowPages + StackRedPages) * os::vm_page_size();
+
+ if (os::allocate_stack_guard_pages()) {
+ if (os::uncommit_memory((char *) low_addr, len)) {
+ _stack_guard_state = stack_guard_unused;
+ } else {
+ warning("Attempt to deallocate stack guard pages failed.");
+ }
+ } else {
+ if (_stack_guard_state == stack_guard_unused) return;
+ if (os::unguard_memory((char *) low_addr, len)) {
+ _stack_guard_state = stack_guard_unused;
+ } else {
+ warning("Attempt to unprotect stack guard pages failed.");
+ }
+ }
+}
+
+void JavaThread::enable_stack_yellow_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_yellow_zone_base() - stack_yellow_zone_size();
+
+ 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_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_zone() {
+ assert(_stack_guard_state != stack_guard_unused, "must be using guard pages.");
+ assert(_stack_guard_state != stack_guard_yellow_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_yellow_zone_base() - stack_yellow_zone_size();
+
+ if (os::unguard_memory((char *)base, stack_yellow_zone_size())) {
+ _stack_guard_state = stack_guard_yellow_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());
+ }
+ }
+}
+
+
+// GC support
+static void frame_gc_epilogue(frame* f, const RegisterMap* map) { f->gc_epilogue(); }
+
+void JavaThread::gc_epilogue() {
+ frames_do(frame_gc_epilogue);
+}
+
+
+static void frame_gc_prologue(frame* f, const RegisterMap* map) { f->gc_prologue(); }
+
+void JavaThread::gc_prologue() {
+ frames_do(frame_gc_prologue);
+}
+
+
+void JavaThread::oops_do(OopClosure* f) {
+ // The ThreadProfiler oops_do is done from FlatProfiler::oops_do
+ // since there may be more than one thread using each ThreadProfiler.
+
+ // Traverse the GCHandles
+ Thread::oops_do(f);
+
+ 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 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, 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*) &_vm_result_2);
+ 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() {
+ // Traverse the GCHandles
+ Thread::nmethods_do();
+
+ 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();
+ }
+ }
+}
+
+// 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("\"%s\" ", get_thread_name());
+ oop thread_oop = threadObj();
+ if (thread_oop != NULL && java_lang_Thread::is_daemon(thread_oop)) st->print("daemon ");
+ Thread::print_on(st);
+ // print guess for valid stack memory region (assume 4K pages); helps lock debugging
+ st->print_cr("[" INTPTR_FORMAT ".." INTPTR_FORMAT "]", (intptr_t)last_Java_sp() & ~right_n_bits(12), highest_lock());
+ if (thread_oop != NULL && JDK_Version::is_gte_jdk15x_version()) {
+ 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
+}
+
+// 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 ")",
+ _stack_base - _stack_size, _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);
+
+ // 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) {
+ typeArrayOop name = java_lang_Thread::name(thread_obj);
+ if (name != NULL) {
+ if (buf == NULL) {
+ name_str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length());
+ }
+ else {
+ name_str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length(), buf, buflen);
+ }
+ }
+ else if (is_attaching()) { // 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) {
+ typeArrayOop name = java_lang_ThreadGroup::name(thread_group);
+ // ThreadGroup.name can be null
+ if (name != NULL) {
+ const char* str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length());
+ return str;
+ }
+ }
+ }
+ 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) {
+ typeArrayOop name = java_lang_ThreadGroup::name(parent);
+ // ThreadGroup.name can be null
+ if (name != NULL) {
+ const char* str = UNICODE::as_utf8((jchar*) name->base(T_CHAR), name->length());
+ return str;
+ }
+ }
+ }
+ }
+ 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);
+
+ // 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::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));
+ _popframe_preserved_args_size = in_bytes(size_in_bytes);
+ Copy::conjoint_bytes(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();
+ }
+}
+
+
+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;
+}
+
+
+klassOop 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();
+}
+
+// Create a CompilerThread
+CompilerThread::CompilerThread(CompileQueue* queue, CompilerCounters* counters)
+: JavaThread(&compiler_thread_entry) {
+ _env = NULL;
+ _log = NULL;
+ _task = NULL;
+ _queue = queue;
+ _counters = counters;
+
+#ifndef PRODUCT
+ _ideal_graph_printer = NULL;
+#endif
+}
+
+
+// ======= 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;
+size_t JavaThread::_stack_size_at_create = 0;
+
+// All JavaThreads
+#define ALL_JAVA_THREADS(X) for (JavaThread* X = _thread_list; X; X = X->next())
+
+void os_stream();
+
+// 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);
+ tc->do_thread(WatcherThread::watcher_thread());
+ // If CompilerThreads ever become non-JavaThreads, add them here
+}
+
+jint Threads::create_vm(JavaVMInitArgs* args, bool* canTryAgain) {
+
+ // Check version
+ if (!is_supported_jni_version(args->version)) return JNI_EVERSION;
+
+ // Initialize the output stream module
+ ostream_init();
+
+ // Process java launcher properties.
+ Arguments::process_sun_java_launcher_properties(args);
+
+ // Initialize the os module before using TLS
+ os::init();
+
+ // Initialize system properties.
+ Arguments::init_system_properties();
+
+ // Parse arguments
+ jint parse_result = Arguments::parse(args);
+ if (parse_result != JNI_OK) return parse_result;
+
+ if (PauseAtStartup) {
+ os::pause();
+ }
+
+ HS_DTRACE_PROBE(hotspot, vm__init__begin);
+
+ // Record VM creation timing statistics
+ TraceVmCreationTime create_vm_timer;
+ create_vm_timer.start();
+
+ // Timing (must come after argument parsing)
+ TraceTime timer("Create VM", TraceStartupTime);
+
+ // 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;
+
+ // 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 TLS
+ ThreadLocalStorage::init();
+
+ // Initialize global data structures and create system classes in heap
+ vm_init_globals();
+
+ // Attach the main thread to this os thread
+ JavaThread* main_thread = new JavaThread();
+ main_thread->set_thread_state(_thread_in_vm);
+ // must do this before set_active_handles and initialize_thread_local_storage
+ // Note: on solaris initialize_thread_local_storage() will (indirectly)
+ // change the stack size recorded here to one based on the java thread
+ // stacksize. This adjusted size is what is used to figure the placement
+ // of the guard pages.
+ main_thread->record_stack_base_and_size();
+ main_thread->initialize_thread_local_storage();
+
+ 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-Leve synchronization subsystem
+ ObjectSynchronizer::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;
+ }
+
+ 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();
+
+ if (VerifyBeforeGC &&
+ Universe::heap()->total_collections() >= VerifyGCStartAt) {
+ Universe::heap()->prepare_for_verify();
+ Universe::verify(); // make sure we're starting with a clean slate
+ }
+
+ // Create the VMThread
+ { TraceTime timer("Start VMThread", TraceStartupTime);
+ 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");
+ EXCEPTION_MARK;
+
+ // At this point, the Universe is initialized, but we have not executed
+ // any byte code. Now is a good time (the only time) to dump out the
+ // internal state of the JVM for sharing.
+
+ if (DumpSharedSpaces) {
+ Universe::heap()->preload_and_dump(CHECK_0);
+ ShouldNotReachHere();
+ }
+
+ // 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();
+
+ {
+ TraceTime timer("Initialize java.lang classes", TraceStartupTime);
+
+ if (EagerXrunInit && Arguments::init_libraries_at_startup()) {
+ create_vm_init_libraries();
+ }
+
+ if (InitializeJavaLangString) {
+ initialize_class(vmSymbolHandles::java_lang_String(), CHECK_0);
+ } else {
+ warning("java.lang.String not initialized");
+ }
+
+ // Initialize java_lang.System (needed before creating the thread)
+ if (InitializeJavaLangSystem) {
+ initialize_class(vmSymbolHandles::java_lang_System(), CHECK_0);
+ initialize_class(vmSymbolHandles::java_lang_ThreadGroup(), CHECK_0);
+ Handle thread_group = create_initial_thread_group(CHECK_0);
+ Universe::set_main_thread_group(thread_group());
+ initialize_class(vmSymbolHandles::java_lang_Thread(), CHECK_0);
+ oop thread_object = create_initial_thread(thread_group, main_thread, CHECK_0);
+ 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 preresolve methods to these classes. Make sure that get initialized
+ initialize_class(vmSymbolHandles::java_lang_reflect_Method(), CHECK_0);
+ initialize_class(vmSymbolHandles::java_lang_ref_Finalizer(), CHECK_0);
+ // The VM creates & returns objects of this class. Make sure it's initialized.
+ initialize_class(vmSymbolHandles::java_lang_Class(), CHECK_0);
+ call_initializeSystemClass(CHECK_0);
+ } else {
+ warning("java.lang.System not initialized");
+ }
+
+ // an instance of OutOfMemory exception has been allocated earlier
+ if (InitializeJavaLangExceptionsErrors) {
+ initialize_class(vmSymbolHandles::java_lang_OutOfMemoryError(), CHECK_0);
+ initialize_class(vmSymbolHandles::java_lang_NullPointerException(), CHECK_0);
+ initialize_class(vmSymbolHandles::java_lang_ClassCastException(), CHECK_0);
+ initialize_class(vmSymbolHandles::java_lang_ArrayStoreException(), CHECK_0);
+ initialize_class(vmSymbolHandles::java_lang_ArithmeticException(), CHECK_0);
+ initialize_class(vmSymbolHandles::java_lang_StackOverflowError(), CHECK_0);
+ initialize_class(vmSymbolHandles::java_lang_IllegalMonitorStateException(), CHECK_0);
+ } else {
+ warning("java.lang.OutOfMemoryError has not been initialized");
+ warning("java.lang.NullPointerException has not been initialized");
+ warning("java.lang.ClassCastException has not been initialized");
+ warning("java.lang.ArrayStoreException has not been initialized");
+ warning("java.lang.ArithmeticException has not been initialized");
+ warning("java.lang.StackOverflowError has not been initialized");
+ }
+ }
+
+ // See : bugid 4211085.
+ // Background : the static initializer of java.lang.Compiler tries to read
+ // property"java.compiler" and read & write property "java.vm.info".
+ // When a security manager is installed through the command line
+ // option "-Djava.security.manager", the above properties are not
+ // readable and the static initializer for java.lang.Compiler fails
+ // resulting in a NoClassDefFoundError. This can happen in any
+ // user code which calls methods in java.lang.Compiler.
+ // Hack : the hack is to pre-load and initialize this class, so that only
+ // system domains are on the stack when the properties are read.
+ // Currently even the AWT code has calls to methods in java.lang.Compiler.
+ // On the classic VM, java.lang.Compiler is loaded very early to load the JIT.
+ // Future Fix : the best fix is to grant everyone permissions to read "java.compiler" and
+ // read and write"java.vm.info" in the default policy file. See bugid 4211383
+ // Once that is done, we should remove this hack.
+ initialize_class(vmSymbolHandles::java_lang_Compiler(), CHECK_0);
+
+ // More hackery - the static initializer of java.lang.Compiler adds the string "nojit" to
+ // the java.vm.info property if no jit gets loaded through java.lang.Compiler (the hotspot
+ // compiler does not get loaded through java.lang.Compiler). "java -version" with the
+ // hotspot vm says "nojit" all the time which is confusing. So, we reset it here.
+ // This should also be taken out as soon as 4211383 gets fixed.
+ reset_vm_info_property(CHECK_0);
+
+ quicken_jni_functions();
+
+ // 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();
+
+ HS_DTRACE_PROBE(hotspot, vm__init__end);
+
+ // record VM initialization completion time
+ Management::record_vm_init_completed();
+
+ // Compute system loader. Note that this has to occur after set_init_completed, since
+ // valid exceptions may be thrown in the process.
+ // Note that we do not use CHECK_0 here since we are inside an EXCEPTION_MARK and
+ // set_init_completed has just been called, causing exceptions not to be shortcut
+ // anymore. We call vm_exit_during_initialization directly instead.
+ SystemDictionary::compute_java_system_loader(THREAD);
+ if (HAS_PENDING_EXCEPTION) {
+ vm_exit_during_initialization(Handle(THREAD, PENDING_EXCEPTION));
+ }
+
+#ifndef SERIALGC
+ // Support for ConcurrentMarkSweep. This should be cleaned up
+ // and better encapsulated. XXX YSR
+ if (UseConcMarkSweepGC) {
+ ConcurrentMarkSweepThread::makeSurrogateLockerThread(THREAD);
+ if (HAS_PENDING_EXCEPTION) {
+ vm_exit_during_initialization(Handle(THREAD, PENDING_EXCEPTION));
+ }
+ }
+#endif // SERIALGC
+
+ // 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();
+
+ // Signal Dispatcher needs to be started before VMInit event is posted
+ os::signal_init();
+
+ // Start Attach Listener if +StartAttachListener or it can't be started lazily
+ if (!DisableAttachMechanism) {
+ 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();
+ }
+
+ // Notify JVMTI agents that VM initialization is complete - nop if no agents.
+ JvmtiExport::post_vm_initialized();
+
+ Chunk::start_chunk_pool_cleaner_task();
+
+ // initialize compiler(s)
+ CompileBroker::compilation_init();
+
+ 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);
+ }
+
+ if (Arguments::has_profile()) FlatProfiler::engage(main_thread, true);
+ if (Arguments::has_alloc_profile()) AllocationProfiler::engage();
+ if (MemProfiling) MemProfiler::engage();
+ StatSampler::engage();
+ if (CheckJNICalls) JniPeriodicChecker::engage();
+ if (CacheTimeMillis) TimeMillisUpdateTask::engage();
+
+ BiasedLocking::init();
+
+
+ // 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();
+ 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 = agent->os_lib(); // check if we have looked it up before
+
+ if (library == NULL) {
+ char buffer[JVM_MAXPATHLEN];
+ char ebuf[1024];
+ const char *name = agent->name();
+
+ if (agent->is_absolute_path()) {
+ library = hpi::dll_load(name, ebuf, sizeof ebuf);
+ if (library == NULL) {
+ // If we can't find the agent, exit.
+ vm_exit_during_initialization("Could not find agent library in absolute path", name);
+ }
+ } else {
+ // Try to load the agent from the standard dll directory
+ hpi::dll_build_name(buffer, sizeof(buffer), Arguments::get_dll_dir(), name);
+ library = hpi::dll_load(buffer, ebuf, sizeof ebuf);
+#ifdef KERNEL
+ // Download instrument dll
+ if (library == NULL && strcmp(name, "instrument") == 0) {
+ char *props = Arguments::get_kernel_properties();
+ char *home = Arguments::get_java_home();
+ const char *fmt = "%s/bin/java %s -Dkernel.background.download=false"
+ " sun.jkernel.DownloadManager -download client_jvm";
+ int length = strlen(props) + strlen(home) + strlen(fmt) + 1;
+ char *cmd = AllocateHeap(length);
+ jio_snprintf(cmd, length, fmt, home, props);
+ int status = os::fork_and_exec(cmd);
+ FreeHeap(props);
+ FreeHeap(cmd);
+ if (status == -1) {
+ warning(cmd);
+ vm_exit_during_initialization("fork_and_exec failed: %s",
+ strerror(errno));
+ }
+ // when this comes back the instrument.dll should be where it belongs.
+ library = hpi::dll_load(buffer, ebuf, sizeof ebuf);
+ }
+#endif // KERNEL
+ if (library == NULL) { // Try the local directory
+ char ns[1] = {0};
+ hpi::dll_build_name(buffer, sizeof(buffer), ns, name);
+ library = hpi::dll_load(buffer, ebuf, sizeof ebuf);
+ if (library == NULL) {
+ // If we can't find the agent, exit.
+ vm_exit_during_initialization("Could not find agent library on the library path or in the local directory", name);
+ }
+ }
+ }
+ agent->set_os_lib(library);
+ }
+
+ // Find the OnLoad function.
+ for (size_t symbol_index = 0; symbol_index < num_symbol_entries; symbol_index++) {
+ on_load_entry = CAST_TO_FN_PTR(OnLoadEntry_t, hpi::dll_lookup(library, on_load_symbols[symbol_index]));
+ if (on_load_entry != NULL) break;
+ }
+ 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;
+ extern struct JavaVM_ main_vm;
+ for (AgentLibrary* agent = Arguments::agents(); agent != NULL; agent = agent->next()) {
+
+ // Find the Agent_OnUnload function.
+ for (uint symbol_index = 0; symbol_index < ARRAY_SIZE(on_unload_symbols); symbol_index++) {
+ Agent_OnUnload_t unload_entry = CAST_TO_FN_PTR(Agent_OnUnload_t,
+ hpi::dll_lookup(agent->os_lib(), on_unload_symbols[symbol_index]));
+
+ // Invoke the Agent_OnUnload function
+ if (unload_entry != NULL) {
+ JavaThread* thread = JavaThread::current();
+ ThreadToNativeFromVM ttn(thread);
+ HandleMark hm(thread);
+ (*unload_entry)(&main_vm);
+ break;
+ }
+ }
+ }
+}
+
+// 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());
+ }
+ }
+}
+
+// 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;
+ klassOop k =
+ SystemDictionary::resolve_or_null(vmSymbolHandles::java_lang_Shutdown(),
+ THREAD);
+ if (k != 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).
+ instanceKlassHandle shutdown_klass (THREAD, k);
+ JavaValue result(T_VOID);
+ JavaCalls::call_static(&result,
+ shutdown_klass,
+ vmSymbolHandles::shutdown_method_name(),
+ vmSymbolHandles::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:
+// + 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 flat profiler, 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();
+
+ // 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.
+ //
+ // Note: If the FlatProfiler is running and this thread is waiting
+ // for another non-daemon thread to finish, then the FlatProfiler
+ // is waiting for the external suspend request on this thread to
+ // complete. wait_for_ext_suspend_completion() will eventually
+ // timeout, but that takes time. Making this wait a suspend-
+ // equivalent condition solves that timeout problem.
+ //
+ 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 && is_error_reported()) {
+ os::infinite_sleep();
+ }
+
+ if (JDK_Version::is_jdk12x_version()) {
+ // We are the last thread running, so check if finalizers should be run.
+ // For 1.3 or later this is done in thread->invoke_shutdown_hooks()
+ HandleMark rm(thread);
+ Universe::run_finalizers_on_exit();
+ } else {
+ // 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.
+ 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.
+
+#ifndef PRODUCT
+ // disable function tracing at JNI/JVM barriers
+ TraceHPI = false;
+ TraceJNICalls = false;
+ TraceJVMCalls = false;
+ TraceRuntimeCalls = false;
+#endif
+
+ VM_Exit::set_vm_exited();
+
+ notify_vm_shutdown();
+
+ delete thread;
+
+ // exit_globals() will delete tty
+ exit_globals();
+
+ 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;
+ 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);
+ 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("Thread added: " INTPTR_FORMAT, p);
+}
+
+void Threads::remove(JavaThread* 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("Thread exited: " INTPTR_FORMAT, 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 gurantee this property. It also makes sure that
+// all threads gets blocked when exiting or starting).
+
+void Threads::oops_do(OopClosure* f) {
+ ALL_JAVA_THREADS(p) {
+ p->oops_do(f);
+ }
+ VMThread::vm_thread()->oops_do(f);
+}
+
+void Threads::possibly_parallel_oops_do(OopClosure* f) {
+ // Introduce a mechanism allowing parallel threads to claim threads as
+ // root groups. Overhead should be small enough to use all the time,
+ // even in sequential code.
+ SharedHeap* sh = SharedHeap::heap();
+ bool is_par = (sh->n_par_threads() > 0);
+ int cp = SharedHeap::heap()->strong_roots_parity();
+ ALL_JAVA_THREADS(p) {
+ if (p->claim_oops_do(is_par, cp)) {
+ p->oops_do(f);
+ }
+ }
+ VMThread* vmt = VMThread::vm_thread();
+ if (vmt->claim_oops_do(is_par, cp))
+ vmt->oops_do(f);
+}
+
+#ifndef SERIALGC
+// 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 // SERIALGC
+
+void Threads::nmethods_do() {
+ ALL_JAVA_THREADS(p) {
+ p->nmethods_do();
+ }
+ VMThread::vm_thread()->nmethods_do();
+}
+
+void Threads::gc_epilogue() {
+ ALL_JAVA_THREADS(p) {
+ p->gc_epilogue();
+ }
+}
+
+void Threads::gc_prologue() {
+ ALL_JAVA_THREADS(p) {
+ p->gc_prologue();
+ }
+}
+
+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->is_Compiler_thread()) 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;
+ }
+ }
+ assert(UseHeavyMonitors == false, "Did not find owning Java thread with UseHeavyMonitors enabled");
+ 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.
+ //
+ // We can't use Thread::is_lock_owned() or Thread::lock_is_in_stack() because
+ // those routines rely on the "current" stack pointer. That would be our
+ // stack pointer which is not relevant to the question. Instead we use the
+ // highest lock ever entered by the thread and find the thread that is
+ // higher than and closest to our target stack address.
+ //
+ address least_diff = 0;
+ bool least_diff_initialized = false;
+ JavaThread* the_owner = NULL;
+ {
+ MutexLockerEx ml(doLock ? Threads_lock : NULL);
+ ALL_JAVA_THREADS(q) {
+ address addr = q->highest_lock();
+ if (addr == NULL || addr < owner) continue; // thread has entered no monitors or is too low
+ address diff = (address)(addr - owner);
+ if (!least_diff_initialized || diff < least_diff) {
+ least_diff_initialized = true;
+ least_diff = diff;
+ the_owner = q;
+ }
+ }
+ }
+ assert(the_owner != NULL, "Did not find owning Java thread for lock word address");
+ 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_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();
+
+#ifndef SERIALGC
+ // Dump concurrent locks
+ ConcurrentLocksDump concurrent_locks;
+ if (print_concurrent_locks) {
+ concurrent_locks.dump_at_safepoint();
+ }
+#endif // SERIALGC
+
+ 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();
+#ifndef SERIALGC
+ if (print_concurrent_locks) {
+ concurrent_locks.print_locks_on(p, st);
+ }
+#endif // SERIALGC
+ }
+
+ 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();
+ CompileBroker::print_compiler_threads_on(st);
+ st->flush();
+}
+
+// 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) {
+ bool is_current = (current == thread);
+ found_current = found_current || is_current;
+
+ st->print("%s", is_current ? "=>" : " ");
+
+ st->print(PTR_FORMAT, thread);
+ st->print(" ");
+ thread->print_on_error(st, buf, buflen);
+ st->cr();
+ }
+ st->cr();
+
+ st->print_cr("Other Threads:");
+ if (VMThread::vm_thread()) {
+ bool is_current = (current == VMThread::vm_thread());
+ found_current = found_current || is_current;
+ st->print("%s", current == VMThread::vm_thread() ? "=>" : " ");
+
+ st->print(PTR_FORMAT, VMThread::vm_thread());
+ st->print(" ");
+ VMThread::vm_thread()->print_on_error(st, buf, buflen);
+ st->cr();
+ }
+ WatcherThread* wt = WatcherThread::watcher_thread();
+ if (wt != NULL) {
+ bool is_current = (current == wt);
+ found_current = found_current || is_current;
+ st->print("%s", is_current ? "=>" : " ");
+
+ st->print(PTR_FORMAT, wt);
+ st->print(" ");
+ wt->print_on_error(st, buf, buflen);
+ st->cr();
+ }
+ if (!found_current) {
+ st->cr();
+ st->print("=>" PTR_FORMAT " (exited) ", current);
+ current->print_on_error(st, buf, buflen);
+ st->cr();
+ }
+}
+
+
+// Lifecycle management for TSM ParkEvents.
+// ParkEvents are type-stable (TSM).
+// In our particular implementation they happen to be immortal.
+//
+// We manage concurrency on the FreeList with a CAS-based
+// detach-modify-reattach idiom that avoids the ABA problems
+// that would otherwise be present in a simple CAS-based
+// push-pop implementation. (push-one and pop-all)
+//
+// Caveat: Allocate() and Release() may be called from threads
+// other than the thread associated with the Event!
+// If we need to call Allocate() when running as the thread in
+// question then look for the PD calls to initialize native TLS.
+// Native TLS (Win32/Linux/Solaris) can only be initialized or
+// accessed by the associated thread.
+// See also pd_initialize().
+//
+// Note that we could defer associating a ParkEvent with a thread
+// until the 1st time the thread calls park(). unpark() calls to
+// an unprovisioned thread would be ignored. The first park() call
+// for a thread would allocate and associate a ParkEvent and return
+// immediately.
+
+volatile int ParkEvent::ListLock = 0 ;
+ParkEvent * volatile ParkEvent::FreeList = NULL ;
+
+ParkEvent * ParkEvent::Allocate (Thread * t) {
+ // In rare cases -- JVM_RawMonitor* operations -- we can find t == null.
+ ParkEvent * ev ;
+
+ // Start by trying to recycle an existing but unassociated
+ // ParkEvent from the global free list.
+ for (;;) {
+ ev = FreeList ;
+ if (ev == NULL) break ;
+ // 1: Detach - sequester or privatize the list
+ // Tantamount to ev = Swap (&FreeList, NULL)
+ if (Atomic::cmpxchg_ptr (NULL, &FreeList, ev) != ev) {
+ continue ;
+ }
+
+ // We've detached the list. The list in-hand is now
+ // local to this thread. This thread can operate on the
+ // list without risk of interference from other threads.
+ // 2: Extract -- pop the 1st element from the list.
+ ParkEvent * List = ev->FreeNext ;
+ if (List == NULL) break ;
+ for (;;) {
+ // 3: Try to reattach the residual list
+ guarantee (List != NULL, "invariant") ;
+ ParkEvent * Arv = (ParkEvent *) Atomic::cmpxchg_ptr (List, &FreeList, NULL) ;
+ if (Arv == NULL) break ;
+
+ // New nodes arrived. Try to detach the recent arrivals.
+ if (Atomic::cmpxchg_ptr (NULL, &FreeList, Arv) != Arv) {
+ continue ;
+ }
+ guarantee (Arv != NULL, "invariant") ;
+ // 4: Merge Arv into List
+ ParkEvent * Tail = List ;
+ while (Tail->FreeNext != NULL) Tail = Tail->FreeNext ;
+ Tail->FreeNext = Arv ;
+ }
+ break ;
+ }
+
+ if (ev != NULL) {
+ guarantee (ev->AssociatedWith == NULL, "invariant") ;
+ } else {
+ // Do this the hard way -- materialize a new ParkEvent.
+ // In rare cases an allocating thread might detach a long list --
+ // installing null into FreeList -- and then stall or be obstructed.
+ // A 2nd thread calling Allocate() would see FreeList == null.
+ // The list held privately by the 1st thread is unavailable to the 2nd thread.
+ // In that case the 2nd thread would have to materialize a new ParkEvent,
+ // even though free ParkEvents existed in the system. In this case we end up
+ // with more ParkEvents in circulation than we need, but the race is
+ // rare and the outcome is benign. Ideally, the # of extant ParkEvents
+ // is equal to the maximum # of threads that existed at any one time.
+ // Because of the race mentioned above, segments of the freelist
+ // can be transiently inaccessible. At worst we may end up with the
+ // # of ParkEvents in circulation slightly above the ideal.
+ // Note that if we didn't have the TSM/immortal constraint, then
+ // when reattaching, above, we could trim the list.
+ ev = new ParkEvent () ;
+ guarantee ((intptr_t(ev) & 0xFF) == 0, "invariant") ;
+ }
+ ev->reset() ; // courtesy to caller
+ ev->AssociatedWith = t ; // Associate ev with t
+ ev->FreeNext = NULL ;
+ return ev ;
+}
+
+void ParkEvent::Release (ParkEvent * ev) {
+ if (ev == NULL) return ;
+ guarantee (ev->FreeNext == NULL , "invariant") ;
+ ev->AssociatedWith = NULL ;
+ for (;;) {
+ // Push ev onto FreeList
+ // The mechanism is "half" lock-free.
+ ParkEvent * List = FreeList ;
+ ev->FreeNext = List ;
+ if (Atomic::cmpxchg_ptr (ev, &FreeList, List) == List) break ;
+ }
+}
+
+// Override operator new and delete so we can ensure that the
+// least significant byte of ParkEvent addresses is 0.
+// Beware that excessive address alignment is undesirable
+// as it can result in D$ index usage imbalance as
+// well as bank access imbalance on Niagara-like platforms,
+// although Niagara's hash function should help.
+
+void * ParkEvent::operator new (size_t sz) {
+ return (void *) ((intptr_t (CHeapObj::operator new (sz + 256)) + 256) & -256) ;
+}
+
+void ParkEvent::operator delete (void * a) {
+ // ParkEvents are type-stable and immortal ...
+ ShouldNotReachHere();
+}
+
+
+// 6399321 As a temporary measure we copied & modified the ParkEvent::
+// allocate() and release() code for use by Parkers. The Parker:: forms
+// will eventually be removed as we consolide and shift over to ParkEvents
+// for both builtin synchronization and JSR166 operations.
+
+volatile int Parker::ListLock = 0 ;
+Parker * volatile Parker::FreeList = NULL ;
+
+Parker * Parker::Allocate (JavaThread * t) {
+ guarantee (t != NULL, "invariant") ;
+ Parker * p ;
+
+ // Start by trying to recycle an existing but unassociated
+ // Parker from the global free list.
+ for (;;) {
+ p = FreeList ;
+ if (p == NULL) break ;
+ // 1: Detach
+ // Tantamount to p = Swap (&FreeList, NULL)
+ if (Atomic::cmpxchg_ptr (NULL, &FreeList, p) != p) {
+ continue ;
+ }
+
+ // We've detached the list. The list in-hand is now
+ // local to this thread. This thread can operate on the
+ // list without risk of interference from other threads.
+ // 2: Extract -- pop the 1st element from the list.
+ Parker * List = p->FreeNext ;
+ if (List == NULL) break ;
+ for (;;) {
+ // 3: Try to reattach the residual list
+ guarantee (List != NULL, "invariant") ;
+ Parker * Arv = (Parker *) Atomic::cmpxchg_ptr (List, &FreeList, NULL) ;
+ if (Arv == NULL) break ;
+
+ // New nodes arrived. Try to detach the recent arrivals.
+ if (Atomic::cmpxchg_ptr (NULL, &FreeList, Arv) != Arv) {
+ continue ;
+ }
+ guarantee (Arv != NULL, "invariant") ;
+ // 4: Merge Arv into List
+ Parker * Tail = List ;
+ while (Tail->FreeNext != NULL) Tail = Tail->FreeNext ;
+ Tail->FreeNext = Arv ;
+ }
+ break ;
+ }
+
+ if (p != NULL) {
+ guarantee (p->AssociatedWith == NULL, "invariant") ;
+ } else {
+ // Do this the hard way -- materialize a new Parker..
+ // In rare cases an allocating thread might detach
+ // a long list -- installing null into FreeList --and
+ // then stall. Another thread calling Allocate() would see
+ // FreeList == null and then invoke the ctor. In this case we
+ // end up with more Parkers in circulation than we need, but
+ // the race is rare and the outcome is benign.
+ // Ideally, the # of extant Parkers is equal to the
+ // maximum # of threads that existed at any one time.
+ // Because of the race mentioned above, segments of the
+ // freelist can be transiently inaccessible. At worst
+ // we may end up with the # of Parkers in circulation
+ // slightly above the ideal.
+ p = new Parker() ;
+ }
+ p->AssociatedWith = t ; // Associate p with t
+ p->FreeNext = NULL ;
+ return p ;
+}
+
+
+void Parker::Release (Parker * p) {
+ if (p == NULL) return ;
+ guarantee (p->AssociatedWith != NULL, "invariant") ;
+ guarantee (p->FreeNext == NULL , "invariant") ;
+ p->AssociatedWith = NULL ;
+ for (;;) {
+ // Push p onto FreeList
+ Parker * List = FreeList ;
+ p->FreeNext = List ;
+ if (Atomic::cmpxchg_ptr (p, &FreeList, List) == List) break ;
+ }
+}
+
+void Threads::verify() {
+ ALL_JAVA_THREADS(p) {
+ p->verify();
+ }
+ VMThread* thread = VMThread::vm_thread();
+ if (thread != NULL) thread->verify();
+}