/*
* Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*
*/
#ifndef SHARE_VM_RUNTIME_THREAD_HPP
#define SHARE_VM_RUNTIME_THREAD_HPP
#include "memory/allocation.hpp"
#include "memory/threadLocalAllocBuffer.hpp"
#include "oops/oop.hpp"
#include "prims/jni.h"
#include "prims/jvmtiExport.hpp"
#include "runtime/frame.hpp"
#include "runtime/javaFrameAnchor.hpp"
#include "runtime/jniHandles.hpp"
#include "runtime/mutexLocker.hpp"
#include "runtime/os.hpp"
#include "runtime/osThread.hpp"
#include "runtime/park.hpp"
#include "runtime/safepoint.hpp"
#include "runtime/stubRoutines.hpp"
#include "runtime/threadLocalStorage.hpp"
#include "runtime/unhandledOops.hpp"
#include "utilities/macros.hpp"
#if INCLUDE_NMT
#include "services/memRecorder.hpp"
#endif // INCLUDE_NMT
#include "trace/traceBackend.hpp"
#include "trace/traceMacros.hpp"
#include "utilities/exceptions.hpp"
#include "utilities/top.hpp"
#if INCLUDE_ALL_GCS
#include "gc_implementation/g1/dirtyCardQueue.hpp"
#include "gc_implementation/g1/satbQueue.hpp"
#endif // INCLUDE_ALL_GCS
#ifdef ZERO
#ifdef TARGET_ARCH_zero
# include "stack_zero.hpp"
#endif
#endif
class ThreadSafepointState;
class ThreadProfiler;
class JvmtiThreadState;
class JvmtiGetLoadedClassesClosure;
class ThreadStatistics;
class ConcurrentLocksDump;
class ParkEvent;
class Parker;
class ciEnv;
class CompileThread;
class CompileLog;
class CompileTask;
class CompileQueue;
class CompilerCounters;
class vframeArray;
class DeoptResourceMark;
class jvmtiDeferredLocalVariableSet;
class GCTaskQueue;
class ThreadClosure;
class IdealGraphPrinter;
class WorkerThread;
// Class hierarchy
// - Thread
// - NamedThread
// - VMThread
// - ConcurrentGCThread
// - WorkerThread
// - GangWorker
// - GCTaskThread
// - JavaThread
// - WatcherThread
class Thread: public ThreadShadow {
friend class VMStructs;
private:
// Exception handling
// (Note: _pending_exception and friends are in ThreadShadow)
//oop _pending_exception; // pending exception for current thread
// const char* _exception_file; // file information for exception (debugging only)
// int _exception_line; // line information for exception (debugging only)
protected:
// Support for forcing alignment of thread objects for biased locking
void* _real_malloc_address;
public:
void* operator new(size_t size) { return allocate(size, true); }
void* operator new(size_t size, const std::nothrow_t& nothrow_constant) { return allocate(size, false); }
void operator delete(void* p);
protected:
static void* allocate(size_t size, bool throw_excpt, MEMFLAGS flags = mtThread);
private:
// ***************************************************************
// Suspend and resume support
// ***************************************************************
//
// VM suspend/resume no longer exists - it was once used for various
// things including safepoints but was deprecated and finally removed
// in Java 7. Because VM suspension was considered "internal" Java-level
// suspension was considered "external", and this legacy naming scheme
// remains.
//
// External suspend/resume requests come from JVM_SuspendThread,
// JVM_ResumeThread, JVMTI SuspendThread, and finally JVMTI
// ResumeThread. External
// suspend requests cause _external_suspend to be set and external
// resume requests cause _external_suspend to be cleared.
// External suspend requests do not nest on top of other external
// suspend requests. The higher level APIs reject suspend requests
// for already suspended threads.
//
// The external_suspend
// flag is checked by has_special_runtime_exit_condition() and java thread
// will self-suspend when handle_special_runtime_exit_condition() is
// called. Most uses of the _thread_blocked state in JavaThreads are
// considered the same as being externally suspended; if the blocking
// condition lifts, the JavaThread will self-suspend. Other places
// where VM checks for external_suspend include:
// + mutex granting (do not enter monitors when thread is suspended)
// + state transitions from _thread_in_native
//
// In general, java_suspend() does not wait for an external suspend
// request to complete. When it returns, the only guarantee is that
// the _external_suspend field is true.
//
// wait_for_ext_suspend_completion() is used to wait for an external
// suspend request to complete. External suspend requests are usually
// followed by some other interface call that requires the thread to
// be quiescent, e.g., GetCallTrace(). By moving the "wait time" into
// the interface that requires quiescence, we give the JavaThread a
// chance to self-suspend before we need it to be quiescent. This
// improves overall suspend/query performance.
//
// _suspend_flags controls the behavior of java_ suspend/resume.
// It must be set under the protection of SR_lock. Read from the flag is
// OK without SR_lock as long as the value is only used as a hint.
// (e.g., check _external_suspend first without lock and then recheck
// inside SR_lock and finish the suspension)
//
// _suspend_flags is also overloaded for other "special conditions" so
// that a single check indicates whether any special action is needed
// eg. for async exceptions.
// -------------------------------------------------------------------
// Notes:
// 1. The suspend/resume logic no longer uses ThreadState in OSThread
// but we still update its value to keep other part of the system (mainly
// JVMTI) happy. ThreadState is legacy code (see notes in
// osThread.hpp).
//
// 2. It would be more natural if set_external_suspend() is private and
// part of java_suspend(), but that probably would affect the suspend/query
// performance. Need more investigation on this.
//
// suspend/resume lock: used for self-suspend
Monitor* _SR_lock;
protected:
enum SuspendFlags {
// NOTE: avoid using the sign-bit as cc generates different test code
// when the sign-bit is used, and sometimes incorrectly - see CR 6398077
_external_suspend = 0x20000000U, // thread is asked to self suspend
_ext_suspended = 0x40000000U, // thread has self-suspended
_deopt_suspend = 0x10000000U, // thread needs to self suspend for deopt
_has_async_exception = 0x00000001U, // there is a pending async exception
_critical_native_unlock = 0x00000002U // Must call back to unlock JNI critical lock
};
// various suspension related flags - atomically updated
// overloaded for async exception checking in check_special_condition_for_native_trans.
volatile uint32_t _suspend_flags;
private:
int _num_nested_signal;
public:
void enter_signal_handler() { _num_nested_signal++; }
void leave_signal_handler() { _num_nested_signal--; }
bool is_inside_signal_handler() const { return _num_nested_signal > 0; }
private:
// Debug tracing
static void trace(const char* msg, const Thread* const thread) PRODUCT_RETURN;
// Active_handles points to a block of handles
JNIHandleBlock* _active_handles;
// One-element thread local free list
JNIHandleBlock* _free_handle_block;
// Point to the last handle mark
HandleMark* _last_handle_mark;
// The parity of the last strong_roots iteration in which this thread was
// claimed as a task.
jint _oops_do_parity;
public:
void set_last_handle_mark(HandleMark* mark) { _last_handle_mark = mark; }
HandleMark* last_handle_mark() const { return _last_handle_mark; }
private:
// debug support for checking if code does allow safepoints or not
// GC points in the VM can happen because of allocation, invoking a VM operation, or blocking on
// mutex, or blocking on an object synchronizer (Java locking).
// If !allow_safepoint(), then an assertion failure will happen in any of the above cases
// If !allow_allocation(), then an assertion failure will happen during allocation
// (Hence, !allow_safepoint() => !allow_allocation()).
//
// The two classes No_Safepoint_Verifier and No_Allocation_Verifier are used to set these counters.
//
NOT_PRODUCT(int _allow_safepoint_count;) // If 0, thread allow a safepoint to happen
debug_only (int _allow_allocation_count;) // If 0, the thread is allowed to allocate oops.
// Used by SkipGCALot class.
NOT_PRODUCT(bool _skip_gcalot;) // Should we elide gc-a-lot?
// Record when GC is locked out via the GC_locker mechanism
CHECK_UNHANDLED_OOPS_ONLY(int _gc_locked_out_count;)
friend class No_Alloc_Verifier;
friend class No_Safepoint_Verifier;
friend class Pause_No_Safepoint_Verifier;
friend class ThreadLocalStorage;
friend class GC_locker;
ThreadLocalAllocBuffer _tlab; // Thread-local eden
jlong _allocated_bytes; // Cumulative number of bytes allocated on
// the Java heap
TRACE_DATA _trace_data; // Thread-local data for tracing
int _vm_operation_started_count; // VM_Operation support
int _vm_operation_completed_count; // VM_Operation support
ObjectMonitor* _current_pending_monitor; // ObjectMonitor this thread
// is waiting to lock
bool _current_pending_monitor_is_from_java; // locking is from Java code
// ObjectMonitor on which this thread called Object.wait()
ObjectMonitor* _current_waiting_monitor;
// Private thread-local objectmonitor list - a simple cache organized as a SLL.
public:
ObjectMonitor* omFreeList;
int omFreeCount; // length of omFreeList
int omFreeProvision; // reload chunk size
ObjectMonitor* omInUseList; // SLL to track monitors in circulation
int omInUseCount; // length of omInUseList
#ifdef ASSERT
private:
bool _visited_for_critical_count;
public:
void set_visited_for_critical_count(bool z) { _visited_for_critical_count = z; }
bool was_visited_for_critical_count() const { return _visited_for_critical_count; }
#endif
public:
enum {
is_definitely_current_thread = true
};
// Constructor
Thread();
virtual ~Thread();
// initializtion
void initialize_thread_local_storage();
// thread entry point
virtual void run();
// Testers
virtual bool is_VM_thread() const { return false; }
virtual bool is_Java_thread() const { return false; }
virtual bool is_Compiler_thread() const { return false; }
virtual bool is_hidden_from_external_view() const { return false; }
virtual bool is_jvmti_agent_thread() const { return false; }
// True iff the thread can perform GC operations at a safepoint.
// Generally will be true only of VM thread and parallel GC WorkGang
// threads.
virtual bool is_GC_task_thread() const { return false; }
virtual bool is_Watcher_thread() const { return false; }
virtual bool is_ConcurrentGC_thread() const { return false; }
virtual bool is_Named_thread() const { return false; }
virtual bool is_Worker_thread() const { return false; }
// Casts
virtual WorkerThread* as_Worker_thread() const { return NULL; }
virtual char* name() const { return (char*)"Unknown thread"; }
// Returns the current thread
static inline Thread* current();
// Common thread operations
static void set_priority(Thread* thread, ThreadPriority priority);
static ThreadPriority get_priority(const Thread* const thread);
static void start(Thread* thread);
static void interrupt(Thread* thr);
static bool is_interrupted(Thread* thr, bool clear_interrupted);
void set_native_thread_name(const char *name) {
assert(Thread::current() == this, "set_native_thread_name can only be called on the current thread");
os::set_native_thread_name(name);
}
ObjectMonitor** omInUseList_addr() { return (ObjectMonitor **)&omInUseList; }
Monitor* SR_lock() const { return _SR_lock; }
bool has_async_exception() const { return (_suspend_flags & _has_async_exception) != 0; }
void set_suspend_flag(SuspendFlags f) {
assert(sizeof(jint) == sizeof(_suspend_flags), "size mismatch");
uint32_t flags;
do {
flags = _suspend_flags;
}
while (Atomic::cmpxchg((jint)(flags | f),
(volatile jint*)&_suspend_flags,
(jint)flags) != (jint)flags);
}
void clear_suspend_flag(SuspendFlags f) {
assert(sizeof(jint) == sizeof(_suspend_flags), "size mismatch");
uint32_t flags;
do {
flags = _suspend_flags;
}
while (Atomic::cmpxchg((jint)(flags & ~f),
(volatile jint*)&_suspend_flags,
(jint)flags) != (jint)flags);
}
void set_has_async_exception() {
set_suspend_flag(_has_async_exception);
}
void clear_has_async_exception() {
clear_suspend_flag(_has_async_exception);
}
bool do_critical_native_unlock() const { return (_suspend_flags & _critical_native_unlock) != 0; }
void set_critical_native_unlock() {
set_suspend_flag(_critical_native_unlock);
}
void clear_critical_native_unlock() {
clear_suspend_flag(_critical_native_unlock);
}
// Support for Unhandled Oop detection
#ifdef CHECK_UNHANDLED_OOPS
private:
UnhandledOops* _unhandled_oops;
public:
UnhandledOops* unhandled_oops() { return _unhandled_oops; }
// Mark oop safe for gc. It may be stack allocated but won't move.
void allow_unhandled_oop(oop *op) {
if (CheckUnhandledOops) unhandled_oops()->allow_unhandled_oop(op);
}
// Clear oops at safepoint so crashes point to unhandled oop violator
void clear_unhandled_oops() {
if (CheckUnhandledOops) unhandled_oops()->clear_unhandled_oops();
}
bool is_gc_locked_out() { return _gc_locked_out_count > 0; }
#endif // CHECK_UNHANDLED_OOPS
#ifndef PRODUCT
bool skip_gcalot() { return _skip_gcalot; }
void set_skip_gcalot(bool v) { _skip_gcalot = v; }
#endif
public:
// Installs a pending exception to be inserted later
static void send_async_exception(oop thread_oop, oop java_throwable);
// Resource area
ResourceArea* resource_area() const { return _resource_area; }
void set_resource_area(ResourceArea* area) { _resource_area = area; }
OSThread* osthread() const { return _osthread; }
void set_osthread(OSThread* thread) { _osthread = thread; }
// JNI handle support
JNIHandleBlock* active_handles() const { return _active_handles; }
void set_active_handles(JNIHandleBlock* block) { _active_handles = block; }
JNIHandleBlock* free_handle_block() const { return _free_handle_block; }
void set_free_handle_block(JNIHandleBlock* block) { _free_handle_block = block; }
// Internal handle support
HandleArea* handle_area() const { return _handle_area; }
void set_handle_area(HandleArea* area) { _handle_area = area; }
GrowableArray<Metadata*>* metadata_handles() const { return _metadata_handles; }
void set_metadata_handles(GrowableArray<Metadata*>* handles){ _metadata_handles = handles; }
// Thread-Local Allocation Buffer (TLAB) support
ThreadLocalAllocBuffer& tlab() { return _tlab; }
void initialize_tlab() {
if (UseTLAB) {
tlab().initialize();
}
}
jlong allocated_bytes() { return _allocated_bytes; }
void set_allocated_bytes(jlong value) { _allocated_bytes = value; }
void incr_allocated_bytes(jlong size) { _allocated_bytes += size; }
jlong cooked_allocated_bytes() {
jlong allocated_bytes = OrderAccess::load_acquire(&_allocated_bytes);
if (UseTLAB) {
size_t used_bytes = tlab().used_bytes();
if ((ssize_t)used_bytes > 0) {
// More-or-less valid tlab. The load_acquire above should ensure
// that the result of the add is <= the instantaneous value
return allocated_bytes + used_bytes;
}
}
return allocated_bytes;
}
TRACE_DATA* trace_data() { return &_trace_data; }
// VM operation support
int vm_operation_ticket() { return ++_vm_operation_started_count; }
int vm_operation_completed_count() { return _vm_operation_completed_count; }
void increment_vm_operation_completed_count() { _vm_operation_completed_count++; }
// For tracking the heavyweight monitor the thread is pending on.
ObjectMonitor* current_pending_monitor() {
return _current_pending_monitor;
}
void set_current_pending_monitor(ObjectMonitor* monitor) {
_current_pending_monitor = monitor;
}
void set_current_pending_monitor_is_from_java(bool from_java) {
_current_pending_monitor_is_from_java = from_java;
}
bool current_pending_monitor_is_from_java() {
return _current_pending_monitor_is_from_java;
}
// For tracking the ObjectMonitor on which this thread called Object.wait()
ObjectMonitor* current_waiting_monitor() {
return _current_waiting_monitor;
}
void set_current_waiting_monitor(ObjectMonitor* monitor) {
_current_waiting_monitor = monitor;
}
// GC support
// Apply "f->do_oop" to all root oops in "this".
// Apply "cld_f->do_cld" to CLDs that are otherwise not kept alive.
// Used by JavaThread::oops_do.
// Apply "cf->do_code_blob" (if !NULL) to all code blobs active in frames
virtual void oops_do(OopClosure* f, CLDToOopClosure* cld_f, CodeBlobClosure* cf);
// Handles the parallel case for the method below.
private:
bool claim_oops_do_par_case(int collection_parity);
public:
// Requires that "collection_parity" is that of the current strong roots
// iteration. If "is_par" is false, sets the parity of "this" to
// "collection_parity", and returns "true". If "is_par" is true,
// uses an atomic instruction to set the current threads parity to
// "collection_parity", if it is not already. Returns "true" iff the
// calling thread does the update, this indicates that the calling thread
// has claimed the thread's stack as a root groop in the current
// collection.
bool claim_oops_do(bool is_par, int collection_parity) {
if (!is_par) {
_oops_do_parity = collection_parity;
return true;
} else {
return claim_oops_do_par_case(collection_parity);
}
}
// Sweeper support
void nmethods_do(CodeBlobClosure* cf);
// jvmtiRedefineClasses support
void metadata_do(void f(Metadata*));
// Used by fast lock support
virtual bool is_lock_owned(address adr) const;
// Check if address is in the stack of the thread (not just for locks).
// Warning: the method can only be used on the running thread
bool is_in_stack(address adr) const;
// Sets this thread as starting thread. Returns failure if thread
// creation fails due to lack of memory, too many threads etc.
bool set_as_starting_thread();
protected:
// OS data associated with the thread
OSThread* _osthread; // Platform-specific thread information
// Thread local resource area for temporary allocation within the VM
ResourceArea* _resource_area;
// Thread local handle area for allocation of handles within the VM
HandleArea* _handle_area;
GrowableArray<Metadata*>* _metadata_handles;
// Support for stack overflow handling, get_thread, etc.
address _stack_base;
size_t _stack_size;
uintptr_t _self_raw_id; // used by get_thread (mutable)
int _lgrp_id;
public:
// Stack overflow support
address stack_base() const { assert(_stack_base != NULL,"Sanity check"); return _stack_base; }
void set_stack_base(address base) { _stack_base = base; }
size_t stack_size() const { return _stack_size; }
void set_stack_size(size_t size) { _stack_size = size; }
void record_stack_base_and_size();
bool on_local_stack(address adr) const {
/* QQQ this has knowledge of direction, ought to be a stack method */
return (_stack_base >= adr && adr >= (_stack_base - _stack_size));
}
uintptr_t self_raw_id() { return _self_raw_id; }
void set_self_raw_id(uintptr_t value) { _self_raw_id = value; }
int lgrp_id() const { return _lgrp_id; }
void set_lgrp_id(int value) { _lgrp_id = value; }
// Printing
void print_on(outputStream* st) const;
void print() const { print_on(tty); }
virtual void print_on_error(outputStream* st, char* buf, int buflen) const;
// Debug-only code
#ifdef ASSERT
private:
// Deadlock detection support for Mutex locks. List of locks own by thread.
Monitor* _owned_locks;
// Mutex::set_owner_implementation is the only place where _owned_locks is modified,
// thus the friendship
friend class Mutex;
friend class Monitor;
public:
void print_owned_locks_on(outputStream* st) const;
void print_owned_locks() const { print_owned_locks_on(tty); }
Monitor* owned_locks() const { return _owned_locks; }
bool owns_locks() const { return owned_locks() != NULL; }
bool owns_locks_but_compiled_lock() const;
// Deadlock detection
bool allow_allocation() { return _allow_allocation_count == 0; }
#endif
void check_for_valid_safepoint_state(bool potential_vm_operation) PRODUCT_RETURN;
private:
volatile int _jvmti_env_iteration_count;
public:
void entering_jvmti_env_iteration() { ++_jvmti_env_iteration_count; }
void leaving_jvmti_env_iteration() { --_jvmti_env_iteration_count; }
bool is_inside_jvmti_env_iteration() { return _jvmti_env_iteration_count > 0; }
// Code generation
static ByteSize exception_file_offset() { return byte_offset_of(Thread, _exception_file ); }
static ByteSize exception_line_offset() { return byte_offset_of(Thread, _exception_line ); }
static ByteSize active_handles_offset() { return byte_offset_of(Thread, _active_handles ); }
static ByteSize stack_base_offset() { return byte_offset_of(Thread, _stack_base ); }
static ByteSize stack_size_offset() { return byte_offset_of(Thread, _stack_size ); }
#define TLAB_FIELD_OFFSET(name) \
static ByteSize tlab_##name##_offset() { return byte_offset_of(Thread, _tlab) + ThreadLocalAllocBuffer::name##_offset(); }
TLAB_FIELD_OFFSET(start)
TLAB_FIELD_OFFSET(end)
TLAB_FIELD_OFFSET(top)
TLAB_FIELD_OFFSET(pf_top)
TLAB_FIELD_OFFSET(size) // desired_size
TLAB_FIELD_OFFSET(refill_waste_limit)
TLAB_FIELD_OFFSET(number_of_refills)
TLAB_FIELD_OFFSET(fast_refill_waste)
TLAB_FIELD_OFFSET(slow_allocations)
#undef TLAB_FIELD_OFFSET
static ByteSize allocated_bytes_offset() { return byte_offset_of(Thread, _allocated_bytes ); }
public:
volatile intptr_t _Stalled ;
volatile int _TypeTag ;
ParkEvent * _ParkEvent ; // for synchronized()
ParkEvent * _SleepEvent ; // for Thread.sleep
ParkEvent * _MutexEvent ; // for native internal Mutex/Monitor
ParkEvent * _MuxEvent ; // for low-level muxAcquire-muxRelease
int NativeSyncRecursion ; // diagnostic
volatile int _OnTrap ; // Resume-at IP delta
jint _hashStateW ; // Marsaglia Shift-XOR thread-local RNG
jint _hashStateX ; // thread-specific hashCode generator state
jint _hashStateY ;
jint _hashStateZ ;
void * _schedctl ;
volatile jint rng [4] ; // RNG for spin loop
// Low-level leaf-lock primitives used to implement synchronization
// and native monitor-mutex infrastructure.
// Not for general synchronization use.
static void SpinAcquire (volatile int * Lock, const char * Name) ;
static void SpinRelease (volatile int * Lock) ;
static void muxAcquire (volatile intptr_t * Lock, const char * Name) ;
static void muxAcquireW (volatile intptr_t * Lock, ParkEvent * ev) ;
static void muxRelease (volatile intptr_t * Lock) ;
};
// Inline implementation of Thread::current()
// Thread::current is "hot" it's called > 128K times in the 1st 500 msecs of
// startup.
// ThreadLocalStorage::thread is warm -- it's called > 16K times in the same
// period. This is inlined in thread_<os_family>.inline.hpp.
inline Thread* Thread::current() {
#ifdef ASSERT
// This function is very high traffic. Define PARANOID to enable expensive
// asserts.
#ifdef PARANOID
// Signal handler should call ThreadLocalStorage::get_thread_slow()
Thread* t = ThreadLocalStorage::get_thread_slow();
assert(t != NULL && !t->is_inside_signal_handler(),
"Don't use Thread::current() inside signal handler");
#endif
#endif
Thread* thread = ThreadLocalStorage::thread();
assert(thread != NULL, "just checking");
return thread;
}
// Name support for threads. non-JavaThread subclasses with multiple
// uniquely named instances should derive from this.
class NamedThread: public Thread {
friend class VMStructs;
enum {
max_name_len = 64
};
private:
char* _name;
// log JavaThread being processed by oops_do
JavaThread* _processed_thread;
public:
NamedThread();
~NamedThread();
// May only be called once per thread.
void set_name(const char* format, ...);
virtual bool is_Named_thread() const { return true; }
virtual char* name() const { return _name == NULL ? (char*)"Unknown Thread" : _name; }
JavaThread *processed_thread() { return _processed_thread; }
void set_processed_thread(JavaThread *thread) { _processed_thread = thread; }
};
// Worker threads are named and have an id of an assigned work.
class WorkerThread: public NamedThread {
private:
uint _id;
public:
WorkerThread() : _id(0) { }
virtual bool is_Worker_thread() const { return true; }
virtual WorkerThread* as_Worker_thread() const {
assert(is_Worker_thread(), "Dubious cast to WorkerThread*?");
return (WorkerThread*) this;
}
void set_id(uint work_id) { _id = work_id; }
uint id() const { return _id; }
};
// A single WatcherThread is used for simulating timer interrupts.
class WatcherThread: public Thread {
friend class VMStructs;
public:
virtual void run();
private:
static WatcherThread* _watcher_thread;
static bool _startable;
volatile static bool _should_terminate; // updated without holding lock
public:
enum SomeConstants {
delay_interval = 10 // interrupt delay in milliseconds
};
// Constructor
WatcherThread();
// Tester
bool is_Watcher_thread() const { return true; }
// Printing
char* name() const { return (char*)"VM Periodic Task Thread"; }
void print_on(outputStream* st) const;
void print() const { print_on(tty); }
void unpark();
// Returns the single instance of WatcherThread
static WatcherThread* watcher_thread() { return _watcher_thread; }
// Create and start the single instance of WatcherThread, or stop it on shutdown
static void start();
static void stop();
// Only allow start once the VM is sufficiently initialized
// Otherwise the first task to enroll will trigger the start
static void make_startable();
private:
int sleep() const;
};
class CompilerThread;
typedef void (*ThreadFunction)(JavaThread*, TRAPS);
class JavaThread: public Thread {
friend class VMStructs;
private:
JavaThread* _next; // The next thread in the Threads list
oop _threadObj; // The Java level thread object
#ifdef ASSERT
private:
int _java_call_counter;
public:
int java_call_counter() { return _java_call_counter; }
void inc_java_call_counter() { _java_call_counter++; }
void dec_java_call_counter() {
assert(_java_call_counter > 0, "Invalid nesting of JavaCallWrapper");
_java_call_counter--;
}
private: // restore original namespace restriction
#endif // ifdef ASSERT
#ifndef PRODUCT
public:
enum {
jump_ring_buffer_size = 16
};
private: // restore original namespace restriction
#endif
JavaFrameAnchor _anchor; // Encapsulation of current java frame and it state
ThreadFunction _entry_point;
JNIEnv _jni_environment;
// Deopt support
DeoptResourceMark* _deopt_mark; // Holds special ResourceMark for deoptimization
intptr_t* _must_deopt_id; // id of frame that needs to be deopted once we
// transition out of native
nmethod* _deopt_nmethod; // nmethod that is currently being deoptimized
vframeArray* _vframe_array_head; // Holds the heap of the active vframeArrays
vframeArray* _vframe_array_last; // Holds last vFrameArray we popped
// Because deoptimization is lazy we must save jvmti requests to set locals
// in compiled frames until we deoptimize and we have an interpreter frame.
// This holds the pointer to array (yeah like there might be more than one) of
// description of compiled vframes that have locals that need to be updated.
GrowableArray<jvmtiDeferredLocalVariableSet*>* _deferred_locals_updates;
// Handshake value for fixing 6243940. We need a place for the i2c
// adapter to store the callee Method*. This value is NEVER live
// across a gc point so it does NOT have to be gc'd
// The handshake is open ended since we can't be certain that it will
// be NULLed. This is because we rarely ever see the race and end up
// in handle_wrong_method which is the backend of the handshake. See
// code in i2c adapters and handle_wrong_method.
Method* _callee_target;
// Used to pass back results to the interpreter or generated code running Java code.
oop _vm_result; // oop result is GC-preserved
Metadata* _vm_result_2; // non-oop result
// See ReduceInitialCardMarks: this holds the precise space interval of
// the most recent slow path allocation for which compiled code has
// elided card-marks for performance along the fast-path.
MemRegion _deferred_card_mark;
MonitorChunk* _monitor_chunks; // Contains the off stack monitors
// allocated during deoptimization
// and by JNI_MonitorEnter/Exit
// Async. requests support
enum AsyncRequests {
_no_async_condition = 0,
_async_exception,
_async_unsafe_access_error
};
AsyncRequests _special_runtime_exit_condition; // Enum indicating pending async. request
oop _pending_async_exception;
// Safepoint support
public: // Expose _thread_state for SafeFetchInt()
volatile JavaThreadState _thread_state;
private:
ThreadSafepointState *_safepoint_state; // Holds information about a thread during a safepoint
address _saved_exception_pc; // Saved pc of instruction where last implicit exception happened
// JavaThread termination support
enum TerminatedTypes {
_not_terminated = 0xDEAD - 2,
_thread_exiting, // JavaThread::exit() has been called for this thread
_thread_terminated, // JavaThread is removed from thread list
_vm_exited // JavaThread is still executing native code, but VM is terminated
// only VM_Exit can set _vm_exited
};
// In general a JavaThread's _terminated field transitions as follows:
//
// _not_terminated => _thread_exiting => _thread_terminated
//
// _vm_exited is a special value to cover the case of a JavaThread
// executing native code after the VM itself is terminated.
volatile TerminatedTypes _terminated;
// suspend/resume support
volatile bool _suspend_equivalent; // Suspend equivalent condition
jint _in_deopt_handler; // count of deoptimization
// handlers thread is in
volatile bool _doing_unsafe_access; // Thread may fault due to unsafe access
bool _do_not_unlock_if_synchronized; // Do not unlock the receiver of a synchronized method (since it was
// never locked) when throwing an exception. Used by interpreter only.
// JNI attach states:
enum JNIAttachStates {
_not_attaching_via_jni = 1, // thread is not attaching via JNI
_attaching_via_jni, // thread is attaching via JNI
_attached_via_jni // thread has attached via JNI
};
// A regular JavaThread's _jni_attach_state is _not_attaching_via_jni.
// A native thread that is attaching via JNI starts with a value
// of _attaching_via_jni and transitions to _attached_via_jni.
volatile JNIAttachStates _jni_attach_state;
public:
// State of the stack guard pages for this thread.
enum StackGuardState {
stack_guard_unused, // not needed
stack_guard_yellow_disabled,// disabled (temporarily) after stack overflow
stack_guard_enabled // enabled
};
private:
StackGuardState _stack_guard_state;
// Compiler exception handling (NOTE: The _exception_oop is *NOT* the same as _pending_exception. It is
// used to temp. parsing values into and out of the runtime system during exception handling for compiled
// code)
volatile oop _exception_oop; // Exception thrown in compiled code
volatile address _exception_pc; // PC where exception happened
volatile address _exception_handler_pc; // PC for handler of exception
volatile int _is_method_handle_return; // true (== 1) if the current exception PC is a MethodHandle call site.
// support for compilation
bool _is_compiling; // is true if a compilation is active inthis thread (one compilation per thread possible)
// support for JNI critical regions
jint _jni_active_critical; // count of entries into JNI critical region
// For deadlock detection.
int _depth_first_number;
// JVMTI PopFrame support
// This is set to popframe_pending to signal that top Java frame should be popped immediately
int _popframe_condition;
#ifndef PRODUCT
int _jmp_ring_index;
struct {
// We use intptr_t instead of address so debugger doesn't try and display strings
intptr_t _target;
intptr_t _instruction;
const char* _file;
int _line;
} _jmp_ring[ jump_ring_buffer_size ];
#endif /* PRODUCT */
#if INCLUDE_ALL_GCS
// Support for G1 barriers
ObjPtrQueue _satb_mark_queue; // Thread-local log for SATB barrier.
// Set of all such queues.
static SATBMarkQueueSet _satb_mark_queue_set;
DirtyCardQueue _dirty_card_queue; // Thread-local log for dirty cards.
// Set of all such queues.
static DirtyCardQueueSet _dirty_card_queue_set;
void flush_barrier_queues();
#endif // INCLUDE_ALL_GCS
friend class VMThread;
friend class ThreadWaitTransition;
friend class VM_Exit;
void initialize(); // Initialized the instance variables
public:
// Constructor
JavaThread(bool is_attaching_via_jni = false); // for main thread and JNI attached threads
JavaThread(ThreadFunction entry_point, size_t stack_size = 0);
~JavaThread();
#ifdef ASSERT
// verify this JavaThread hasn't be published in the Threads::list yet
void verify_not_published();
#endif
//JNI functiontable getter/setter for JVMTI jni function table interception API.
void set_jni_functions(struct JNINativeInterface_* functionTable) {
_jni_environment.functions = functionTable;
}
struct JNINativeInterface_* get_jni_functions() {
return (struct JNINativeInterface_ *)_jni_environment.functions;
}
// This function is called at thread creation to allow
// platform specific thread variables to be initialized.
void cache_global_variables();
// Executes Shutdown.shutdown()
void invoke_shutdown_hooks();
// Cleanup on thread exit
enum ExitType {
normal_exit,
jni_detach
};
void exit(bool destroy_vm, ExitType exit_type = normal_exit);
void cleanup_failed_attach_current_thread();
// Testers
virtual bool is_Java_thread() const { return true; }
// compilation
void set_is_compiling(bool f) { _is_compiling = f; }
bool is_compiling() const { return _is_compiling; }
// Thread chain operations
JavaThread* next() const { return _next; }
void set_next(JavaThread* p) { _next = p; }
// Thread oop. threadObj() can be NULL for initial JavaThread
// (or for threads attached via JNI)
oop threadObj() const { return _threadObj; }
void set_threadObj(oop p) { _threadObj = p; }
ThreadPriority java_priority() const; // Read from threadObj()
// Prepare thread and add to priority queue. If a priority is
// not specified, use the priority of the thread object. Threads_lock
// must be held while this function is called.
void prepare(jobject jni_thread, ThreadPriority prio=NoPriority);
void set_saved_exception_pc(address pc) { _saved_exception_pc = pc; }
address saved_exception_pc() { return _saved_exception_pc; }
ThreadFunction entry_point() const { return _entry_point; }
// Allocates a new Java level thread object for this thread. thread_name may be NULL.
void allocate_threadObj(Handle thread_group, char* thread_name, bool daemon, TRAPS);
// Last frame anchor routines
JavaFrameAnchor* frame_anchor(void) { return &_anchor; }
// last_Java_sp
bool has_last_Java_frame() const { return _anchor.has_last_Java_frame(); }
intptr_t* last_Java_sp() const { return _anchor.last_Java_sp(); }
// last_Java_pc
address last_Java_pc(void) { return _anchor.last_Java_pc(); }
// Safepoint support
JavaThreadState thread_state() const { return _thread_state; }
void set_thread_state(JavaThreadState s) { _thread_state=s; }
ThreadSafepointState *safepoint_state() const { return _safepoint_state; }
void set_safepoint_state(ThreadSafepointState *state) { _safepoint_state = state; }
bool is_at_poll_safepoint() { return _safepoint_state->is_at_poll_safepoint(); }
// thread has called JavaThread::exit() or is terminated
bool is_exiting() { return _terminated == _thread_exiting || is_terminated(); }
// thread is terminated (no longer on the threads list); we compare
// against the two non-terminated values so that a freed JavaThread
// will also be considered terminated.
bool is_terminated() { return _terminated != _not_terminated && _terminated != _thread_exiting; }
void set_terminated(TerminatedTypes t) { _terminated = t; }
// special for Threads::remove() which is static:
void set_terminated_value() { _terminated = _thread_terminated; }
void block_if_vm_exited();
bool doing_unsafe_access() { return _doing_unsafe_access; }
void set_doing_unsafe_access(bool val) { _doing_unsafe_access = val; }
bool do_not_unlock_if_synchronized() { return _do_not_unlock_if_synchronized; }
void set_do_not_unlock_if_synchronized(bool val) { _do_not_unlock_if_synchronized = val; }
#if INCLUDE_NMT
// native memory tracking
inline MemRecorder* get_recorder() const { return (MemRecorder*)_recorder; }
inline void set_recorder(MemRecorder* rc) { _recorder = rc; }
private:
// per-thread memory recorder
MemRecorder* volatile _recorder;
#endif // INCLUDE_NMT
// Suspend/resume support for JavaThread
private:
void set_ext_suspended() { set_suspend_flag (_ext_suspended); }
void clear_ext_suspended() { clear_suspend_flag(_ext_suspended); }
public:
void java_suspend();
void java_resume();
int java_suspend_self();
void check_and_wait_while_suspended() {
assert(JavaThread::current() == this, "sanity check");
bool do_self_suspend;
do {
// were we externally suspended while we were waiting?
do_self_suspend = handle_special_suspend_equivalent_condition();
if (do_self_suspend) {
// don't surprise the thread that suspended us by returning
java_suspend_self();
set_suspend_equivalent();
}
} while (do_self_suspend);
}
static void check_safepoint_and_suspend_for_native_trans(JavaThread *thread);
// Check for async exception in addition to safepoint and suspend request.
static void check_special_condition_for_native_trans(JavaThread *thread);
// Same as check_special_condition_for_native_trans but finishes the
// transition into thread_in_Java mode so that it can potentially
// block.
static void check_special_condition_for_native_trans_and_transition(JavaThread *thread);
bool is_ext_suspend_completed(bool called_by_wait, int delay, uint32_t *bits);
bool is_ext_suspend_completed_with_lock(uint32_t *bits) {
MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
// 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.
return is_ext_suspend_completed(false /*!called_by_wait */,
SuspendRetryDelay, bits);
}
// We cannot allow wait_for_ext_suspend_completion() to run forever or
// we could hang. SuspendRetryCount and SuspendRetryDelay are normally
// passed as the count and delay parameters. Experiments with specific
// calls to wait_for_ext_suspend_completion() can be done by passing
// other values in the code. Experiments with all calls can be done
// via the appropriate -XX options.
bool wait_for_ext_suspend_completion(int count, int delay, uint32_t *bits);
void set_external_suspend() { set_suspend_flag (_external_suspend); }
void clear_external_suspend() { clear_suspend_flag(_external_suspend); }
void set_deopt_suspend() { set_suspend_flag (_deopt_suspend); }
void clear_deopt_suspend() { clear_suspend_flag(_deopt_suspend); }
bool is_deopt_suspend() { return (_suspend_flags & _deopt_suspend) != 0; }
bool is_external_suspend() const {
return (_suspend_flags & _external_suspend) != 0;
}
// Whenever a thread transitions from native to vm/java it must suspend
// if external|deopt suspend is present.
bool is_suspend_after_native() const {
return (_suspend_flags & (_external_suspend | _deopt_suspend) ) != 0;
}
// external suspend request is completed
bool is_ext_suspended() const {
return (_suspend_flags & _ext_suspended) != 0;
}
bool is_external_suspend_with_lock() const {
MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
return is_external_suspend();
}
// Special method to handle a pending external suspend request
// when a suspend equivalent condition lifts.
bool handle_special_suspend_equivalent_condition() {
assert(is_suspend_equivalent(),
"should only be called in a suspend equivalence condition");
MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
bool ret = is_external_suspend();
if (!ret) {
// not about to self-suspend so clear suspend equivalence
clear_suspend_equivalent();
}
// implied else:
// We have a pending external suspend request so we leave the
// suspend_equivalent flag set until java_suspend_self() sets
// the ext_suspended flag and clears the suspend_equivalent
// flag. This insures that wait_for_ext_suspend_completion()
// will return consistent values.
return ret;
}
// utility methods to see if we are doing some kind of suspension
bool is_being_ext_suspended() const {
MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
return is_ext_suspended() || is_external_suspend();
}
bool is_suspend_equivalent() const { return _suspend_equivalent; }
void set_suspend_equivalent() { _suspend_equivalent = true; };
void clear_suspend_equivalent() { _suspend_equivalent = false; };
// Thread.stop support
void send_thread_stop(oop throwable);
AsyncRequests clear_special_runtime_exit_condition() {
AsyncRequests x = _special_runtime_exit_condition;
_special_runtime_exit_condition = _no_async_condition;
return x;
}
// Are any async conditions present?
bool has_async_condition() { return (_special_runtime_exit_condition != _no_async_condition); }
void check_and_handle_async_exceptions(bool check_unsafe_error = true);
// these next two are also used for self-suspension and async exception support
void handle_special_runtime_exit_condition(bool check_asyncs = true);
// Return true if JavaThread has an asynchronous condition or
// if external suspension is requested.
bool has_special_runtime_exit_condition() {
// We call is_external_suspend() last since external suspend should
// be less common. Because we don't use is_external_suspend_with_lock
// it is possible that we won't see an asynchronous external suspend
// request that has just gotten started, i.e., SR_lock grabbed but
// _external_suspend field change either not made yet or not visible
// yet. However, this is okay because the request is asynchronous and
// we will see the new flag value the next time through. It's also
// possible that the external suspend request is dropped after
// we have checked is_external_suspend(), we will recheck its value
// under SR_lock in java_suspend_self().
return (_special_runtime_exit_condition != _no_async_condition) ||
is_external_suspend() || is_deopt_suspend();
}
void set_pending_unsafe_access_error() { _special_runtime_exit_condition = _async_unsafe_access_error; }
void set_pending_async_exception(oop e) {
_pending_async_exception = e;
_special_runtime_exit_condition = _async_exception;
set_has_async_exception();
}
// Fast-locking support
bool is_lock_owned(address adr) const;
// Accessors for vframe array top
// The linked list of vframe arrays are sorted on sp. This means when we
// unpack the head must contain the vframe array to unpack.
void set_vframe_array_head(vframeArray* value) { _vframe_array_head = value; }
vframeArray* vframe_array_head() const { return _vframe_array_head; }
// Side structure for defering update of java frame locals until deopt occurs
GrowableArray<jvmtiDeferredLocalVariableSet*>* deferred_locals() const { return _deferred_locals_updates; }
void set_deferred_locals(GrowableArray<jvmtiDeferredLocalVariableSet *>* vf) { _deferred_locals_updates = vf; }
// These only really exist to make debugging deopt problems simpler
void set_vframe_array_last(vframeArray* value) { _vframe_array_last = value; }
vframeArray* vframe_array_last() const { return _vframe_array_last; }
// The special resourceMark used during deoptimization
void set_deopt_mark(DeoptResourceMark* value) { _deopt_mark = value; }
DeoptResourceMark* deopt_mark(void) { return _deopt_mark; }
intptr_t* must_deopt_id() { return _must_deopt_id; }
void set_must_deopt_id(intptr_t* id) { _must_deopt_id = id; }
void clear_must_deopt_id() { _must_deopt_id = NULL; }
void set_deopt_nmethod(nmethod* nm) { _deopt_nmethod = nm; }
nmethod* deopt_nmethod() { return _deopt_nmethod; }
Method* callee_target() const { return _callee_target; }
void set_callee_target (Method* x) { _callee_target = x; }
// Oop results of vm runtime calls
oop vm_result() const { return _vm_result; }
void set_vm_result (oop x) { _vm_result = x; }
Metadata* vm_result_2() const { return _vm_result_2; }
void set_vm_result_2 (Metadata* x) { _vm_result_2 = x; }
MemRegion deferred_card_mark() const { return _deferred_card_mark; }
void set_deferred_card_mark(MemRegion mr) { _deferred_card_mark = mr; }
// Exception handling for compiled methods
oop exception_oop() const { return _exception_oop; }
address exception_pc() const { return _exception_pc; }
address exception_handler_pc() const { return _exception_handler_pc; }
bool is_method_handle_return() const { return _is_method_handle_return == 1; }
void set_exception_oop(oop o) { _exception_oop = o; }
void set_exception_pc(address a) { _exception_pc = a; }
void set_exception_handler_pc(address a) { _exception_handler_pc = a; }
void set_is_method_handle_return(bool value) { _is_method_handle_return = value ? 1 : 0; }
// Stack overflow support
inline size_t stack_available(address cur_sp);
address stack_yellow_zone_base()
{ return (address)(stack_base() - (stack_size() - (stack_red_zone_size() + stack_yellow_zone_size()))); }
size_t stack_yellow_zone_size()
{ return StackYellowPages * os::vm_page_size(); }
address stack_red_zone_base()
{ return (address)(stack_base() - (stack_size() - stack_red_zone_size())); }
size_t stack_red_zone_size()
{ return StackRedPages * os::vm_page_size(); }
bool in_stack_yellow_zone(address a)
{ return (a <= stack_yellow_zone_base()) && (a >= stack_red_zone_base()); }
bool in_stack_red_zone(address a)
{ return (a <= stack_red_zone_base()) && (a >= (address)((intptr_t)stack_base() - stack_size())); }
void create_stack_guard_pages();
void remove_stack_guard_pages();
void enable_stack_yellow_zone();
void disable_stack_yellow_zone();
void enable_stack_red_zone();
void disable_stack_red_zone();
inline bool stack_guard_zone_unused();
inline bool stack_yellow_zone_disabled();
inline bool stack_yellow_zone_enabled();
// Attempt to reguard the stack after a stack overflow may have occurred.
// Returns true if (a) guard pages are not needed on this thread, (b) the
// pages are already guarded, or (c) the pages were successfully reguarded.
// Returns false if there is not enough stack space to reguard the pages, in
// which case the caller should unwind a frame and try again. The argument
// should be the caller's (approximate) sp.
bool reguard_stack(address cur_sp);
// Similar to above but see if current stackpoint is out of the guard area
// and reguard if possible.
bool reguard_stack(void);
// Misc. accessors/mutators
void set_do_not_unlock(void) { _do_not_unlock_if_synchronized = true; }
void clr_do_not_unlock(void) { _do_not_unlock_if_synchronized = false; }
bool do_not_unlock(void) { return _do_not_unlock_if_synchronized; }
#ifndef PRODUCT
void record_jump(address target, address instr, const char* file, int line);
#endif /* PRODUCT */
// For assembly stub generation
static ByteSize threadObj_offset() { return byte_offset_of(JavaThread, _threadObj ); }
#ifndef PRODUCT
static ByteSize jmp_ring_index_offset() { return byte_offset_of(JavaThread, _jmp_ring_index ); }
static ByteSize jmp_ring_offset() { return byte_offset_of(JavaThread, _jmp_ring ); }
#endif /* PRODUCT */
static ByteSize jni_environment_offset() { return byte_offset_of(JavaThread, _jni_environment ); }
static ByteSize last_Java_sp_offset() {
return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_sp_offset();
}
static ByteSize last_Java_pc_offset() {
return byte_offset_of(JavaThread, _anchor) + JavaFrameAnchor::last_Java_pc_offset();
}
static ByteSize frame_anchor_offset() {
return byte_offset_of(JavaThread, _anchor);
}
static ByteSize callee_target_offset() { return byte_offset_of(JavaThread, _callee_target ); }
static ByteSize vm_result_offset() { return byte_offset_of(JavaThread, _vm_result ); }
static ByteSize vm_result_2_offset() { return byte_offset_of(JavaThread, _vm_result_2 ); }
static ByteSize thread_state_offset() { return byte_offset_of(JavaThread, _thread_state ); }
static ByteSize saved_exception_pc_offset() { return byte_offset_of(JavaThread, _saved_exception_pc ); }
static ByteSize osthread_offset() { return byte_offset_of(JavaThread, _osthread ); }
static ByteSize exception_oop_offset() { return byte_offset_of(JavaThread, _exception_oop ); }
static ByteSize exception_pc_offset() { return byte_offset_of(JavaThread, _exception_pc ); }
static ByteSize exception_handler_pc_offset() { return byte_offset_of(JavaThread, _exception_handler_pc); }
static ByteSize is_method_handle_return_offset() { return byte_offset_of(JavaThread, _is_method_handle_return); }
static ByteSize stack_guard_state_offset() { return byte_offset_of(JavaThread, _stack_guard_state ); }
static ByteSize suspend_flags_offset() { return byte_offset_of(JavaThread, _suspend_flags ); }
static ByteSize do_not_unlock_if_synchronized_offset() { return byte_offset_of(JavaThread, _do_not_unlock_if_synchronized); }
static ByteSize should_post_on_exceptions_flag_offset() {
return byte_offset_of(JavaThread, _should_post_on_exceptions_flag);
}
#if INCLUDE_ALL_GCS
static ByteSize satb_mark_queue_offset() { return byte_offset_of(JavaThread, _satb_mark_queue); }
static ByteSize dirty_card_queue_offset() { return byte_offset_of(JavaThread, _dirty_card_queue); }
#endif // INCLUDE_ALL_GCS
// Returns the jni environment for this thread
JNIEnv* jni_environment() { return &_jni_environment; }
static JavaThread* thread_from_jni_environment(JNIEnv* env) {
JavaThread *thread_from_jni_env = (JavaThread*)((intptr_t)env - in_bytes(jni_environment_offset()));
// Only return NULL if thread is off the thread list; starting to
// exit should not return NULL.
if (thread_from_jni_env->is_terminated()) {
thread_from_jni_env->block_if_vm_exited();
return NULL;
} else {
return thread_from_jni_env;
}
}
// JNI critical regions. These can nest.
bool in_critical() { return _jni_active_critical > 0; }
bool in_last_critical() { return _jni_active_critical == 1; }
void enter_critical() { assert(Thread::current() == this ||
Thread::current()->is_VM_thread() && SafepointSynchronize::is_synchronizing(),
"this must be current thread or synchronizing");
_jni_active_critical++; }
void exit_critical() { assert(Thread::current() == this,
"this must be current thread");
_jni_active_critical--;
assert(_jni_active_critical >= 0,
"JNI critical nesting problem?"); }
// For deadlock detection
int depth_first_number() { return _depth_first_number; }
void set_depth_first_number(int dfn) { _depth_first_number = dfn; }
private:
void set_monitor_chunks(MonitorChunk* monitor_chunks) { _monitor_chunks = monitor_chunks; }
public:
MonitorChunk* monitor_chunks() const { return _monitor_chunks; }
void add_monitor_chunk(MonitorChunk* chunk);
void remove_monitor_chunk(MonitorChunk* chunk);
bool in_deopt_handler() const { return _in_deopt_handler > 0; }
void inc_in_deopt_handler() { _in_deopt_handler++; }
void dec_in_deopt_handler() {
assert(_in_deopt_handler > 0, "mismatched deopt nesting");
if (_in_deopt_handler > 0) { // robustness
_in_deopt_handler--;
}
}
private:
void set_entry_point(ThreadFunction entry_point) { _entry_point = entry_point; }
public:
// Frame iteration; calls the function f for all frames on the stack
void frames_do(void f(frame*, const RegisterMap*));
// Memory operations
void oops_do(OopClosure* f, CLDToOopClosure* cld_f, CodeBlobClosure* cf);
// Sweeper operations
void nmethods_do(CodeBlobClosure* cf);
// RedefineClasses Support
void metadata_do(void f(Metadata*));
// Memory management operations
void gc_epilogue();
void gc_prologue();
// Misc. operations
char* name() const { return (char*)get_thread_name(); }
void print_on(outputStream* st) const;
void print() const { print_on(tty); }
void print_value();
void print_thread_state_on(outputStream* ) const PRODUCT_RETURN;
void print_thread_state() const PRODUCT_RETURN;
void print_on_error(outputStream* st, char* buf, int buflen) const;
void verify();
const char* get_thread_name() const;
private:
// factor out low-level mechanics for use in both normal and error cases
const char* get_thread_name_string(char* buf = NULL, int buflen = 0) const;
public:
const char* get_threadgroup_name() const;
const char* get_parent_name() const;
// Accessing frames
frame last_frame() {
_anchor.make_walkable(this);
return pd_last_frame();
}
javaVFrame* last_java_vframe(RegisterMap* reg_map);
// Returns method at 'depth' java or native frames down the stack
// Used for security checks
Klass* security_get_caller_class(int depth);
// Print stack trace in external format
void print_stack_on(outputStream* st);
void print_stack() { print_stack_on(tty); }
// Print stack traces in various internal formats
void trace_stack() PRODUCT_RETURN;
void trace_stack_from(vframe* start_vf) PRODUCT_RETURN;
void trace_frames() PRODUCT_RETURN;
void trace_oops() PRODUCT_RETURN;
// Print an annotated view of the stack frames
void print_frame_layout(int depth = 0, bool validate_only = false) NOT_DEBUG_RETURN;
void validate_frame_layout() {
print_frame_layout(0, true);
}
// Returns the number of stack frames on the stack
int depth() const;
// Function for testing deoptimization
void deoptimize();
void make_zombies();
void deoptimized_wrt_marked_nmethods();
// Profiling operation (see fprofile.cpp)
public:
bool profile_last_Java_frame(frame* fr);
private:
ThreadProfiler* _thread_profiler;
private:
friend class FlatProfiler; // uses both [gs]et_thread_profiler.
friend class FlatProfilerTask; // uses get_thread_profiler.
friend class ThreadProfilerMark; // uses get_thread_profiler.
ThreadProfiler* get_thread_profiler() { return _thread_profiler; }
ThreadProfiler* set_thread_profiler(ThreadProfiler* tp) {
ThreadProfiler* result = _thread_profiler;
_thread_profiler = tp;
return result;
}
// NMT (Native memory tracking) support.
// This flag helps NMT to determine if this JavaThread will be blocked
// at safepoint. If not, ThreadCritical is needed for writing memory records.
// JavaThread is only safepoint visible when it is in Threads' thread list,
// it is not visible until it is added to the list and becomes invisible
// once it is removed from the list.
public:
bool is_safepoint_visible() const { return _safepoint_visible; }
void set_safepoint_visible(bool visible) { _safepoint_visible = visible; }
private:
bool _safepoint_visible;
// Static operations
public:
// Returns the running thread as a JavaThread
static inline JavaThread* current();
// Returns the active Java thread. Do not use this if you know you are calling
// from a JavaThread, as it's slower than JavaThread::current. If called from
// the VMThread, it also returns the JavaThread that instigated the VMThread's
// operation. You may not want that either.
static JavaThread* active();
inline CompilerThread* as_CompilerThread();
public:
virtual void run();
void thread_main_inner();
private:
// PRIVILEGED STACK
PrivilegedElement* _privileged_stack_top;
GrowableArray<oop>* _array_for_gc;
public:
// Returns the privileged_stack information.
PrivilegedElement* privileged_stack_top() const { return _privileged_stack_top; }
void set_privileged_stack_top(PrivilegedElement *e) { _privileged_stack_top = e; }
void register_array_for_gc(GrowableArray<oop>* array) { _array_for_gc = array; }
public:
// Thread local information maintained by JVMTI.
void set_jvmti_thread_state(JvmtiThreadState *value) { _jvmti_thread_state = value; }
// A JvmtiThreadState is lazily allocated. This jvmti_thread_state()
// getter is used to get this JavaThread's JvmtiThreadState if it has
// one which means NULL can be returned. JvmtiThreadState::state_for()
// is used to get the specified JavaThread's JvmtiThreadState if it has
// one or it allocates a new JvmtiThreadState for the JavaThread and
// returns it. JvmtiThreadState::state_for() will return NULL only if
// the specified JavaThread is exiting.
JvmtiThreadState *jvmti_thread_state() const { return _jvmti_thread_state; }
static ByteSize jvmti_thread_state_offset() { return byte_offset_of(JavaThread, _jvmti_thread_state); }
void set_jvmti_get_loaded_classes_closure(JvmtiGetLoadedClassesClosure* value) { _jvmti_get_loaded_classes_closure = value; }
JvmtiGetLoadedClassesClosure* get_jvmti_get_loaded_classes_closure() const { return _jvmti_get_loaded_classes_closure; }
// JVMTI PopFrame support
// Setting and clearing popframe_condition
// All of these enumerated values are bits. popframe_pending
// indicates that a PopFrame() has been requested and not yet been
// completed. popframe_processing indicates that that PopFrame() is in
// the process of being completed. popframe_force_deopt_reexecution_bit
// indicates that special handling is required when returning to a
// deoptimized caller.
enum PopCondition {
popframe_inactive = 0x00,
popframe_pending_bit = 0x01,
popframe_processing_bit = 0x02,
popframe_force_deopt_reexecution_bit = 0x04
};
PopCondition popframe_condition() { return (PopCondition) _popframe_condition; }
void set_popframe_condition(PopCondition c) { _popframe_condition = c; }
void set_popframe_condition_bit(PopCondition c) { _popframe_condition |= c; }
void clear_popframe_condition() { _popframe_condition = popframe_inactive; }
static ByteSize popframe_condition_offset() { return byte_offset_of(JavaThread, _popframe_condition); }
bool has_pending_popframe() { return (popframe_condition() & popframe_pending_bit) != 0; }
bool popframe_forcing_deopt_reexecution() { return (popframe_condition() & popframe_force_deopt_reexecution_bit) != 0; }
void clear_popframe_forcing_deopt_reexecution() { _popframe_condition &= ~popframe_force_deopt_reexecution_bit; }
#ifdef CC_INTERP
bool pop_frame_pending(void) { return ((_popframe_condition & popframe_pending_bit) != 0); }
void clr_pop_frame_pending(void) { _popframe_condition = popframe_inactive; }
bool pop_frame_in_process(void) { return ((_popframe_condition & popframe_processing_bit) != 0); }
void set_pop_frame_in_process(void) { _popframe_condition |= popframe_processing_bit; }
void clr_pop_frame_in_process(void) { _popframe_condition &= ~popframe_processing_bit; }
#endif
private:
// Saved incoming arguments to popped frame.
// Used only when popped interpreted frame returns to deoptimized frame.
void* _popframe_preserved_args;
int _popframe_preserved_args_size;
public:
void popframe_preserve_args(ByteSize size_in_bytes, void* start);
void* popframe_preserved_args();
ByteSize popframe_preserved_args_size();
WordSize popframe_preserved_args_size_in_words();
void popframe_free_preserved_args();
private:
JvmtiThreadState *_jvmti_thread_state;
JvmtiGetLoadedClassesClosure* _jvmti_get_loaded_classes_closure;
// Used by the interpreter in fullspeed mode for frame pop, method
// entry, method exit and single stepping support. This field is
// only set to non-zero by the VM_EnterInterpOnlyMode VM operation.
// It can be set to zero asynchronously (i.e., without a VM operation
// or a lock) so we have to be very careful.
int _interp_only_mode;
public:
// used by the interpreter for fullspeed debugging support (see above)
static ByteSize interp_only_mode_offset() { return byte_offset_of(JavaThread, _interp_only_mode); }
bool is_interp_only_mode() { return (_interp_only_mode != 0); }
int get_interp_only_mode() { return _interp_only_mode; }
void increment_interp_only_mode() { ++_interp_only_mode; }
void decrement_interp_only_mode() { --_interp_only_mode; }
// support for cached flag that indicates whether exceptions need to be posted for this thread
// if this is false, we can avoid deoptimizing when events are thrown
// this gets set to reflect whether jvmtiExport::post_exception_throw would actually do anything
private:
int _should_post_on_exceptions_flag;
public:
int should_post_on_exceptions_flag() { return _should_post_on_exceptions_flag; }
void set_should_post_on_exceptions_flag(int val) { _should_post_on_exceptions_flag = val; }
private:
ThreadStatistics *_thread_stat;
public:
ThreadStatistics* get_thread_stat() const { return _thread_stat; }
// Return a blocker object for which this thread is blocked parking.
oop current_park_blocker();
private:
static size_t _stack_size_at_create;
public:
static inline size_t stack_size_at_create(void) {
return _stack_size_at_create;
}
static inline void set_stack_size_at_create(size_t value) {
_stack_size_at_create = value;
}
#if INCLUDE_ALL_GCS
// SATB marking queue support
ObjPtrQueue& satb_mark_queue() { return _satb_mark_queue; }
static SATBMarkQueueSet& satb_mark_queue_set() {
return _satb_mark_queue_set;
}
// Dirty card queue support
DirtyCardQueue& dirty_card_queue() { return _dirty_card_queue; }
static DirtyCardQueueSet& dirty_card_queue_set() {
return _dirty_card_queue_set;
}
#endif // INCLUDE_ALL_GCS
// This method initializes the SATB and dirty card queues before a
// JavaThread is added to the Java thread list. Right now, we don't
// have to do anything to the dirty card queue (it should have been
// activated when the thread was created), but we have to activate
// the SATB queue if the thread is created while a marking cycle is
// in progress. The activation / de-activation of the SATB queues at
// the beginning / end of a marking cycle is done during safepoints
// so we have to make sure this method is called outside one to be
// able to safely read the active field of the SATB queue set. Right
// now, it is called just before the thread is added to the Java
// thread list in the Threads::add() method. That method is holding
// the Threads_lock which ensures we are outside a safepoint. We
// cannot do the obvious and set the active field of the SATB queue
// when the thread is created given that, in some cases, safepoints
// might happen between the JavaThread constructor being called and the
// thread being added to the Java thread list (an example of this is
// when the structure for the DestroyJavaVM thread is created).
#if INCLUDE_ALL_GCS
void initialize_queues();
#else // INCLUDE_ALL_GCS
void initialize_queues() { }
#endif // INCLUDE_ALL_GCS
// Machine dependent stuff
#ifdef TARGET_OS_ARCH_linux_x86
# include "thread_linux_x86.hpp"
#endif
#ifdef TARGET_OS_ARCH_linux_sparc
# include "thread_linux_sparc.hpp"
#endif
#ifdef TARGET_OS_ARCH_linux_zero
# include "thread_linux_zero.hpp"
#endif
#ifdef TARGET_OS_ARCH_solaris_x86
# include "thread_solaris_x86.hpp"
#endif
#ifdef TARGET_OS_ARCH_solaris_sparc
# include "thread_solaris_sparc.hpp"
#endif
#ifdef TARGET_OS_ARCH_windows_x86
# include "thread_windows_x86.hpp"
#endif
#ifdef TARGET_OS_ARCH_linux_arm
# include "thread_linux_arm.hpp"
#endif
#ifdef TARGET_OS_ARCH_linux_ppc
# include "thread_linux_ppc.hpp"
#endif
#ifdef TARGET_OS_ARCH_bsd_x86
# include "thread_bsd_x86.hpp"
#endif
#ifdef TARGET_OS_ARCH_bsd_zero
# include "thread_bsd_zero.hpp"
#endif
public:
void set_blocked_on_compilation(bool value) {
_blocked_on_compilation = value;
}
bool blocked_on_compilation() {
return _blocked_on_compilation;
}
protected:
bool _blocked_on_compilation;
// JSR166 per-thread parker
private:
Parker* _parker;
public:
Parker* parker() { return _parker; }
// Biased locking support
private:
GrowableArray<MonitorInfo*>* _cached_monitor_info;
public:
GrowableArray<MonitorInfo*>* cached_monitor_info() { return _cached_monitor_info; }
void set_cached_monitor_info(GrowableArray<MonitorInfo*>* info) { _cached_monitor_info = info; }
// clearing/querying jni attach status
bool is_attaching_via_jni() const { return _jni_attach_state == _attaching_via_jni; }
bool has_attached_via_jni() const { return is_attaching_via_jni() || _jni_attach_state == _attached_via_jni; }
void set_done_attaching_via_jni() { _jni_attach_state = _attached_via_jni; OrderAccess::fence(); }
private:
// This field is used to determine if a thread has claimed
// a par_id: it is -1 if the thread has not claimed a par_id;
// otherwise its value is the par_id that has been claimed.
int _claimed_par_id;
public:
int get_claimed_par_id() { return _claimed_par_id; }
void set_claimed_par_id(int id) { _claimed_par_id = id;}
};
// Inline implementation of JavaThread::current
inline JavaThread* JavaThread::current() {
Thread* thread = ThreadLocalStorage::thread();
assert(thread != NULL && thread->is_Java_thread(), "just checking");
return (JavaThread*)thread;
}
inline CompilerThread* JavaThread::as_CompilerThread() {
assert(is_Compiler_thread(), "just checking");
return (CompilerThread*)this;
}
inline bool JavaThread::stack_guard_zone_unused() {
return _stack_guard_state == stack_guard_unused;
}
inline bool JavaThread::stack_yellow_zone_disabled() {
return _stack_guard_state == stack_guard_yellow_disabled;
}
inline bool JavaThread::stack_yellow_zone_enabled() {
#ifdef ASSERT
if (os::uses_stack_guard_pages()) {
assert(_stack_guard_state != stack_guard_unused, "guard pages must be in use");
}
#endif
return _stack_guard_state == stack_guard_enabled;
}
inline size_t JavaThread::stack_available(address cur_sp) {
// This code assumes java stacks grow down
address low_addr; // Limit on the address for deepest stack depth
if ( _stack_guard_state == stack_guard_unused) {
low_addr = stack_base() - stack_size();
} else {
low_addr = stack_yellow_zone_base();
}
return cur_sp > low_addr ? cur_sp - low_addr : 0;
}
// A thread used for Compilation.
class CompilerThread : public JavaThread {
friend class VMStructs;
private:
CompilerCounters* _counters;
ciEnv* _env;
CompileLog* _log;
CompileTask* _task;
CompileQueue* _queue;
BufferBlob* _buffer_blob;
nmethod* _scanned_nmethod; // nmethod being scanned by the sweeper
public:
static CompilerThread* current();
CompilerThread(CompileQueue* queue, CompilerCounters* counters);
bool is_Compiler_thread() const { return true; }
// Hide this compiler thread from external view.
bool is_hidden_from_external_view() const { return true; }
CompileQueue* queue() { return _queue; }
CompilerCounters* counters() { return _counters; }
// Get/set the thread's compilation environment.
ciEnv* env() { return _env; }
void set_env(ciEnv* env) { _env = env; }
BufferBlob* get_buffer_blob() { return _buffer_blob; }
void set_buffer_blob(BufferBlob* b) { _buffer_blob = b; };
// Get/set the thread's logging information
CompileLog* log() { return _log; }
void init_log(CompileLog* log) {
// Set once, for good.
assert(_log == NULL, "set only once");
_log = log;
}
// GC support
// Apply "f->do_oop" to all root oops in "this".
// Apply "cf->do_code_blob" (if !NULL) to all code blobs active in frames
void oops_do(OopClosure* f, CLDToOopClosure* cld_f, CodeBlobClosure* cf);
#ifndef PRODUCT
private:
IdealGraphPrinter *_ideal_graph_printer;
public:
IdealGraphPrinter *ideal_graph_printer() { return _ideal_graph_printer; }
void set_ideal_graph_printer(IdealGraphPrinter *n) { _ideal_graph_printer = n; }
#endif
// Get/set the thread's current task
CompileTask* task() { return _task; }
void set_task(CompileTask* task) { _task = task; }
// Track the nmethod currently being scanned by the sweeper
void set_scanned_nmethod(nmethod* nm) {
assert(_scanned_nmethod == NULL || nm == NULL, "should reset to NULL before writing a new value");
_scanned_nmethod = nm;
}
};
inline CompilerThread* CompilerThread::current() {
return JavaThread::current()->as_CompilerThread();
}
// The active thread queue. It also keeps track of the current used
// thread priorities.
class Threads: AllStatic {
friend class VMStructs;
private:
static JavaThread* _thread_list;
static int _number_of_threads;
static int _number_of_non_daemon_threads;
static int _return_code;
#ifdef ASSERT
static bool _vm_complete;
#endif
public:
// Thread management
// force_daemon is a concession to JNI, where we may need to add a
// thread to the thread list before allocating its thread object
static void add(JavaThread* p, bool force_daemon = false);
static void remove(JavaThread* p);
static bool includes(JavaThread* p);
static JavaThread* first() { return _thread_list; }
static void threads_do(ThreadClosure* tc);
// Initializes the vm and creates the vm thread
static jint create_vm(JavaVMInitArgs* args, bool* canTryAgain);
static void convert_vm_init_libraries_to_agents();
static void create_vm_init_libraries();
static void create_vm_init_agents();
static void shutdown_vm_agents();
static bool destroy_vm();
// Supported VM versions via JNI
// Includes JNI_VERSION_1_1
static jboolean is_supported_jni_version_including_1_1(jint version);
// Does not include JNI_VERSION_1_1
static jboolean is_supported_jni_version(jint version);
// Garbage collection
static void follow_other_roots(void f(oop*));
// Apply "f->do_oop" to all root oops in all threads.
// This version may only be called by sequential code.
static void oops_do(OopClosure* f, CLDToOopClosure* cld_f, CodeBlobClosure* cf);
// This version may be called by sequential or parallel code.
static void possibly_parallel_oops_do(OopClosure* f, CLDToOopClosure* cld_f, CodeBlobClosure* cf);
// This creates a list of GCTasks, one per thread.
static void create_thread_roots_tasks(GCTaskQueue* q);
// This creates a list of GCTasks, one per thread, for marking objects.
static void create_thread_roots_marking_tasks(GCTaskQueue* q);
// Apply "f->do_oop" to roots in all threads that
// are part of compiled frames
static void compiled_frame_oops_do(OopClosure* f, CodeBlobClosure* cf);
static void convert_hcode_pointers();
static void restore_hcode_pointers();
// Sweeper
static void nmethods_do(CodeBlobClosure* cf);
// RedefineClasses support
static void metadata_do(void f(Metadata*));
static void gc_epilogue();
static void gc_prologue();
#ifdef ASSERT
static bool is_vm_complete() { return _vm_complete; }
#endif
// Verification
static void verify();
static void print_on(outputStream* st, bool print_stacks, bool internal_format, bool print_concurrent_locks);
static void print(bool print_stacks, bool internal_format) {
// this function is only used by debug.cpp
print_on(tty, print_stacks, internal_format, false /* no concurrent lock printed */);
}
static void print_on_error(outputStream* st, Thread* current, char* buf, int buflen);
// Get Java threads that are waiting to enter a monitor. If doLock
// is true, then Threads_lock is grabbed as needed. Otherwise, the
// VM needs to be at a safepoint.
static GrowableArray<JavaThread*>* get_pending_threads(int count,
address monitor, bool doLock);
// Get owning Java thread from the monitor's owner field. If doLock
// is true, then Threads_lock is grabbed as needed. Otherwise, the
// VM needs to be at a safepoint.
static JavaThread *owning_thread_from_monitor_owner(address owner,
bool doLock);
// Number of threads on the active threads list
static int number_of_threads() { return _number_of_threads; }
// Number of non-daemon threads on the active threads list
static int number_of_non_daemon_threads() { return _number_of_non_daemon_threads; }
// Deoptimizes all frames tied to marked nmethods
static void deoptimized_wrt_marked_nmethods();
};
// Thread iterator
class ThreadClosure: public StackObj {
public:
virtual void do_thread(Thread* thread) = 0;
};
class SignalHandlerMark: public StackObj {
private:
Thread* _thread;
public:
SignalHandlerMark(Thread* t) {
_thread = t;
if (_thread) _thread->enter_signal_handler();
}
~SignalHandlerMark() {
if (_thread) _thread->leave_signal_handler();
_thread = NULL;
}
};
#endif // SHARE_VM_RUNTIME_THREAD_HPP