truffle: src/share/vm/runtime/thread.hpp comparison

comparison src/share/vm/runtime/thread.hpp @ 0:a61af66fc99e jdk7-b24

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author	duke
date	Sat, 01 Dec 2007 00:00:00 +0000
parents
children	37f87013dfd8

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--1:000000000000
+:a61af66fc99e
+/*
+* 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.
+*
+*/
+class ThreadSafepointState;
+class ThreadProfiler;
+class JvmtiThreadState;
+class JvmtiGetLoadedClassesClosure;
+class ThreadStatistics;
+class ConcurrentLocksDump;
+class ParkEvent ;
+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 hierarchy
+// - Thread
+//   - VMThread
+//   - 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)
+// Support for forcing alignment of thread objects for biased locking
+void*       _real_malloc_address;
+public:
+void* operator new(size_t size);
+void  operator delete(void* p);
+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
+};
+// 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.
+// 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;
+// In order for all threads to be able to use fast locking, we need to know the highest stack
+// address of where a lock is on the stack (stacks normally grow towards lower addresses). This
+// variable is initially set to NULL, indicating no locks are used by the thread. During the thread's
+// execution, it will be set whenever locking can happen, i.e., when we call out to Java code or use
+// an ObjectLocker. The value is never decreased, hence, it will over the lifetime of a thread
+// approximate the real stackbase.
+address _highest_lock;                         // Highest stack address where a JavaLock exist
+ThreadLocalAllocBuffer _tlab;                  // Thread-local eden
+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
+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; }
+// Remove this ifdef when C1 is ported to the compiler interface.
+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 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);
+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);
+}
+// 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
+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; }
+// Thread-Local Allocation Buffer (TLAB) support
+ThreadLocalAllocBuffer& tlab()                 { return _tlab; }
+void initialize_tlab() {
+if (UseTLAB) {
+tlab().initialize();
+}
+}
+// 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".
+void oops_do(OopClosure* f);
+// 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();
+// Fast-locking support
+address highest_lock() const                   { return _highest_lock; }
+void update_highest_lock(address base)         { if (base > _highest_lock) _highest_lock = base; }
+// Tells if adr belong to this thread. This is used
+// for checking if a lock is owned by the running thread.
+// Warning: the method can only be used on the running thread
+// Fast lock support uses these methods
+virtual bool lock_is_in_stack(address adr) const;
+virtual bool is_lock_owned(address adr) const;
+// Check if address is in the stack of the thread (not just for locks).
+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;
+// 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();
+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 ); }
+static ByteSize omFreeList_offset()            { return byte_offset_of(Thread, omFreeList); }
+#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
+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 ;
+intptr_t _ScratchA, _ScratchB ;              // Scratch locations for fast-path sync code
+static ByteSize ScratchA_offset()            { return byte_offset_of(Thread, _ScratchA ); }
+static ByteSize ScratchB_offset()            { return byte_offset_of(Thread, _ScratchB ); }
+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;
+public:
+NamedThread();
+~NamedThread();
+// May only be called once per thread.
+void set_name(const char* format, ...);
+virtual char* name() const { return _name == NULL ? (char*)"Unknown Thread" : _name; }
+};
+// Worker threads are named and have an id of an assigned work.
+class WorkerThread: public NamedThread {
+private:
+uint _id;
+public:
+WorkerThread() : _id(0) { }
+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 _should_terminate;
+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); }
+// 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();
+};
+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
+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 methodOop. 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.
+methodOop     _callee_target;
+// Oop results of VM runtime calls
+oop           _vm_result;                      // Used to pass back an oop result into Java code, GC-preserved
+oop           _vm_result_2;                    // Used to pass back an oop result into Java code, GC-preserved
+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.
+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.
+//  Flag to mark a JNI thread in the process of attaching - See CR 6404306
+//  This flag is never set true other than at construction, and in that case
+//  is shortly thereafter set false
+volatile bool _is_attaching;
+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     _exception_stack_size;        // Size of frame where exception happened
+// 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 */
+friend class VMThread;
+friend class ThreadWaitTransition;
+friend class VM_Exit;
+void initialize();                             // Initialized the instance variables
+public:
+// Constructor
+JavaThread(bool is_attaching = 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;
+}
+// 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; }
+// 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);
+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;
+}
+// legacy method that checked for either external suspension or vm suspension
+bool is_any_suspended() const {
+return is_ext_suspended();
+}
+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;
+}
+bool is_any_suspended_with_lock() const {
+MutexLockerEx ml(SR_lock(), Mutex::_no_safepoint_check_flag);
+return is_any_suspended();
+}
+// 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; }
+methodOop  callee_target() const               { return _callee_target; }
+void set_callee_target  (methodOop 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; }
+oop  vm_result_2() const                       { return _vm_result_2; }
+void set_vm_result_2  (oop x)                  { _vm_result_2   = x; }
+// Exception handling for compiled methods
+oop      exception_oop() const                 { return _exception_oop; }
+int      exception_stack_size() const          { return _exception_stack_size; }
+address  exception_pc() const                  { return _exception_pc; }
+address  exception_handler_pc() const          { return _exception_handler_pc; }
+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_exception_stack_size(int size)        { _exception_stack_size = size; }
+// 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_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 exception_stack_size_offset()  { return byte_offset_of(JavaThread, _exception_stack_size); }
+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); }
+// 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; }
+void enter_critical() { assert(Thread::current() == this,
+"this must be current thread");
+_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);
+// Sweeper operations
+void nmethods_do();
+// 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
+klassOop 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;
+// 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;
+}
+// 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; }
+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; }
+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;
+}
+// Machine dependent stuff
+#include "incls/_thread_pd.hpp.incl"
+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() const { return _is_attaching; }
+void set_attached() { _is_attaching = false; OrderAccess::fence(); }
+};
+// 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_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 JavaThread for low memory detection support
+class LowMemoryDetectorThread : public JavaThread {
+friend class VMStructs;
+public:
+LowMemoryDetectorThread(ThreadFunction entry_point) : JavaThread(entry_point) {};
+// Hide this thread from external view.
+bool is_hidden_from_external_view() const      { return true; }
+};
+// A thread used for Compilation.
+class CompilerThread : public JavaThread {
+friend class VMStructs;
+private:
+CompilerCounters* _counters;
+ciEnv*        _env;
+CompileLog*   _log;
+CompileTask*  _task;
+CompileQueue* _queue;
+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; }
+// 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;
+}
+#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; }
+};
+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;
+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);
+// This version may be called by sequential or parallel code.
+static void possibly_parallel_oops_do(OopClosure* f);
+// 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);
+static void convert_hcode_pointers();
+static void restore_hcode_pointers();
+// Sweeper
+static void nmethods_do();
+static void gc_epilogue();
+static void gc_prologue();
+// 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;
+}
+};
+// ParkEvents are type-stable and immortal.
+//
+// Lifecycle: Once a ParkEvent is associated with a thread that ParkEvent remains
+// associated with the thread for the thread's entire lifetime - the relationship is
+// stable. A thread will be associated at most one ParkEvent.  When the thread
+// expires, the ParkEvent moves to the EventFreeList.  New threads attempt to allocate from
+// the EventFreeList before creating a new Event.  Type-stability frees us from
+// worrying about stale Event or Thread references in the objectMonitor subsystem.
+// (A reference to ParkEvent is always valid, even though the event may no longer be associated
+// with the desired or expected thread.  A key aspect of this design is that the callers of
+// park, unpark, etc must tolerate stale references and spurious wakeups).
+//
+// Only the "associated" thread can block (park) on the ParkEvent, although
+// any other thread can unpark a reachable parkevent.  Park() is allowed to
+// return spuriously.  In fact park-unpark a really just an optimization to
+// avoid unbounded spinning and surrender the CPU to be a polite system citizen.
+// A degenerate albeit "impolite" park-unpark implementation could simply return.
+// See http://blogs.sun.com/dave for more details.
+//
+// Eventually I'd like to eliminate Events and ObjectWaiters, both of which serve as
+// thread proxies, and simply make the THREAD structure type-stable and persistent.
+// Currently, we unpark events associated with threads, but ideally we'd just
+// unpark threads.
+//
+// The base-class, PlatformEvent, is platform-specific while the ParkEvent is
+// platform-independent.  PlatformEvent provides park(), unpark(), etc., and
+// is abstract -- that is, a PlatformEvent should never be instantiated except
+// as part of a ParkEvent.
+// Equivalently we could have defined a platform-independent base-class that
+// exported Allocate(), Release(), etc.  The platform-specific class would extend
+// that base-class, adding park(), unpark(), etc.
+//
+// A word of caution: The JVM uses 2 very similar constructs:
+// 1. ParkEvent are used for Java-level "monitor" synchronization.
+// 2. Parkers are used by JSR166-JUC park-unpark.
+//
+// We'll want to eventually merge these redundant facilities and use ParkEvent.
+class ParkEvent : public os::PlatformEvent {
+private:
+ParkEvent * FreeNext ;
+// Current association
+Thread * AssociatedWith ;
+intptr_t RawThreadIdentity ;        // LWPID etc
+volatile int Incarnation ;
+// diagnostic : keep track of last thread to wake this thread.
+// this is useful for construction of dependency graphs.
+void * LastWaker ;
+public:
+// MCS-CLH list linkage and Native Mutex/Monitor
+ParkEvent * volatile ListNext ;
+ParkEvent * volatile ListPrev ;
+volatile intptr_t OnList ;
+volatile int TState ;
+volatile int Notified ;             // for native monitor construct
+volatile int IsWaiting ;            // Enqueued on WaitSet
+private:
+static ParkEvent * volatile FreeList ;
+static volatile int ListLock ;
+// It's prudent to mark the dtor as "private"
+// ensuring that it's not visible outside the package.
+// Unfortunately gcc warns about such usage, so
+// we revert to the less desirable "protected" visibility.
+// The other compilers accept private dtors.
+protected:        // Ensure dtor is never invoked
+~ParkEvent() { guarantee (0, "invariant") ; }
+ParkEvent() : PlatformEvent() {
+AssociatedWith = NULL ;
+FreeNext       = NULL ;
+ListNext       = NULL ;
+ListPrev       = NULL ;
+OnList         = 0 ;
+TState         = 0 ;
+Notified       = 0 ;
+IsWaiting      = 0 ;
+}
+// We use placement-new to force ParkEvent instances to be
+// aligned on 256-byte address boundaries.  This ensures that the least
+// significant byte of a ParkEvent address is always 0.
+void * operator new (size_t sz) ;
+void operator delete (void * a) ;
+public:
+static ParkEvent * Allocate (Thread * t) ;
+static void Release (ParkEvent * e) ;
+} ;

Mercurial > hg > truffle

comparison src/share/vm/runtime/thread.hpp @ 0:a61af66fc99e jdk7-b24