diff -r fd16c54261b3 -r 489c9b5090e2 hotspot/src/share/vm/runtime/synchronizer.hpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/hotspot/src/share/vm/runtime/synchronizer.hpp Sat Dec 01 00:00:00 2007 +0000 @@ -0,0 +1,216 @@ +/* + * Copyright 1998-2007 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 BasicLock VALUE_OBJ_CLASS_SPEC { + friend class VMStructs; + private: + volatile markOop _displaced_header; + public: + markOop displaced_header() const { return _displaced_header; } + void set_displaced_header(markOop header) { _displaced_header = header; } + + void print_on(outputStream* st) const; + + // move a basic lock (used during deoptimization + void move_to(oop obj, BasicLock* dest); + + static int displaced_header_offset_in_bytes() { return offset_of(BasicLock, _displaced_header); } +}; + +// A BasicObjectLock associates a specific Java object with a BasicLock. +// It is currently embedded in an interpreter frame. + +// Because some machines have alignment restrictions on the control stack, +// the actual space allocated by the interpreter may include padding words +// after the end of the BasicObjectLock. Also, in order to guarantee +// alignment of the embedded BasicLock objects on such machines, we +// put the embedded BasicLock at the beginning of the struct. + +class BasicObjectLock VALUE_OBJ_CLASS_SPEC { + friend class VMStructs; + private: + BasicLock _lock; // the lock, must be double word aligned + oop _obj; // object holds the lock; + + public: + // Manipulation + oop obj() const { return _obj; } + void set_obj(oop obj) { _obj = obj; } + BasicLock* lock() { return &_lock; } + + // Note: Use frame::interpreter_frame_monitor_size() for the size of BasicObjectLocks + // in interpreter activation frames since it includes machine-specific padding. + static int size() { return sizeof(BasicObjectLock)/wordSize; } + + // GC support + void oops_do(OopClosure* f) { f->do_oop(&_obj); } + + static int obj_offset_in_bytes() { return offset_of(BasicObjectLock, _obj); } + static int lock_offset_in_bytes() { return offset_of(BasicObjectLock, _lock); } +}; + +class ObjectMonitor; + +class ObjectSynchronizer : AllStatic { + friend class VMStructs; + public: + typedef enum { + owner_self, + owner_none, + owner_other + } LockOwnership; + // exit must be implemented non-blocking, since the compiler cannot easily handle + // deoptimization at monitor exit. Hence, it does not take a Handle argument. + + // This is full version of monitor enter and exit. I choose not + // to use enter() and exit() in order to make sure user be ware + // of the performance and semantics difference. They are normally + // used by ObjectLocker etc. The interpreter and compiler use + // assembly copies of these routines. Please keep them synchornized. + // + // attempt_rebias flag is used by UseBiasedLocking implementation + static void fast_enter (Handle obj, BasicLock* lock, bool attempt_rebias, TRAPS); + static void fast_exit (oop obj, BasicLock* lock, Thread* THREAD); + + // WARNING: They are ONLY used to handle the slow cases. They should + // only be used when the fast cases failed. Use of these functions + // without previous fast case check may cause fatal error. + static void slow_enter (Handle obj, BasicLock* lock, TRAPS); + static void slow_exit (oop obj, BasicLock* lock, Thread* THREAD); + + // Used only to handle jni locks or other unmatched monitor enter/exit + // Internally they will use heavy weight monitor. + static void jni_enter (Handle obj, TRAPS); + static bool jni_try_enter(Handle obj, Thread* THREAD); // Implements Unsafe.tryMonitorEnter + static void jni_exit (oop obj, Thread* THREAD); + + // Handle all interpreter, compiler and jni cases + static void wait (Handle obj, jlong millis, TRAPS); + static void notify (Handle obj, TRAPS); + static void notifyall (Handle obj, TRAPS); + + // Special internal-use-only method for use by JVM infrastructure + // that needs to wait() on a java-level object but that can't risk + // throwing unexpected InterruptedExecutionExceptions. + static void waitUninterruptibly (Handle obj, jlong Millis, Thread * THREAD) ; + + // used by classloading to free classloader object lock, + // wait on an internal lock, and reclaim original lock + // with original recursion count + static intptr_t complete_exit (Handle obj, TRAPS); + static void reenter (Handle obj, intptr_t recursion, TRAPS); + + // thread-specific and global objectMonitor free list accessors + static ObjectMonitor * omAlloc (Thread * Self) ; + static void omRelease (Thread * Self, ObjectMonitor * m) ; + static void omFlush (Thread * Self) ; + + // Inflate light weight monitor to heavy weight monitor + static ObjectMonitor* inflate(Thread * Self, oop obj); + // This version is only for internal use + static ObjectMonitor* inflate_helper(oop obj); + + // Returns the identity hash value for an oop + // NOTE: It may cause monitor inflation + static intptr_t identity_hash_value_for(Handle obj); + static intptr_t FastHashCode (Thread * Self, oop obj) ; + + // java.lang.Thread support + static bool current_thread_holds_lock(JavaThread* thread, Handle h_obj); + static LockOwnership query_lock_ownership(JavaThread * self, Handle h_obj); + + static JavaThread* get_lock_owner(Handle h_obj, bool doLock); + + // JNI detach support + static void release_monitors_owned_by_thread(TRAPS); + static void monitors_iterate(MonitorClosure* m); + + // GC: we current use aggressive monitor deflation policy + // Basically we deflate all monitors that are not busy. + // An adaptive profile-based deflation policy could be used if needed + static void deflate_idle_monitors(); + static void oops_do(OopClosure* f); + + // debugging + static void trace_locking(Handle obj, bool is_compiled, bool is_method, bool is_locking) PRODUCT_RETURN; + static void verify() PRODUCT_RETURN; + static int verify_objmon_isinpool(ObjectMonitor *addr) PRODUCT_RETURN0; + + private: + enum { _BLOCKSIZE = 128 }; + static ObjectMonitor* gBlockList; + static ObjectMonitor * volatile gFreeList; + + public: + static void Initialize () ; + static PerfCounter * _sync_ContendedLockAttempts ; + static PerfCounter * _sync_FutileWakeups ; + static PerfCounter * _sync_Parks ; + static PerfCounter * _sync_EmptyNotifications ; + static PerfCounter * _sync_Notifications ; + static PerfCounter * _sync_SlowEnter ; + static PerfCounter * _sync_SlowExit ; + static PerfCounter * _sync_SlowNotify ; + static PerfCounter * _sync_SlowNotifyAll ; + static PerfCounter * _sync_FailedSpins ; + static PerfCounter * _sync_SuccessfulSpins ; + static PerfCounter * _sync_PrivateA ; + static PerfCounter * _sync_PrivateB ; + static PerfCounter * _sync_MonInCirculation ; + static PerfCounter * _sync_MonScavenged ; + static PerfCounter * _sync_Inflations ; + static PerfCounter * _sync_Deflations ; + static PerfLongVariable * _sync_MonExtant ; + + public: + static void RegisterSpinCallback (int (*)(intptr_t, int), intptr_t) ; + +}; + +// ObjectLocker enforced balanced locking and can never thrown an +// IllegalMonitorStateException. However, a pending exception may +// have to pass through, and we must also be able to deal with +// asynchronous exceptions. The caller is responsible for checking +// the threads pending exception if needed. +// doLock was added to support classloading with UnsyncloadClass which +// requires flag based choice of locking the classloader lock. +class ObjectLocker : public StackObj { + private: + Thread* _thread; + Handle _obj; + BasicLock _lock; + bool _dolock; // default true + public: + ObjectLocker(Handle obj, Thread* thread, bool doLock = true); + ~ObjectLocker(); + + // Monitor behavior + void wait (TRAPS) { ObjectSynchronizer::wait (_obj, 0, CHECK); } // wait forever + void notify_all(TRAPS) { ObjectSynchronizer::notifyall(_obj, CHECK); } + void waitUninterruptibly (TRAPS) { ObjectSynchronizer::waitUninterruptibly (_obj, 0, CHECK);} + // complete_exit gives up lock completely, returning recursion count + // reenter reclaims lock with original recursion count + intptr_t complete_exit(TRAPS) { return ObjectSynchronizer::complete_exit(_obj, CHECK_0); } + void reenter(intptr_t recursion, TRAPS) { ObjectSynchronizer::reenter(_obj, recursion, CHECK); } +};