diff -r 4ebc2e2fb97c -r 71c04702a3d5 src/hotspot/share/runtime/synchronizer.hpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/hotspot/share/runtime/synchronizer.hpp Tue Sep 12 19:03:39 2017 +0200 @@ -0,0 +1,209 @@ +/* + * Copyright (c) 1998, 2017, Oracle and/or its affiliates. All rights reserved. + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * This code is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 only, as + * published by the Free Software Foundation. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA + * or visit www.oracle.com if you need additional information or have any + * questions. + * + */ + +#ifndef SHARE_VM_RUNTIME_SYNCHRONIZER_HPP +#define SHARE_VM_RUNTIME_SYNCHRONIZER_HPP + +#include "oops/markOop.hpp" +#include "runtime/basicLock.hpp" +#include "runtime/handles.hpp" +#include "runtime/perfData.hpp" + +class ObjectMonitor; + +struct DeflateMonitorCounters { + int nInuse; // currently associated with objects + int nInCirculation; // extant + int nScavenged; // reclaimed +}; + +class ObjectSynchronizer : AllStatic { + friend class VMStructs; + public: + typedef enum { + owner_self, + owner_none, + owner_other + } LockOwnership; + + typedef enum { + inflate_cause_vm_internal = 0, + inflate_cause_monitor_enter = 1, + inflate_cause_wait = 2, + inflate_cause_notify = 3, + inflate_cause_hash_code = 4, + inflate_cause_jni_enter = 5, + inflate_cause_jni_exit = 6, + inflate_cause_nof = 7 // Number of causes + } InflateCause; + + // 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 synchronized. + // + // 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 void jni_exit(oop obj, Thread* THREAD); + + // Handle all interpreter, compiler and jni cases + static int wait(Handle obj, jlong millis, TRAPS); + static void notify(Handle obj, TRAPS); + static void notifyall(Handle obj, TRAPS); + + static bool quick_notify(oopDesc* obj, Thread* Self, bool All); + static bool quick_enter(oop obj, Thread* Self, BasicLock* Lock); + + // 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 void verifyInUse(Thread * Self); + static ObjectMonitor * omAlloc(Thread * Self); + static void omRelease(Thread * Self, ObjectMonitor * m, + bool FromPerThreadAlloc); + static void omFlush(Thread * Self); + + // Inflate light weight monitor to heavy weight monitor + static ObjectMonitor* inflate(Thread * Self, oop obj, const InflateCause cause); + // This version is only for internal use + static ObjectMonitor* inflate_helper(oop obj); + static const char* inflate_cause_name(const InflateCause cause); + + // 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(DeflateMonitorCounters* counters); + static void deflate_thread_local_monitors(Thread* thread, DeflateMonitorCounters* counters); + static void prepare_deflate_idle_monitors(DeflateMonitorCounters* counters); + static void finish_deflate_idle_monitors(DeflateMonitorCounters* counters); + + // For a given monitor list: global or per-thread, deflate idle monitors + static int deflate_monitor_list(ObjectMonitor** listheadp, + ObjectMonitor** freeHeadp, + ObjectMonitor** freeTailp); + static bool deflate_monitor(ObjectMonitor* mid, oop obj, + ObjectMonitor** freeHeadp, + ObjectMonitor** freeTailp); + static bool is_cleanup_needed(); + static void oops_do(OopClosure* f); + // Process oops in thread local used monitors + static void thread_local_used_oops_do(Thread* thread, OopClosure* f); + + // debugging + static void sanity_checks(const bool verbose, + const unsigned int cache_line_size, + int *error_cnt_ptr, int *warning_cnt_ptr); + static int verify_objmon_isinpool(ObjectMonitor *addr) PRODUCT_RETURN0; + + private: + enum { _BLOCKSIZE = 128 }; + // global list of blocks of monitors + // gBlockList is really PaddedEnd *, but we don't + // want to expose the PaddedEnd template more than necessary. + static ObjectMonitor * volatile gBlockList; + // global monitor free list + static ObjectMonitor * volatile gFreeList; + // global monitor in-use list, for moribund threads, + // monitors they inflated need to be scanned for deflation + static ObjectMonitor * volatile gOmInUseList; + // count of entries in gOmInUseList + static int gOmInUseCount; + + // Process oops in all monitors + static void global_oops_do(OopClosure* f); + // Process oops in all global used monitors (i.e. moribund thread's monitors) + static void global_used_oops_do(OopClosure* f); + // Process oops in monitors on the given list + static void list_oops_do(ObjectMonitor* list, OopClosure* f); + +}; + +// 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, THREAD); } + void reenter(intptr_t recursion, TRAPS) { ObjectSynchronizer::reenter(_obj, recursion, CHECK); } +}; + +#endif // SHARE_VM_RUNTIME_SYNCHRONIZER_HPP