| /* |
| * 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<ObjectMonitor> *, 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 |