--- /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<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