# HG changeset patch # User kamg # Date 1296675481 18000 # Node ID bf8517f4e4d0f4f81ddca852dd0a19ad70bafc7d # Parent face83fc888274e6bfd7adff7103a3f3b6e49cfc 6766644: Redefinition of compiled method fails with assertion "Can not load classes with the Compiler thread" Summary: Defer posting events from the compiler thread: use service thread Reviewed-by: coleenp, dholmes, never, dcubed diff -r face83fc8882 -r bf8517f4e4d0 agent/src/share/classes/sun/jvm/hotspot/runtime/LowMemoryDetectorThread.java --- a/agent/src/share/classes/sun/jvm/hotspot/runtime/LowMemoryDetectorThread.java Wed Feb 02 18:38:40 2011 -0500 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,41 +0,0 @@ -/* - * Copyright (c) 2003, 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. - * - */ - -package sun.jvm.hotspot.runtime; - -import java.io.*; - -import sun.jvm.hotspot.debugger.*; -import sun.jvm.hotspot.types.*; - -public class LowMemoryDetectorThread extends JavaThread { - public LowMemoryDetectorThread(Address addr) { - super(addr); - } - - public boolean isJavaThread() { return false; } - public boolean isHiddenFromExternalView() { return true; } - public boolean isLowMemoryDetectorThread() { return true; } - -} diff -r face83fc8882 -r bf8517f4e4d0 agent/src/share/classes/sun/jvm/hotspot/runtime/ServiceThread.java --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/agent/src/share/classes/sun/jvm/hotspot/runtime/ServiceThread.java Wed Feb 02 14:38:01 2011 -0500 @@ -0,0 +1,41 @@ +/* + * Copyright (c) 2003, 2011 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. + * + */ + +package sun.jvm.hotspot.runtime; + +import java.io.*; + +import sun.jvm.hotspot.debugger.*; +import sun.jvm.hotspot.types.*; + +public class ServiceThread extends JavaThread { + public ServiceThread(Address addr) { + super(addr); + } + + public boolean isJavaThread() { return false; } + public boolean isHiddenFromExternalView() { return true; } + public boolean isServiceThread() { return true; } + +} diff -r face83fc8882 -r bf8517f4e4d0 agent/src/share/classes/sun/jvm/hotspot/runtime/Thread.java --- a/agent/src/share/classes/sun/jvm/hotspot/runtime/Thread.java Wed Feb 02 18:38:40 2011 -0500 +++ b/agent/src/share/classes/sun/jvm/hotspot/runtime/Thread.java Wed Feb 02 14:38:01 2011 -0500 @@ -1,5 +1,5 @@ /* - * Copyright (c) 2000, 2009, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 2000, 2011, 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 @@ -111,7 +111,7 @@ public boolean isJvmtiAgentThread() { return false; } public boolean isWatcherThread() { return false; } public boolean isConcurrentMarkSweepThread() { return false; } - public boolean isLowMemoryDetectorThread() { return false; } + public boolean isServiceThread() { return false; } /** Memory operations */ public void oopsDo(AddressVisitor oopVisitor) { diff -r face83fc8882 -r bf8517f4e4d0 agent/src/share/classes/sun/jvm/hotspot/runtime/Threads.java --- a/agent/src/share/classes/sun/jvm/hotspot/runtime/Threads.java Wed Feb 02 18:38:40 2011 -0500 +++ b/agent/src/share/classes/sun/jvm/hotspot/runtime/Threads.java Wed Feb 02 14:38:01 2011 -0500 @@ -1,5 +1,5 @@ /* - * Copyright (c) 2000, 2009, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 2000, 2011, 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 @@ -107,14 +107,14 @@ // for now, use JavaThread itself. fix it later with appropriate class if needed virtualConstructor.addMapping("SurrogateLockerThread", JavaThread.class); virtualConstructor.addMapping("JvmtiAgentThread", JvmtiAgentThread.class); - virtualConstructor.addMapping("LowMemoryDetectorThread", LowMemoryDetectorThread.class); + virtualConstructor.addMapping("ServiceThread", ServiceThread.class); } public Threads() { } /** NOTE: this returns objects of type JavaThread, CompilerThread, - JvmtiAgentThread, and LowMemoryDetectorThread. + JvmtiAgentThread, and ServiceThread. The latter four are subclasses of the former. Most operations (fetching the top frame, etc.) are only allowed to be performed on a "pure" JavaThread. For this reason, {@link @@ -143,7 +143,7 @@ return thread; } catch (Exception e) { throw new RuntimeException("Unable to deduce type of thread from address " + threadAddr + - " (expected type JavaThread, CompilerThread, LowMemoryDetectorThread, JvmtiAgentThread, or SurrogateLockerThread)", e); + " (expected type JavaThread, CompilerThread, ServiceThread, JvmtiAgentThread, or SurrogateLockerThread)", e); } } diff -r face83fc8882 -r bf8517f4e4d0 src/share/vm/code/nmethod.cpp --- a/src/share/vm/code/nmethod.cpp Wed Feb 02 18:38:40 2011 -0500 +++ b/src/share/vm/code/nmethod.cpp Wed Feb 02 14:38:01 2011 -0500 @@ -34,6 +34,7 @@ #include "interpreter/bytecode.hpp" #include "oops/methodDataOop.hpp" #include "prims/jvmtiRedefineClassesTrace.hpp" +#include "prims/jvmtiImpl.hpp" #include "runtime/sharedRuntime.hpp" #include "runtime/sweeper.hpp" #include "utilities/dtrace.hpp" @@ -1533,7 +1534,10 @@ } if (JvmtiExport::should_post_compiled_method_load()) { - JvmtiExport::post_compiled_method_load(this); + // Let the Service thread (which is a real Java thread) post the event + MutexLockerEx ml(Service_lock, Mutex::_no_safepoint_check_flag); + JvmtiDeferredEventQueue::enqueue( + JvmtiDeferredEvent::compiled_method_load_event(this)); } } @@ -1566,8 +1570,17 @@ // ref will have been cleared. if (_jmethod_id != NULL && JvmtiExport::should_post_compiled_method_unload()) { assert(!unload_reported(), "already unloaded"); - HandleMark hm; - JvmtiExport::post_compiled_method_unload(_jmethod_id, insts_begin()); + JvmtiDeferredEvent event = + JvmtiDeferredEvent::compiled_method_unload_event( + _jmethod_id, insts_begin()); + if (SafepointSynchronize::is_at_safepoint()) { + // Don't want to take the queueing lock. Add it as pending and + // it will get enqueued later. + JvmtiDeferredEventQueue::add_pending_event(event); + } else { + MutexLockerEx ml(Service_lock, Mutex::_no_safepoint_check_flag); + JvmtiDeferredEventQueue::enqueue(event); + } } // The JVMTI CompiledMethodUnload event can be enabled or disabled at diff -r face83fc8882 -r bf8517f4e4d0 src/share/vm/code/nmethod.hpp --- a/src/share/vm/code/nmethod.hpp Wed Feb 02 18:38:40 2011 -0500 +++ b/src/share/vm/code/nmethod.hpp Wed Feb 02 14:38:01 2011 -0500 @@ -1,5 +1,5 @@ /* - * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 1997, 2011, 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 @@ -696,10 +696,11 @@ class nmethodLocker : public StackObj { nmethod* _nm; + public: + static void lock_nmethod(nmethod* nm); // note: nm can be NULL static void unlock_nmethod(nmethod* nm); // (ditto) - public: nmethodLocker(address pc); // derive nm from pc nmethodLocker(nmethod *nm) { _nm = nm; lock_nmethod(_nm); } nmethodLocker() { _nm = NULL; } diff -r face83fc8882 -r bf8517f4e4d0 src/share/vm/prims/jvmtiExport.cpp --- a/src/share/vm/prims/jvmtiExport.cpp Wed Feb 02 18:38:40 2011 -0500 +++ b/src/share/vm/prims/jvmtiExport.cpp Wed Feb 02 14:38:01 2011 -0500 @@ -1,5 +1,5 @@ /* - * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 2003, 2011, 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 @@ -750,15 +750,12 @@ // pending CompiledMethodUnload support // -bool JvmtiExport::_have_pending_compiled_method_unload_events; -GrowableArray* JvmtiExport::_pending_compiled_method_unload_method_ids; -GrowableArray* JvmtiExport::_pending_compiled_method_unload_code_begins; -JavaThread* JvmtiExport::_current_poster; - -void JvmtiExport::post_compiled_method_unload_internal(JavaThread* self, jmethodID method, const void *code_begin) { +void JvmtiExport::post_compiled_method_unload( + jmethodID method, const void *code_begin) { + JavaThread* thread = JavaThread::current(); EVT_TRIG_TRACE(JVMTI_EVENT_COMPILED_METHOD_UNLOAD, ("JVMTI [%s] method compile unload event triggered", - JvmtiTrace::safe_get_thread_name(self))); + JvmtiTrace::safe_get_thread_name(thread))); // post the event for each environment that has this event enabled. JvmtiEnvIterator it; @@ -767,12 +764,12 @@ EVT_TRACE(JVMTI_EVENT_COMPILED_METHOD_UNLOAD, ("JVMTI [%s] class compile method unload event sent jmethodID " PTR_FORMAT, - JvmtiTrace::safe_get_thread_name(self), method)); + JvmtiTrace::safe_get_thread_name(thread), method)); - ResourceMark rm(self); + ResourceMark rm(thread); - JvmtiEventMark jem(self); - JvmtiJavaThreadEventTransition jet(self); + JvmtiEventMark jem(thread); + JvmtiJavaThreadEventTransition jet(thread); jvmtiEventCompiledMethodUnload callback = env->callbacks()->CompiledMethodUnload; if (callback != NULL) { (*callback)(env->jvmti_external(), method, code_begin); @@ -781,90 +778,6 @@ } } -// post any pending CompiledMethodUnload events - -void JvmtiExport::post_pending_compiled_method_unload_events() { - JavaThread* self = JavaThread::current(); - assert(!self->owns_locks(), "can't hold locks"); - - // Indicates if this is the first activiation of this function. - // In theory the profiler's callback could call back into VM and provoke - // another CompiledMethodLoad event to be posted from this thread. As the - // stack rewinds we need to ensure that the original activation does the - // completion and notifies any waiters. - bool first_activation = false; - - // the jmethodID (may not be valid) to be used for a single event - jmethodID method; - const void *code_begin; - - // grab the monitor and check if another thread is already posting - // events. If there is another thread posting events then we wait - // until it completes. (In theory we could check the pending events to - // see if any of the addresses overlap with the event that we want to - // post but as it will happen so rarely we just block any thread waiting - // to post a CompiledMethodLoad or DynamicCodeGenerated event until all - // pending CompiledMethodUnload events have been posted). - // - // If another thread isn't posting we examine the list of pending jmethodIDs. - // If the list is empty then we are done. If it's not empty then this thread - // (self) becomes the pending event poster and we remove the top (last) - // event from the list. Note that this means we remove the newest event first - // but as they are all CompiledMethodUnload events the order doesn't matter. - // Once we have removed a jmethodID then we exit the monitor. Any other thread - // wanting to post a CompiledMethodLoad or DynamicCodeGenerated event will - // be forced to wait on the monitor. - { - MutexLocker mu(JvmtiPendingEvent_lock); - if (_current_poster != self) { - while (_current_poster != NULL) { - JvmtiPendingEvent_lock->wait(); - } - } - if ((_pending_compiled_method_unload_method_ids == NULL) || - (_pending_compiled_method_unload_method_ids->length() == 0)) { - return; - } - if (_current_poster == NULL) { - _current_poster = self; - first_activation = true; - } else { - // re-entrant - guarantee(_current_poster == self, "checking"); - } - method = _pending_compiled_method_unload_method_ids->pop(); - code_begin = _pending_compiled_method_unload_code_begins->pop(); - } - - // This thread is the pending event poster so it first posts the CompiledMethodUnload - // event for the jmethodID that has been removed from the list. Once posted it - // re-grabs the monitor and checks the list again. If the list is empty then and this - // is the first activation of the function then we reset the _have_pending_events - // flag, cleanup _current_poster to indicate that no thread is now servicing the - // pending events list, and finally notify any thread that might be waiting. - for (;;) { - post_compiled_method_unload_internal(self, method, code_begin); - - // event posted, now re-grab monitor and get the next event - // If there's no next event then we are done. If this is the first - // activiation of this function by this thread notify any waiters - // so that they can post. - { - MutexLocker ml(JvmtiPendingEvent_lock); - if (_pending_compiled_method_unload_method_ids->length() == 0) { - if (first_activation) { - _have_pending_compiled_method_unload_events = false; - _current_poster = NULL; - JvmtiPendingEvent_lock->notify_all(); - } - return; - } - method = _pending_compiled_method_unload_method_ids->pop(); - code_begin = _pending_compiled_method_unload_code_begins->pop(); - } - } -} - /////////////////////////////////////////////////////////////// // // JvmtiExport @@ -1830,16 +1743,7 @@ } void JvmtiExport::post_compiled_method_load(nmethod *nm) { - // If there are pending CompiledMethodUnload events then these are - // posted before this CompiledMethodLoad event. We "lock" the nmethod and - // maintain a handle to the methodOop to ensure that the nmethod isn't - // flushed or unloaded while posting the events. JavaThread* thread = JavaThread::current(); - if (have_pending_compiled_method_unload_events()) { - methodHandle mh(thread, nm->method()); - nmethodLocker nml(nm); - post_pending_compiled_method_unload_events(); - } EVT_TRIG_TRACE(JVMTI_EVENT_COMPILED_METHOD_LOAD, ("JVMTI [%s] method compile load event triggered", @@ -1854,8 +1758,8 @@ JvmtiTrace::safe_get_thread_name(thread), (nm->method() == NULL) ? "NULL" : nm->method()->klass_name()->as_C_string(), (nm->method() == NULL) ? "NULL" : nm->method()->name()->as_C_string())); - ResourceMark rm(thread); + HandleMark hm(thread); // Add inlining information jvmtiCompiledMethodLoadInlineRecord* inlinerecord = create_inline_record(nm); @@ -1899,28 +1803,6 @@ } } -// used at a safepoint to post a CompiledMethodUnload event -void JvmtiExport::post_compiled_method_unload(jmethodID mid, const void *code_begin) { - if (SafepointSynchronize::is_at_safepoint()) { - // Class unloading can cause nmethod unloading which is reported - // by the VMThread. These must be batched to be processed later. - if (_pending_compiled_method_unload_method_ids == NULL) { - // create list lazily - _pending_compiled_method_unload_method_ids = new (ResourceObj::C_HEAP) GrowableArray(10,true); - _pending_compiled_method_unload_code_begins = new (ResourceObj::C_HEAP) GrowableArray(10,true); - } - _pending_compiled_method_unload_method_ids->append(mid); - _pending_compiled_method_unload_code_begins->append(code_begin); - _have_pending_compiled_method_unload_events = true; - } else { - // Unloading caused by the sweeper can be reported synchronously. - if (have_pending_compiled_method_unload_events()) { - post_pending_compiled_method_unload_events(); - } - post_compiled_method_unload_internal(JavaThread::current(), mid, code_begin); - } -} - void JvmtiExport::post_dynamic_code_generated_internal(const char *name, const void *code_begin, const void *code_end) { JavaThread* thread = JavaThread::current(); EVT_TRIG_TRACE(JVMTI_EVENT_DYNAMIC_CODE_GENERATED, @@ -1953,9 +1835,9 @@ return; } - if (have_pending_compiled_method_unload_events()) { - post_pending_compiled_method_unload_events(); - } + // Blocks until everything now in the queue has been posted + JvmtiDeferredEventQueue::flush_queue(Thread::current()); + post_dynamic_code_generated_internal(name, code_begin, code_end); } diff -r face83fc8882 -r bf8517f4e4d0 src/share/vm/prims/jvmtiExport.hpp --- a/src/share/vm/prims/jvmtiExport.hpp Wed Feb 02 18:38:40 2011 -0500 +++ b/src/share/vm/prims/jvmtiExport.hpp Wed Feb 02 14:38:01 2011 -0500 @@ -1,5 +1,5 @@ /* - * Copyright (c) 1998, 2010, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 1998, 2011, 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 @@ -141,25 +141,6 @@ private: - // CompiledMethodUnload events are reported from the VM thread so they - // are collected in lists (of jmethodID/addresses) and the events are posted later - // from threads posting CompieldMethodLoad or DynamicCodeGenerated events. - static bool _have_pending_compiled_method_unload_events; - static GrowableArray* _pending_compiled_method_unload_method_ids; - static GrowableArray* _pending_compiled_method_unload_code_begins; - static JavaThread* _current_poster; - - // tests if there are CompiledMethodUnload events pending - inline static bool have_pending_compiled_method_unload_events() { - return _have_pending_compiled_method_unload_events; - } - - // posts any pending CompiledMethodUnload events. - static void post_pending_compiled_method_unload_events(); - - // Perform the actual notification to interested JvmtiEnvs. - static void post_compiled_method_unload_internal(JavaThread* self, jmethodID mid, const void* code_begin); - // posts a DynamicCodeGenerated event (internal/private implementation). // The public post_dynamic_code_generated* functions make use of the // internal implementation. @@ -256,7 +237,7 @@ // single stepping management methods static void at_single_stepping_point(JavaThread *thread, methodOop method, address location) KERNEL_RETURN; static void expose_single_stepping(JavaThread *thread) KERNEL_RETURN; - static bool hide_single_stepping(JavaThread *thread) KERNEL_RETURN_(return false;); + static bool hide_single_stepping(JavaThread *thread) KERNEL_RETURN_(false); // Methods that notify the debugger that something interesting has happened in the VM. static void post_vm_start (); @@ -271,20 +252,20 @@ static oop jni_GetField_probe (JavaThread *thread, jobject jobj, oop obj, klassOop klass, jfieldID fieldID, bool is_static) - KERNEL_RETURN_(return NULL;); + KERNEL_RETURN_(NULL); static oop jni_GetField_probe_nh (JavaThread *thread, jobject jobj, oop obj, klassOop klass, jfieldID fieldID, bool is_static) - KERNEL_RETURN_(return NULL;); + KERNEL_RETURN_(NULL); static void post_field_access_by_jni (JavaThread *thread, oop obj, klassOop klass, jfieldID fieldID, bool is_static) KERNEL_RETURN; static void post_field_access (JavaThread *thread, methodOop method, address location, KlassHandle field_klass, Handle object, jfieldID field) KERNEL_RETURN; static oop jni_SetField_probe (JavaThread *thread, jobject jobj, oop obj, klassOop klass, jfieldID fieldID, bool is_static, char sig_type, - jvalue *value) KERNEL_RETURN_(return NULL;); + jvalue *value) KERNEL_RETURN_(NULL); static oop jni_SetField_probe_nh (JavaThread *thread, jobject jobj, oop obj, klassOop klass, jfieldID fieldID, bool is_static, char sig_type, - jvalue *value) KERNEL_RETURN_(return NULL;); + jvalue *value) KERNEL_RETURN_(NULL); static void post_field_modification_by_jni(JavaThread *thread, oop obj, klassOop klass, jfieldID fieldID, bool is_static, char sig_type, jvalue *value); diff -r face83fc8882 -r bf8517f4e4d0 src/share/vm/prims/jvmtiImpl.cpp --- a/src/share/vm/prims/jvmtiImpl.cpp Wed Feb 02 18:38:40 2011 -0500 +++ b/src/share/vm/prims/jvmtiImpl.cpp Wed Feb 02 14:38:01 2011 -0500 @@ -1,5 +1,5 @@ /* - * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 2003, 2011, 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 @@ -32,11 +32,13 @@ #include "prims/jvmtiEventController.inline.hpp" #include "prims/jvmtiImpl.hpp" #include "prims/jvmtiRedefineClasses.hpp" +#include "runtime/atomic.hpp" #include "runtime/deoptimization.hpp" #include "runtime/handles.hpp" #include "runtime/handles.inline.hpp" #include "runtime/interfaceSupport.hpp" #include "runtime/javaCalls.hpp" +#include "runtime/serviceThread.hpp" #include "runtime/signature.hpp" #include "runtime/vframe.hpp" #include "runtime/vframe_hp.hpp" @@ -910,3 +912,207 @@ tty->print_cr("]"); #endif } + +#ifndef KERNEL + +JvmtiDeferredEvent JvmtiDeferredEvent::compiled_method_load_event( + nmethod* nm) { + JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_COMPILED_METHOD_LOAD); + event.set_compiled_method_load(nm); + nmethodLocker::lock_nmethod(nm); // will be unlocked when posted + return event; +} + +JvmtiDeferredEvent JvmtiDeferredEvent::compiled_method_unload_event( + jmethodID id, const void* code) { + JvmtiDeferredEvent event = JvmtiDeferredEvent(TYPE_COMPILED_METHOD_UNLOAD); + event.set_compiled_method_unload(id, code); + return event; +} + +void JvmtiDeferredEvent::post() { + switch(_type) { + case TYPE_COMPILED_METHOD_LOAD: + JvmtiExport::post_compiled_method_load(compiled_method_load()); + nmethodLocker::unlock_nmethod(compiled_method_load()); + break; + case TYPE_COMPILED_METHOD_UNLOAD: + JvmtiExport::post_compiled_method_unload( + compiled_method_unload_method_id(), + compiled_method_unload_code_begin()); + break; + case TYPE_FLUSH: + JvmtiDeferredEventQueue::flush_complete(flush_state_addr()); + break; + default: + ShouldNotReachHere(); + } +} + +JvmtiDeferredEventQueue::QueueNode* JvmtiDeferredEventQueue::_queue_tail = NULL; +JvmtiDeferredEventQueue::QueueNode* JvmtiDeferredEventQueue::_queue_head = NULL; + +volatile JvmtiDeferredEventQueue::QueueNode* + JvmtiDeferredEventQueue::_pending_list = NULL; + +bool JvmtiDeferredEventQueue::has_events() { + assert(Service_lock->owned_by_self(), "Must own Service_lock"); + return _queue_head != NULL || _pending_list != NULL; +} + +void JvmtiDeferredEventQueue::enqueue(const JvmtiDeferredEvent& event) { + assert(Service_lock->owned_by_self(), "Must own Service_lock"); + + process_pending_events(); + + // Events get added to the end of the queue (and are pulled off the front). + QueueNode* node = new QueueNode(event); + if (_queue_tail == NULL) { + _queue_tail = _queue_head = node; + } else { + assert(_queue_tail->next() == NULL, "Must be the last element in the list"); + _queue_tail->set_next(node); + _queue_tail = node; + } + + Service_lock->notify_all(); + assert((_queue_head == NULL) == (_queue_tail == NULL), + "Inconsistent queue markers"); +} + +JvmtiDeferredEvent JvmtiDeferredEventQueue::dequeue() { + assert(Service_lock->owned_by_self(), "Must own Service_lock"); + + process_pending_events(); + + assert(_queue_head != NULL, "Nothing to dequeue"); + + if (_queue_head == NULL) { + // Just in case this happens in product; it shouldn't but let's not crash + return JvmtiDeferredEvent(); + } + + QueueNode* node = _queue_head; + _queue_head = _queue_head->next(); + if (_queue_head == NULL) { + _queue_tail = NULL; + } + + assert((_queue_head == NULL) == (_queue_tail == NULL), + "Inconsistent queue markers"); + + JvmtiDeferredEvent event = node->event(); + delete node; + return event; +} + +void JvmtiDeferredEventQueue::add_pending_event( + const JvmtiDeferredEvent& event) { + + QueueNode* node = new QueueNode(event); + + bool success = false; + QueueNode* prev_value = (QueueNode*)_pending_list; + do { + node->set_next(prev_value); + prev_value = (QueueNode*)Atomic::cmpxchg_ptr( + (void*)node, (volatile void*)&_pending_list, (void*)node->next()); + } while (prev_value != node->next()); +} + +// This method transfers any events that were added by someone NOT holding +// the lock into the mainline queue. +void JvmtiDeferredEventQueue::process_pending_events() { + assert(Service_lock->owned_by_self(), "Must own Service_lock"); + + if (_pending_list != NULL) { + QueueNode* head = + (QueueNode*)Atomic::xchg_ptr(NULL, (volatile void*)&_pending_list); + + assert((_queue_head == NULL) == (_queue_tail == NULL), + "Inconsistent queue markers"); + + if (head != NULL) { + // Since we've treated the pending list as a stack (with newer + // events at the beginning), we need to join the bottom of the stack + // with the 'tail' of the queue in order to get the events in the + // right order. We do this by reversing the pending list and appending + // it to the queue. + + QueueNode* new_tail = head; + QueueNode* new_head = NULL; + + // This reverses the list + QueueNode* prev = new_tail; + QueueNode* node = new_tail->next(); + new_tail->set_next(NULL); + while (node != NULL) { + QueueNode* next = node->next(); + node->set_next(prev); + prev = node; + node = next; + } + new_head = prev; + + // Now append the new list to the queue + if (_queue_tail != NULL) { + _queue_tail->set_next(new_head); + } else { // _queue_head == NULL + _queue_head = new_head; + } + _queue_tail = new_tail; + } + } +} + +enum { + // Random - used for debugging + FLUSHING = 0x50403020, + FLUSHED = 0x09080706 +}; + +void JvmtiDeferredEventQueue::flush_queue(Thread* thread) { + + volatile int flush_state = FLUSHING; + + JvmtiDeferredEvent flush(JvmtiDeferredEvent::TYPE_FLUSH); + flush.set_flush_state_addr((int*)&flush_state); + + if (ServiceThread::is_service_thread(thread)) { + // If we are the service thread we have to post all preceding events + // Use the flush event as a token to indicate when we can stop + JvmtiDeferredEvent event; + { + MutexLockerEx ml(Service_lock, Mutex::_no_safepoint_check_flag); + enqueue(flush); + event = dequeue(); + } + while (!event.is_flush_event() || + event.flush_state_addr() != &flush_state) { + event.post(); + { + MutexLockerEx ml(Service_lock, Mutex::_no_safepoint_check_flag); + event = dequeue(); + } + } + } else { + // Wake up the service thread so it will process events. When it gets + // to the flush event it will set 'flush_complete' and notify us. + MutexLockerEx ml(Service_lock, Mutex::_no_safepoint_check_flag); + enqueue(flush); + while (flush_state != FLUSHED) { + assert(flush_state == FLUSHING || flush_state == FLUSHED, + "only valid values for this"); + Service_lock->wait(Mutex::_no_safepoint_check_flag); + } + } +} + +void JvmtiDeferredEventQueue::flush_complete(int* state_addr) { + assert(state_addr != NULL && *state_addr == FLUSHING, "must be"); + MutexLockerEx ml(Service_lock, Mutex::_no_safepoint_check_flag); + *state_addr = FLUSHED; + Service_lock->notify_all(); +} + +#endif // ndef KERNEL diff -r face83fc8882 -r bf8517f4e4d0 src/share/vm/prims/jvmtiImpl.hpp --- a/src/share/vm/prims/jvmtiImpl.hpp Wed Feb 02 18:38:40 2011 -0500 +++ b/src/share/vm/prims/jvmtiImpl.hpp Wed Feb 02 14:38:01 2011 -0500 @@ -1,5 +1,5 @@ /* - * Copyright (c) 1999, 2010, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 1999, 2011, 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 @@ -433,6 +433,149 @@ #endif // !JVMTI_KERNEL +/** + * When a thread (such as the compiler thread or VM thread) cannot post a + * JVMTI event itself because the event needs to be posted from a Java + * thread, then it can defer the event to the Service thread for posting. + * The information needed to post the event is encapsulated into this class + * and then enqueued onto the JvmtiDeferredEventQueue, where the Service + * thread will pick it up and post it. + * + * This is currently only used for posting compiled-method-load and unload + * events, which we don't want posted from the compiler thread. + */ +class JvmtiDeferredEvent VALUE_OBJ_CLASS_SPEC { + friend class JvmtiDeferredEventQueue; + private: + typedef enum { + TYPE_NONE, + TYPE_COMPILED_METHOD_LOAD, + TYPE_COMPILED_METHOD_UNLOAD, + TYPE_FLUSH // pseudo-event used to implement flush_queue() + } Type; + + Type _type; + union { + nmethod* compiled_method_load; + struct { + jmethodID method_id; + const void* code_begin; + } compiled_method_unload; + int* flush_state_addr; + } _event_data; + + JvmtiDeferredEvent(Type t) : _type(t) {} + + void set_compiled_method_load(nmethod* nm) { + assert(_type == TYPE_COMPILED_METHOD_LOAD, "must be"); + _event_data.compiled_method_load = nm; + } + + nmethod* compiled_method_load() const { + assert(_type == TYPE_COMPILED_METHOD_LOAD, "must be"); + return _event_data.compiled_method_load; + } + + void set_compiled_method_unload(jmethodID id, const void* code) { + assert(_type == TYPE_COMPILED_METHOD_UNLOAD, "must be"); + _event_data.compiled_method_unload.method_id = id; + _event_data.compiled_method_unload.code_begin = code; + } + + jmethodID compiled_method_unload_method_id() const { + assert(_type == TYPE_COMPILED_METHOD_UNLOAD, "must be"); + return _event_data.compiled_method_unload.method_id; + } + + const void* compiled_method_unload_code_begin() const { + assert(_type == TYPE_COMPILED_METHOD_UNLOAD, "must be"); + return _event_data.compiled_method_unload.code_begin; + } + + bool is_flush_event() const { return _type == TYPE_FLUSH; } + + int* flush_state_addr() const { + assert(is_flush_event(), "must be"); + return _event_data.flush_state_addr; + } + + void set_flush_state_addr(int* flag) { + assert(is_flush_event(), "must be"); + _event_data.flush_state_addr = flag; + } + + public: + + JvmtiDeferredEvent() : _type(TYPE_NONE) {} + + // Factory methods + static JvmtiDeferredEvent compiled_method_load_event(nmethod* nm) + KERNEL_RETURN_(JvmtiDeferredEvent()); + static JvmtiDeferredEvent compiled_method_unload_event( + jmethodID id, const void* code) KERNEL_RETURN_(JvmtiDeferredEvent()); + + // Actually posts the event. + void post() KERNEL_RETURN; +}; + +/** + * Events enqueued on this queue wake up the Service thread which dequeues + * and posts the events. The Service_lock is required to be held + * when operating on the queue (except for the "pending" events). + */ +class JvmtiDeferredEventQueue : AllStatic { + friend class JvmtiDeferredEvent; + private: + class QueueNode : public CHeapObj { + private: + JvmtiDeferredEvent _event; + QueueNode* _next; + + public: + QueueNode(const JvmtiDeferredEvent& event) + : _event(event), _next(NULL) {} + + const JvmtiDeferredEvent& event() const { return _event; } + QueueNode* next() const { return _next; } + + void set_next(QueueNode* next) { _next = next; } + }; + + static QueueNode* _queue_head; // Hold Service_lock to access + static QueueNode* _queue_tail; // Hold Service_lock to access + static volatile QueueNode* _pending_list; // Uses CAS for read/update + + // Transfers events from the _pending_list to the _queue. + static void process_pending_events() KERNEL_RETURN; + + static void flush_complete(int* flush_state) KERNEL_RETURN; + + public: + // Must be holding Service_lock when calling these + static bool has_events() KERNEL_RETURN_(false); + static void enqueue(const JvmtiDeferredEvent& event) KERNEL_RETURN; + static JvmtiDeferredEvent dequeue() KERNEL_RETURN_(JvmtiDeferredEvent()); + + // This call blocks until all events enqueued prior to this call + // have been posted. The Service_lock is acquired and waited upon. + // + // Implemented by creating a "flush" event and placing it in the queue. + // When the flush event is "posted" it will call flush_complete(), which + // will release the caller. + // + // Can be called by any thread (maybe even the service thread itself). + // Not necessary for the caller to be a JavaThread. + static void flush_queue(Thread* current) KERNEL_RETURN; + + // Used to enqueue events without using a lock, for times (such as during + // safepoint) when we can't or don't want to lock the Service_lock. + // + // Events will be held off to the side until there's a call to + // dequeue(), enqueue(), or process_pending_events() (all of which require + // the holding of the Service_lock), and will be enqueued at that time. + static void add_pending_event(const JvmtiDeferredEvent&) KERNEL_RETURN; +}; + // Utility macro that checks for NULL pointers: #define NULL_CHECK(X, Y) if ((X) == NULL) { return (Y); } diff -r face83fc8882 -r bf8517f4e4d0 src/share/vm/runtime/fprofiler.hpp --- a/src/share/vm/runtime/fprofiler.hpp Wed Feb 02 18:38:40 2011 -0500 +++ b/src/share/vm/runtime/fprofiler.hpp Wed Feb 02 14:38:01 2011 -0500 @@ -231,13 +231,13 @@ static void engage(JavaThread* mainThread, bool fullProfile) KERNEL_RETURN ; static void disengage() KERNEL_RETURN ; static void print(int unused) KERNEL_RETURN ; - static bool is_active() KERNEL_RETURN_(return false;) ; + static bool is_active() KERNEL_RETURN_(false) ; // This is NULL if each thread has its own thread profiler, // else this is the single thread profiler used by all threads. // In particular it makes a difference during garbage collection, // where you only want to traverse each thread profiler once. - static ThreadProfiler* get_thread_profiler() KERNEL_RETURN_(return NULL;); + static ThreadProfiler* get_thread_profiler() KERNEL_RETURN_(NULL); // Garbage Collection Support static void oops_do(OopClosure* f) KERNEL_RETURN ; @@ -246,13 +246,13 @@ // Returns the start address for a given pc // NULL is returned if the PCRecorder is inactive - static address bucket_start_for(address pc) KERNEL_RETURN_(return NULL;); + static address bucket_start_for(address pc) KERNEL_RETURN_(NULL); enum { MillisecsPerTick = 10 }; // ms per profiling ticks // Returns the number of ticks recorded for the bucket // pc belongs to. - static int bucket_count_for(address pc) KERNEL_RETURN_(return 0;); + static int bucket_count_for(address pc) KERNEL_RETURN_(0); #ifndef FPROF_KERNEL diff -r face83fc8882 -r bf8517f4e4d0 src/share/vm/runtime/mutexLocker.cpp --- a/src/share/vm/runtime/mutexLocker.cpp Wed Feb 02 18:38:40 2011 -0500 +++ b/src/share/vm/runtime/mutexLocker.cpp Wed Feb 02 14:38:01 2011 -0500 @@ -129,7 +129,7 @@ Monitor* GCTaskManager_lock = NULL; Mutex* Management_lock = NULL; -Monitor* LowMemory_lock = NULL; +Monitor* Service_lock = NULL; #define MAX_NUM_MUTEX 128 static Monitor * _mutex_array[MAX_NUM_MUTEX]; @@ -203,7 +203,7 @@ def(Patching_lock , Mutex , special, true ); // used for safepointing and code patching. def(ObjAllocPost_lock , Monitor, special, false); - def(LowMemory_lock , Monitor, special, true ); // used for low memory detection + def(Service_lock , Monitor, special, true ); // used for service thread operations def(JmethodIdCreation_lock , Mutex , leaf, true ); // used for creating jmethodIDs. def(SystemDictionary_lock , Monitor, leaf, true ); // lookups done by VM thread diff -r face83fc8882 -r bf8517f4e4d0 src/share/vm/runtime/mutexLocker.hpp --- a/src/share/vm/runtime/mutexLocker.hpp Wed Feb 02 18:38:40 2011 -0500 +++ b/src/share/vm/runtime/mutexLocker.hpp Wed Feb 02 14:38:01 2011 -0500 @@ -131,7 +131,7 @@ extern Mutex* HotCardCache_lock; // protects the hot card cache extern Mutex* Management_lock; // a lock used to serialize JVM management -extern Monitor* LowMemory_lock; // a lock used for low memory detection +extern Monitor* Service_lock; // a lock used for service thread operation // A MutexLocker provides mutual exclusion with respect to a given mutex // for the scope which contains the locker. The lock is an OS lock, not diff -r face83fc8882 -r bf8517f4e4d0 src/share/vm/runtime/serviceThread.cpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/share/vm/runtime/serviceThread.cpp Wed Feb 02 14:38:01 2011 -0500 @@ -0,0 +1,122 @@ +/* + * Copyright (c) 2011, 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. + * + */ + +#include "precompiled.hpp" +#include "runtime/interfaceSupport.hpp" +#include "runtime/javaCalls.hpp" +#include "runtime/serviceThread.hpp" +#include "runtime/mutexLocker.hpp" +#include "prims/jvmtiImpl.hpp" + +ServiceThread* ServiceThread::_instance = NULL; + +void ServiceThread::initialize() { + EXCEPTION_MARK; + + instanceKlassHandle klass (THREAD, SystemDictionary::Thread_klass()); + instanceHandle thread_oop = klass->allocate_instance_handle(CHECK); + + const char* name = JDK_Version::is_gte_jdk17x_version() ? + "Service Thread" : "Low Memory Detector"; + + Handle string = java_lang_String::create_from_str(name, CHECK); + + // Initialize thread_oop to put it into the system threadGroup + Handle thread_group (THREAD, Universe::system_thread_group()); + JavaValue result(T_VOID); + JavaCalls::call_special(&result, thread_oop, + klass, + vmSymbols::object_initializer_name(), + vmSymbols::threadgroup_string_void_signature(), + thread_group, + string, + CHECK); + + { + MutexLocker mu(Threads_lock); + ServiceThread* thread = new ServiceThread(&service_thread_entry); + + // At this point it may be possible that no osthread was created for the + // JavaThread due to lack of memory. We would have to throw an exception + // in that case. However, since this must work and we do not allow + // exceptions anyway, check and abort if this fails. + if (thread == NULL || thread->osthread() == NULL) { + vm_exit_during_initialization("java.lang.OutOfMemoryError", + "unable to create new native thread"); + } + + java_lang_Thread::set_thread(thread_oop(), thread); + java_lang_Thread::set_priority(thread_oop(), NearMaxPriority); + java_lang_Thread::set_daemon(thread_oop()); + thread->set_threadObj(thread_oop()); + + Threads::add(thread); + Thread::start(thread); + + _instance = thread; + } +} + +void ServiceThread::service_thread_entry(JavaThread* jt, TRAPS) { + while (true) { + bool sensors_changed = false; + bool has_jvmti_events = false; + JvmtiDeferredEvent jvmti_event; + { + // Need state transition ThreadBlockInVM so that this thread + // will be handled by safepoint correctly when this thread is + // notified at a safepoint. + + // This ThreadBlockInVM object is not also considered to be + // suspend-equivalent because ServiceThread is not visible to + // external suspension. + + ThreadBlockInVM tbivm(jt); + + MutexLockerEx ml(Service_lock, Mutex::_no_safepoint_check_flag); + while (!(sensors_changed = LowMemoryDetector::has_pending_requests()) && + !(has_jvmti_events = JvmtiDeferredEventQueue::has_events())) { + // wait until one of the sensors has pending requests, or there is a + // pending JVMTI event to post + Service_lock->wait(Mutex::_no_safepoint_check_flag); + } + + if (has_jvmti_events) { + jvmti_event = JvmtiDeferredEventQueue::dequeue(); + } + } + + if (has_jvmti_events) { + jvmti_event.post(); + } + + if (sensors_changed) { + LowMemoryDetector::process_sensor_changes(jt); + } + } +} + +bool ServiceThread::is_service_thread(Thread* thread) { + return thread == _instance; +} diff -r face83fc8882 -r bf8517f4e4d0 src/share/vm/runtime/serviceThread.hpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/share/vm/runtime/serviceThread.hpp Wed Feb 02 14:38:01 2011 -0500 @@ -0,0 +1,51 @@ +/* + * Copyright (c) 2011, 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_SERVICETHREAD_HPP +#define SHARE_VM_RUNTIME_SERVICETHREAD_HPP + +#include "runtime/thread.hpp" + +// A JavaThread for low memory detection support and JVMTI +// compiled-method-load events. +class ServiceThread : public JavaThread { + friend class VMStructs; + private: + + static ServiceThread* _instance; + + static void service_thread_entry(JavaThread* thread, TRAPS); + ServiceThread(ThreadFunction entry_point) : JavaThread(entry_point) {}; + + public: + static void initialize(); + + // Hide this thread from external view. + bool is_hidden_from_external_view() const { return true; } + + // Returns true if the passed thread is the service thread. + static bool is_service_thread(Thread* thread); +}; + +#endif // SHARE_VM_RUNTIME_SERVICETHREAD_HPP diff -r face83fc8882 -r bf8517f4e4d0 src/share/vm/runtime/thread.hpp --- a/src/share/vm/runtime/thread.hpp Wed Feb 02 18:38:40 2011 -0500 +++ b/src/share/vm/runtime/thread.hpp Wed Feb 02 14:38:01 2011 -0500 @@ -1680,16 +1680,6 @@ 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; diff -r face83fc8882 -r bf8517f4e4d0 src/share/vm/runtime/vmStructs.cpp --- a/src/share/vm/runtime/vmStructs.cpp Wed Feb 02 18:38:40 2011 -0500 +++ b/src/share/vm/runtime/vmStructs.cpp Wed Feb 02 14:38:01 2011 -0500 @@ -93,6 +93,7 @@ #include "runtime/java.hpp" #include "runtime/javaCalls.hpp" #include "runtime/perfMemory.hpp" +#include "runtime/serviceThread.hpp" #include "runtime/sharedRuntime.hpp" #include "runtime/stubRoutines.hpp" #include "runtime/virtualspace.hpp" @@ -1250,7 +1251,7 @@ declare_type(WatcherThread, Thread) \ declare_type(JavaThread, Thread) \ declare_type(JvmtiAgentThread, JavaThread) \ - declare_type(LowMemoryDetectorThread, JavaThread) \ + declare_type(ServiceThread, JavaThread) \ declare_type(CompilerThread, JavaThread) \ declare_toplevel_type(OSThread) \ declare_toplevel_type(JavaFrameAnchor) \ diff -r face83fc8882 -r bf8517f4e4d0 src/share/vm/services/attachListener.hpp --- a/src/share/vm/services/attachListener.hpp Wed Feb 02 18:38:40 2011 -0500 +++ b/src/share/vm/services/attachListener.hpp Wed Feb 02 14:38:01 2011 -0500 @@ -59,10 +59,10 @@ static void detachall() KERNEL_RETURN; // indicates if the Attach Listener needs to be created at startup - static bool init_at_startup() KERNEL_RETURN_(return false;); + static bool init_at_startup() KERNEL_RETURN_(false); // indicates if we have a trigger to start the Attach Listener - static bool is_init_trigger() KERNEL_RETURN_(return false;); + static bool is_init_trigger() KERNEL_RETURN_(false); #ifdef SERVICES_KERNEL static bool is_attach_supported() { return false; } diff -r face83fc8882 -r bf8517f4e4d0 src/share/vm/services/lowMemoryDetector.cpp --- a/src/share/vm/services/lowMemoryDetector.cpp Wed Feb 02 18:38:40 2011 -0500 +++ b/src/share/vm/services/lowMemoryDetector.cpp Wed Feb 02 14:38:01 2011 -0500 @@ -1,5 +1,5 @@ /* - * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 2003, 2011, 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 @@ -34,55 +34,11 @@ #include "services/lowMemoryDetector.hpp" #include "services/management.hpp" -LowMemoryDetectorThread* LowMemoryDetector::_detector_thread = NULL; volatile bool LowMemoryDetector::_enabled_for_collected_pools = false; volatile jint LowMemoryDetector::_disabled_count = 0; -void LowMemoryDetector::initialize() { - EXCEPTION_MARK; - - instanceKlassHandle klass (THREAD, SystemDictionary::Thread_klass()); - instanceHandle thread_oop = klass->allocate_instance_handle(CHECK); - - const char thread_name[] = "Low Memory Detector"; - Handle string = java_lang_String::create_from_str(thread_name, CHECK); - - // Initialize thread_oop to put it into the system threadGroup - Handle thread_group (THREAD, Universe::system_thread_group()); - JavaValue result(T_VOID); - JavaCalls::call_special(&result, thread_oop, - klass, - vmSymbols::object_initializer_name(), - vmSymbols::threadgroup_string_void_signature(), - thread_group, - string, - CHECK); - - { - MutexLocker mu(Threads_lock); - _detector_thread = new LowMemoryDetectorThread(&low_memory_detector_thread_entry); - - // At this point it may be possible that no osthread was created for the - // JavaThread due to lack of memory. We would have to throw an exception - // in that case. However, since this must work and we do not allow - // exceptions anyway, check and abort if this fails. - if (_detector_thread == NULL || _detector_thread->osthread() == NULL) { - vm_exit_during_initialization("java.lang.OutOfMemoryError", - "unable to create new native thread"); - } - - java_lang_Thread::set_thread(thread_oop(), _detector_thread); - java_lang_Thread::set_priority(thread_oop(), NearMaxPriority); - java_lang_Thread::set_daemon(thread_oop()); - _detector_thread->set_threadObj(thread_oop()); - - Threads::add(_detector_thread); - Thread::start(_detector_thread); - } -} - bool LowMemoryDetector::has_pending_requests() { - assert(LowMemory_lock->owned_by_self(), "Must own LowMemory_lock"); + assert(Service_lock->owned_by_self(), "Must own Service_lock"); bool has_requests = false; int num_memory_pools = MemoryService::num_memory_pools(); for (int i = 0; i < num_memory_pools; i++) { @@ -100,47 +56,21 @@ return has_requests; } -void LowMemoryDetector::low_memory_detector_thread_entry(JavaThread* jt, TRAPS) { - while (true) { - bool sensors_changed = false; - - { - // _no_safepoint_check_flag is used here as LowMemory_lock is a - // special lock and the VMThread may acquire this lock at safepoint. - // Need state transition ThreadBlockInVM so that this thread - // will be handled by safepoint correctly when this thread is - // notified at a safepoint. - - // This ThreadBlockInVM object is not also considered to be - // suspend-equivalent because LowMemoryDetector threads are - // not visible to external suspension. - - ThreadBlockInVM tbivm(jt); +void LowMemoryDetector::process_sensor_changes(TRAPS) { + ResourceMark rm(THREAD); + HandleMark hm(THREAD); - MutexLockerEx ml(LowMemory_lock, Mutex::_no_safepoint_check_flag); - while (!(sensors_changed = has_pending_requests())) { - // wait until one of the sensors has pending requests - LowMemory_lock->wait(Mutex::_no_safepoint_check_flag); - } + // No need to hold Service_lock to call out to Java + int num_memory_pools = MemoryService::num_memory_pools(); + for (int i = 0; i < num_memory_pools; i++) { + MemoryPool* pool = MemoryService::get_memory_pool(i); + SensorInfo* sensor = pool->usage_sensor(); + SensorInfo* gc_sensor = pool->gc_usage_sensor(); + if (sensor != NULL && sensor->has_pending_requests()) { + sensor->process_pending_requests(CHECK); } - - { - ResourceMark rm(THREAD); - HandleMark hm(THREAD); - - // No need to hold LowMemory_lock to call out to Java - int num_memory_pools = MemoryService::num_memory_pools(); - for (int i = 0; i < num_memory_pools; i++) { - MemoryPool* pool = MemoryService::get_memory_pool(i); - SensorInfo* sensor = pool->usage_sensor(); - SensorInfo* gc_sensor = pool->gc_usage_sensor(); - if (sensor != NULL && sensor->has_pending_requests()) { - sensor->process_pending_requests(CHECK); - } - if (gc_sensor != NULL && gc_sensor->has_pending_requests()) { - gc_sensor->process_pending_requests(CHECK); - } - } + if (gc_sensor != NULL && gc_sensor->has_pending_requests()) { + gc_sensor->process_pending_requests(CHECK); } } } @@ -148,7 +78,7 @@ // This method could be called from any Java threads // and also VMThread. void LowMemoryDetector::detect_low_memory() { - MutexLockerEx ml(LowMemory_lock, Mutex::_no_safepoint_check_flag); + MutexLockerEx ml(Service_lock, Mutex::_no_safepoint_check_flag); bool has_pending_requests = false; int num_memory_pools = MemoryService::num_memory_pools(); @@ -166,7 +96,7 @@ } if (has_pending_requests) { - LowMemory_lock->notify_all(); + Service_lock->notify_all(); } } @@ -181,14 +111,14 @@ } { - MutexLockerEx ml(LowMemory_lock, Mutex::_no_safepoint_check_flag); + MutexLockerEx ml(Service_lock, Mutex::_no_safepoint_check_flag); MemoryUsage usage = pool->get_memory_usage(); sensor->set_gauge_sensor_level(usage, pool->usage_threshold()); if (sensor->has_pending_requests()) { // notify sensor state update - LowMemory_lock->notify_all(); + Service_lock->notify_all(); } } } @@ -203,14 +133,14 @@ } { - MutexLockerEx ml(LowMemory_lock, Mutex::_no_safepoint_check_flag); + MutexLockerEx ml(Service_lock, Mutex::_no_safepoint_check_flag); MemoryUsage usage = pool->get_last_collection_usage(); sensor->set_counter_sensor_level(usage, pool->gc_usage_threshold()); if (sensor->has_pending_requests()) { // notify sensor state update - LowMemory_lock->notify_all(); + Service_lock->notify_all(); } } } @@ -384,8 +314,8 @@ } { - // Holds LowMemory_lock and update the sensor state - MutexLockerEx ml(LowMemory_lock, Mutex::_no_safepoint_check_flag); + // Holds Service_lock and update the sensor state + MutexLockerEx ml(Service_lock, Mutex::_no_safepoint_check_flag); _sensor_on = true; _sensor_count += count; _pending_trigger_count = _pending_trigger_count - count; @@ -410,8 +340,8 @@ } { - // Holds LowMemory_lock and update the sensor state - MutexLockerEx ml(LowMemory_lock, Mutex::_no_safepoint_check_flag); + // Holds Service_lock and update the sensor state + MutexLockerEx ml(Service_lock, Mutex::_no_safepoint_check_flag); _sensor_on = false; _pending_clear_count = 0; _pending_trigger_count = _pending_trigger_count - count; diff -r face83fc8882 -r bf8517f4e4d0 src/share/vm/services/lowMemoryDetector.hpp --- a/src/share/vm/services/lowMemoryDetector.hpp Wed Feb 02 18:38:40 2011 -0500 +++ b/src/share/vm/services/lowMemoryDetector.hpp Wed Feb 02 14:38:01 2011 -0500 @@ -1,5 +1,5 @@ /* - * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 2003, 2011, 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 @@ -58,8 +58,8 @@ // // May need to deal with hysteresis effect. // +// Memory detection code runs in the Service thread (serviceThread.hpp). -class LowMemoryDetectorThread; class OopClosure; class MemoryPool; @@ -211,23 +211,22 @@ }; class LowMemoryDetector : public AllStatic { -friend class LowMemoryDetectorDisabler; + friend class LowMemoryDetectorDisabler; + friend class ServiceThread; private: // true if any collected heap has low memory detection enabled static volatile bool _enabled_for_collected_pools; // > 0 if temporary disabed static volatile jint _disabled_count; - static LowMemoryDetectorThread* _detector_thread; - static void low_memory_detector_thread_entry(JavaThread* thread, TRAPS); static void check_memory_usage(); static bool has_pending_requests(); static bool temporary_disabled() { return _disabled_count > 0; } static void disable() { Atomic::inc(&_disabled_count); } static void enable() { Atomic::dec(&_disabled_count); } + static void process_sensor_changes(TRAPS); public: - static void initialize(); static void detect_low_memory(); static void detect_low_memory(MemoryPool* pool); static void detect_after_gc_memory(MemoryPool* pool); @@ -275,7 +274,6 @@ } } } - }; class LowMemoryDetectorDisabler: public StackObj { diff -r face83fc8882 -r bf8517f4e4d0 src/share/vm/services/management.cpp --- a/src/share/vm/services/management.cpp Wed Feb 02 18:38:40 2011 -0500 +++ b/src/share/vm/services/management.cpp Wed Feb 02 14:38:01 2011 -0500 @@ -38,6 +38,7 @@ #include "runtime/javaCalls.hpp" #include "runtime/jniHandles.hpp" #include "runtime/os.hpp" +#include "runtime/serviceThread.hpp" #include "services/classLoadingService.hpp" #include "services/heapDumper.hpp" #include "services/lowMemoryDetector.hpp" @@ -112,8 +113,8 @@ } void Management::initialize(TRAPS) { - // Start the low memory detector thread - LowMemoryDetector::initialize(); + // Start the service thread + ServiceThread::initialize(); if (ManagementServer) { ResourceMark rm(THREAD); diff -r face83fc8882 -r bf8517f4e4d0 src/share/vm/utilities/macros.hpp --- a/src/share/vm/utilities/macros.hpp Wed Feb 02 18:38:40 2011 -0500 +++ b/src/share/vm/utilities/macros.hpp Wed Feb 02 14:38:01 2011 -0500 @@ -46,7 +46,7 @@ #define SERVICES_KERNEL #define KERNEL_RETURN {} -#define KERNEL_RETURN_(code) { code } +#define KERNEL_RETURN_(code) { return code; } #else // KERNEL