Mercurial > hg > graal-compiler
view src/share/vm/services/lowMemoryDetector.cpp @ 900:9987d9d5eb0e
6833129: specjvm98 fails with NullPointerException in the compiler with -XX:DeoptimizeALot
Summary: developed a reexecute logic for the interpreter to reexecute the bytecode when deopt happens
Reviewed-by: kvn, never, jrose, twisti
author | cfang |
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date | Fri, 31 Jul 2009 17:12:33 -0700 |
parents | a61af66fc99e |
children | 4ce7240d622c |
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/* * Copyright 2003-2007 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. * */ # include "incls/_precompiled.incl" # include "incls/_lowMemoryDetector.cpp.incl" 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, vmSymbolHandles::object_initializer_name(), vmSymbolHandles::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"); bool has_requests = false; 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(); if (sensor != NULL) { has_requests = has_requests || sensor->has_pending_requests(); } SensorInfo* gc_sensor = pool->gc_usage_sensor(); if (gc_sensor != NULL) { has_requests = has_requests || gc_sensor->has_pending_requests(); } } 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); 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); } } { 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); } } } } } // 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); bool has_pending_requests = false; 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(); if (sensor != NULL && pool->usage_threshold()->is_high_threshold_supported() && pool->usage_threshold()->high_threshold() != 0) { MemoryUsage usage = pool->get_memory_usage(); sensor->set_gauge_sensor_level(usage, pool->usage_threshold()); has_pending_requests = has_pending_requests || sensor->has_pending_requests(); } } if (has_pending_requests) { LowMemory_lock->notify_all(); } } // This method could be called from any Java threads // and also VMThread. void LowMemoryDetector::detect_low_memory(MemoryPool* pool) { SensorInfo* sensor = pool->usage_sensor(); if (sensor == NULL || !pool->usage_threshold()->is_high_threshold_supported() || pool->usage_threshold()->high_threshold() == 0) { return; } { MutexLockerEx ml(LowMemory_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(); } } } // Only called by VMThread at GC time void LowMemoryDetector::detect_after_gc_memory(MemoryPool* pool) { SensorInfo* sensor = pool->gc_usage_sensor(); if (sensor == NULL || !pool->gc_usage_threshold()->is_high_threshold_supported() || pool->gc_usage_threshold()->high_threshold() == 0) { return; } { MutexLockerEx ml(LowMemory_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(); } } } // recompute enabled flag void LowMemoryDetector::recompute_enabled_for_collected_pools() { bool enabled = false; int num_memory_pools = MemoryService::num_memory_pools(); for (int i=0; i<num_memory_pools; i++) { MemoryPool* pool = MemoryService::get_memory_pool(i); if (pool->is_collected_pool() && is_enabled(pool)) { enabled = true; break; } } _enabled_for_collected_pools = enabled; } SensorInfo::SensorInfo() { _sensor_obj = NULL; _sensor_on = false; _sensor_count = 0; _pending_trigger_count = 0; _pending_clear_count = 0; } // When this method is used, the memory usage is monitored // as a gauge attribute. Sensor notifications (trigger or // clear) is only emitted at the first time it crosses // a threshold. // // High and low thresholds are designed to provide a // hysteresis mechanism to avoid repeated triggering // of notifications when the attribute value makes small oscillations // around the high or low threshold value. // // The sensor will be triggered if: // (1) the usage is crossing above the high threshold and // the sensor is currently off and no pending // trigger requests; or // (2) the usage is crossing above the high threshold and // the sensor will be off (i.e. sensor is currently on // and has pending clear requests). // // Subsequent crossings of the high threshold value do not cause // any triggers unless the usage becomes less than the low threshold. // // The sensor will be cleared if: // (1) the usage is crossing below the low threshold and // the sensor is currently on and no pending // clear requests; or // (2) the usage is crossing below the low threshold and // the sensor will be on (i.e. sensor is currently off // and has pending trigger requests). // // Subsequent crossings of the low threshold value do not cause // any clears unless the usage becomes greater than or equal // to the high threshold. // // If the current level is between high and low threhsold, no change. // void SensorInfo::set_gauge_sensor_level(MemoryUsage usage, ThresholdSupport* high_low_threshold) { assert(high_low_threshold->is_high_threshold_supported(), "just checking"); bool is_over_high = high_low_threshold->is_high_threshold_crossed(usage); bool is_below_low = high_low_threshold->is_low_threshold_crossed(usage); assert(!(is_over_high && is_below_low), "Can't be both true"); if (is_over_high && ((!_sensor_on && _pending_trigger_count == 0) || _pending_clear_count > 0)) { // low memory detected and need to increment the trigger pending count // if the sensor is off or will be off due to _pending_clear_ > 0 // Request to trigger the sensor _pending_trigger_count++; _usage = usage; if (_pending_clear_count > 0) { // non-zero pending clear requests indicates that there are // pending requests to clear this sensor. // This trigger request needs to clear this clear count // since the resulting sensor flag should be on. _pending_clear_count = 0; } } else if (is_below_low && ((_sensor_on && _pending_clear_count == 0) || (_pending_trigger_count > 0 && _pending_clear_count == 0))) { // memory usage returns below the threshold // Request to clear the sensor if the sensor is on or will be on due to // _pending_trigger_count > 0 and also no clear request _pending_clear_count++; } } // When this method is used, the memory usage is monitored as a // simple counter attribute. The sensor will be triggered // whenever the usage is crossing the threshold to keep track // of the number of times the VM detects such a condition occurs. // // High and low thresholds are designed to provide a // hysteresis mechanism to avoid repeated triggering // of notifications when the attribute value makes small oscillations // around the high or low threshold value. // // The sensor will be triggered if: // - the usage is crossing above the high threshold regardless // of the current sensor state. // // The sensor will be cleared if: // (1) the usage is crossing below the low threshold and // the sensor is currently on; or // (2) the usage is crossing below the low threshold and // the sensor will be on (i.e. sensor is currently off // and has pending trigger requests). void SensorInfo::set_counter_sensor_level(MemoryUsage usage, ThresholdSupport* counter_threshold) { assert(counter_threshold->is_high_threshold_supported(), "just checking"); bool is_over_high = counter_threshold->is_high_threshold_crossed(usage); bool is_below_low = counter_threshold->is_low_threshold_crossed(usage); assert(!(is_over_high && is_below_low), "Can't be both true"); if (is_over_high) { _pending_trigger_count++; _usage = usage; _pending_clear_count = 0; } else if (is_below_low && (_sensor_on || _pending_trigger_count > 0)) { _pending_clear_count++; } } void SensorInfo::oops_do(OopClosure* f) { f->do_oop((oop*) &_sensor_obj); } void SensorInfo::process_pending_requests(TRAPS) { if (!has_pending_requests()) { return; } int pending_count = pending_trigger_count(); if (pending_clear_count() > 0) { clear(pending_count, CHECK); } else { trigger(pending_count, CHECK); } } void SensorInfo::trigger(int count, TRAPS) { assert(count <= _pending_trigger_count, "just checking"); if (_sensor_obj != NULL) { klassOop k = Management::sun_management_Sensor_klass(CHECK); instanceKlassHandle sensorKlass (THREAD, k); Handle sensor_h(THREAD, _sensor_obj); Handle usage_h = MemoryService::create_MemoryUsage_obj(_usage, CHECK); JavaValue result(T_VOID); JavaCallArguments args(sensor_h); args.push_int((int) count); args.push_oop(usage_h); JavaCalls::call_virtual(&result, sensorKlass, vmSymbolHandles::trigger_name(), vmSymbolHandles::trigger_method_signature(), &args, CHECK); } { // Holds LowMemory_lock and update the sensor state MutexLockerEx ml(LowMemory_lock, Mutex::_no_safepoint_check_flag); _sensor_on = true; _sensor_count += count; _pending_trigger_count = _pending_trigger_count - count; } } void SensorInfo::clear(int count, TRAPS) { if (_sensor_obj != NULL) { klassOop k = Management::sun_management_Sensor_klass(CHECK); instanceKlassHandle sensorKlass (THREAD, k); Handle sensor(THREAD, _sensor_obj); JavaValue result(T_VOID); JavaCallArguments args(sensor); args.push_int((int) count); JavaCalls::call_virtual(&result, sensorKlass, vmSymbolHandles::clear_name(), vmSymbolHandles::int_void_signature(), &args, CHECK); } { // Holds LowMemory_lock and update the sensor state MutexLockerEx ml(LowMemory_lock, Mutex::_no_safepoint_check_flag); _sensor_on = false; _pending_clear_count = 0; _pending_trigger_count = _pending_trigger_count - count; } } //-------------------------------------------------------------- // Non-product code #ifndef PRODUCT void SensorInfo::print() { tty->print_cr("%s count = %ld pending_triggers = %ld pending_clears = %ld", (_sensor_on ? "on" : "off"), _sensor_count, _pending_trigger_count, _pending_clear_count); } #endif // PRODUCT