1 2 /* 3 * Copyright (c) 2002, 2015, Oracle and/or its affiliates. All rights reserved. 4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 5 * 6 * This code is free software; you can redistribute it and/or modify it 7 * under the terms of the GNU General Public License version 2 only, as 8 * published by the Free Software Foundation. 9 * 10 * This code is distributed in the hope that it will be useful, but WITHOUT 11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 13 * version 2 for more details (a copy is included in the LICENSE file that 14 * accompanied this code). 15 * 16 * You should have received a copy of the GNU General Public License version 17 * 2 along with this work; if not, write to the Free Software Foundation, 18 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 19 * 20 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 21 * or visit www.oracle.com if you need additional information or have any 22 * questions. 23 * 24 */ 25 26 #include "precompiled.hpp" 27 #include "gc/parallel/gcTaskManager.hpp" 28 #include "gc/parallel/gcTaskThread.hpp" 29 #include "gc/shared/gcId.hpp" 30 #include "memory/allocation.hpp" 31 #include "memory/allocation.inline.hpp" 32 #include "memory/resourceArea.hpp" 33 #include "runtime/handles.hpp" 34 #include "runtime/handles.inline.hpp" 35 #include "runtime/os.hpp" 36 #include "runtime/thread.hpp" 37 38 GCTaskThread::GCTaskThread(GCTaskManager* manager, 39 uint which, 40 uint processor_id) : 41 _manager(manager), 42 _processor_id(processor_id), 43 _time_stamps(NULL), 44 _time_stamp_index(0) 45 { 46 if (!os::create_thread(this, os::pgc_thread)) 47 vm_exit_out_of_memory(0, OOM_MALLOC_ERROR, "Cannot create GC thread. Out of system resources."); 48 49 if (PrintGCTaskTimeStamps) { 50 _time_stamps = NEW_C_HEAP_ARRAY(GCTaskTimeStamp, GCTaskTimeStampEntries, mtGC); 51 52 guarantee(_time_stamps != NULL, "Sanity"); 53 } 54 set_id(which); 55 set_name("ParGC Thread#%d", which); 56 } 57 58 GCTaskThread::~GCTaskThread() { 59 if (_time_stamps != NULL) { 60 FREE_C_HEAP_ARRAY(GCTaskTimeStamp, _time_stamps); 61 } 62 } 63 64 void GCTaskThread::start() { 65 os::start_thread(this); 66 } 67 68 GCTaskTimeStamp* GCTaskThread::time_stamp_at(uint index) { 69 guarantee(index < GCTaskTimeStampEntries, "increase GCTaskTimeStampEntries"); 70 71 return &(_time_stamps[index]); 72 } 73 74 void GCTaskThread::print_task_time_stamps() { 75 assert(PrintGCTaskTimeStamps, "Sanity"); 76 assert(_time_stamps != NULL, "Sanity (Probably set PrintGCTaskTimeStamps late)"); 77 78 tty->print_cr("GC-Thread %u entries: %d", id(), _time_stamp_index); 79 for(uint i=0; i<_time_stamp_index; i++) { 80 GCTaskTimeStamp* time_stamp = time_stamp_at(i); 81 tty->print_cr("\t[ %s " JLONG_FORMAT " " JLONG_FORMAT " ]", 82 time_stamp->name(), 83 time_stamp->entry_time(), 84 time_stamp->exit_time()); 85 } 86 87 // Reset after dumping the data 88 _time_stamp_index = 0; 89 } 90 91 // GC workers get tasks from the GCTaskManager and execute 92 // them in this method. If there are no tasks to execute, 93 // the GC workers wait in the GCTaskManager's get_task() 94 // for tasks to be enqueued for execution. 95 96 void GCTaskThread::run() { 97 // Set up the thread for stack overflow support 98 this->record_stack_base_and_size(); 99 this->initialize_named_thread(); 100 // Bind yourself to your processor. 101 if (processor_id() != GCTaskManager::sentinel_worker()) { 102 if (TraceGCTaskThread) { 103 tty->print_cr("GCTaskThread::run: " 104 " binding to processor %u", processor_id()); 105 } 106 if (!os::bind_to_processor(processor_id())) { 107 DEBUG_ONLY( 108 warning("Couldn't bind GCTaskThread %u to processor %u", 109 which(), processor_id()); 110 ) 111 } 112 } 113 // Part of thread setup. 114 // ??? Are these set up once here to make subsequent ones fast? 115 HandleMark hm_outer; 116 ResourceMark rm_outer; 117 118 TimeStamp timer; 119 120 for (;/* ever */;) { 121 // These are so we can flush the resources allocated in the inner loop. 122 HandleMark hm_inner; 123 ResourceMark rm_inner; 124 for (; /* break */; ) { 125 // This will block until there is a task to be gotten. 126 GCTask* task = manager()->get_task(which()); 127 GCIdMark gc_id_mark(task->gc_id()); 128 // Record if this is an idle task for later use. 129 bool is_idle_task = task->is_idle_task(); 130 // In case the update is costly 131 if (PrintGCTaskTimeStamps) { 132 timer.update(); 133 } 134 135 jlong entry_time = timer.ticks(); 136 char* name = task->name(); 137 138 // If this is the barrier task, it can be destroyed 139 // by the GC task manager once the do_it() executes. 140 task->do_it(manager(), which()); 141 142 // Use the saved value of is_idle_task because references 143 // using "task" are not reliable for the barrier task. 144 if (!is_idle_task) { 145 manager()->note_completion(which()); 146 147 if (PrintGCTaskTimeStamps) { 148 assert(_time_stamps != NULL, 149 "Sanity (PrintGCTaskTimeStamps set late?)"); 150 151 timer.update(); 152 153 GCTaskTimeStamp* time_stamp = time_stamp_at(_time_stamp_index++); 154 155 time_stamp->set_name(name); 156 time_stamp->set_entry_time(entry_time); 157 time_stamp->set_exit_time(timer.ticks()); 158 } 159 } else { 160 // idle tasks complete outside the normal accounting 161 // so that a task can complete without waiting for idle tasks. 162 // They have to be terminated separately. 163 IdleGCTask::destroy((IdleGCTask*)task); 164 set_is_working(true); 165 } 166 167 // Check if we should release our inner resources. 168 if (manager()->should_release_resources(which())) { 169 manager()->note_release(which()); 170 break; 171 } 172 } 173 } 174 }