Mercurial > hg > truffle
diff src/share/vm/utilities/workgroup.cpp @ 0:a61af66fc99e jdk7-b24
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author | duke |
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date | Sat, 01 Dec 2007 00:00:00 +0000 |
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children | 37f87013dfd8 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/share/vm/utilities/workgroup.cpp Sat Dec 01 00:00:00 2007 +0000 @@ -0,0 +1,444 @@ +/* + * Copyright 2001-2007 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/_workgroup.cpp.incl" + +// Definitions of WorkGang methods. + +AbstractWorkGang::AbstractWorkGang(const char* name, + bool are_GC_threads) : + _name(name), + _are_GC_threads(are_GC_threads) { + // Other initialization. + _monitor = new Monitor(/* priority */ Mutex::leaf, + /* name */ "WorkGroup monitor", + /* allow_vm_block */ are_GC_threads); + assert(monitor() != NULL, "Failed to allocate monitor"); + _terminate = false; + _task = NULL; + _sequence_number = 0; + _started_workers = 0; + _finished_workers = 0; +} + +WorkGang::WorkGang(const char* name, + int workers, + bool are_GC_threads) : + AbstractWorkGang(name, are_GC_threads) { + // Save arguments. + _total_workers = workers; + if (TraceWorkGang) { + tty->print_cr("Constructing work gang %s with %d threads", name, workers); + } + _gang_workers = NEW_C_HEAP_ARRAY(GangWorker*, workers); + assert(gang_workers() != NULL, "Failed to allocate gang workers"); + for (int worker = 0; worker < total_workers(); worker += 1) { + GangWorker* new_worker = new GangWorker(this, worker); + assert(new_worker != NULL, "Failed to allocate GangWorker"); + _gang_workers[worker] = new_worker; + if (new_worker == NULL || !os::create_thread(new_worker, os::pgc_thread)) + vm_exit_out_of_memory(0, "Cannot create worker GC thread. Out of system resources."); + if (!DisableStartThread) { + os::start_thread(new_worker); + } + } +} + +AbstractWorkGang::~AbstractWorkGang() { + if (TraceWorkGang) { + tty->print_cr("Destructing work gang %s", name()); + } + stop(); // stop all the workers + for (int worker = 0; worker < total_workers(); worker += 1) { + delete gang_worker(worker); + } + delete gang_workers(); + delete monitor(); +} + +GangWorker* AbstractWorkGang::gang_worker(int i) const { + // Array index bounds checking. + GangWorker* result = NULL; + assert(gang_workers() != NULL, "No workers for indexing"); + assert(((i >= 0) && (i < total_workers())), "Worker index out of bounds"); + result = _gang_workers[i]; + assert(result != NULL, "Indexing to null worker"); + return result; +} + +void WorkGang::run_task(AbstractGangTask* task) { + // This thread is executed by the VM thread which does not block + // on ordinary MutexLocker's. + MutexLockerEx ml(monitor(), Mutex::_no_safepoint_check_flag); + if (TraceWorkGang) { + tty->print_cr("Running work gang %s task %s", name(), task->name()); + } + // Tell all the workers to run a task. + assert(task != NULL, "Running a null task"); + // Initialize. + _task = task; + _sequence_number += 1; + _started_workers = 0; + _finished_workers = 0; + // Tell the workers to get to work. + monitor()->notify_all(); + // Wait for them to be finished + while (finished_workers() < total_workers()) { + if (TraceWorkGang) { + tty->print_cr("Waiting in work gang %s: %d/%d finished sequence %d", + name(), finished_workers(), total_workers(), + _sequence_number); + } + monitor()->wait(/* no_safepoint_check */ true); + } + _task = NULL; + if (TraceWorkGang) { + tty->print_cr("/nFinished work gang %s: %d/%d sequence %d", + name(), finished_workers(), total_workers(), + _sequence_number); + } +} + +void AbstractWorkGang::stop() { + // Tell all workers to terminate, then wait for them to become inactive. + MutexLockerEx ml(monitor(), Mutex::_no_safepoint_check_flag); + if (TraceWorkGang) { + tty->print_cr("Stopping work gang %s task %s", name(), task()->name()); + } + _task = NULL; + _terminate = true; + monitor()->notify_all(); + while (finished_workers() < total_workers()) { + if (TraceWorkGang) { + tty->print_cr("Waiting in work gang %s: %d/%d finished", + name(), finished_workers(), total_workers()); + } + monitor()->wait(/* no_safepoint_check */ true); + } +} + +void AbstractWorkGang::internal_worker_poll(WorkData* data) const { + assert(monitor()->owned_by_self(), "worker_poll is an internal method"); + assert(data != NULL, "worker data is null"); + data->set_terminate(terminate()); + data->set_task(task()); + data->set_sequence_number(sequence_number()); +} + +void AbstractWorkGang::internal_note_start() { + assert(monitor()->owned_by_self(), "note_finish is an internal method"); + _started_workers += 1; +} + +void AbstractWorkGang::internal_note_finish() { + assert(monitor()->owned_by_self(), "note_finish is an internal method"); + _finished_workers += 1; +} + +void AbstractWorkGang::print_worker_threads_on(outputStream* st) const { + uint num_thr = total_workers(); + for (uint i = 0; i < num_thr; i++) { + gang_worker(i)->print_on(st); + st->cr(); + } +} + +void AbstractWorkGang::threads_do(ThreadClosure* tc) const { + assert(tc != NULL, "Null ThreadClosure"); + uint num_thr = total_workers(); + for (uint i = 0; i < num_thr; i++) { + tc->do_thread(gang_worker(i)); + } +} + +// GangWorker methods. + +GangWorker::GangWorker(AbstractWorkGang* gang, uint id) { + _gang = gang; + set_id(id); + set_name("Gang worker#%d (%s)", id, gang->name()); +} + +void GangWorker::run() { + initialize(); + loop(); +} + +void GangWorker::initialize() { + this->initialize_thread_local_storage(); + assert(_gang != NULL, "No gang to run in"); + os::set_priority(this, NearMaxPriority); + if (TraceWorkGang) { + tty->print_cr("Running gang worker for gang %s id %d", + gang()->name(), id()); + } + // The VM thread should not execute here because MutexLocker's are used + // as (opposed to MutexLockerEx's). + assert(!Thread::current()->is_VM_thread(), "VM thread should not be part" + " of a work gang"); +} + +void GangWorker::loop() { + int previous_sequence_number = 0; + Monitor* gang_monitor = gang()->monitor(); + for ( ; /* !terminate() */; ) { + WorkData data; + int part; // Initialized below. + { + // Grab the gang mutex. + MutexLocker ml(gang_monitor); + // Wait for something to do. + // Polling outside the while { wait } avoids missed notifies + // in the outer loop. + gang()->internal_worker_poll(&data); + if (TraceWorkGang) { + tty->print("Polled outside for work in gang %s worker %d", + gang()->name(), id()); + tty->print(" terminate: %s", + data.terminate() ? "true" : "false"); + tty->print(" sequence: %d (prev: %d)", + data.sequence_number(), previous_sequence_number); + if (data.task() != NULL) { + tty->print(" task: %s", data.task()->name()); + } else { + tty->print(" task: NULL"); + } + tty->cr(); + } + for ( ; /* break or return */; ) { + // Terminate if requested. + if (data.terminate()) { + gang()->internal_note_finish(); + gang_monitor->notify_all(); + return; + } + // Check for new work. + if ((data.task() != NULL) && + (data.sequence_number() != previous_sequence_number)) { + gang()->internal_note_start(); + gang_monitor->notify_all(); + part = gang()->started_workers() - 1; + break; + } + // Nothing to do. + gang_monitor->wait(/* no_safepoint_check */ true); + gang()->internal_worker_poll(&data); + if (TraceWorkGang) { + tty->print("Polled inside for work in gang %s worker %d", + gang()->name(), id()); + tty->print(" terminate: %s", + data.terminate() ? "true" : "false"); + tty->print(" sequence: %d (prev: %d)", + data.sequence_number(), previous_sequence_number); + if (data.task() != NULL) { + tty->print(" task: %s", data.task()->name()); + } else { + tty->print(" task: NULL"); + } + tty->cr(); + } + } + // Drop gang mutex. + } + if (TraceWorkGang) { + tty->print("Work for work gang %s id %d task %s part %d", + gang()->name(), id(), data.task()->name(), part); + } + assert(data.task() != NULL, "Got null task"); + data.task()->work(part); + { + if (TraceWorkGang) { + tty->print("Finish for work gang %s id %d task %s part %d", + gang()->name(), id(), data.task()->name(), part); + } + // Grab the gang mutex. + MutexLocker ml(gang_monitor); + gang()->internal_note_finish(); + // Tell the gang you are done. + gang_monitor->notify_all(); + // Drop the gang mutex. + } + previous_sequence_number = data.sequence_number(); + } +} + +bool GangWorker::is_GC_task_thread() const { + return gang()->are_GC_threads(); +} + +void GangWorker::print_on(outputStream* st) const { + st->print("\"%s\" ", name()); + Thread::print_on(st); + st->cr(); +} + +// Printing methods + +const char* AbstractWorkGang::name() const { + return _name; +} + +#ifndef PRODUCT + +const char* AbstractGangTask::name() const { + return _name; +} + +#endif /* PRODUCT */ + +// *** WorkGangBarrierSync + +WorkGangBarrierSync::WorkGangBarrierSync() + : _monitor(Mutex::safepoint, "work gang barrier sync", true), + _n_workers(0), _n_completed(0) { +} + +WorkGangBarrierSync::WorkGangBarrierSync(int n_workers, const char* name) + : _monitor(Mutex::safepoint, name, true), + _n_workers(n_workers), _n_completed(0) { +} + +void WorkGangBarrierSync::set_n_workers(int n_workers) { + _n_workers = n_workers; + _n_completed = 0; +} + +void WorkGangBarrierSync::enter() { + MutexLockerEx x(monitor(), Mutex::_no_safepoint_check_flag); + inc_completed(); + if (n_completed() == n_workers()) { + monitor()->notify_all(); + } + else { + while (n_completed() != n_workers()) { + monitor()->wait(/* no_safepoint_check */ true); + } + } +} + +// SubTasksDone functions. + +SubTasksDone::SubTasksDone(int n) : + _n_tasks(n), _n_threads(1), _tasks(NULL) { + _tasks = NEW_C_HEAP_ARRAY(jint, n); + guarantee(_tasks != NULL, "alloc failure"); + clear(); +} + +bool SubTasksDone::valid() { + return _tasks != NULL; +} + +void SubTasksDone::set_par_threads(int t) { +#ifdef ASSERT + assert(_claimed == 0 || _threads_completed == _n_threads, + "should not be called while tasks are being processed!"); +#endif + _n_threads = (t == 0 ? 1 : t); +} + +void SubTasksDone::clear() { + for (int i = 0; i < _n_tasks; i++) { + _tasks[i] = 0; + } + _threads_completed = 0; +#ifdef ASSERT + _claimed = 0; +#endif +} + +bool SubTasksDone::is_task_claimed(int t) { + assert(0 <= t && t < _n_tasks, "bad task id."); + jint old = _tasks[t]; + if (old == 0) { + old = Atomic::cmpxchg(1, &_tasks[t], 0); + } + assert(_tasks[t] == 1, "What else?"); + bool res = old != 0; +#ifdef ASSERT + if (!res) { + assert(_claimed < _n_tasks, "Too many tasks claimed; missing clear?"); + Atomic::inc(&_claimed); + } +#endif + return res; +} + +void SubTasksDone::all_tasks_completed() { + jint observed = _threads_completed; + jint old; + do { + old = observed; + observed = Atomic::cmpxchg(old+1, &_threads_completed, old); + } while (observed != old); + // If this was the last thread checking in, clear the tasks. + if (observed+1 == _n_threads) clear(); +} + + +SubTasksDone::~SubTasksDone() { + if (_tasks != NULL) FREE_C_HEAP_ARRAY(jint, _tasks); +} + +// *** SequentialSubTasksDone + +void SequentialSubTasksDone::clear() { + _n_tasks = _n_claimed = 0; + _n_threads = _n_completed = 0; +} + +bool SequentialSubTasksDone::valid() { + return _n_threads > 0; +} + +bool SequentialSubTasksDone::is_task_claimed(int& t) { + jint* n_claimed_ptr = &_n_claimed; + t = *n_claimed_ptr; + while (t < _n_tasks) { + jint res = Atomic::cmpxchg(t+1, n_claimed_ptr, t); + if (res == t) { + return false; + } + t = *n_claimed_ptr; + } + return true; +} + +bool SequentialSubTasksDone::all_tasks_completed() { + jint* n_completed_ptr = &_n_completed; + jint complete = *n_completed_ptr; + while (true) { + jint res = Atomic::cmpxchg(complete+1, n_completed_ptr, complete); + if (res == complete) { + break; + } + complete = res; + } + if (complete+1 == _n_threads) { + clear(); + return true; + } + return false; +}