1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/gc_implementation/parallelScavenge/gcTaskManager.hpp Wed Apr 27 01:25:04 2016 +0800
1.3 @@ -0,0 +1,786 @@
1.4 +/*
1.5 + * Copyright (c) 2002, 2012, Oracle and/or its affiliates. All rights reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation.
1.11 + *
1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.15 + * version 2 for more details (a copy is included in the LICENSE file that
1.16 + * accompanied this code).
1.17 + *
1.18 + * You should have received a copy of the GNU General Public License version
1.19 + * 2 along with this work; if not, write to the Free Software Foundation,
1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.21 + *
1.22 + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
1.23 + * or visit www.oracle.com if you need additional information or have any
1.24 + * questions.
1.25 + *
1.26 + */
1.27 +
1.28 +#ifndef SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_GCTASKMANAGER_HPP
1.29 +#define SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_GCTASKMANAGER_HPP
1.30 +
1.31 +#include "runtime/mutex.hpp"
1.32 +#include "utilities/growableArray.hpp"
1.33 +
1.34 +//
1.35 +// The GCTaskManager is a queue of GCTasks, and accessors
1.36 +// to allow the queue to be accessed from many threads.
1.37 +//
1.38 +
1.39 +// Forward declarations of types defined in this file.
1.40 +class GCTask;
1.41 +class GCTaskQueue;
1.42 +class SynchronizedGCTaskQueue;
1.43 +class GCTaskManager;
1.44 +class NotifyDoneClosure;
1.45 +// Some useful subclasses of GCTask. You can also make up your own.
1.46 +class NoopGCTask;
1.47 +class BarrierGCTask;
1.48 +class ReleasingBarrierGCTask;
1.49 +class NotifyingBarrierGCTask;
1.50 +class WaitForBarrierGCTask;
1.51 +class IdleGCTask;
1.52 +// A free list of Monitor*'s.
1.53 +class MonitorSupply;
1.54 +
1.55 +// Forward declarations of classes referenced in this file via pointer.
1.56 +class GCTaskThread;
1.57 +class Mutex;
1.58 +class Monitor;
1.59 +class ThreadClosure;
1.60 +
1.61 +// The abstract base GCTask.
1.62 +class GCTask : public ResourceObj {
1.63 +public:
1.64 + // Known kinds of GCTasks, for predicates.
1.65 + class Kind : AllStatic {
1.66 + public:
1.67 + enum kind {
1.68 + unknown_task,
1.69 + ordinary_task,
1.70 + barrier_task,
1.71 + noop_task,
1.72 + idle_task
1.73 + };
1.74 + static const char* to_string(kind value);
1.75 + };
1.76 +private:
1.77 + // Instance state.
1.78 + const Kind::kind _kind; // For runtime type checking.
1.79 + const uint _affinity; // Which worker should run task.
1.80 + GCTask* _newer; // Tasks are on doubly-linked ...
1.81 + GCTask* _older; // ... lists.
1.82 +public:
1.83 + virtual char* name() { return (char *)"task"; }
1.84 +
1.85 + // Abstract do_it method
1.86 + virtual void do_it(GCTaskManager* manager, uint which) = 0;
1.87 + // Accessors
1.88 + Kind::kind kind() const {
1.89 + return _kind;
1.90 + }
1.91 + uint affinity() const {
1.92 + return _affinity;
1.93 + }
1.94 + GCTask* newer() const {
1.95 + return _newer;
1.96 + }
1.97 + void set_newer(GCTask* n) {
1.98 + _newer = n;
1.99 + }
1.100 + GCTask* older() const {
1.101 + return _older;
1.102 + }
1.103 + void set_older(GCTask* p) {
1.104 + _older = p;
1.105 + }
1.106 + // Predicates.
1.107 + bool is_ordinary_task() const {
1.108 + return kind()==Kind::ordinary_task;
1.109 + }
1.110 + bool is_barrier_task() const {
1.111 + return kind()==Kind::barrier_task;
1.112 + }
1.113 + bool is_noop_task() const {
1.114 + return kind()==Kind::noop_task;
1.115 + }
1.116 + bool is_idle_task() const {
1.117 + return kind()==Kind::idle_task;
1.118 + }
1.119 + void print(const char* message) const PRODUCT_RETURN;
1.120 +protected:
1.121 + // Constructors: Only create subclasses.
1.122 + // An ordinary GCTask.
1.123 + GCTask();
1.124 + // A GCTask of a particular kind, usually barrier or noop.
1.125 + GCTask(Kind::kind kind);
1.126 + // An ordinary GCTask with an affinity.
1.127 + GCTask(uint affinity);
1.128 + // A GCTask of a particular kind, with and affinity.
1.129 + GCTask(Kind::kind kind, uint affinity);
1.130 + // We want a virtual destructor because virtual methods,
1.131 + // but since ResourceObj's don't have their destructors
1.132 + // called, we don't have one at all. Instead we have
1.133 + // this method, which gets called by subclasses to clean up.
1.134 + virtual void destruct();
1.135 + // Methods.
1.136 + void initialize();
1.137 +};
1.138 +
1.139 +// A doubly-linked list of GCTasks.
1.140 +// The list is not synchronized, because sometimes we want to
1.141 +// build up a list and then make it available to other threads.
1.142 +// See also: SynchronizedGCTaskQueue.
1.143 +class GCTaskQueue : public ResourceObj {
1.144 +private:
1.145 + // Instance state.
1.146 + GCTask* _insert_end; // Tasks are enqueued at this end.
1.147 + GCTask* _remove_end; // Tasks are dequeued from this end.
1.148 + uint _length; // The current length of the queue.
1.149 + const bool _is_c_heap_obj; // Is this a CHeapObj?
1.150 +public:
1.151 + // Factory create and destroy methods.
1.152 + // Create as ResourceObj.
1.153 + static GCTaskQueue* create();
1.154 + // Create as CHeapObj.
1.155 + static GCTaskQueue* create_on_c_heap();
1.156 + // Destroyer.
1.157 + static void destroy(GCTaskQueue* that);
1.158 + // Accessors.
1.159 + // These just examine the state of the queue.
1.160 + bool is_empty() const {
1.161 + assert(((insert_end() == NULL && remove_end() == NULL) ||
1.162 + (insert_end() != NULL && remove_end() != NULL)),
1.163 + "insert_end and remove_end don't match");
1.164 + assert((insert_end() != NULL) || (_length == 0), "Not empty");
1.165 + return insert_end() == NULL;
1.166 + }
1.167 + uint length() const {
1.168 + return _length;
1.169 + }
1.170 + // Methods.
1.171 + // Enqueue one task.
1.172 + void enqueue(GCTask* task);
1.173 + // Enqueue a list of tasks. Empties the argument list.
1.174 + void enqueue(GCTaskQueue* list);
1.175 + // Dequeue one task.
1.176 + GCTask* dequeue();
1.177 + // Dequeue one task, preferring one with affinity.
1.178 + GCTask* dequeue(uint affinity);
1.179 +protected:
1.180 + // Constructor. Clients use factory, but there might be subclasses.
1.181 + GCTaskQueue(bool on_c_heap);
1.182 + // Destructor-like method.
1.183 + // Because ResourceMark doesn't call destructors.
1.184 + // This method cleans up like one.
1.185 + virtual void destruct();
1.186 + // Accessors.
1.187 + GCTask* insert_end() const {
1.188 + return _insert_end;
1.189 + }
1.190 + void set_insert_end(GCTask* value) {
1.191 + _insert_end = value;
1.192 + }
1.193 + GCTask* remove_end() const {
1.194 + return _remove_end;
1.195 + }
1.196 + void set_remove_end(GCTask* value) {
1.197 + _remove_end = value;
1.198 + }
1.199 + void increment_length() {
1.200 + _length += 1;
1.201 + }
1.202 + void decrement_length() {
1.203 + _length -= 1;
1.204 + }
1.205 + void set_length(uint value) {
1.206 + _length = value;
1.207 + }
1.208 + bool is_c_heap_obj() const {
1.209 + return _is_c_heap_obj;
1.210 + }
1.211 + // Methods.
1.212 + void initialize();
1.213 + GCTask* remove(); // Remove from remove end.
1.214 + GCTask* remove(GCTask* task); // Remove from the middle.
1.215 + void print(const char* message) const PRODUCT_RETURN;
1.216 + // Debug support
1.217 + void verify_length() const PRODUCT_RETURN;
1.218 +};
1.219 +
1.220 +// A GCTaskQueue that can be synchronized.
1.221 +// This "has-a" GCTaskQueue and a mutex to do the exclusion.
1.222 +class SynchronizedGCTaskQueue : public CHeapObj<mtGC> {
1.223 +private:
1.224 + // Instance state.
1.225 + GCTaskQueue* _unsynchronized_queue; // Has-a unsynchronized queue.
1.226 + Monitor * _lock; // Lock to control access.
1.227 +public:
1.228 + // Factory create and destroy methods.
1.229 + static SynchronizedGCTaskQueue* create(GCTaskQueue* queue, Monitor * lock) {
1.230 + return new SynchronizedGCTaskQueue(queue, lock);
1.231 + }
1.232 + static void destroy(SynchronizedGCTaskQueue* that) {
1.233 + if (that != NULL) {
1.234 + delete that;
1.235 + }
1.236 + }
1.237 + // Accessors
1.238 + GCTaskQueue* unsynchronized_queue() const {
1.239 + return _unsynchronized_queue;
1.240 + }
1.241 + Monitor * lock() const {
1.242 + return _lock;
1.243 + }
1.244 + // GCTaskQueue wrapper methods.
1.245 + // These check that you hold the lock
1.246 + // and then call the method on the queue.
1.247 + bool is_empty() const {
1.248 + guarantee(own_lock(), "don't own the lock");
1.249 + return unsynchronized_queue()->is_empty();
1.250 + }
1.251 + void enqueue(GCTask* task) {
1.252 + guarantee(own_lock(), "don't own the lock");
1.253 + unsynchronized_queue()->enqueue(task);
1.254 + }
1.255 + void enqueue(GCTaskQueue* list) {
1.256 + guarantee(own_lock(), "don't own the lock");
1.257 + unsynchronized_queue()->enqueue(list);
1.258 + }
1.259 + GCTask* dequeue() {
1.260 + guarantee(own_lock(), "don't own the lock");
1.261 + return unsynchronized_queue()->dequeue();
1.262 + }
1.263 + GCTask* dequeue(uint affinity) {
1.264 + guarantee(own_lock(), "don't own the lock");
1.265 + return unsynchronized_queue()->dequeue(affinity);
1.266 + }
1.267 + uint length() const {
1.268 + guarantee(own_lock(), "don't own the lock");
1.269 + return unsynchronized_queue()->length();
1.270 + }
1.271 + // For guarantees.
1.272 + bool own_lock() const {
1.273 + return lock()->owned_by_self();
1.274 + }
1.275 +protected:
1.276 + // Constructor. Clients use factory, but there might be subclasses.
1.277 + SynchronizedGCTaskQueue(GCTaskQueue* queue, Monitor * lock);
1.278 + // Destructor. Not virtual because no virtuals.
1.279 + ~SynchronizedGCTaskQueue();
1.280 +};
1.281 +
1.282 +// This is an abstract base class for getting notifications
1.283 +// when a GCTaskManager is done.
1.284 +class NotifyDoneClosure : public CHeapObj<mtGC> {
1.285 +public:
1.286 + // The notification callback method.
1.287 + virtual void notify(GCTaskManager* manager) = 0;
1.288 +protected:
1.289 + // Constructor.
1.290 + NotifyDoneClosure() {
1.291 + // Nothing to do.
1.292 + }
1.293 + // Virtual destructor because virtual methods.
1.294 + virtual ~NotifyDoneClosure() {
1.295 + // Nothing to do.
1.296 + }
1.297 +};
1.298 +
1.299 +// Dynamic number of GC threads
1.300 +//
1.301 +// GC threads wait in get_task() for work (i.e., a task) to perform.
1.302 +// When the number of GC threads was static, the number of tasks
1.303 +// created to do a job was equal to or greater than the maximum
1.304 +// number of GC threads (ParallelGCThreads). The job might be divided
1.305 +// into a number of tasks greater than the number of GC threads for
1.306 +// load balancing (i.e., over partitioning). The last task to be
1.307 +// executed by a GC thread in a job is a work stealing task. A
1.308 +// GC thread that gets a work stealing task continues to execute
1.309 +// that task until the job is done. In the static number of GC theads
1.310 +// case, tasks are added to a queue (FIFO). The work stealing tasks are
1.311 +// the last to be added. Once the tasks are added, the GC threads grab
1.312 +// a task and go. A single thread can do all the non-work stealing tasks
1.313 +// and then execute a work stealing and wait for all the other GC threads
1.314 +// to execute their work stealing task.
1.315 +// In the dynamic number of GC threads implementation, idle-tasks are
1.316 +// created to occupy the non-participating or "inactive" threads. An
1.317 +// idle-task makes the GC thread wait on a barrier that is part of the
1.318 +// GCTaskManager. The GC threads that have been "idled" in a IdleGCTask
1.319 +// are released once all the active GC threads have finished their work
1.320 +// stealing tasks. The GCTaskManager does not wait for all the "idled"
1.321 +// GC threads to resume execution. When those GC threads do resume
1.322 +// execution in the course of the thread scheduling, they call get_tasks()
1.323 +// as all the other GC threads do. Because all the "idled" threads are
1.324 +// not required to execute in order to finish a job, it is possible for
1.325 +// a GC thread to still be "idled" when the next job is started. Such
1.326 +// a thread stays "idled" for the next job. This can result in a new
1.327 +// job not having all the expected active workers. For example if on
1.328 +// job requests 4 active workers out of a total of 10 workers so the
1.329 +// remaining 6 are "idled", if the next job requests 6 active workers
1.330 +// but all 6 of the "idled" workers are still idle, then the next job
1.331 +// will only get 4 active workers.
1.332 +// The implementation for the parallel old compaction phase has an
1.333 +// added complication. In the static case parold partitions the chunks
1.334 +// ready to be filled into stacks, one for each GC thread. A GC thread
1.335 +// executing a draining task (drains the stack of ready chunks)
1.336 +// claims a stack according to it's id (the unique ordinal value assigned
1.337 +// to each GC thread). In the dynamic case not all GC threads will
1.338 +// actively participate so stacks with ready to fill chunks can only be
1.339 +// given to the active threads. An initial implementation chose stacks
1.340 +// number 1-n to get the ready chunks and required that GC threads
1.341 +// 1-n be the active workers. This was undesirable because it required
1.342 +// certain threads to participate. In the final implementation a
1.343 +// list of stacks equal in number to the active workers are filled
1.344 +// with ready chunks. GC threads that participate get a stack from
1.345 +// the task (DrainStacksCompactionTask), empty the stack, and then add it to a
1.346 +// recycling list at the end of the task. If the same GC thread gets
1.347 +// a second task, it gets a second stack to drain and returns it. The
1.348 +// stacks are added to a recycling list so that later stealing tasks
1.349 +// for this tasks can get a stack from the recycling list. Stealing tasks
1.350 +// use the stacks in its work in a way similar to the draining tasks.
1.351 +// A thread is not guaranteed to get anything but a stealing task and
1.352 +// a thread that only gets a stealing task has to get a stack. A failed
1.353 +// implementation tried to have the GC threads keep the stack they used
1.354 +// during a draining task for later use in the stealing task but that didn't
1.355 +// work because as noted a thread is not guaranteed to get a draining task.
1.356 +//
1.357 +// For PSScavenge and ParCompactionManager the GC threads are
1.358 +// held in the GCTaskThread** _thread array in GCTaskManager.
1.359 +
1.360 +
1.361 +class GCTaskManager : public CHeapObj<mtGC> {
1.362 + friend class ParCompactionManager;
1.363 + friend class PSParallelCompact;
1.364 + friend class PSScavenge;
1.365 + friend class PSRefProcTaskExecutor;
1.366 + friend class RefProcTaskExecutor;
1.367 + friend class GCTaskThread;
1.368 + friend class IdleGCTask;
1.369 +private:
1.370 + // Instance state.
1.371 + NotifyDoneClosure* _ndc; // Notify on completion.
1.372 + const uint _workers; // Number of workers.
1.373 + Monitor* _monitor; // Notification of changes.
1.374 + SynchronizedGCTaskQueue* _queue; // Queue of tasks.
1.375 + GCTaskThread** _thread; // Array of worker threads.
1.376 + uint _active_workers; // Number of active workers.
1.377 + uint _busy_workers; // Number of busy workers.
1.378 + uint _blocking_worker; // The worker that's blocking.
1.379 + bool* _resource_flag; // Array of flag per threads.
1.380 + uint _delivered_tasks; // Count of delivered tasks.
1.381 + uint _completed_tasks; // Count of completed tasks.
1.382 + uint _barriers; // Count of barrier tasks.
1.383 + uint _emptied_queue; // Times we emptied the queue.
1.384 + NoopGCTask* _noop_task; // The NoopGCTask instance.
1.385 + uint _noop_tasks; // Count of noop tasks.
1.386 + WaitForBarrierGCTask* _idle_inactive_task;// Task for inactive workers
1.387 + volatile uint _idle_workers; // Number of idled workers
1.388 +public:
1.389 + // Factory create and destroy methods.
1.390 + static GCTaskManager* create(uint workers) {
1.391 + return new GCTaskManager(workers);
1.392 + }
1.393 + static GCTaskManager* create(uint workers, NotifyDoneClosure* ndc) {
1.394 + return new GCTaskManager(workers, ndc);
1.395 + }
1.396 + static void destroy(GCTaskManager* that) {
1.397 + if (that != NULL) {
1.398 + delete that;
1.399 + }
1.400 + }
1.401 + // Accessors.
1.402 + uint busy_workers() const {
1.403 + return _busy_workers;
1.404 + }
1.405 + volatile uint idle_workers() const {
1.406 + return _idle_workers;
1.407 + }
1.408 + // Pun between Monitor* and Mutex*
1.409 + Monitor* monitor() const {
1.410 + return _monitor;
1.411 + }
1.412 + Monitor * lock() const {
1.413 + return _monitor;
1.414 + }
1.415 + WaitForBarrierGCTask* idle_inactive_task() {
1.416 + return _idle_inactive_task;
1.417 + }
1.418 + // Methods.
1.419 + // Add the argument task to be run.
1.420 + void add_task(GCTask* task);
1.421 + // Add a list of tasks. Removes task from the argument list.
1.422 + void add_list(GCTaskQueue* list);
1.423 + // Claim a task for argument worker.
1.424 + GCTask* get_task(uint which);
1.425 + // Note the completion of a task by the argument worker.
1.426 + void note_completion(uint which);
1.427 + // Is the queue blocked from handing out new tasks?
1.428 + bool is_blocked() const {
1.429 + return (blocking_worker() != sentinel_worker());
1.430 + }
1.431 + // Request that all workers release their resources.
1.432 + void release_all_resources();
1.433 + // Ask if a particular worker should release its resources.
1.434 + bool should_release_resources(uint which); // Predicate.
1.435 + // Note the release of resources by the argument worker.
1.436 + void note_release(uint which);
1.437 + // Create IdleGCTasks for inactive workers and start workers
1.438 + void task_idle_workers();
1.439 + // Release the workers in IdleGCTasks
1.440 + void release_idle_workers();
1.441 + // Constants.
1.442 + // A sentinel worker identifier.
1.443 + static uint sentinel_worker() {
1.444 + return (uint) -1; // Why isn't there a max_uint?
1.445 + }
1.446 +
1.447 + // Execute the task queue and wait for the completion.
1.448 + void execute_and_wait(GCTaskQueue* list);
1.449 +
1.450 + void print_task_time_stamps();
1.451 + void print_threads_on(outputStream* st);
1.452 + void threads_do(ThreadClosure* tc);
1.453 +
1.454 +protected:
1.455 + // Constructors. Clients use factory, but there might be subclasses.
1.456 + // Create a GCTaskManager with the appropriate number of workers.
1.457 + GCTaskManager(uint workers);
1.458 + // Create a GCTaskManager that calls back when there's no more work.
1.459 + GCTaskManager(uint workers, NotifyDoneClosure* ndc);
1.460 + // Make virtual if necessary.
1.461 + ~GCTaskManager();
1.462 + // Accessors.
1.463 + uint workers() const {
1.464 + return _workers;
1.465 + }
1.466 + void set_active_workers(uint v) {
1.467 + assert(v <= _workers, "Trying to set more workers active than there are");
1.468 + _active_workers = MIN2(v, _workers);
1.469 + assert(v != 0, "Trying to set active workers to 0");
1.470 + _active_workers = MAX2(1U, _active_workers);
1.471 + }
1.472 + // Sets the number of threads that will be used in a collection
1.473 + void set_active_gang();
1.474 +
1.475 + NotifyDoneClosure* notify_done_closure() const {
1.476 + return _ndc;
1.477 + }
1.478 + SynchronizedGCTaskQueue* queue() const {
1.479 + return _queue;
1.480 + }
1.481 + NoopGCTask* noop_task() const {
1.482 + return _noop_task;
1.483 + }
1.484 + // Bounds-checking per-thread data accessors.
1.485 + GCTaskThread* thread(uint which);
1.486 + void set_thread(uint which, GCTaskThread* value);
1.487 + bool resource_flag(uint which);
1.488 + void set_resource_flag(uint which, bool value);
1.489 + // Modifier methods with some semantics.
1.490 + // Is any worker blocking handing out new tasks?
1.491 + uint blocking_worker() const {
1.492 + return _blocking_worker;
1.493 + }
1.494 + void set_blocking_worker(uint value) {
1.495 + _blocking_worker = value;
1.496 + }
1.497 + void set_unblocked() {
1.498 + set_blocking_worker(sentinel_worker());
1.499 + }
1.500 + // Count of busy workers.
1.501 + void reset_busy_workers() {
1.502 + _busy_workers = 0;
1.503 + }
1.504 + uint increment_busy_workers();
1.505 + uint decrement_busy_workers();
1.506 + // Count of tasks delivered to workers.
1.507 + uint delivered_tasks() const {
1.508 + return _delivered_tasks;
1.509 + }
1.510 + void increment_delivered_tasks() {
1.511 + _delivered_tasks += 1;
1.512 + }
1.513 + void reset_delivered_tasks() {
1.514 + _delivered_tasks = 0;
1.515 + }
1.516 + // Count of tasks completed by workers.
1.517 + uint completed_tasks() const {
1.518 + return _completed_tasks;
1.519 + }
1.520 + void increment_completed_tasks() {
1.521 + _completed_tasks += 1;
1.522 + }
1.523 + void reset_completed_tasks() {
1.524 + _completed_tasks = 0;
1.525 + }
1.526 + // Count of barrier tasks completed.
1.527 + uint barriers() const {
1.528 + return _barriers;
1.529 + }
1.530 + void increment_barriers() {
1.531 + _barriers += 1;
1.532 + }
1.533 + void reset_barriers() {
1.534 + _barriers = 0;
1.535 + }
1.536 + // Count of how many times the queue has emptied.
1.537 + uint emptied_queue() const {
1.538 + return _emptied_queue;
1.539 + }
1.540 + void increment_emptied_queue() {
1.541 + _emptied_queue += 1;
1.542 + }
1.543 + void reset_emptied_queue() {
1.544 + _emptied_queue = 0;
1.545 + }
1.546 + // Count of the number of noop tasks we've handed out,
1.547 + // e.g., to handle resource release requests.
1.548 + uint noop_tasks() const {
1.549 + return _noop_tasks;
1.550 + }
1.551 + void increment_noop_tasks() {
1.552 + _noop_tasks += 1;
1.553 + }
1.554 + void reset_noop_tasks() {
1.555 + _noop_tasks = 0;
1.556 + }
1.557 + void increment_idle_workers() {
1.558 + _idle_workers++;
1.559 + }
1.560 + void decrement_idle_workers() {
1.561 + _idle_workers--;
1.562 + }
1.563 + // Other methods.
1.564 + void initialize();
1.565 +
1.566 + public:
1.567 + // Return true if all workers are currently active.
1.568 + bool all_workers_active() { return workers() == active_workers(); }
1.569 + uint active_workers() const {
1.570 + return _active_workers;
1.571 + }
1.572 +};
1.573 +
1.574 +//
1.575 +// Some exemplary GCTasks.
1.576 +//
1.577 +
1.578 +// A noop task that does nothing,
1.579 +// except take us around the GCTaskThread loop.
1.580 +class NoopGCTask : public GCTask {
1.581 +private:
1.582 + const bool _is_c_heap_obj; // Is this a CHeapObj?
1.583 +public:
1.584 + // Factory create and destroy methods.
1.585 + static NoopGCTask* create();
1.586 + static NoopGCTask* create_on_c_heap();
1.587 + static void destroy(NoopGCTask* that);
1.588 +
1.589 + virtual char* name() { return (char *)"noop task"; }
1.590 + // Methods from GCTask.
1.591 + void do_it(GCTaskManager* manager, uint which) {
1.592 + // Nothing to do.
1.593 + }
1.594 +protected:
1.595 + // Constructor.
1.596 + NoopGCTask(bool on_c_heap) :
1.597 + GCTask(GCTask::Kind::noop_task),
1.598 + _is_c_heap_obj(on_c_heap) {
1.599 + // Nothing to do.
1.600 + }
1.601 + // Destructor-like method.
1.602 + void destruct();
1.603 + // Accessors.
1.604 + bool is_c_heap_obj() const {
1.605 + return _is_c_heap_obj;
1.606 + }
1.607 +};
1.608 +
1.609 +// A BarrierGCTask blocks other tasks from starting,
1.610 +// and waits until it is the only task running.
1.611 +class BarrierGCTask : public GCTask {
1.612 +public:
1.613 + // Factory create and destroy methods.
1.614 + static BarrierGCTask* create() {
1.615 + return new BarrierGCTask();
1.616 + }
1.617 + static void destroy(BarrierGCTask* that) {
1.618 + if (that != NULL) {
1.619 + that->destruct();
1.620 + delete that;
1.621 + }
1.622 + }
1.623 + // Methods from GCTask.
1.624 + void do_it(GCTaskManager* manager, uint which);
1.625 +protected:
1.626 + // Constructor. Clients use factory, but there might be subclasses.
1.627 + BarrierGCTask() :
1.628 + GCTask(GCTask::Kind::barrier_task) {
1.629 + // Nothing to do.
1.630 + }
1.631 + // Destructor-like method.
1.632 + void destruct();
1.633 +
1.634 + virtual char* name() { return (char *)"barrier task"; }
1.635 + // Methods.
1.636 + // Wait for this to be the only task running.
1.637 + void do_it_internal(GCTaskManager* manager, uint which);
1.638 +};
1.639 +
1.640 +// A ReleasingBarrierGCTask is a BarrierGCTask
1.641 +// that tells all the tasks to release their resource areas.
1.642 +class ReleasingBarrierGCTask : public BarrierGCTask {
1.643 +public:
1.644 + // Factory create and destroy methods.
1.645 + static ReleasingBarrierGCTask* create() {
1.646 + return new ReleasingBarrierGCTask();
1.647 + }
1.648 + static void destroy(ReleasingBarrierGCTask* that) {
1.649 + if (that != NULL) {
1.650 + that->destruct();
1.651 + delete that;
1.652 + }
1.653 + }
1.654 + // Methods from GCTask.
1.655 + void do_it(GCTaskManager* manager, uint which);
1.656 +protected:
1.657 + // Constructor. Clients use factory, but there might be subclasses.
1.658 + ReleasingBarrierGCTask() :
1.659 + BarrierGCTask() {
1.660 + // Nothing to do.
1.661 + }
1.662 + // Destructor-like method.
1.663 + void destruct();
1.664 +};
1.665 +
1.666 +// A NotifyingBarrierGCTask is a BarrierGCTask
1.667 +// that calls a notification method when it is the only task running.
1.668 +class NotifyingBarrierGCTask : public BarrierGCTask {
1.669 +private:
1.670 + // Instance state.
1.671 + NotifyDoneClosure* _ndc; // The callback object.
1.672 +public:
1.673 + // Factory create and destroy methods.
1.674 + static NotifyingBarrierGCTask* create(NotifyDoneClosure* ndc) {
1.675 + return new NotifyingBarrierGCTask(ndc);
1.676 + }
1.677 + static void destroy(NotifyingBarrierGCTask* that) {
1.678 + if (that != NULL) {
1.679 + that->destruct();
1.680 + delete that;
1.681 + }
1.682 + }
1.683 + // Methods from GCTask.
1.684 + void do_it(GCTaskManager* manager, uint which);
1.685 +protected:
1.686 + // Constructor. Clients use factory, but there might be subclasses.
1.687 + NotifyingBarrierGCTask(NotifyDoneClosure* ndc) :
1.688 + BarrierGCTask(),
1.689 + _ndc(ndc) {
1.690 + assert(notify_done_closure() != NULL, "can't notify on NULL");
1.691 + }
1.692 + // Destructor-like method.
1.693 + void destruct();
1.694 + // Accessor.
1.695 + NotifyDoneClosure* notify_done_closure() const { return _ndc; }
1.696 +};
1.697 +
1.698 +// A WaitForBarrierGCTask is a BarrierGCTask
1.699 +// with a method you can call to wait until
1.700 +// the BarrierGCTask is done.
1.701 +// This may cover many of the uses of NotifyingBarrierGCTasks.
1.702 +class WaitForBarrierGCTask : public BarrierGCTask {
1.703 + friend class GCTaskManager;
1.704 + friend class IdleGCTask;
1.705 +private:
1.706 + // Instance state.
1.707 + Monitor* _monitor; // Guard and notify changes.
1.708 + volatile bool _should_wait; // true=>wait, false=>proceed.
1.709 + const bool _is_c_heap_obj; // Was allocated on the heap.
1.710 +public:
1.711 + virtual char* name() { return (char *) "waitfor-barrier-task"; }
1.712 +
1.713 + // Factory create and destroy methods.
1.714 + static WaitForBarrierGCTask* create();
1.715 + static WaitForBarrierGCTask* create_on_c_heap();
1.716 + static void destroy(WaitForBarrierGCTask* that);
1.717 + // Methods.
1.718 + void do_it(GCTaskManager* manager, uint which);
1.719 + void wait_for(bool reset);
1.720 + void set_should_wait(bool value) {
1.721 + _should_wait = value;
1.722 + }
1.723 +protected:
1.724 + // Constructor. Clients use factory, but there might be subclasses.
1.725 + WaitForBarrierGCTask(bool on_c_heap);
1.726 + // Destructor-like method.
1.727 + void destruct();
1.728 + // Accessors.
1.729 + Monitor* monitor() const {
1.730 + return _monitor;
1.731 + }
1.732 + bool should_wait() const {
1.733 + return _should_wait;
1.734 + }
1.735 + bool is_c_heap_obj() {
1.736 + return _is_c_heap_obj;
1.737 + }
1.738 +};
1.739 +
1.740 +// Task that is used to idle a GC task when fewer than
1.741 +// the maximum workers are wanted.
1.742 +class IdleGCTask : public GCTask {
1.743 + const bool _is_c_heap_obj; // Was allocated on the heap.
1.744 + public:
1.745 + bool is_c_heap_obj() {
1.746 + return _is_c_heap_obj;
1.747 + }
1.748 + // Factory create and destroy methods.
1.749 + static IdleGCTask* create();
1.750 + static IdleGCTask* create_on_c_heap();
1.751 + static void destroy(IdleGCTask* that);
1.752 +
1.753 + virtual char* name() { return (char *)"idle task"; }
1.754 + // Methods from GCTask.
1.755 + virtual void do_it(GCTaskManager* manager, uint which);
1.756 +protected:
1.757 + // Constructor.
1.758 + IdleGCTask(bool on_c_heap) :
1.759 + GCTask(GCTask::Kind::idle_task),
1.760 + _is_c_heap_obj(on_c_heap) {
1.761 + // Nothing to do.
1.762 + }
1.763 + // Destructor-like method.
1.764 + void destruct();
1.765 +};
1.766 +
1.767 +class MonitorSupply : public AllStatic {
1.768 +private:
1.769 + // State.
1.770 + // Control multi-threaded access.
1.771 + static Mutex* _lock;
1.772 + // The list of available Monitor*'s.
1.773 + static GrowableArray<Monitor*>* _freelist;
1.774 +public:
1.775 + // Reserve a Monitor*.
1.776 + static Monitor* reserve();
1.777 + // Release a Monitor*.
1.778 + static void release(Monitor* instance);
1.779 +private:
1.780 + // Accessors.
1.781 + static Mutex* lock() {
1.782 + return _lock;
1.783 + }
1.784 + static GrowableArray<Monitor*>* freelist() {
1.785 + return _freelist;
1.786 + }
1.787 +};
1.788 +
1.789 +#endif // SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_GCTASKMANAGER_HPP
