431 uint GenericTaskQueueSet<T, F>::tasks() const {
432 uint n = 0;
433 for (uint j = 0; j < _n; j++) {
434 n += _queues[j]->size();
435 }
436 return n;
437 }
438
439 // When to terminate from the termination protocol.
440 class TerminatorTerminator: public CHeapObj<mtInternal> {
441 public:
442 virtual bool should_exit_termination() = 0;
443 };
444
445 // A class to aid in the termination of a set of parallel tasks using
446 // TaskQueueSet's for work stealing.
447
448 #undef TRACESPINNING
449
450 class ParallelTaskTerminator: public StackObj {
451 private:
452 uint _n_threads;
453 TaskQueueSetSuper* _queue_set;
454 volatile uint _offered_termination;
455
456 #ifdef TRACESPINNING
457 static uint _total_yields;
458 static uint _total_spins;
459 static uint _total_peeks;
460 #endif
461
462 bool peek_in_queue_set();
463 protected:
464 virtual void yield();
465 void sleep(uint millis);
466
467 public:
468
469 // "n_threads" is the number of threads to be terminated. "queue_set" is a
470 // queue sets of work queues of other threads.
471 ParallelTaskTerminator(uint n_threads, TaskQueueSetSuper* queue_set);
472
473 // The current thread has no work, and is ready to terminate if everyone
474 // else is. If returns "true", all threads are terminated. If returns
475 // "false", available work has been observed in one of the task queues,
476 // so the global task is not complete.
477 bool offer_termination() {
478 return offer_termination(NULL);
479 }
480
481 // As above, but it also terminates if the should_exit_termination()
482 // method of the terminator parameter returns true. If terminator is
483 // NULL, then it is ignored.
484 bool offer_termination(TerminatorTerminator* terminator);
485
486 // Reset the terminator, so that it may be reused again.
487 // The caller is responsible for ensuring that this is done
488 // in an MT-safe manner, once the previous round of use of
489 // the terminator is finished.
490 void reset_for_reuse();
491 // Same as above but the number of parallel threads is set to the
492 // given number.
493 void reset_for_reuse(uint n_threads);
494
495 #ifdef TRACESPINNING
496 static uint total_yields() { return _total_yields; }
497 static uint total_spins() { return _total_spins; }
498 static uint total_peeks() { return _total_peeks; }
499 static void print_termination_counts();
500 #endif
501 };
502
503 typedef GenericTaskQueue<oop, mtGC> OopTaskQueue;
504 typedef GenericTaskQueueSet<OopTaskQueue, mtGC> OopTaskQueueSet;
|
431 uint GenericTaskQueueSet<T, F>::tasks() const {
432 uint n = 0;
433 for (uint j = 0; j < _n; j++) {
434 n += _queues[j]->size();
435 }
436 return n;
437 }
438
439 // When to terminate from the termination protocol.
440 class TerminatorTerminator: public CHeapObj<mtInternal> {
441 public:
442 virtual bool should_exit_termination() = 0;
443 };
444
445 // A class to aid in the termination of a set of parallel tasks using
446 // TaskQueueSet's for work stealing.
447
448 #undef TRACESPINNING
449
450 class ParallelTaskTerminator: public StackObj {
451 protected:
452 uint _n_threads;
453 TaskQueueSetSuper* _queue_set;
454 volatile uint _offered_termination;
455
456 #ifdef TRACESPINNING
457 static uint _total_yields;
458 static uint _total_spins;
459 static uint _total_peeks;
460 #endif
461
462 bool peek_in_queue_set();
463 protected:
464 virtual void yield();
465 void sleep(uint millis);
466
467 public:
468
469 // "n_threads" is the number of threads to be terminated. "queue_set" is a
470 // queue sets of work queues of other threads.
471 ParallelTaskTerminator(uint n_threads, TaskQueueSetSuper* queue_set);
472
473 // The current thread has no work, and is ready to terminate if everyone
474 // else is. If returns "true", all threads are terminated. If returns
475 // "false", available work has been observed in one of the task queues,
476 // so the global task is not complete.
477 bool offer_termination() {
478 return offer_termination(NULL);
479 }
480
481 // As above, but it also terminates if the should_exit_termination()
482 // method of the terminator parameter returns true. If terminator is
483 // NULL, then it is ignored.
484 virtual bool offer_termination(TerminatorTerminator* terminator);
485
486 // Reset the terminator, so that it may be reused again.
487 // The caller is responsible for ensuring that this is done
488 // in an MT-safe manner, once the previous round of use of
489 // the terminator is finished.
490 void reset_for_reuse();
491 // Same as above but the number of parallel threads is set to the
492 // given number.
493 void reset_for_reuse(uint n_threads);
494
495 #ifdef TRACESPINNING
496 static uint total_yields() { return _total_yields; }
497 static uint total_spins() { return _total_spins; }
498 static uint total_peeks() { return _total_peeks; }
499 static void print_termination_counts();
500 #endif
501 };
502
503 typedef GenericTaskQueue<oop, mtGC> OopTaskQueue;
504 typedef GenericTaskQueueSet<OopTaskQueue, mtGC> OopTaskQueueSet;
|