Mercurial > jdk8-mips64-public > hotspot / file revision

 /*

  * Copyright 2001-2006 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/_taskqueue.cpp.incl"

 bool TaskQueueSuper::peek() {

   return _bottom != _age.top();

 }

 int TaskQueueSetSuper::randomParkAndMiller(int *seed0) {

   const int a =      16807;

   const int m = 2147483647;

   const int q =     127773;  /* m div a */

   const int r =       2836;  /* m mod a */

   assert(sizeof(int) == 4, "I think this relies on that");

   int seed = *seed0;

   int hi   = seed / q;

   int lo   = seed % q;

   int test = a * lo - r * hi;

   if (test > 0)

     seed = test;

   else

     seed = test + m;

   *seed0 = seed;

   return seed;

 }

 ParallelTaskTerminator::

 ParallelTaskTerminator(int n_threads, TaskQueueSetSuper* queue_set) :

   _n_threads(n_threads),

   _queue_set(queue_set),

   _offered_termination(0) {}

 bool ParallelTaskTerminator::peek_in_queue_set() {

   return _queue_set->peek();

 }

 void ParallelTaskTerminator::yield() {

   os::yield();

 }

 void ParallelTaskTerminator::sleep(uint millis) {

   os::sleep(Thread::current(), millis, false);

 }

 bool ParallelTaskTerminator::offer_termination() {

   Atomic::inc(&_offered_termination);

   juint yield_count = 0;

   while (true) {

     if (_offered_termination == _n_threads) {

       //inner_termination_loop();

       return true;

     } else {

       if (yield_count <= WorkStealingYieldsBeforeSleep) {

         yield_count++;

         yield();

       } else {

         if (PrintGCDetails && Verbose) {

          gclog_or_tty->print_cr("ParallelTaskTerminator::offer_termination() "

            "thread %d sleeps after %d yields",

            Thread::current(), yield_count);

         }

         yield_count = 0;

         // A sleep will cause this processor to seek work on another processor's

         // runqueue, if it has nothing else to run (as opposed to the yield

         // which may only move the thread to the end of the this processor's

         // runqueue).

         sleep(WorkStealingSleepMillis);

       }

       if (peek_in_queue_set()) {

         Atomic::dec(&_offered_termination);

         return false;

       }

     }

   }

 }

 void ParallelTaskTerminator::reset_for_reuse() {

   if (_offered_termination != 0) {

     assert(_offered_termination == _n_threads,

            "Terminator may still be in use");

     _offered_termination = 0;

   }

 }

 bool ChunkTaskQueueWithOverflow::is_empty() {

   return (_chunk_queue.size() == 0) &&

          (_overflow_stack->length() == 0);

 }

 bool ChunkTaskQueueWithOverflow::stealable_is_empty() {

   return _chunk_queue.size() == 0;

 }

 bool ChunkTaskQueueWithOverflow::overflow_is_empty() {

   return _overflow_stack->length() == 0;

 }

 void ChunkTaskQueueWithOverflow::initialize() {

   _chunk_queue.initialize();

   assert(_overflow_stack == 0, "Creating memory leak");

   _overflow_stack =

     new (ResourceObj::C_HEAP) GrowableArray<ChunkTask>(10, true);

 }

 void ChunkTaskQueueWithOverflow::save(ChunkTask t) {

   if (TraceChunkTasksQueuing && Verbose) {

     gclog_or_tty->print_cr("CTQ: save " PTR_FORMAT, t);

   }

   if(!_chunk_queue.push(t)) {

     _overflow_stack->push(t);

   }

 }

 // Note that using this method will retrieve all chunks

 // that have been saved but that it will always check

 // the overflow stack.  It may be more efficient to

 // check the stealable queue and the overflow stack

 // separately.

 bool ChunkTaskQueueWithOverflow::retrieve(ChunkTask& chunk_task) {

   bool result = retrieve_from_overflow(chunk_task);

   if (!result) {

     result = retrieve_from_stealable_queue(chunk_task);

   }

   if (TraceChunkTasksQueuing && Verbose && result) {

     gclog_or_tty->print_cr("  CTQ: retrieve " PTR_FORMAT, result);

   }

   return result;

 }

 bool ChunkTaskQueueWithOverflow::retrieve_from_stealable_queue(

                                    ChunkTask& chunk_task) {

   bool result = _chunk_queue.pop_local(chunk_task);

   if (TraceChunkTasksQueuing && Verbose) {

     gclog_or_tty->print_cr("CTQ: retrieve_stealable " PTR_FORMAT, chunk_task);

   }

   return result;

 }

 bool ChunkTaskQueueWithOverflow::retrieve_from_overflow(

                                         ChunkTask& chunk_task) {

   bool result;

   if (!_overflow_stack->is_empty()) {

     chunk_task = _overflow_stack->pop();

     result = true;

   } else {

     chunk_task = (ChunkTask) NULL;

     result = false;

   }

   if (TraceChunkTasksQueuing && Verbose) {

     gclog_or_tty->print_cr("CTQ: retrieve_stealable " PTR_FORMAT, chunk_task);

   }

   return result;

 }