jdk8-mips64-public/hotspot: comparison src/share/vm/utilities/taskqueue.cpp

--1:000000000000
+:f90c822e73f8
+/*
+* Copyright (c) 2001, 2014, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+* or visit www.oracle.com if you need additional information or have any
+* questions.
+*
+*/
+#include "precompiled.hpp"
+#include "oops/oop.inline.hpp"
+#include "runtime/os.hpp"
+#include "runtime/thread.inline.hpp"
+#include "utilities/debug.hpp"
+#include "utilities/stack.inline.hpp"
+#include "utilities/taskqueue.hpp"
+PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
+#ifdef TRACESPINNING
+uint ParallelTaskTerminator::_total_yields = 0;
+uint ParallelTaskTerminator::_total_spins = 0;
+uint ParallelTaskTerminator::_total_peeks = 0;
+#endif
+#if TASKQUEUE_STATS
+const char * const TaskQueueStats::_names[last_stat_id] = {
+"qpush", "qpop", "qpop-s", "qattempt", "qsteal", "opush", "omax"
+};
+TaskQueueStats & TaskQueueStats::operator +=(const TaskQueueStats & addend)
+{
+for (unsigned int i = 0; i < last_stat_id; ++i) {
+_stats[i] += addend._stats[i];
+}
+return *this;
+}
+void TaskQueueStats::print_header(unsigned int line, outputStream* const stream,
+unsigned int width)
+{
+// Use a width w: 1 <= w <= max_width
+const unsigned int max_width = 40;
+const unsigned int w = MAX2(MIN2(width, max_width), 1U);
+if (line == 0) { // spaces equal in width to the header
+const unsigned int hdr_width = w * last_stat_id + last_stat_id - 1;
+stream->print("%*s", hdr_width, " ");
+} else if (line == 1) { // labels
+stream->print("%*s", w, _names[0]);
+for (unsigned int i = 1; i < last_stat_id; ++i) {
+stream->print(" %*s", w, _names[i]);
+}
+} else if (line == 2) { // dashed lines
+char dashes[max_width + 1];
+memset(dashes, '-', w);
+dashes[w] = '\0';
+stream->print("%s", dashes);
+for (unsigned int i = 1; i < last_stat_id; ++i) {
+stream->print(" %s", dashes);
+}
+}
+}
+void TaskQueueStats::print(outputStream* stream, unsigned int width) const
+{
+#define FMT SIZE_FORMAT_W(*)
+stream->print(FMT, width, _stats[0]);
+for (unsigned int i = 1; i < last_stat_id; ++i) {
+stream->print(" " FMT, width, _stats[i]);
+}
+#undef FMT
+}
+#ifdef ASSERT
+// Invariants which should hold after a TaskQueue has been emptied and is
+// quiescent; they do not hold at arbitrary times.
+void TaskQueueStats::verify() const
+{
+assert(get(push) == get(pop) + get(steal),
+err_msg("push=" SIZE_FORMAT " pop=" SIZE_FORMAT " steal=" SIZE_FORMAT,
+get(push), get(pop), get(steal)));
+assert(get(pop_slow) <= get(pop),
+err_msg("pop_slow=" SIZE_FORMAT " pop=" SIZE_FORMAT,
+get(pop_slow), get(pop)));
+assert(get(steal) <= get(steal_attempt),
+err_msg("steal=" SIZE_FORMAT " steal_attempt=" SIZE_FORMAT,
+get(steal), get(steal_attempt)));
+assert(get(overflow) == 0 || get(push) != 0,
+err_msg("overflow=" SIZE_FORMAT " push=" SIZE_FORMAT,
+get(overflow), get(push)));
+assert(get(overflow_max_len) == 0 || get(overflow) != 0,
+err_msg("overflow_max_len=" SIZE_FORMAT " overflow=" SIZE_FORMAT,
+get(overflow_max_len), get(overflow)));
+}
+#endif // ASSERT
+#endif // TASKQUEUE_STATS
+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() {
+assert(_offered_termination <= _n_threads, "Invariant");
+os::yield();
+}
+void ParallelTaskTerminator::sleep(uint millis) {
+assert(_offered_termination <= _n_threads, "Invariant");
+os::sleep(Thread::current(), millis, false);
+}
+bool
+ParallelTaskTerminator::offer_termination(TerminatorTerminator* terminator) {
+assert(_n_threads > 0, "Initialization is incorrect");
+assert(_offered_termination < _n_threads, "Invariant");
+Atomic::inc(&_offered_termination);
+uint yield_count = 0;
+// Number of hard spin loops done since last yield
+uint hard_spin_count = 0;
+// Number of iterations in the hard spin loop.
+uint hard_spin_limit = WorkStealingHardSpins;
+// If WorkStealingSpinToYieldRatio is 0, no hard spinning is done.
+// If it is greater than 0, then start with a small number
+// of spins and increase number with each turn at spinning until
+// the count of hard spins exceeds WorkStealingSpinToYieldRatio.
+// Then do a yield() call and start spinning afresh.
+if (WorkStealingSpinToYieldRatio > 0) {
+hard_spin_limit = WorkStealingHardSpins >> WorkStealingSpinToYieldRatio;
+hard_spin_limit = MAX2(hard_spin_limit, 1U);
+}
+// Remember the initial spin limit.
+uint hard_spin_start = hard_spin_limit;
+// Loop waiting for all threads to offer termination or
+// more work.
+while (true) {
+assert(_offered_termination <= _n_threads, "Invariant");
+// Are all threads offering termination?
+if (_offered_termination == _n_threads) {
+return true;
+} else {
+// Look for more work.
+// Periodically sleep() instead of yield() to give threads
+// waiting on the cores the chance to grab this code
+if (yield_count <= WorkStealingYieldsBeforeSleep) {
+// Do a yield or hardspin.  For purposes of deciding whether
+// to sleep, count this as a yield.
+yield_count++;
+// Periodically call yield() instead spinning
+// After WorkStealingSpinToYieldRatio spins, do a yield() call
+// and reset the counts and starting limit.
+if (hard_spin_count > WorkStealingSpinToYieldRatio) {
+yield();
+hard_spin_count = 0;
+hard_spin_limit = hard_spin_start;
+#ifdef TRACESPINNING
+_total_yields++;
+#endif
+} else {
+// Hard spin this time
+// Increase the hard spinning period but only up to a limit.
+hard_spin_limit = MIN2(2*hard_spin_limit,
+(uint) WorkStealingHardSpins);
+for (uint j = 0; j < hard_spin_limit; j++) {
+SpinPause();
+}
+hard_spin_count++;
+#ifdef TRACESPINNING
+_total_spins++;
+#endif
+}
+} 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);
+}
+#ifdef TRACESPINNING
+_total_peeks++;
+#endif
+if (peek_in_queue_set() ||
+(terminator != NULL && terminator->should_exit_termination())) {
+Atomic::dec(&_offered_termination);
+assert(_offered_termination < _n_threads, "Invariant");
+return false;
+}
+}
+}
+}
+#ifdef TRACESPINNING
+void ParallelTaskTerminator::print_termination_counts() {
+gclog_or_tty->print_cr("ParallelTaskTerminator Total yields: " UINT32_FORMAT
+" Total spins: " UINT32_FORMAT " Total peeks: " UINT32_FORMAT,
+total_yields(),
+total_spins(),
+total_peeks());
+}
+#endif
+void ParallelTaskTerminator::reset_for_reuse() {
+if (_offered_termination != 0) {
+assert(_offered_termination == _n_threads,
+"Terminator may still be in use");
+_offered_termination = 0;
+}
+}
+#ifdef ASSERT
+bool ObjArrayTask::is_valid() const {
+return _obj != NULL && _obj->is_objArray() && _index > 0 &&
+_index < objArrayOop(_obj)->length();
+}
+#endif // ASSERT
+void ParallelTaskTerminator::reset_for_reuse(int n_threads) {
+reset_for_reuse();
+_n_threads = n_threads;
+}

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

comparison: src/share/vm/utilities/taskqueue.cpp

src/share/vm/utilities/taskqueue.cpp