8187443: Forest Consolidation: Move files to unified layout
Reviewed-by: darcy, ihse
/*
* Copyright (c) 2001, 2016, 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 "gc/shared/taskqueue.hpp"
#include "oops/oop.inline.hpp"
#include "logging/log.hpp"
#include "runtime/atomic.hpp"
#include "runtime/os.hpp"
#include "runtime/thread.inline.hpp"
#include "utilities/debug.hpp"
#include "utilities/stack.inline.hpp"
#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),
"push=" SIZE_FORMAT " pop=" SIZE_FORMAT " steal=" SIZE_FORMAT,
get(push), get(pop), get(steal));
assert(get(pop_slow) <= get(pop),
"pop_slow=" SIZE_FORMAT " pop=" SIZE_FORMAT,
get(pop_slow), get(pop));
assert(get(steal) <= get(steal_attempt),
"steal=" SIZE_FORMAT " steal_attempt=" SIZE_FORMAT,
get(steal), get(steal_attempt));
assert(get(overflow) == 0 || get(push) != 0,
"overflow=" SIZE_FORMAT " push=" SIZE_FORMAT,
get(overflow), get(push));
assert(get(overflow_max_len) == 0 || get(overflow) != 0,
"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(uint 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::naked_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((int *)&_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 {
log_develop_trace(gc, task)("ParallelTaskTerminator::offer_termination() thread " PTR_FORMAT " sleeps after %u yields",
p2i(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((int *)&_offered_termination);
assert(_offered_termination < _n_threads, "Invariant");
return false;
}
}
}
}
#ifdef TRACESPINNING
void ParallelTaskTerminator::print_termination_counts() {
log_trace(gc, task)("ParallelTaskTerminator Total yields: %u"
" Total spins: %u Total peeks: %u",
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(uint n_threads) {
reset_for_reuse();
_n_threads = n_threads;
}