v8/src/optimizing-compiler-thread.cc

387 lines
12 KiB
C++

// Copyright 2012 the V8 project authors. All rights reserved.
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// * Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above
// copyright notice, this list of conditions and the following
// disclaimer in the documentation and/or other materials provided
// with the distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#include "optimizing-compiler-thread.h"
#include "v8.h"
#include "full-codegen.h"
#include "hydrogen.h"
#include "isolate.h"
#include "v8threads.h"
namespace v8 {
namespace internal {
OptimizingCompilerThread::~OptimizingCompilerThread() {
ASSERT_EQ(0, input_queue_length_);
DeleteArray(input_queue_);
if (FLAG_concurrent_osr) {
#ifdef DEBUG
for (int i = 0; i < osr_buffer_capacity_; i++) {
CHECK_EQ(NULL, osr_buffer_[i]);
}
#endif
DeleteArray(osr_buffer_);
}
}
void OptimizingCompilerThread::Run() {
#ifdef DEBUG
{ LockGuard<Mutex> lock_guard(&thread_id_mutex_);
thread_id_ = ThreadId::Current().ToInteger();
}
#endif
Isolate::SetIsolateThreadLocals(isolate_, NULL);
DisallowHeapAllocation no_allocation;
DisallowHandleAllocation no_handles;
DisallowHandleDereference no_deref;
ElapsedTimer total_timer;
if (FLAG_trace_concurrent_recompilation) total_timer.Start();
while (true) {
input_queue_semaphore_.Wait();
Logger::TimerEventScope timer(
isolate_, Logger::TimerEventScope::v8_recompile_concurrent);
if (FLAG_concurrent_recompilation_delay != 0) {
OS::Sleep(FLAG_concurrent_recompilation_delay);
}
switch (static_cast<StopFlag>(Acquire_Load(&stop_thread_))) {
case CONTINUE:
break;
case STOP:
if (FLAG_trace_concurrent_recompilation) {
time_spent_total_ = total_timer.Elapsed();
}
stop_semaphore_.Signal();
return;
case FLUSH:
// The main thread is blocked, waiting for the stop semaphore.
{ AllowHandleDereference allow_handle_dereference;
FlushInputQueue(true);
}
Release_Store(&stop_thread_, static_cast<AtomicWord>(CONTINUE));
stop_semaphore_.Signal();
// Return to start of consumer loop.
continue;
}
ElapsedTimer compiling_timer;
if (FLAG_trace_concurrent_recompilation) compiling_timer.Start();
CompileNext();
if (FLAG_trace_concurrent_recompilation) {
time_spent_compiling_ += compiling_timer.Elapsed();
}
}
}
RecompileJob* OptimizingCompilerThread::NextInput() {
LockGuard<Mutex> access_input_queue_(&input_queue_mutex_);
if (input_queue_length_ == 0) return NULL;
RecompileJob* job = input_queue_[InputQueueIndex(0)];
ASSERT_NE(NULL, job);
input_queue_shift_ = InputQueueIndex(1);
input_queue_length_--;
return job;
}
void OptimizingCompilerThread::CompileNext() {
RecompileJob* job = NextInput();
ASSERT_NE(NULL, job);
// The function may have already been optimized by OSR. Simply continue.
RecompileJob::Status status = job->OptimizeGraph();
USE(status); // Prevent an unused-variable error in release mode.
ASSERT(status != RecompileJob::FAILED);
// The function may have already been optimized by OSR. Simply continue.
// Use a mutex to make sure that functions marked for install
// are always also queued.
output_queue_.Enqueue(job);
isolate_->stack_guard()->RequestInstallCode();
}
static void DisposeRecompileJob(RecompileJob* job,
bool restore_function_code) {
// The recompile job is allocated in the CompilationInfo's zone.
CompilationInfo* info = job->info();
if (restore_function_code) {
if (info->is_osr()) {
if (!job->IsWaitingForInstall()) BackEdgeTable::RemoveStackCheck(info);
} else {
Handle<JSFunction> function = info->closure();
function->ReplaceCode(function->shared()->code());
}
}
delete info;
}
void OptimizingCompilerThread::FlushInputQueue(bool restore_function_code) {
RecompileJob* job;
while ((job = NextInput())) {
// This should not block, since we have one signal on the input queue
// semaphore corresponding to each element in the input queue.
input_queue_semaphore_.Wait();
// OSR jobs are dealt with separately.
if (!job->info()->is_osr()) {
DisposeRecompileJob(job, restore_function_code);
}
}
}
void OptimizingCompilerThread::FlushOutputQueue(bool restore_function_code) {
RecompileJob* job;
while (output_queue_.Dequeue(&job)) {
// OSR jobs are dealt with separately.
if (!job->info()->is_osr()) {
DisposeRecompileJob(job, restore_function_code);
}
}
}
void OptimizingCompilerThread::FlushOsrBuffer(bool restore_function_code) {
for (int i = 0; i < osr_buffer_capacity_; i++) {
if (osr_buffer_[i] != NULL) {
DisposeRecompileJob(osr_buffer_[i], restore_function_code);
osr_buffer_[i] = NULL;
}
}
}
void OptimizingCompilerThread::Flush() {
ASSERT(!IsOptimizerThread());
Release_Store(&stop_thread_, static_cast<AtomicWord>(FLUSH));
if (FLAG_block_concurrent_recompilation) Unblock();
input_queue_semaphore_.Signal();
stop_semaphore_.Wait();
FlushOutputQueue(true);
if (FLAG_concurrent_osr) FlushOsrBuffer(true);
if (FLAG_trace_concurrent_recompilation) {
PrintF(" ** Flushed concurrent recompilation queues.\n");
}
}
void OptimizingCompilerThread::Stop() {
ASSERT(!IsOptimizerThread());
Release_Store(&stop_thread_, static_cast<AtomicWord>(STOP));
if (FLAG_block_concurrent_recompilation) Unblock();
input_queue_semaphore_.Signal();
stop_semaphore_.Wait();
if (FLAG_concurrent_recompilation_delay != 0) {
// At this point the optimizing compiler thread's event loop has stopped.
// There is no need for a mutex when reading input_queue_length_.
while (input_queue_length_ > 0) CompileNext();
InstallOptimizedFunctions();
} else {
FlushInputQueue(false);
FlushOutputQueue(false);
}
if (FLAG_concurrent_osr) FlushOsrBuffer(false);
if (FLAG_trace_concurrent_recompilation) {
double percentage = time_spent_compiling_.PercentOf(time_spent_total_);
PrintF(" ** Compiler thread did %.2f%% useful work\n", percentage);
}
if ((FLAG_trace_osr || FLAG_trace_concurrent_recompilation) &&
FLAG_concurrent_osr) {
PrintF("[COSR hit rate %d / %d]\n", osr_hits_, osr_attempts_);
}
Join();
}
void OptimizingCompilerThread::InstallOptimizedFunctions() {
ASSERT(!IsOptimizerThread());
HandleScope handle_scope(isolate_);
RecompileJob* job;
while (output_queue_.Dequeue(&job)) {
CompilationInfo* info = job->info();
if (info->is_osr()) {
if (FLAG_trace_osr) {
PrintF("[COSR - ");
info->closure()->PrintName();
PrintF(" is ready for install and entry at AST id %d]\n",
info->osr_ast_id().ToInt());
}
job->WaitForInstall();
BackEdgeTable::RemoveStackCheck(info);
} else {
Compiler::InstallOptimizedCode(job);
}
}
}
void OptimizingCompilerThread::QueueForOptimization(RecompileJob* job) {
ASSERT(IsQueueAvailable());
ASSERT(!IsOptimizerThread());
CompilationInfo* info = job->info();
if (info->is_osr()) {
if (FLAG_trace_concurrent_recompilation) {
PrintF(" ** Queueing ");
info->closure()->PrintName();
PrintF(" for concurrent on-stack replacement.\n");
}
osr_attempts_++;
BackEdgeTable::AddStackCheck(info);
AddToOsrBuffer(job);
// Add job to the front of the input queue.
LockGuard<Mutex> access_input_queue(&input_queue_mutex_);
ASSERT_LT(input_queue_length_, input_queue_capacity_);
// Move shift_ back by one.
input_queue_shift_ = InputQueueIndex(input_queue_capacity_ - 1);
input_queue_[InputQueueIndex(0)] = job;
input_queue_length_++;
} else {
info->closure()->MarkInRecompileQueue();
// Add job to the back of the input queue.
LockGuard<Mutex> access_input_queue(&input_queue_mutex_);
ASSERT_LT(input_queue_length_, input_queue_capacity_);
input_queue_[InputQueueIndex(input_queue_length_)] = job;
input_queue_length_++;
}
if (FLAG_block_concurrent_recompilation) {
blocked_jobs_++;
} else {
input_queue_semaphore_.Signal();
}
}
void OptimizingCompilerThread::Unblock() {
ASSERT(!IsOptimizerThread());
while (blocked_jobs_ > 0) {
input_queue_semaphore_.Signal();
blocked_jobs_--;
}
}
RecompileJob* OptimizingCompilerThread::FindReadyOSRCandidate(
Handle<JSFunction> function, uint32_t osr_pc_offset) {
ASSERT(!IsOptimizerThread());
for (int i = 0; i < osr_buffer_capacity_; i++) {
RecompileJob* current = osr_buffer_[i];
if (current != NULL &&
current->IsWaitingForInstall() &&
current->info()->HasSameOsrEntry(function, osr_pc_offset)) {
osr_hits_++;
osr_buffer_[i] = NULL;
return current;
}
}
return NULL;
}
bool OptimizingCompilerThread::IsQueuedForOSR(Handle<JSFunction> function,
uint32_t osr_pc_offset) {
ASSERT(!IsOptimizerThread());
for (int i = 0; i < osr_buffer_capacity_; i++) {
RecompileJob* current = osr_buffer_[i];
if (current != NULL &&
current->info()->HasSameOsrEntry(function, osr_pc_offset)) {
return !current->IsWaitingForInstall();
}
}
return false;
}
bool OptimizingCompilerThread::IsQueuedForOSR(JSFunction* function) {
ASSERT(!IsOptimizerThread());
for (int i = 0; i < osr_buffer_capacity_; i++) {
RecompileJob* current = osr_buffer_[i];
if (current != NULL && *current->info()->closure() == function) {
return !current->IsWaitingForInstall();
}
}
return false;
}
void OptimizingCompilerThread::AddToOsrBuffer(RecompileJob* job) {
ASSERT(!IsOptimizerThread());
// Find the next slot that is empty or has a stale job.
RecompileJob* stale = NULL;
while (true) {
stale = osr_buffer_[osr_buffer_cursor_];
if (stale == NULL || stale->IsWaitingForInstall()) break;
osr_buffer_cursor_ = (osr_buffer_cursor_ + 1) % osr_buffer_capacity_;
}
// Add to found slot and dispose the evicted job.
if (stale != NULL) {
ASSERT(stale->IsWaitingForInstall());
CompilationInfo* info = stale->info();
if (FLAG_trace_osr) {
PrintF("[COSR - Discarded ");
info->closure()->PrintName();
PrintF(", AST id %d]\n", info->osr_ast_id().ToInt());
}
DisposeRecompileJob(stale, false);
}
osr_buffer_[osr_buffer_cursor_] = job;
osr_buffer_cursor_ = (osr_buffer_cursor_ + 1) % osr_buffer_capacity_;
}
#ifdef DEBUG
bool OptimizingCompilerThread::IsOptimizerThread(Isolate* isolate) {
return isolate->concurrent_recompilation_enabled() &&
isolate->optimizing_compiler_thread()->IsOptimizerThread();
}
bool OptimizingCompilerThread::IsOptimizerThread() {
LockGuard<Mutex> lock_guard(&thread_id_mutex_);
return ThreadId::Current().ToInteger() == thread_id_;
}
#endif
} } // namespace v8::internal