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// 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 "hydrogen.h"
#include "isolate.h"
#include "v8threads.h"
namespace v8 {
namespace internal {
void OptimizingCompilerThread::Run() {
#ifdef DEBUG
{ ScopedLock lock(thread_id_mutex_);
thread_id_ = ThreadId::Current().ToInteger();
}
#endif
Isolate::SetIsolateThreadLocals(isolate_, NULL);
DisallowHeapAllocation no_allocation;
DisallowHandleAllocation no_handles;
DisallowHandleDereference no_deref;
int64_t epoch = 0;
if (FLAG_trace_parallel_recompilation) epoch = OS::Ticks();
while (true) {
input_queue_semaphore_->Wait();
Logger::TimerEventScope timer(
isolate_, Logger::TimerEventScope::v8_recompile_parallel);
if (FLAG_parallel_recompilation_delay != 0) {
OS::Sleep(FLAG_parallel_recompilation_delay);
}
if (Acquire_Load(&stop_thread_)) {
stop_semaphore_->Signal();
if (FLAG_trace_parallel_recompilation) {
time_spent_total_ = OS::Ticks() - epoch;
}
return;
}
int64_t compiling_start = 0;
if (FLAG_trace_parallel_recompilation) compiling_start = OS::Ticks();
CompileNext();
if (FLAG_trace_parallel_recompilation) {
time_spent_compiling_ += OS::Ticks() - compiling_start;
}
}
}
void OptimizingCompilerThread::CompileNext() {
OptimizingCompiler* optimizing_compiler = NULL;
input_queue_.Dequeue(&optimizing_compiler);
Barrier_AtomicIncrement(&queue_length_, static_cast<Atomic32>(-1));
// The function may have already been optimized by OSR. Simply continue.
OptimizingCompiler::Status status = optimizing_compiler->OptimizeGraph();
USE(status); // Prevent an unused-variable error in release mode.
ASSERT(status != OptimizingCompiler::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.
ScopedLock mark_and_queue(install_mutex_);
{ Heap::RelocationLock relocation_lock(isolate_->heap());
AllowHandleDereference ahd;
optimizing_compiler->info()->closure()->MarkForInstallingRecompiledCode();
}
output_queue_.Enqueue(optimizing_compiler);
}
void OptimizingCompilerThread::Stop() {
ASSERT(!IsOptimizerThread());
Release_Store(&stop_thread_, static_cast<AtomicWord>(true));
input_queue_semaphore_->Signal();
stop_semaphore_->Wait();
if (FLAG_parallel_recompilation_delay != 0) {
// Barrier when loading queue length is not necessary since the write
// happens in CompileNext on the same thread.
while (NoBarrier_Load(&queue_length_) > 0) CompileNext();
InstallOptimizedFunctions();
} else {
OptimizingCompiler* optimizing_compiler;
// The optimizing compiler is allocated in the CompilationInfo's zone.
while (input_queue_.Dequeue(&optimizing_compiler)) {
delete optimizing_compiler->info();
}
while (output_queue_.Dequeue(&optimizing_compiler)) {
delete optimizing_compiler->info();
}
}
if (FLAG_trace_parallel_recompilation) {
double compile_time = static_cast<double>(time_spent_compiling_);
double total_time = static_cast<double>(time_spent_total_);
double percentage = (compile_time * 100) / total_time;
PrintF(" ** Compiler thread did %.2f%% useful work\n", percentage);
}
Join();
}
void OptimizingCompilerThread::InstallOptimizedFunctions() {
ASSERT(!IsOptimizerThread());
HandleScope handle_scope(isolate_);
OptimizingCompiler* compiler;
while (true) {
{ // Memory barrier to ensure marked functions are queued.
ScopedLock marked_and_queued(install_mutex_);
if (!output_queue_.Dequeue(&compiler)) return;
}
Compiler::InstallOptimizedCode(compiler);
}
}
void OptimizingCompilerThread::QueueForOptimization(
OptimizingCompiler* optimizing_compiler) {
ASSERT(IsQueueAvailable());
ASSERT(!IsOptimizerThread());
Barrier_AtomicIncrement(&queue_length_, static_cast<Atomic32>(1));
optimizing_compiler->info()->closure()->MarkInRecompileQueue();
input_queue_.Enqueue(optimizing_compiler);
input_queue_semaphore_->Signal();
}
#ifdef DEBUG
bool OptimizingCompilerThread::IsOptimizerThread() {
if (!FLAG_parallel_recompilation) return false;
ScopedLock lock(thread_id_mutex_);
return ThreadId::Current().ToInteger() == thread_id_;
}
#endif
} } // namespace v8::internal
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