Reland "Remove support for thread-based recompilation"

src/optimizing-compiler-thread.cc

Index: src/optimizing-compiler-thread.cc
diff --git a/src/optimizing-compiler-thread.cc b/src/optimizing-compiler-thread.cc
deleted file mode 100644
index eda4f5ca9d9cb868a6c5df4cbc4b2675ff31f662..0000000000000000000000000000000000000000
--- a/src/optimizing-compiler-thread.cc
+++ /dev/null
@@ -1,463 +0,0 @@
-// Copyright 2012 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "src/optimizing-compiler-thread.h"
-
-#include "src/v8.h"
-
-#include "src/base/atomicops.h"
-#include "src/full-codegen.h"
-#include "src/hydrogen.h"
-#include "src/isolate.h"
-#include "src/v8threads.h"
-
-namespace v8 {
-namespace internal {
-
-namespace {
-
-void DisposeOptimizedCompileJob(OptimizedCompileJob* 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()) {
-        // Remove stack check that guards OSR entry on original code.
-        Handle<Code> code = info->unoptimized_code();
-        uint32_t offset = code->TranslateAstIdToPcOffset(info->osr_ast_id());
-        BackEdgeTable::RemoveStackCheck(code, offset);
-      }
-    } else {
-      Handle<JSFunction> function = info->closure();
-      function->ReplaceCode(function->shared()->code());
-    }
-  }
-  delete info;
-}
-
-}  // namespace
-
-
-class OptimizingCompilerThread::CompileTask : public v8::Task {
- public:
-  explicit CompileTask(Isolate* isolate) : isolate_(isolate) {
-    OptimizingCompilerThread* thread = isolate_->optimizing_compiler_thread();
-    base::LockGuard<base::Mutex> lock_guard(&thread->ref_count_mutex_);
-    ++thread->ref_count_;
-  }
-
-  virtual ~CompileTask() {}
-
- private:
-  // v8::Task overrides.
-  void Run() OVERRIDE {
-    DisallowHeapAllocation no_allocation;
-    DisallowHandleAllocation no_handles;
-    DisallowHandleDereference no_deref;
-
-    OptimizingCompilerThread* thread = isolate_->optimizing_compiler_thread();
-    {
-      TimerEventScope<TimerEventRecompileConcurrent> timer(isolate_);
-
-      if (thread->recompilation_delay_ != 0) {
-        base::OS::Sleep(thread->recompilation_delay_);
-      }
-
-      thread->CompileNext(thread->NextInput(true));
-    }
-    {
-      base::LockGuard<base::Mutex> lock_guard(&thread->ref_count_mutex_);
-      if (--thread->ref_count_ == 0) {
-        thread->ref_count_zero_.NotifyOne();
-      }
-    }
-  }
-
-  Isolate* isolate_;
-
-  DISALLOW_COPY_AND_ASSIGN(CompileTask);
-};
-
-
-OptimizingCompilerThread::~OptimizingCompilerThread() {
-#ifdef DEBUG
-  {
-    base::LockGuard<base::Mutex> lock_guard(&ref_count_mutex_);
-    DCHECK_EQ(0, ref_count_);
-  }
-#endif
-  DCHECK_EQ(0, input_queue_length_);
-  DeleteArray(input_queue_);
-  if (FLAG_concurrent_osr) {
-#ifdef DEBUG
-    for (int i = 0; i < osr_buffer_capacity_; i++) {
-      CHECK_NULL(osr_buffer_[i]);
-    }
-#endif
-    DeleteArray(osr_buffer_);
-  }
-}
-
-
-void OptimizingCompilerThread::Run() {
-#ifdef DEBUG
-  { base::LockGuard<base::Mutex> lock_guard(&thread_id_mutex_);
-    thread_id_ = ThreadId::Current().ToInteger();
-  }
-#endif
-  DisallowHeapAllocation no_allocation;
-  DisallowHandleAllocation no_handles;
-  DisallowHandleDereference no_deref;
-
-  if (job_based_recompilation_) {
-    return;
-  }
-
-  base::ElapsedTimer total_timer;
-  if (tracing_enabled_) total_timer.Start();
-
-  while (true) {
-    input_queue_semaphore_.Wait();
-    TimerEventScope<TimerEventRecompileConcurrent> timer(isolate_);
-
-    if (recompilation_delay_ != 0) {
-      base::OS::Sleep(recompilation_delay_);
-    }
-
-    switch (static_cast<StopFlag>(base::Acquire_Load(&stop_thread_))) {
-      case CONTINUE:
-        break;
-      case STOP:
-        if (tracing_enabled_) {
-          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);
-        }
-        base::Release_Store(&stop_thread_,
-                            static_cast<base::AtomicWord>(CONTINUE));
-        stop_semaphore_.Signal();
-        // Return to start of consumer loop.
-        continue;
-    }
-
-    base::ElapsedTimer compiling_timer;
-    if (tracing_enabled_) compiling_timer.Start();
-
-    CompileNext(NextInput());
-
-    if (tracing_enabled_) {
-      time_spent_compiling_ += compiling_timer.Elapsed();
-    }
-  }
-}
-
-
-OptimizedCompileJob* OptimizingCompilerThread::NextInput(
-    bool check_if_flushing) {
-  base::LockGuard<base::Mutex> access_input_queue_(&input_queue_mutex_);
-  if (input_queue_length_ == 0) return NULL;
-  OptimizedCompileJob* job = input_queue_[InputQueueIndex(0)];
-  DCHECK_NOT_NULL(job);
-  input_queue_shift_ = InputQueueIndex(1);
-  input_queue_length_--;
-  if (check_if_flushing) {
-    if (static_cast<StopFlag>(base::Acquire_Load(&stop_thread_)) != CONTINUE) {
-      if (!job->info()->is_osr()) {
-        AllowHandleDereference allow_handle_dereference;
-        DisposeOptimizedCompileJob(job, true);
-      }
-      return NULL;
-    }
-  }
-  return job;
-}
-
-
-void OptimizingCompilerThread::CompileNext(OptimizedCompileJob* job) {
-  if (!job) return;
-
-  // The function may have already been optimized by OSR.  Simply continue.
-  OptimizedCompileJob::Status status = job->OptimizeGraph();
-  USE(status);   // Prevent an unused-variable error in release mode.
-  DCHECK(status != OptimizedCompileJob::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.
-  if (job_based_recompilation_) output_queue_mutex_.Lock();
-  output_queue_.Enqueue(job);
-  if (job_based_recompilation_) output_queue_mutex_.Unlock();
-  isolate_->stack_guard()->RequestInstallCode();
-}
-
-
-void OptimizingCompilerThread::FlushInputQueue(bool restore_function_code) {
-  OptimizedCompileJob* job;
-  while ((job = NextInput())) {
-    DCHECK(!job_based_recompilation_);
-    // 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()) {
-      DisposeOptimizedCompileJob(job, restore_function_code);
-    }
-  }
-}
-
-
-void OptimizingCompilerThread::FlushOutputQueue(bool restore_function_code) {
-  OptimizedCompileJob* job;
-  while (output_queue_.Dequeue(&job)) {
-    // OSR jobs are dealt with separately.
-    if (!job->info()->is_osr()) {
-      DisposeOptimizedCompileJob(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) {
-      DisposeOptimizedCompileJob(osr_buffer_[i], restore_function_code);
-      osr_buffer_[i] = NULL;
-    }
-  }
-}
-
-
-void OptimizingCompilerThread::Flush() {
-  DCHECK(!IsOptimizerThread());
-  base::Release_Store(&stop_thread_, static_cast<base::AtomicWord>(FLUSH));
-  if (FLAG_block_concurrent_recompilation) Unblock();
-  if (!job_based_recompilation_) {
-    input_queue_semaphore_.Signal();
-    stop_semaphore_.Wait();
-  } else {
-    base::LockGuard<base::Mutex> lock_guard(&ref_count_mutex_);
-    while (ref_count_ > 0) ref_count_zero_.Wait(&ref_count_mutex_);
-    base::Release_Store(&stop_thread_, static_cast<base::AtomicWord>(CONTINUE));
-  }
-  FlushOutputQueue(true);
-  if (FLAG_concurrent_osr) FlushOsrBuffer(true);
-  if (tracing_enabled_) {
-    PrintF("  ** Flushed concurrent recompilation queues.\n");
-  }
-}
-
-
-void OptimizingCompilerThread::Stop() {
-  DCHECK(!IsOptimizerThread());
-  base::Release_Store(&stop_thread_, static_cast<base::AtomicWord>(STOP));
-  if (FLAG_block_concurrent_recompilation) Unblock();
-  if (!job_based_recompilation_) {
-    input_queue_semaphore_.Signal();
-    stop_semaphore_.Wait();
-  } else {
-    base::LockGuard<base::Mutex> lock_guard(&ref_count_mutex_);
-    while (ref_count_ > 0) ref_count_zero_.Wait(&ref_count_mutex_);
-    base::Release_Store(&stop_thread_, static_cast<base::AtomicWord>(CONTINUE));
-  }
-
-  if (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(NextInput());
-    InstallOptimizedFunctions();
-  } else {
-    FlushInputQueue(false);
-    FlushOutputQueue(false);
-  }
-
-  if (FLAG_concurrent_osr) FlushOsrBuffer(false);
-
-  if (tracing_enabled_) {
-    double percentage = time_spent_compiling_.PercentOf(time_spent_total_);
-    if (job_based_recompilation_) percentage = 100.0;
-    PrintF("  ** Compiler thread did %.2f%% useful work\n", percentage);
-  }
-
-  if ((FLAG_trace_osr || tracing_enabled_) && FLAG_concurrent_osr) {
-    PrintF("[COSR hit rate %d / %d]\n", osr_hits_, osr_attempts_);
-  }
-
-  Join();
-}
-
-
-void OptimizingCompilerThread::InstallOptimizedFunctions() {
-  DCHECK(!IsOptimizerThread());
-  HandleScope handle_scope(isolate_);
-
-  OptimizedCompileJob* job;
-  while (output_queue_.Dequeue(&job)) {
-    CompilationInfo* info = job->info();
-    Handle<JSFunction> function(*info->closure());
-    if (info->is_osr()) {
-      if (FLAG_trace_osr) {
-        PrintF("[COSR - ");
-        function->ShortPrint();
-        PrintF(" is ready for install and entry at AST id %d]\n",
-               info->osr_ast_id().ToInt());
-      }
-      job->WaitForInstall();
-      // Remove stack check that guards OSR entry on original code.
-      Handle<Code> code = info->unoptimized_code();
-      uint32_t offset = code->TranslateAstIdToPcOffset(info->osr_ast_id());
-      BackEdgeTable::RemoveStackCheck(code, offset);
-    } else {
-      if (function->IsOptimized()) {
-        if (tracing_enabled_) {
-          PrintF("  ** Aborting compilation for ");
-          function->ShortPrint();
-          PrintF(" as it has already been optimized.\n");
-        }
-        DisposeOptimizedCompileJob(job, false);
-      } else {
-        Handle<Code> code = Compiler::GetConcurrentlyOptimizedCode(job);
-        function->ReplaceCode(
-            code.is_null() ? function->shared()->code() : *code);
-      }
-    }
-  }
-}
-
-
-void OptimizingCompilerThread::QueueForOptimization(OptimizedCompileJob* job) {
-  DCHECK(IsQueueAvailable());
-  DCHECK(!IsOptimizerThread());
-  CompilationInfo* info = job->info();
-  if (info->is_osr()) {
-    osr_attempts_++;
-    AddToOsrBuffer(job);
-    // Add job to the front of the input queue.
-    base::LockGuard<base::Mutex> access_input_queue(&input_queue_mutex_);
-    DCHECK_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 {
-    // Add job to the back of the input queue.
-    base::LockGuard<base::Mutex> access_input_queue(&input_queue_mutex_);
-    DCHECK_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 if (job_based_recompilation_) {
-    V8::GetCurrentPlatform()->CallOnBackgroundThread(
-        new CompileTask(isolate_), v8::Platform::kShortRunningTask);
-  } else {
-    input_queue_semaphore_.Signal();
-  }
-}
-
-
-void OptimizingCompilerThread::Unblock() {
-  DCHECK(!IsOptimizerThread());
-  while (blocked_jobs_ > 0) {
-    if (job_based_recompilation_) {
-      V8::GetCurrentPlatform()->CallOnBackgroundThread(
-          new CompileTask(isolate_), v8::Platform::kShortRunningTask);
-    } else {
-      input_queue_semaphore_.Signal();
-    }
-    blocked_jobs_--;
-  }
-}
-
-
-OptimizedCompileJob* OptimizingCompilerThread::FindReadyOSRCandidate(
-    Handle<JSFunction> function, BailoutId osr_ast_id) {
-  DCHECK(!IsOptimizerThread());
-  for (int i = 0; i < osr_buffer_capacity_; i++) {
-    OptimizedCompileJob* current = osr_buffer_[i];
-    if (current != NULL &&
-        current->IsWaitingForInstall() &&
-        current->info()->HasSameOsrEntry(function, osr_ast_id)) {
-      osr_hits_++;
-      osr_buffer_[i] = NULL;
-      return current;
-    }
-  }
-  return NULL;
-}
-
-
-bool OptimizingCompilerThread::IsQueuedForOSR(Handle<JSFunction> function,
-                                              BailoutId osr_ast_id) {
-  DCHECK(!IsOptimizerThread());
-  for (int i = 0; i < osr_buffer_capacity_; i++) {
-    OptimizedCompileJob* current = osr_buffer_[i];
-    if (current != NULL &&
-        current->info()->HasSameOsrEntry(function, osr_ast_id)) {
-      return !current->IsWaitingForInstall();
-    }
-  }
-  return false;
-}
-
-
-bool OptimizingCompilerThread::IsQueuedForOSR(JSFunction* function) {
-  DCHECK(!IsOptimizerThread());
-  for (int i = 0; i < osr_buffer_capacity_; i++) {
-    OptimizedCompileJob* current = osr_buffer_[i];
-    if (current != NULL && *current->info()->closure() == function) {
-      return !current->IsWaitingForInstall();
-    }
-  }
-  return false;
-}
-
-
-void OptimizingCompilerThread::AddToOsrBuffer(OptimizedCompileJob* job) {
-  DCHECK(!IsOptimizerThread());
-  // Find the next slot that is empty or has a stale job.
-  OptimizedCompileJob* 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) {
-    DCHECK(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());
-    }
-    DisposeOptimizedCompileJob(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() {
-  base::LockGuard<base::Mutex> lock_guard(&thread_id_mutex_);
-  return ThreadId::Current().ToInteger() == thread_id_;
-}
-#endif
-
-
-} }  // namespace v8::internal