Reland "Remove support for thread-based recompilation"

src/optimizing-compile-dispatcher.h

 // 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.
 
-#ifndef V8_OPTIMIZING_COMPILER_THREAD_H_
-#define V8_OPTIMIZING_COMPILER_THREAD_H_
+#ifndef V8_OPTIMIZING_COMPILE_DISPATCHER_H_
+#define V8_OPTIMIZING_COMPILE_DISPATCHER_H_
+
+#include <queue>
 
 #include "src/base/atomicops.h"
 #include "src/base/platform/condition-variable.h"
 #include "src/base/platform/mutex.h"
 #include "src/base/platform/platform.h"
-#include "src/base/platform/time.h"
 #include "src/flags.h"
 #include "src/list.h"
-#include "src/unbound-queue-inl.h"
 
 namespace v8 {
 namespace internal {
 
 class HOptimizedGraphBuilder;
 class OptimizedCompileJob;
 class SharedFunctionInfo;
 
-class OptimizingCompilerThread : public base::Thread {
+class OptimizingCompileDispatcher {
  public:
-  explicit OptimizingCompilerThread(Isolate* isolate)
-      : Thread(Options("OptimizingCompilerThread")),
-#ifdef DEBUG
-        thread_id_(0),
-#endif
-        isolate_(isolate),
-        stop_semaphore_(0),
-        input_queue_semaphore_(0),
+  explicit OptimizingCompileDispatcher(Isolate* isolate)
+      : isolate_(isolate),
         input_queue_capacity_(FLAG_concurrent_recompilation_queue_length),
         input_queue_length_(0),
         input_queue_shift_(0),
         osr_buffer_capacity_(FLAG_concurrent_recompilation_queue_length + 4),
         osr_buffer_cursor_(0),
         osr_hits_(0),
         osr_attempts_(0),
         blocked_jobs_(0),
         ref_count_(0),
-        tracing_enabled_(FLAG_trace_concurrent_recompilation),
-        job_based_recompilation_(FLAG_job_based_recompilation),
         recompilation_delay_(FLAG_concurrent_recompilation_delay) {
-    base::NoBarrier_Store(&stop_thread_,
-                          static_cast<base::AtomicWord>(CONTINUE));
+    base::NoBarrier_Store(&mode_, static_cast<base::AtomicWord>(COMPILE));
     input_queue_ = NewArray<OptimizedCompileJob*>(input_queue_capacity_);
     if (FLAG_concurrent_osr) {
       // Allocate and mark OSR buffer slots as empty.
       osr_buffer_ = NewArray<OptimizedCompileJob*>(osr_buffer_capacity_);
       for (int i = 0; i < osr_buffer_capacity_; i++) osr_buffer_[i] = NULL;
     }
   }
 
-  ~OptimizingCompilerThread();
+  ~OptimizingCompileDispatcher();
 
   void Run();
   void Stop();
   void Flush();
   void QueueForOptimization(OptimizedCompileJob* optimizing_compiler);
   void Unblock();
   void InstallOptimizedFunctions();
   OptimizedCompileJob* FindReadyOSRCandidate(Handle<JSFunction> function,
                                              BailoutId osr_ast_id);
   bool IsQueuedForOSR(Handle<JSFunction> function, BailoutId osr_ast_id);
 
   bool IsQueuedForOSR(JSFunction* function);
 
   inline bool IsQueueAvailable() {
     base::LockGuard<base::Mutex> access_input_queue(&input_queue_mutex_);
     return input_queue_length_ < input_queue_capacity_;
   }
 
   inline void AgeBufferedOsrJobs() {
     // Advance cursor of the cyclic buffer to next empty slot or stale OSR job.
     // Dispose said OSR job in the latter case.  Calling this on every GC
     // should make sure that we do not hold onto stale jobs indefinitely.
     AddToOsrBuffer(NULL);
   }
 
   static bool Enabled(int max_available) {
     return (FLAG_concurrent_recompilation && max_available > 1);
   }
 
-#ifdef DEBUG
-  static bool IsOptimizerThread(Isolate* isolate);
-  bool IsOptimizerThread();
-#endif
-
  private:
   class CompileTask;
 
-  enum StopFlag { CONTINUE, STOP, FLUSH };
+  enum ModeFlag { COMPILE, FLUSH };
 
-  void FlushInputQueue(bool restore_function_code);
   void FlushOutputQueue(bool restore_function_code);
   void FlushOsrBuffer(bool restore_function_code);
   void CompileNext(OptimizedCompileJob* job);
   OptimizedCompileJob* NextInput(bool check_if_flushing = false);
 
   // Add a recompilation task for OSR to the cyclic buffer, awaiting OSR entry.
   // Tasks evicted from the cyclic buffer are discarded.
   void AddToOsrBuffer(OptimizedCompileJob* compiler);
 
   inline int InputQueueIndex(int i) {
     int result = (i + input_queue_shift_) % input_queue_capacity_;
     DCHECK_LE(0, result);
     DCHECK_LT(result, input_queue_capacity_);
     return result;
   }
 
-#ifdef DEBUG
-  int thread_id_;
-  base::Mutex thread_id_mutex_;
-#endif
-
   Isolate* isolate_;
-  base::Semaphore stop_semaphore_;
-  base::Semaphore input_queue_semaphore_;
 
   // Circular queue of incoming recompilation tasks (including OSR).
   OptimizedCompileJob** input_queue_;
   int input_queue_capacity_;
   int input_queue_length_;
   int input_queue_shift_;
   base::Mutex input_queue_mutex_;
 
   // Queue of recompilation tasks ready to be installed (excluding OSR).
-  UnboundQueue<OptimizedCompileJob*> output_queue_;
+  std::queue<OptimizedCompileJob*> output_queue_;
   // Used for job based recompilation which has multiple producers on
   // different threads.
   base::Mutex output_queue_mutex_;
 
   // Cyclic buffer of recompilation tasks for OSR.
   OptimizedCompileJob** osr_buffer_;
   int osr_buffer_capacity_;
   int osr_buffer_cursor_;
 
-  volatile base::AtomicWord stop_thread_;
-  base::TimeDelta time_spent_compiling_;
-  base::TimeDelta time_spent_total_;
+  volatile base::AtomicWord mode_;
 
   int osr_hits_;
   int osr_attempts_;
 
   int blocked_jobs_;
 
   int ref_count_;
   base::Mutex ref_count_mutex_;
   base::ConditionVariable ref_count_zero_;
 
-  // Copies of FLAG_trace_concurrent_recompilation,
-  // FLAG_concurrent_recompilation_delay and
-  // FLAG_job_based_recompilation that will be used from the background thread.
+  // Copy of FLAG_concurrent_recompilation_delay that will be used from the
+  // background thread.
   //
   // Since flags might get modified while the background thread is running, it
   // is not safe to access them directly.
-  bool tracing_enabled_;
-  bool job_based_recompilation_;
   int recompilation_delay_;
 };
+}
+}  // namespace v8::internal
 
-} }  // namespace v8::internal
-
-#endif  // V8_OPTIMIZING_COMPILER_THREAD_H_
+#endif  // V8_OPTIMIZING_COMPILE_DISPATCHER_H_