Introduce SynchronizedScope to allow heap access from compiler thread.

src/optimizing-compiler-thread.h

 // 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
@@ skipping 11 matching lines @@
 // 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.
 
 #ifndef V8_OPTIMIZING_COMPILER_THREAD_H_
 #define V8_OPTIMIZING_COMPILER_THREAD_H_
 
 #include "atomicops.h"
+#include "assert-scope.h"
 #include "flags.h"
 #include "list.h"
 #include "platform.h"
 #include "platform/mutex.h"
 #include "platform/time.h"
 #include "unbound-queue-inl.h"
 
 namespace v8 {
 namespace internal {
 
+class CompilationInfo;
 class HOptimizedGraphBuilder;
 class OptimizedCompileJob;
 class SharedFunctionInfo;
 
 class OptimizingCompilerThread : public Thread {
  public:
   explicit OptimizingCompilerThread(Isolate *isolate) :
       Thread("OptimizingCompilerThread"),
 #ifdef DEBUG
       thread_id_(0),
 #endif
       isolate_(isolate),
       stop_semaphore_(0),
       input_queue_semaphore_(0),
+      main_thread_semaphore_(0),
+      compiler_thread_semaphore_(0),
       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) {
-    NoBarrier_Store(&stop_thread_, static_cast<AtomicWord>(CONTINUE));
+    NoBarrier_Store(&loop_switch_, static_cast<AtomicWord>(CONTINUE));
     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();
 
   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() {
-    LockGuard<Mutex> access_input_queue(&input_queue_mutex_);
+    LockGuard<Mutex> access_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
 
+  void PauseMainThread();
+  void ContinueMainThread();
+  void YieldToCompilerThread();
+
+  // Use this scope during the optimization phase to synchronize with
+  // the main thread in order to access the heap.
+  class SynchronizedScope {
+   public:
+    explicit SynchronizedScope(CompilationInfo* info);
+    ~SynchronizedScope();
+
+   private:
+    CompilationInfo* info_;
+    AllowHandleAllocation allow_handle_allocation_;
+    AllowHandleDereference allow_handle_dereference_;
+    AllowHeapAllocation allow_heap_allocation_;
+  };
+
  private:
-  enum StopFlag { CONTINUE, STOP, FLUSH };
+  enum LoopSwitch { CONTINUE, STOP, FLUSH };
+  enum FlushMode { DO_NOT_RESTORE_FUNCTION_CODE, RESTORE_FUNCTION_CODE };
 
-  void FlushInputQueue(bool restore_function_code);
-  void FlushOutputQueue(bool restore_function_code);
-  void FlushOsrBuffer(bool restore_function_code);
+  inline void SetSwitchAndInterceptInterrupt(LoopSwitch loop_switch);
+  inline void PrepareInterruption(LoopSwitch loop_switch);
+  inline void DisposeOptimizedCompileJob(OptimizedCompileJob* job,
+                                         FlushMode mode);
+
+  void FlushInputQueue(FlushMode mode);
+  void FlushOutputQueue(FlushMode mode);
+  void FlushOsrBuffer(FlushMode mode);
+
   void CompileNext();
   OptimizedCompileJob* NextInput();
 
   // 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_;
     ASSERT_LE(0, result);
     ASSERT_LT(result, input_queue_capacity_);
     return result;
   }
 
 #ifdef DEBUG
   int thread_id_;
   Mutex thread_id_mutex_;
 #endif
 
   Isolate* isolate_;
   Semaphore stop_semaphore_;
   Semaphore input_queue_semaphore_;
+  Semaphore main_thread_semaphore_;
+  Semaphore compiler_thread_semaphore_;
+  Mutex mutex_;
 
   // Circular queue of incoming recompilation tasks (including OSR).
   OptimizedCompileJob** input_queue_;
   int input_queue_capacity_;
   int input_queue_length_;
   int input_queue_shift_;
-  Mutex input_queue_mutex_;
 
   // Queue of recompilation tasks ready to be installed (excluding OSR).
   UnboundQueue<OptimizedCompileJob*> output_queue_;
 
   // Cyclic buffer of recompilation tasks for OSR.
   OptimizedCompileJob** osr_buffer_;
   int osr_buffer_capacity_;
   int osr_buffer_cursor_;
 
-  volatile AtomicWord stop_thread_;
+  volatile AtomicWord loop_switch_;
   TimeDelta time_spent_compiling_;
   TimeDelta time_spent_total_;
 
   int osr_hits_;
   int osr_attempts_;
 
   int blocked_jobs_;
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OPTIMIZING_COMPILER_THREAD_H_