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      1 // Copyright 2012 the V8 project authors. All rights reserved.
      2 // Redistribution and use in source and binary forms, with or without
      3 // modification, are permitted provided that the following conditions are
      4 // met:
      5 //
      6 //     * Redistributions of source code must retain the above copyright
      7 //       notice, this list of conditions and the following disclaimer.
      8 //     * Redistributions in binary form must reproduce the above
      9 //       copyright notice, this list of conditions and the following
     10 //       disclaimer in the documentation and/or other materials provided
     11 //       with the distribution.
     12 //     * Neither the name of Google Inc. nor the names of its
     13 //       contributors may be used to endorse or promote products derived
     14 //       from this software without specific prior written permission.
     15 //
     16 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     17 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     18 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     19 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     20 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     21 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     22 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     23 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     24 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     25 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     26 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     27 
     28 #ifndef V8_OPTIMIZING_COMPILER_THREAD_H_
     29 #define V8_OPTIMIZING_COMPILER_THREAD_H_
     30 
     31 #include "atomicops.h"
     32 #include "flags.h"
     33 #include "platform.h"
     34 #include "unbound-queue-inl.h"
     35 
     36 namespace v8 {
     37 namespace internal {
     38 
     39 class HOptimizedGraphBuilder;
     40 class OptimizingCompiler;
     41 class SharedFunctionInfo;
     42 
     43 class OptimizingCompilerThread : public Thread {
     44  public:
     45   explicit OptimizingCompilerThread(Isolate *isolate) :
     46       Thread("OptimizingCompilerThread"),
     47 #ifdef DEBUG
     48       thread_id_(0),
     49       thread_id_mutex_(OS::CreateMutex()),
     50 #endif
     51       isolate_(isolate),
     52       stop_semaphore_(OS::CreateSemaphore(0)),
     53       input_queue_semaphore_(OS::CreateSemaphore(0)),
     54       install_mutex_(OS::CreateMutex()),
     55       time_spent_compiling_(0),
     56       time_spent_total_(0) {
     57     NoBarrier_Store(&stop_thread_, static_cast<AtomicWord>(CONTINUE));
     58     NoBarrier_Store(&queue_length_, static_cast<AtomicWord>(0));
     59   }
     60 
     61   void Run();
     62   void Stop();
     63   void Flush();
     64   void QueueForOptimization(OptimizingCompiler* optimizing_compiler);
     65   void InstallOptimizedFunctions();
     66 
     67   inline bool IsQueueAvailable() {
     68     // We don't need a barrier since we have a data dependency right
     69     // after.
     70     Atomic32 current_length = NoBarrier_Load(&queue_length_);
     71 
     72     // This can be queried only from the execution thread.
     73     ASSERT(!IsOptimizerThread());
     74     // Since only the execution thread increments queue_length_ and
     75     // only one thread can run inside an Isolate at one time, a direct
     76     // doesn't introduce a race -- queue_length_ may decreased in
     77     // meantime, but not increased.
     78     return (current_length < FLAG_parallel_recompilation_queue_length);
     79   }
     80 
     81 #ifdef DEBUG
     82   bool IsOptimizerThread();
     83 #endif
     84 
     85   ~OptimizingCompilerThread() {
     86     delete install_mutex_;
     87     delete input_queue_semaphore_;
     88     delete stop_semaphore_;
     89 #ifdef DEBUG
     90     delete thread_id_mutex_;
     91 #endif
     92   }
     93 
     94  private:
     95   enum StopFlag { CONTINUE, STOP, FLUSH };
     96 
     97   void FlushInputQueue(bool restore_function_code);
     98   void FlushOutputQueue(bool restore_function_code);
     99 
    100   void CompileNext();
    101 
    102 #ifdef DEBUG
    103   int thread_id_;
    104   Mutex* thread_id_mutex_;
    105 #endif
    106 
    107   Isolate* isolate_;
    108   Semaphore* stop_semaphore_;
    109   Semaphore* input_queue_semaphore_;
    110   UnboundQueue<OptimizingCompiler*> input_queue_;
    111   UnboundQueue<OptimizingCompiler*> output_queue_;
    112   Mutex* install_mutex_;
    113   volatile AtomicWord stop_thread_;
    114   volatile Atomic32 queue_length_;
    115   int64_t time_spent_compiling_;
    116   int64_t time_spent_total_;
    117 };
    118 
    119 } }  // namespace v8::internal
    120 
    121 #endif  // V8_OPTIMIZING_COMPILER_THREAD_H_
    122