Implement missing functionality for job based recompilation

BUG=v8:3608
R=bmeurer@chromium.org
LOG=n

Review URL: https://codereview.chromium.org/816363003

Cr-Commit-Position: refs/heads/master@{#25925}

src/flag-definitions.h

@@ -356,7 +356,6 @@ DEFINE_BOOL(job_based_recompilation, false,
             "post tasks to v8::Platform instead of using a thread for "
             "concurrent recompilation")
 DEFINE_IMPLICATION(job_based_recompilation, concurrent_recompilation)
-DEFINE_NEG_IMPLICATION(job_based_recompilation, block_concurrent_recompilation)
 DEFINE_BOOL(trace_concurrent_recompilation, false,
             "track concurrent recompilation")
 DEFINE_INT(concurrent_recompilation_queue_length, 8,

src/optimizing-compiler-thread.h

@@ -35,11 +35,13 @@ class OptimizingCompilerThread : public base::Thread {
         input_queue_shift_(0),
         osr_buffer_capacity_(FLAG_concurrent_recompilation_queue_length + 4),
         osr_buffer_cursor_(0),
+        task_count_(0),
         osr_hits_(0),
         osr_attempts_(0),
         blocked_jobs_(0),
         tracing_enabled_(FLAG_trace_concurrent_recompilation),
-        job_based_recompilation_(FLAG_job_based_recompilation) {
+        job_based_recompilation_(FLAG_job_based_recompilation),
+        recompilation_delay_(FLAG_concurrent_recompilation_delay) {
     base::NoBarrier_Store(&stop_thread_,
                           static_cast<base::AtomicWord>(CONTINUE));
     input_queue_ = NewArray<OptimizedCompileJob*>(input_queue_capacity_);
@@ -93,8 +95,8 @@ class OptimizingCompilerThread : public base::Thread {
   void FlushInputQueue(bool restore_function_code);
   void FlushOutputQueue(bool restore_function_code);
   void FlushOsrBuffer(bool restore_function_code);
-  void CompileNext();
-  OptimizedCompileJob* NextInput();
+  void CompileNext(OptimizedCompileJob* job);
+  OptimizedCompileJob* NextInput(StopFlag* flag = NULL);
 
   // Add a recompilation task for OSR to the cyclic buffer, awaiting OSR entry.
   // Tasks evicted from the cyclic buffer are discarded.
@@ -138,18 +140,27 @@ class OptimizingCompilerThread : public base::Thread {
   base::TimeDelta time_spent_compiling_;
   base::TimeDelta time_spent_total_;
 
+  int task_count_;
+  // TODO(jochen): This is currently a RecursiveMutex since both Flush/Stop and
+  // Unblock try to get it, but the former methods both can call Unblock. Once
+  // job based recompilation is on by default, and the dedicated thread can be
+  // removed, this should be refactored to not use a RecursiveMutex.
+  base::RecursiveMutex task_count_mutex_;
+
   int osr_hits_;
   int osr_attempts_;
 
   int blocked_jobs_;
 
-  // Copies of FLAG_trace_concurrent_recompilation and
+  // Copies of FLAG_trace_concurrent_recompilation,
+  // FLAG_concurrent_recompilation_delay and
   // FLAG_job_based_recompilation 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