1// Copyright 2012 the V8 project authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#ifndef V8_COMPILER_DISPATCHER_OPTIMIZING_COMPILE_DISPATCHER_H_
6#define V8_COMPILER_DISPATCHER_OPTIMIZING_COMPILE_DISPATCHER_H_
7
8#include <atomic>
9#include <queue>
10
11#include "src/base/platform/condition-variable.h"
12#include "src/base/platform/mutex.h"
13#include "src/base/platform/platform.h"
14#include "src/common/globals.h"
15#include "src/flags/flags.h"
16#include "src/utils/allocation.h"
17
18namespace v8 {
19namespace internal {
20
21class LocalHeap;
22class TurbofanCompilationJob;
23class RuntimeCallStats;
24class SharedFunctionInfo;
25
26class V8_EXPORT_PRIVATE OptimizingCompileDispatcher {
27 public:
28  explicit OptimizingCompileDispatcher(Isolate* isolate)
29      : isolate_(isolate),
30        input_queue_capacity_(FLAG_concurrent_recompilation_queue_length),
31        input_queue_length_(0),
32        input_queue_shift_(0),
33        ref_count_(0),
34        recompilation_delay_(FLAG_concurrent_recompilation_delay) {
35    input_queue_ = NewArray<TurbofanCompilationJob*>(input_queue_capacity_);
36  }
37
38  ~OptimizingCompileDispatcher();
39
40  void Stop();
41  void Flush(BlockingBehavior blocking_behavior);
42  // Takes ownership of |job|.
43  void QueueForOptimization(TurbofanCompilationJob* job);
44  void AwaitCompileTasks();
45  void InstallOptimizedFunctions();
46
47  inline bool IsQueueAvailable() {
48    base::MutexGuard access_input_queue(&input_queue_mutex_);
49    return input_queue_length_ < input_queue_capacity_;
50  }
51
52  static bool Enabled() { return FLAG_concurrent_recompilation; }
53
54  // This method must be called on the main thread.
55  bool HasJobs();
56
57  // Whether to finalize and thus install the optimized code.  Defaults to true.
58  // Only set to false for testing (where finalization is then manually
59  // requested using %FinalizeOptimization).
60  bool finalize() const { return finalize_; }
61  void set_finalize(bool finalize) {
62    CHECK(!HasJobs());
63    finalize_ = finalize;
64  }
65
66 private:
67  class CompileTask;
68
69  enum ModeFlag { COMPILE, FLUSH };
70
71  void FlushQueues(BlockingBehavior blocking_behavior,
72                   bool restore_function_code);
73  void FlushInputQueue();
74  void FlushOutputQueue(bool restore_function_code);
75  void CompileNext(TurbofanCompilationJob* job, LocalIsolate* local_isolate);
76  TurbofanCompilationJob* NextInput(LocalIsolate* local_isolate);
77
78  inline int InputQueueIndex(int i) {
79    int result = (i + input_queue_shift_) % input_queue_capacity_;
80    DCHECK_LE(0, result);
81    DCHECK_LT(result, input_queue_capacity_);
82    return result;
83  }
84
85  Isolate* isolate_;
86
87  // Circular queue of incoming recompilation tasks (including OSR).
88  TurbofanCompilationJob** input_queue_;
89  int input_queue_capacity_;
90  int input_queue_length_;
91  int input_queue_shift_;
92  base::Mutex input_queue_mutex_;
93
94  // Queue of recompilation tasks ready to be installed (excluding OSR).
95  std::queue<TurbofanCompilationJob*> output_queue_;
96  // Used for job based recompilation which has multiple producers on
97  // different threads.
98  base::Mutex output_queue_mutex_;
99
100  std::atomic<int> ref_count_;
101  base::Mutex ref_count_mutex_;
102  base::ConditionVariable ref_count_zero_;
103
104  // Copy of FLAG_concurrent_recompilation_delay that will be used from the
105  // background thread.
106  //
107  // Since flags might get modified while the background thread is running, it
108  // is not safe to access them directly.
109  int recompilation_delay_;
110
111  bool finalize_ = true;
112};
113}  // namespace internal
114}  // namespace v8
115
116#endif  // V8_COMPILER_DISPATCHER_OPTIMIZING_COMPILE_DISPATCHER_H_
117