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v8threads.h
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27 
28 #ifndef V8_V8THREADS_H_
29 #define V8_V8THREADS_H_
30 
31 namespace v8 {
32 namespace internal {
33 
34 
35 class ThreadState {
36  public:
37  // Returns NULL after the last one.
38  ThreadState* Next();
39 
41 
42  void LinkInto(List list);
43  void Unlink();
44 
45  // Id of thread.
46  void set_id(ThreadId id) { id_ = id; }
47  ThreadId id() { return id_; }
48 
49  // Should the thread be terminated when it is restored?
50  bool terminate_on_restore() { return terminate_on_restore_; }
52  terminate_on_restore_ = terminate_on_restore;
53  }
54 
55  // Get data area for archiving a thread.
56  char* data() { return data_; }
57 
58  private:
59  explicit ThreadState(ThreadManager* thread_manager);
60  ~ThreadState();
61 
62  void AllocateSpace();
63 
64  ThreadId id_;
65  bool terminate_on_restore_;
66  char* data_;
67  ThreadState* next_;
68  ThreadState* previous_;
69 
70  ThreadManager* thread_manager_;
71 
72  friend class ThreadManager;
73 };
74 
75 
76 // Defined in isolate.h.
77 class ThreadLocalTop;
78 
79 
81  public:
82  // ThreadLocalTop may be only available during this call.
83  virtual void VisitThread(Isolate* isolate, ThreadLocalTop* top) = 0;
84 
85  protected:
86  virtual ~ThreadVisitor() {}
87 };
88 
89 
91  public:
92  void Lock();
93  void Unlock();
94 
95  void ArchiveThread();
96  bool RestoreThread();
97  void FreeThreadResources();
98  bool IsArchived();
99 
100  void Iterate(ObjectVisitor* v);
103  return mutex_owner_.Equals(ThreadId::Current());
104  }
105 
107 
108  void TerminateExecution(ThreadId thread_id);
109 
110  // Iterate over in-use states.
113 
114  private:
115  ThreadManager();
116  ~ThreadManager();
117 
118  void DeleteThreadStateList(ThreadState* anchor);
119 
120  void EagerlyArchiveThread();
121 
122  Mutex* mutex_;
123  ThreadId mutex_owner_;
124  ThreadId lazily_archived_thread_;
125  ThreadState* lazily_archived_thread_state_;
126 
127  // In the following two lists there is always at least one object on the list.
128  // The first object is a flying anchor that is only there to simplify linking
129  // and unlinking.
130  // Head of linked list of free states.
131  ThreadState* free_anchor_;
132  // Head of linked list of states in use.
133  ThreadState* in_use_anchor_;
134 
135  Isolate* isolate_;
136 
137  friend class Isolate;
138  friend class ThreadState;
139 };
140 
141 
142 // The ContextSwitcher thread is used to schedule regular preemptions to
143 // multiple running V8 threads. Generally it is necessary to call
144 // StartPreemption if there is more than one thread running. If not, a single
145 // JavaScript can take full control of V8 and not allow other threads to run.
146 class ContextSwitcher: public Thread {
147  public:
148  // Set the preemption interval for the ContextSwitcher thread.
149  static void StartPreemption(int every_n_ms);
150 
151  // Stop sending preemption requests to threads.
152  static void StopPreemption();
153 
154  // Preempted thread needs to call back to the ContextSwitcher to acknowledge
155  // the handling of a preemption request.
156  static void PreemptionReceived();
157 
158  private:
159  ContextSwitcher(Isolate* isolate, int every_n_ms);
160 
161  Isolate* isolate() const { return isolate_; }
162 
163  void Run();
164 
165  bool keep_going_;
166  int sleep_ms_;
167  Isolate* isolate_;
168 };
169 
170 } } // namespace v8::internal
171 
172 #endif // V8_V8THREADS_H_
void LinkInto(List list)
Definition: v8threads.cc:264
void IterateArchivedThreads(ThreadVisitor *v)
Definition: v8threads.cc:400
void set_id(ThreadId id)
Definition: v8threads.h:46
void TerminateExecution(ThreadId thread_id)
Definition: v8threads.cc:416
static void PreemptionReceived()
Definition: v8threads.cc:481
static ThreadId Current()
Definition: isolate.h:154
void Iterate(ObjectVisitor *v)
Definition: v8threads.cc:387
ThreadState * GetFreeThreadState()
Definition: v8threads.cc:275
virtual void VisitThread(Isolate *isolate, ThreadLocalTop *top)=0
static void StartPreemption(int every_n_ms)
Definition: v8threads.cc:437
void set_terminate_on_restore(bool terminate_on_restore)
Definition: v8threads.h:51
ThreadState * FirstThreadStateInUse()
Definition: v8threads.cc:287
ThreadState * Next()
Definition: v8threads.cc:292