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// 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
// with the distribution.
// * Neither the name of Google Inc. nor the names of its
// contributors may be used to endorse or promote products derived
// from this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
// 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_V8THREADS_H_
#define V8_V8THREADS_H_
namespace v8 {
namespace internal {
class ThreadState {
public:
// Returns NULL after the last one.
ThreadState* Next();
enum List {FREE_LIST, IN_USE_LIST};
void LinkInto(List list);
void Unlink();
// Id of thread.
void set_id(ThreadId id) { id_ = id; }
ThreadId id() { return id_; }
// Should the thread be terminated when it is restored?
bool terminate_on_restore() { return terminate_on_restore_; }
void set_terminate_on_restore(bool terminate_on_restore) {
terminate_on_restore_ = terminate_on_restore;
}
// Get data area for archiving a thread.
char* data() { return data_; }
private:
explicit ThreadState(ThreadManager* thread_manager);
~ThreadState();
void AllocateSpace();
ThreadId id_;
bool terminate_on_restore_;
char* data_;
ThreadState* next_;
ThreadState* previous_;
ThreadManager* thread_manager_;
friend class ThreadManager;
};
// Defined in isolate.h.
class ThreadLocalTop;
class ThreadVisitor {
public:
// ThreadLocalTop may be only available during this call.
virtual void VisitThread(Isolate* isolate, ThreadLocalTop* top) = 0;
protected:
virtual ~ThreadVisitor() {}
};
class ThreadManager {
public:
void Lock();
void Unlock();
void ArchiveThread();
bool RestoreThread();
void FreeThreadResources();
bool IsArchived();
void Iterate(ObjectVisitor* v);
void IterateArchivedThreads(ThreadVisitor* v);
bool IsLockedByCurrentThread() {
return mutex_owner_.Equals(ThreadId::Current());
}
ThreadId CurrentId();
void TerminateExecution(ThreadId thread_id);
// Iterate over in-use states.
ThreadState* FirstThreadStateInUse();
ThreadState* GetFreeThreadState();
private:
ThreadManager();
~ThreadManager();
void DeleteThreadStateList(ThreadState* anchor);
void EagerlyArchiveThread();
Mutex* mutex_;
ThreadId mutex_owner_;
ThreadId lazily_archived_thread_;
ThreadState* lazily_archived_thread_state_;
// In the following two lists there is always at least one object on the list.
// The first object is a flying anchor that is only there to simplify linking
// and unlinking.
// Head of linked list of free states.
ThreadState* free_anchor_;
// Head of linked list of states in use.
ThreadState* in_use_anchor_;
Isolate* isolate_;
friend class Isolate;
friend class ThreadState;
};
// The ContextSwitcher thread is used to schedule regular preemptions to
// multiple running V8 threads. Generally it is necessary to call
// StartPreemption if there is more than one thread running. If not, a single
// JavaScript can take full control of V8 and not allow other threads to run.
class ContextSwitcher: public Thread {
public:
// Set the preemption interval for the ContextSwitcher thread.
static void StartPreemption(int every_n_ms);
// Stop sending preemption requests to threads.
static void StopPreemption();
// Preempted thread needs to call back to the ContextSwitcher to acknowledge
// the handling of a preemption request.
static void PreemptionReceived();
private:
ContextSwitcher(Isolate* isolate, int every_n_ms);
Isolate* isolate() const { return isolate_; }
void Run();
bool keep_going_;
int sleep_ms_;
Isolate* isolate_;
};
} } // namespace v8::internal
#endif // V8_V8THREADS_H_
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