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// Copyright 2008 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:
// Iterate over in-use states.
static ThreadState* FirstInUse();
// Returns NULL after the last one.
ThreadState* Next();
enum List {FREE_LIST, IN_USE_LIST};
void LinkInto(List list);
void Unlink();
static ThreadState* GetFree();
// Id of thread.
void set_id(int id) { id_ = id; }
int 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:
ThreadState();
void AllocateSpace();
int id_;
bool terminate_on_restore_;
char* data_;
ThreadState* next_;
ThreadState* previous_;
// 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.
static ThreadState* free_anchor_;
// Head of linked list of states in use.
static ThreadState* in_use_anchor_;
};
class ThreadManager : public AllStatic {
public:
static void Lock();
static void Unlock();
static void ArchiveThread();
static bool RestoreThread();
static bool IsArchived();
static void Iterate(ObjectVisitor* v);
static void MarkCompactPrologue(bool is_compacting);
static void MarkCompactEpilogue(bool is_compacting);
static bool IsLockedByCurrentThread() { return mutex_owner_.IsSelf(); }
static int CurrentId();
static void AssignId();
static bool HasId();
static void TerminateExecution(int thread_id);
static const int kInvalidId = -1;
private:
static void EagerlyArchiveThread();
static int last_id_; // V8 threads are identified through an integer.
static Mutex* mutex_;
static ThreadHandle mutex_owner_;
static ThreadHandle lazily_archived_thread_;
static ThreadState* lazily_archived_thread_state_;
};
// 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:
explicit ContextSwitcher(int every_n_ms);
void Run();
bool keep_going_;
int sleep_ms_;
static ContextSwitcher* singleton_;
};
} } // namespace v8::internal
#endif // V8_V8THREADS_H_
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