Move platform abstraction to base library

src/platform/condition-variable.h

-// Copyright 2013 the V8 project authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef V8_PLATFORM_CONDITION_VARIABLE_H_
-#define V8_PLATFORM_CONDITION_VARIABLE_H_
-
-#include "src/base/lazy-instance.h"
-#include "src/platform/mutex.h"
-
-namespace v8 {
-namespace internal {
-
-// Forward declarations.
-class ConditionVariableEvent;
-class TimeDelta;
-
-// -----------------------------------------------------------------------------
-// ConditionVariable
-//
-// This class is a synchronization primitive that can be used to block a thread,
-// or multiple threads at the same time, until:
-// - a notification is received from another thread,
-// - a timeout expires, or
-// - a spurious wakeup occurs
-// Any thread that intends to wait on a ConditionVariable has to acquire a lock
-// on a Mutex first. The |Wait()| and |WaitFor()| operations atomically release
-// the mutex and suspend the execution of the calling thread. When the condition
-// variable is notified, the thread is awakened, and the mutex is reacquired.
-
-class ConditionVariable V8_FINAL {
- public:
-  ConditionVariable();
-  ~ConditionVariable();
-
-  // If any threads are waiting on this condition variable, calling
-  // |NotifyOne()| unblocks one of the waiting threads.
-  void NotifyOne();
-
-  // Unblocks all threads currently waiting for this condition variable.
-  void NotifyAll();
-
-  // |Wait()| causes the calling thread to block until the condition variable is
-  // notified or a spurious wakeup occurs. Atomically releases the mutex, blocks
-  // the current executing thread, and adds it to the list of threads waiting on
-  // this condition variable. The thread will be unblocked when |NotifyAll()| or
-  // |NotifyOne()| is executed. It may also be unblocked spuriously. When
-  // unblocked, regardless of the reason, the lock on the mutex is reacquired
-  // and |Wait()| exits.
-  void Wait(Mutex* mutex);
-
-  // Atomically releases the mutex, blocks the current executing thread, and
-  // adds it to the list of threads waiting on this condition variable. The
-  // thread will be unblocked when |NotifyAll()| or |NotifyOne()| is executed,
-  // or when the relative timeout |rel_time| expires. It may also be unblocked
-  // spuriously. When unblocked, regardless of the reason, the lock on the mutex
-  // is reacquired and |WaitFor()| exits. Returns true if the condition variable
-  // was notified prior to the timeout.
-  bool WaitFor(Mutex* mutex, const TimeDelta& rel_time) V8_WARN_UNUSED_RESULT;
-
-  // The implementation-defined native handle type.
-#if V8_OS_POSIX
-  typedef pthread_cond_t NativeHandle;
-#elif V8_OS_WIN
-  struct Event;
-  class NativeHandle V8_FINAL {
-   public:
-    NativeHandle() : waitlist_(NULL), freelist_(NULL) {}
-    ~NativeHandle();
-
-    Event* Pre() V8_WARN_UNUSED_RESULT;
-    void Post(Event* event, bool result);
-
-    Mutex* mutex() { return &mutex_; }
-    Event* waitlist() { return waitlist_; }
-
-   private:
-    Event* waitlist_;
-    Event* freelist_;
-    Mutex mutex_;
-
-    DISALLOW_COPY_AND_ASSIGN(NativeHandle);
-  };
-#endif
-
-  NativeHandle& native_handle() {
-    return native_handle_;
-  }
-  const NativeHandle& native_handle() const {
-    return native_handle_;
-  }
-
- private:
-  NativeHandle native_handle_;
-
-  DISALLOW_COPY_AND_ASSIGN(ConditionVariable);
-};
-
-
-// POD ConditionVariable initialized lazily (i.e. the first time Pointer() is
-// called).
-// Usage:
-//   static LazyConditionVariable my_condvar =
-//       LAZY_CONDITION_VARIABLE_INITIALIZER;
-//
-//   void my_function() {
-//     LockGuard<Mutex> lock_guard(&my_mutex);
-//     my_condvar.Pointer()->Wait(&my_mutex);
-//   }
-typedef base::LazyStaticInstance<
-    ConditionVariable, base::DefaultConstructTrait<ConditionVariable>,
-    base::ThreadSafeInitOnceTrait>::type LazyConditionVariable;
-
-#define LAZY_CONDITION_VARIABLE_INITIALIZER LAZY_STATIC_INSTANCE_INITIALIZER
-
-} }  // namespace v8::internal
-
-#endif  // V8_PLATFORM_CONDITION_VARIABLE_H_