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*
* ---
* This file is an internal part spinlock.cc and once.cc
* It may not be used directly by code outside of //base.
*/
#ifndef BASE_SPINLOCK_INTERNAL_H_
#define BASE_SPINLOCK_INTERNAL_H_
#include <config.h>
#include "base/basictypes.h"
#include "base/atomicops.h"
namespace base {
namespace internal {
// SpinLockWait() waits until it can perform one of several transitions from
// "from" to "to". It returns when it performs a transition where done==true.
struct SpinLockWaitTransition {
int32 from;
int32 to;
bool done;
};
// Wait until *w can transition from trans[i].from to trans[i].to for some i
// satisfying 0<=i<n && trans[i].done, atomically make the transition,
// then return the old value of *w. Make any other atomic tranistions
// where !trans[i].done, but continue waiting.
int32 SpinLockWait(volatile Atomic32 *w, int n,
const SpinLockWaitTransition trans[]);
void SpinLockWake(volatile Atomic32 *w, bool all);
void SpinLockDelay(volatile Atomic32 *w, int32 value, int loop);
} // namespace internal
} // namespace base
#endif