mutex_lock.h

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/* PROLOG END TAG zYx                                              */
#ifndef _PPU_MUTEX_LOCK_H_
#define _PPU_MUTEX_LOCK_H_

#include <ppu_intrinsics.h>
#include "sync_utils.h"
#include "mutex.h"
#include "trace_libsync.h"

/* function:    _mutex_lock
 *
 * Aquire a lock at a location in system memory by waiting for the
 * value to become zero, then atomically storing 1. 
 */
static __inline void _mutex_lock (mutex_ea_t lock)
{
  unsigned int done = 0;
  void *p;
#ifdef LIBSYNC_TRACE
  unsigned int miss = 0;
#endif /* LIBSYNC_TRACE */

  TRACE_MUTEX_LOCK_ENTRY(interval);

  SYNC_ULL_TO_PTR(lock, p);

  do {
    if (__lwarx(p) == 0) done = __stwcx(p, (unsigned int) 1);
#ifdef LIBSYNC_TRACE
    /* if we missed the lock, note it.. */
    if (done == 0) miss = 1;
#endif
  } while (done == 0);
  __isync();

  TRACE_MUTEX_LOCK_EXIT(interval, lock, miss);
}

#endif /* _PPU_MUTEX_LOCK_H_ */