OSThreads.h

/* Always check the result of lock and unlock. */
#define OS_ACQUIRE_LOCK(mutex) \
  LOCK_DEBUG_BELCH("begin ACQUIRE_LOCK...", mutex); \
  { int __result = pthread_mutex_lock(mutex); \
  LOCK_DEBUG_BELCH("end ACQUIRE_LOCK...", mutex); \
  if (__result == EDEADLK) { \
    barf("multiple ACQUIRE_LOCK: %s %d", __FILE__,__LINE__); \
  } \
  }

#define OS_RELEASE_LOCK(mutex) \
  LOCK_DEBUG_BELCH("RELEASE_LOCK", mutex); \
  if (pthread_mutex_unlock(mutex) != 0) { \
    barf("RELEASE_LOCK: I do not own this lock: %s %d", __FILE__,__LINE__); \
  }