/*
	 * Double check inside mutex to avoid race, then initialize condition
	 * variable if necessary.
	 */

	if (*condPtr == NULL) {
#undef attr_p
#if defined(_POSIX_TIMERS) && defined(_POSIX_MONOTONIC_CLOCK)
#define attr_p (&attr)
	    pthread_condattr_t attr;
	    pthread_condattr_init(&attr);
	    pthread_condattr_setclock(&attr,CLOCK_MONOTONIC);
#else
#define attr_p (NULL)
#endif
	    pcondPtr = (pthread_cond_t *) ckalloc(sizeof(pthread_cond_t));
	    pthread_cond_init(pcondPtr, NULL);
	    *condPtr = (Tcl_Condition)pcondPtr;
	    TclRememberCondition(condPtr);
	    pthread_cond_init(pcondPtr, attr_p);

#if defined(_POSIX_TIMERS) && defined(_POSIX_MONOTONIC_CLOCK)
	    pthread_condattr_destroy(&attr);
#endif
#undef attr_p
 	    *condPtr = (Tcl_Condition) pcondPtr;
 	    TclRememberCondition(condPtr);
	}
	MASTER_UNLOCK;
    }
    pmutexPtr = *((pthread_mutex_t **)mutexPtr);
    pcondPtr = *((pthread_cond_t **)condPtr);
    if (timePtr == NULL) {
	pthread_cond_wait(pcondPtr, pmutexPtr);
    } else {
	Tcl_Time now;

	/*
	 * Make sure to take into account the microsecond component of the
	 * current time, including possible overflow situations. [Bug #411603]
	 */

#if defined(_POSIX_TIMERS) && defined(_POSIX_MONOTONIC_CLOCK)
	struct timespec pnow;
	clock_gettime(CLOCK_MONOTONIC, &pnow);
	ptime.tv_sec = timePtr->sec + pnow.tv_sec +
	    (timePtr->usec + pnow.tv_nsec/1000) / 1000000;
	ptime.tv_nsec = 1000 * ((timePtr->usec + pnow.tv_nsec/1000) % 1000000);

#elif defined(_POSIX_TIMERS)
	struct timespec pnow;
	clock_gettime(CLOCK_REALTIME, &pnow);
	ptime.tv_sec = timePtr->sec + pnow.tv_sec +
	    (timePtr->usec + pnow.tv_nsec/1000) / 1000000;
	ptime.tv_nsec = 1000 * ((timePtr->usec + pnow.tv_nsec/1000) % 1000000);

#else
	Tcl_Time now;
	Tcl_GetTime(&now);
	ptime.tv_sec = timePtr->sec + now.sec +
	    (timePtr->usec + now.usec) / 1000000;
	ptime.tv_nsec = 1000 * ((timePtr->usec + now.usec) % 1000000);
#endif
	pthread_cond_timedwait(pcondPtr, pmutexPtr, &ptime);
    }
}

/*
 *----------------------------------------------------------------------
 *