$NetBSD: patch-ab,v 1.2 2007/08/04 12:52:57 joerg Exp $

--- fifo.cpp.orig       2007-07-16 17:54:23.000000000 +0000
+++ fifo.cpp
@@ -39,6 +39,12 @@
 #include "wave.h"
 #include "debug.h"
 
+#ifndef timespeccmp
+#define	timespeccmp(tvp, uvp, cmp)					\
+	(((tvp)->tv_sec == (uvp)->tv_sec) ?				\
+	    ((tvp)->tv_nsec cmp (uvp)->tv_nsec) :			\
+	    ((tvp)->tv_sec cmp (uvp)->tv_sec))
+#endif
 
 //>
 //<decls and function prototypes
@@ -310,10 +316,15 @@ static int sleep_until_start_request_or_
 			to.tv_sec, to.tv_nsec,
 			ts.tv_sec, ts.tv_nsec);
 
-		while ((err = sem_timedwait(&my_sem_start_is_required, &ts)) == -1 
-			&& errno == EINTR)
+		while ((err = sem_trywait(&my_sem_start_is_required)) == -1 
+			&& (errno == EINTR || errno == EAGAIN))
 		{
 			continue;
+		struct timespec help;
+		clock_gettime2(&help);
+		if (timespeccmp(&help, &ts, >=))
+			break;
+		sched_yield();
 		}
 
 		assert (gettimeofday(&tv, NULL) != -1);
