PERFORCE change 38944 for review

[Warner Losh]

http://perforce.freebsd.org/chv.cgi?CH=38944

Change 38944 by imp at imp_koguchi on 2003/09/30 20:34:04

	cv_wait usually loops, per rwatson.

Affected files ...

.. //depot/doc/strawman-driver.c#6 edit

Differences ...

==== //depot/doc/strawman-driver.c#6 (text+ko) ====

@@ -23,17 +23,24 @@
 		return EGONE;
 	if (sc->dead)				/* RACE #1, a */
 		return EGONE;
-...
+	switch (cmd) 
+	{
 	case FOO_GERBIL:
 		/*
 		 * Wait for a weird GERBIL event in the device and return it
 		 */
 		mtx_lock(&sc->mtx);
-		cv_wait(&sc->cv, &sc->mtx);
+		sc->sc_gerbil = 0;
+		while (!sc->sc_gerbil) {
+			if (sc->dead)		/* Race #1, b */
+				return EGONE;
+			cv_wait(&sc->cv, &sc->mtx);
+		}
 		mtx_unlock(&sc->mtx);
-		if (sc->dead)			/* Race #1, b */
-			return EGONE;
-		...
+		return (0);
+	default:
+		return (ENOTTY);
+	}
 }
 
 static void