-
 [rsc] --rw-rw-r-- M 451989 sape sys 1547 Nov  6 11:09 sys/src/games/music/playlistfs/boilerplate.c
	/n/sourcesdump/2005/1106/plan9/sys/src/games/music/playlistfs/boilerplate.c:41,73 - 
	/n/sourcesdump/2005/1107/plan9/sys/src/games/music/playlistfs/boilerplate.c:41,82
	  {
	  	Worker *w;
	  
	- 	if(w = nbrecvp(q))
	- 		send(w->eventc, m);
	- 	return w != nil;
	+ 	while(w = nbrecvp(q)){
	+ 		/* Test for markerdom (see bcastmsg) */
	+ 		if(w->eventc){
	+ 			send(w->eventc, m);
	+ 			return 1;
	+ 		}
	+ 		sendp(q, w);	/* put back */
	+ 	}
	+ 	return 0;
	  }
	  
	  void
	  bcastmsg(Channel *q, Wmsg *m)
	  {
	- 	Worker *w;
	- 	Channel *c;
	+ 	Worker *w, marker;
	  	void *a;
	  
	  	a = m->arg;
	  	/*
	- 	 * Allocate a temp chan to prevent workers from getting the
	- 	 * broadcast and putting themselves back on the workers
	+ 	 * Use a marker to mark the end of the queue.
	+ 	 * This prevents workers from getting the
	+ 	 * broadcast and putting themselves back on the
	  	 * queue before the broadcast has finished
	  	 */
	- 	c = chancreate(sizeof(Worker*), 256);
	- 	while(w = nbrecvp(q))
	- 		sendp(c, w);
	- 	while(w = nbrecvp(c)){
	- 		if(a) m->arg = strdup(a);
	- 		send(w->eventc, m);
	+ 	marker.eventc = nil;
	+ 	sendp(q, &marker);
	+ 	while((w = recvp(q)) != &marker){
	+ 		if(w->eventc == nil){
	+ 			/* somebody else's marker, put it back */
	+ 			sendp(q, w);
	+ 		}else{
	+ 			if(a) m->arg = strdup(a);
	+ 			send(w->eventc, m);
	+ 		}
	  	}
	  	free(a);
	- 	chanfree(c);
	  	m->arg = nil;
	  }