Attachment 217981 Details for Bug 219891 – Patch to convert the sdlfb busy looping with a thread implementation

[patch] Patch to convert the sdlfb busy looping with a thread implementation

xen-sdlfb-thread.patch (text/plain), 3.88 KB, created by Chris Lalancette on 2007-10-05 20:40:12 UTC

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Creator: Chris Lalancette

Created: 2007-10-05 20:40:12 UTC

Size: 3.88 KB

patch

obsolete

>diff -urp xen-3.1.0-src.orig/tools/xenfb/Makefile xen-3.1.0-src/tools/xenfb/Makefile
>--- xen-3.1.0-src.orig/tools/xenfb/Makefile	2007-10-05 16:34:51.000000000 -0400
>+++ xen-3.1.0-src/tools/xenfb/Makefile	2007-10-05 16:35:51.000000000 -0400
>@@ -22,7 +22,7 @@ install: all
> sdlfb: sdlfb.o xenfb.o
> 
> sdlfb.o: CFLAGS += $(shell sdl-config --cflags)
>-sdlfb: LDLIBS += $(shell sdl-config --libs) -lxenctrl -lxenstore
>+sdlfb: LDLIBS += $(shell sdl-config --libs) -lxenctrl -lxenstore -lpthread
> 
> clean:
> 	$(RM) *.o *~ vncfb sdlfb
>diff -urp xen-3.1.0-src.orig/tools/xenfb/sdlfb.c xen-3.1.0-src/tools/xenfb/sdlfb.c
>--- xen-3.1.0-src.orig/tools/xenfb/sdlfb.c	2007-10-05 16:34:51.000000000 -0400
>+++ xen-3.1.0-src/tools/xenfb/sdlfb.c	2007-10-05 16:35:47.000000000 -0400
>@@ -6,8 +6,13 @@
> #include <linux/input.h>
> #include <getopt.h>
> #include <string.h>
>+#include <pthread.h>
>+#include <unistd.h>
> #include "xenfb.h"
> 
>+static int sdlevents[2];
>+static pthread_mutex_t xenfb_mutex = PTHREAD_MUTEX_INITIALIZER;
>+
> struct SDLFBData
> {
> 	SDL_Surface *dst;
>@@ -207,6 +212,31 @@ static struct option options[] = {
> 	{ NULL }
> };
> 
>+void sdleventsthread(void *args)
>+{
>+	char buf[1];
>+	int do_quit, eventret;
>+	SDL_Event event;
>+	struct xenfb *xenfb;
>+
>+	xenfb = (struct xenfb *)args;
>+	do_quit = 0;
>+
>+	for (;;) {
>+		while (SDL_PollEvent(&event)) {
>+			pthread_mutex_lock(&xenfb_mutex);
>+			eventret = sdl_on_event(xenfb, &event);
>+			pthread_mutex_unlock(&xenfb_mutex);
>+			if (!eventret)
>+				do_quit = 1;
>+		}
>+		if (do_quit) {
>+			write(sdlevents[1], buf, 1);
>+			break;
>+		}
>+	}
>+}
>+
> int main(int argc, char **argv)
> {
> 	struct xenfb *xenfb;
>@@ -217,12 +247,12 @@ int main(int argc, char **argv)
> 	int nfds;
> 	struct SDLFBData data;
> 	SDL_Rect r;
>-	struct timeval tv;
>-	SDL_Event event;
> 	int do_quit = 0;
> 	int opt;
> 	char *endp;
> 	int retval;
>+	pthread_t threadpid;
>+	char dummy[1];
> 
> 	while ((opt = getopt_long(argc, argv, "d:t:", options,
> 				  NULL)) != -1) {
>@@ -310,39 +340,63 @@ int main(int argc, char **argv)
> 
> 	/*
> 	 * We need to wait for fds becoming ready or SDL events to
>-	 * arrive.  We time out the select after 10ms to poll for SDL
>-	 * events.  Clunky, but works.  Could avoid the clunkiness
>-	 * with a separate thread.
>+	 * arrive.  Spawn another thread to poll for SDL events and send them
>+	 * back our way over a pipe.  Kind of clunky, but less so than busy
>+	 * polling.
> 	 */
>+	if (pipe(sdlevents) < 0) {
>+		fprintf(stderr, "Error creating pipe for SDL events\n");
>+		exit(2);
>+	}
>+
>+	pthread_create(&threadpid, NULL, (void *)&sdleventsthread, xenfb);
>+
> 	for (;;) {
> 		FD_ZERO(&readfds);
>+		pthread_mutex_lock(&xenfb_mutex);
> 		nfds = xenfb_select_fds(xenfb, &readfds);
>-		tv = (struct timeval){0, 10000};
>-
>-		if (select(nfds, &readfds, NULL, NULL, &tv) < 0) {
>+		pthread_mutex_unlock(&xenfb_mutex);
>+		FD_SET(sdlevents[0], &readfds);
>+		nfds++;
>+		
>+		if (select(nfds, &readfds, NULL, NULL, NULL) < 0) {
> 			if (errno == EINTR)
> 				continue;
> 			fprintf(stderr,
> 				"Can't select() on event channel (%s)\n",
> 				strerror(errno));
>+			do_quit = 1;
> 			break;
> 		}
>-
>-		while (SDL_PollEvent(&event)) {
>-			if (!sdl_on_event(xenfb, &event))
>-				do_quit = 1;
>+		
>+		if (FD_ISSET(sdlevents[0], &readfds)) {
>+			read(sdlevents[0], dummy, 1);
>+			do_quit = 1;
> 		}
>-
>+		
>                 if (do_quit)
>+			/* Don't need to pthread_cancel here, since it was
>+			 * the thread itself that told us to quit */
> 			break;
>-
>+		
>+		pthread_mutex_lock(&xenfb_mutex);
> 		retval = xenfb_poll(xenfb, &readfds);
>-		if (retval == -2)
>-		    xenfb_teardown(xenfb);
>-		if (retval < 0)
>-		    break;
>+		pthread_mutex_unlock(&xenfb_mutex);
>+		if (retval == -2) {
>+			pthread_mutex_lock(&xenfb_mutex);
>+			xenfb_teardown(xenfb);
>+			pthread_mutex_unlock(&xenfb_mutex);
>+		}
>+		if (retval < 0) {
>+			pthread_cancel(threadpid);
>+			break;
>+		}
> 	}
> 
>+	pthread_join(threadpid, NULL);
>+	close(sdlevents[0]);
>+	close(sdlevents[1]);
>+
> 	xenfb_delete(xenfb);
> 
> 	SDL_Quit();

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Attachments on bug 219891: 217981