prefer avio_check() over url_exist()

The problem with url_exist() is that it tries to open a resource in RDONLY mode. If the file is a FIFO and there is already a reading client, the open() call will hang. By using avio_check() with access mode of 0, the second reading process will check if the file exists without attempting to open it, thus avoiding the lock. Fix issue #1663.

Stefano Sabatini committed 15 years ago

Commit 55815ed1 parent 59d96943 files · +6 −6Browse files

Unified · Split

3 files

ffmpeg.c +1 −1
ffserver.c +2 −2
libavformat/img2.c +3 −3

ffmpeg.c+1−1

@@ -3733,7 +3733,7 @@ static void opt_output_file(const char *filename) · 3732 unmodified lines
3733	3733	(strchr(filename, ':') == NULL \|\|
3734	3734	filename[1] == ':' \|\|
3735	3735	av_strstart(filename, "file:", NULL))) {
3736		− if (url_exist(filename)) {
	3736	+ if (avio_check(filename, 0) == 0) {
3737	3737	if (!using_stdin) {
3738	3738	fprintf(stderr,"File '%s' already exists. Overwrite ? [y/N] ", filename);
3739	3739	fflush(stderr);

ffserver.c+2−2

@@ -3679,7 +3679,7 @@ static void build_feed_streams(void) · 3678 unmodified lines
3679	3679	for(feed = first_feed; feed != NULL; feed = feed->next_feed) {
3680	3680	int fd;
3681	3681
3682		− if (url_exist(feed->feed_filename)) {
	3682	+ if (avio_check(feed->feed_filename, AVIO_FLAG_READ) > 0) {
3683	3683	/* See if it matches */
3684	3684	AVFormatContext *s;
3685	3685	int matches = 0;
@@ -3752,7 +3752,7 @@ static void build_feed_streams(void) · 66 unmodified lines
3752	3752	unlink(feed->feed_filename);
3753	3753	}
3754	3754	}
3755		− if (!url_exist(feed->feed_filename)) {
	3755	+ if (avio_check(feed->feed_filename, AVIO_FLAG_WRITE) <= 0) {
3756	3756	AVFormatContext s1 = {0}, *s = &s1;
3757	3757
3758	3758	if (feed->readonly) {

libavformat/img2.c+3−3

@@ -131,11 +131,11 @@ static int find_image_range(int pfirst_index, int plast_index, · 130 unmodified lines
131	131	if (av_get_frame_filename(buf, sizeof(buf), path, first_index) < 0){
132	132	*pfirst_index =
133	133	*plast_index = 1;
134		− if(url_exist(buf))
	134	+ if (avio_check(buf, AVIO_FLAG_READ) > 0)
135	135	return 0;
136	136	return -1;
137	137	}
138		− if (url_exist(buf))
	138	+ if (avio_check(buf, AVIO_FLAG_READ) > 0)
139	139	break;
140	140	}
141	141	if (first_index == 5)
@@ -153,7 +153,7 @@ static int find_image_range(int pfirst_index, int plast_index, · 11 unmodified lines
153	153	if (av_get_frame_filename(buf, sizeof(buf), path,
154	154	last_index + range1) < 0)
155	155	goto fail;
156		− if (!url_exist(buf))
	156	+ if (avio_check(buf, AVIO_FLAG_READ) <= 0)
157	157	break;
158	158	range = range1;
159	159	/* just in case... */

prefer avio_check() over url_exist()

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