aboutsummaryrefslogtreecommitdiffstats
path: root/src/directory.c
diff options
context:
space:
mode:
authorEric Wong <normalperson@yhbt.net>2008-10-07 22:11:16 +0200
committerMax Kellermann <max@duempel.org>2008-10-07 22:11:16 +0200
commit7d8c9cc7e31e15b93af7c08f7d03ed8ca10f5454 (patch)
treed492791706dbf323eec84c2331308bf61566af82 /src/directory.c
parent2b965a5424b9e15f23794c0667c7eff95759dbb5 (diff)
downloadmpd-7d8c9cc7e31e15b93af7c08f7d03ed8ca10f5454.tar.gz
mpd-7d8c9cc7e31e15b93af7c08f7d03ed8ca10f5454.tar.xz
mpd-7d8c9cc7e31e15b93af7c08f7d03ed8ca10f5454.zip
directory: serialize song deletes from playlist during update
This makes the update code thread-safe and doesn't penalize the playlist code by complicating it with complicated and error-prone locks (and the associated overhead, not everybody has a thread-implementation as good as NPTL). The update task blocks during the delete; but the update task is a slow task anyways so we can block w/o people caring too much. This was also our only freeSong call site, so remove that function. Note that deleting entire directories is not fully thread-safe, yet; as their traversals are not yet locked.
Diffstat (limited to '')
-rw-r--r--src/directory.c31
1 files changed, 28 insertions, 3 deletions
diff --git a/src/directory.c b/src/directory.c
index fb8c23e2f..949d249a4 100644
--- a/src/directory.c
+++ b/src/directory.c
@@ -31,6 +31,7 @@
#include "song_save.h"
#include "main_notify.h"
#include "dirvec.h"
+#include "condition.h"
#define DIRECTORY_DIR "directory: "
#define DIRECTORY_MTIME "mtime: " /* DEPRECATED, noop-read-only */
@@ -64,8 +65,13 @@ static time_t directory_dbModTime;
static pthread_t update_thr;
static const int update_task_id_max = 1 << 15;
+
static int update_task_id;
+static Song *delete;
+
+static struct condition delete_cond;
+
static enum update_return
addToDirectory(Directory * directory, const char *name);
@@ -146,6 +152,16 @@ void reap_update_task(void)
assert(pthread_equal(pthread_self(), main_task));
+ cond_enter(&delete_cond);
+ if (delete) {
+ char tmp[MPD_PATH_MAX];
+ LOG("removing: %s\n", get_song_url(tmp, delete));
+ deleteASongFromPlaylist(delete);
+ delete = NULL;
+ cond_signal_async(&delete_cond);
+ }
+ cond_leave(&delete_cond);
+
if (progress != UPDATE_PROGRESS_DONE)
return;
if (pthread_join(update_thr, (void **)&ret))
@@ -217,10 +233,19 @@ static void freeDirectory(Directory * directory)
static void delete_song(Directory *dir, Song *del)
{
- char path_max_tmp[MPD_PATH_MAX]; /* wasteful */
- LOG("removing: %s\n", get_song_url(path_max_tmp, del));
+ /* first, prevent traversers in main task from getting this */
songvec_delete(&dir->songs, del);
- freeSong(del); /* FIXME racy */
+
+ /* now take it out of the playlist (in the main_task) */
+ cond_enter(&delete_cond);
+ assert(!delete);
+ delete = del;
+ wakeup_main_task();
+ do { cond_wait(&delete_cond); } while (delete);
+ cond_leave(&delete_cond);
+
+ /* finally, all possible references gone, free it */
+ freeJustSong(del);
}
static void deleteEmptyDirectoriesInDirectory(Directory * directory)