From 14c232bdbfbb16f427632d579430fa1a522f7f73 Mon Sep 17 00:00:00 2001 From: wm4 Date: Wed, 21 Sep 2016 15:55:34 +0200 Subject: client API: fix init/destruction race conditions mp_new_client() blatantly accessed some mutex-protected state outside of the mutex. The destruction code is in theory OK, but with changes in the following commits it'll be a bit hard to guarantee that it stays this way. Add a simple flag that makes adding new clients impossible, so that having no clients after shutdown_clients() remains guaranteed. --- player/client.c | 18 ++++++++++++++---- 1 file changed, 14 insertions(+), 4 deletions(-) (limited to 'player/client.c') diff --git a/player/client.c b/player/client.c index 5d81f7c93b..93db0bb3d2 100644 --- a/player/client.c +++ b/player/client.c @@ -66,7 +66,8 @@ struct mp_client_api { struct mpv_handle **clients; int num_clients; - uint64_t event_masks; // combined events of all clients, or 0 if unknown + uint64_t event_masks; // combined events of all clients, or 0 if unknown + bool shutting_down; // do not allow new clients struct mp_custom_protocol *custom_protocols; int num_custom_protocols; @@ -206,8 +207,17 @@ bool mp_client_exists(struct MPContext *mpctx, const char *client_name) return r; } +void mp_client_enter_shutdown(struct MPContext *mpctx) +{ + pthread_mutex_lock(&mpctx->clients->lock); + mpctx->clients->shutting_down = true; + pthread_mutex_unlock(&mpctx->clients->lock); +} + struct mpv_handle *mp_new_client(struct mp_client_api *clients, const char *name) { + pthread_mutex_lock(&clients->lock); + char nname[MAX_CLIENT_NAME]; for (int n = 1; n < 1000; n++) { if (!name) @@ -222,10 +232,10 @@ struct mpv_handle *mp_new_client(struct mp_client_api *clients, const char *name nname[0] = '\0'; } - if (!nname[0]) + if (!nname[0] || clients->shutting_down) { + pthread_mutex_unlock(&clients->lock); return NULL; - - pthread_mutex_lock(&clients->lock); + } int num_events = 1000; -- cgit v1.2.3