Sometimes PORT_EXIT messages are lost when a process is exiting. This happens if you subscribe to the announce port with client A, then subscribe to the announce port with client B, then kill client A. Client B will not see the PORT_EXIT message because client A's port is closing and is earlier in the announce port subscription list. The for each loop will try to send the announcement to client A and fail, then will stop trying to broadcast to other ports. Killing B works fine since the announcement will already have gone to A. The CLIENT_EXIT message does not get lost.
How to reproduce problem:
*** termA $ aseqdump -p 0:1 0:1 Port subscribed 0:1 -> 128:0
*** termB $ aseqdump -p 0:1
*** termA 0:1 Client start client 129 0:1 Port start 129:0 0:1 Port subscribed 0:1 -> 129:0
*** termB 0:1 Port subscribed 0:1 -> 129:0
*** termA ^C
*** termB 0:1 Client exit client 128 <--- expected Port exit as well (before client exit)
Signed-off-by: Adam Goode agoode@google.com
diff --git a/sound/core/seq/seq_clientmgr.c b/sound/core/seq/seq_clientmgr.c index 9ca5e64..225c7315 100644 --- a/sound/core/seq/seq_clientmgr.c +++ b/sound/core/seq/seq_clientmgr.c @@ -660,7 +660,7 @@ static int deliver_to_subscribers(struct snd_seq_client *client, int atomic, int hop) { struct snd_seq_subscribers *subs; - int err = 0, num_ev = 0; + int err, result = 0, num_ev = 0; struct snd_seq_event event_saved; struct snd_seq_client_port *src_port; struct snd_seq_port_subs_info *grp; @@ -685,8 +685,12 @@ static int deliver_to_subscribers(struct snd_seq_client *client, subs->info.flags & SNDRV_SEQ_PORT_SUBS_TIME_REAL); err = snd_seq_deliver_single_event(client, event, 0, atomic, hop); - if (err < 0) - break; + if (err < 0) { + /* save first error that occurs and continue */ + if (!result) + result = err; + continue; + } num_ev++; /* restore original event record */ *event = event_saved; @@ -697,7 +701,7 @@ static int deliver_to_subscribers(struct snd_seq_client *client, up_read(&grp->list_mutex); *event = event_saved; /* restore */ snd_seq_port_unlock(src_port); - return (err < 0) ? err : num_ev; + return (result < 0) ? result : num_ev; }
@@ -709,7 +713,7 @@ static int port_broadcast_event(struct snd_seq_client *client, struct snd_seq_event *event, int atomic, int hop) { - int num_ev = 0, err = 0; + int num_ev = 0, err, result = 0; struct snd_seq_client *dest_client; struct snd_seq_client_port *port;
@@ -724,14 +728,18 @@ static int port_broadcast_event(struct snd_seq_client *client, err = snd_seq_deliver_single_event(NULL, event, SNDRV_SEQ_FILTER_BROADCAST, atomic, hop); - if (err < 0) - break; + if (err < 0) { + /* save first error that occurs and continue */ + if (!result) + result = err; + continue; + } num_ev++; } read_unlock(&dest_client->ports_lock); snd_seq_client_unlock(dest_client); event->dest.port = SNDRV_SEQ_ADDRESS_BROADCAST; /* restore */ - return (err < 0) ? err : num_ev; + return (result < 0) ? result : num_ev; }
/* @@ -741,7 +749,7 @@ static int port_broadcast_event(struct snd_seq_client *client, static int broadcast_event(struct snd_seq_client *client, struct snd_seq_event *event, int atomic, int hop) { - int err = 0, num_ev = 0; + int err, result = 0, num_ev = 0; int dest; struct snd_seq_addr addr;
@@ -760,12 +768,16 @@ static int broadcast_event(struct snd_seq_client *client, err = snd_seq_deliver_single_event(NULL, event, SNDRV_SEQ_FILTER_BROADCAST, atomic, hop); - if (err < 0) - break; + if (err < 0) { + /* save first error that occurs and continue */ + if (!result) + result = err; + continue; + } num_ev += err; } event->dest = addr; /* restore */ - return (err < 0) ? err : num_ev; + return (result < 0) ? result : num_ev; }