From e5b21a60d783f22886a8671b7be444f1e1205c14 Mon Sep 17 00:00:00 2001 From: Gerrit Renker Date: Thu, 25 Mar 2010 17:43:22 +0100 Subject: [PATCH] para_recv: handle EAGAIN on non-blocking socket Checking whether the non-blocking socket is readable is not sufficient to guarantee that EAGAIN is not encountered on the non-blocking socket, the following was observed in the middle of a UDP/FEC stream: Mar 24 17:12:44:0533 audi (0) decode_group: writing group 2784 (4232/4374 decoded data bytes) Mar 24 17:12:44:0710 audi (0) get_time_string: slot 0: 32:42 [94:49] (26%/127:31) Mar 24 17:12:44:0710 audi (2) btr_remove_node: removing btr node udp from buffer tree Mar 24 17:12:44:0710 audi (1) unregister_task: unregistering udp receiver node (Resource temporarily unavailable) The patch fixes the problem by not interpreting the case "data not yet ready" as an error, but as a temporary condition. --- dccp_recv.c | 3 +++ udp_recv.c | 3 +++ 2 files changed, 6 insertions(+) diff --git a/dccp_recv.c b/dccp_recv.c index c22fa84d..883451c6 100644 --- a/dccp_recv.c +++ b/dccp_recv.c @@ -166,6 +166,9 @@ static void dccp_recv_post_select(struct sched *s, struct task *t) if (iovcnt == 0) goto err; ret = para_readv(pdd->fd, iov, iovcnt); + /* EAGAIN is possible even if FD_ISSET */ + if (ret < 0 && is_errno(-ret, EAGAIN)) + return; if (ret == 0) ret = -E_RECV_EOF; if (ret < 0) diff --git a/udp_recv.c b/udp_recv.c index 4f363ccb..316957d5 100644 --- a/udp_recv.c +++ b/udp_recv.c @@ -92,6 +92,9 @@ static void udp_recv_post_select(__a_unused struct sched *s, struct task *t) if (iovcnt == 0) goto err; ret = para_readv(purd->fd, iov, iovcnt); + /* EAGAIN is possible even if FD_ISSET */ + if (ret < 0 && is_errno(-ret, EAGAIN)) + return; if (ret == 0) ret = -E_RECV_EOF; if (ret < 0) -- 2.39.5