From d87fad9f086c5e1c8af4ba8e1373bcc73f21dce5 Mon Sep 17 00:00:00 2001 From: rwatson Date: Fri, 18 Jun 2004 02:57:55 +0000 Subject: Merge some additional leaf node socket buffer locking from rwatson_netperf: Introduce conditional locking of the socket buffer in fifofs kqueue filters; KNOTE() will be called holding the socket buffer locks in fifofs, but sometimes the kqueue() system call will poll using the same entry point without holding the socket buffer lock. Introduce conditional locking of the socket buffer in the socket kqueue filters; KNOTE() will be called holding the socket buffer locks in the socket code, but sometimes the kqueue() system call will poll using the same entry points without holding the socket buffer lock. Simplify the logic in sodisconnect() since we no longer need spls. NOTE: To remove conditional locking in the kqueue filters, it would make sense to use a separate kqueue API entry into the socket/fifo code when calling from the kqueue() system call. --- sys/kern/uipc_socket.c | 39 ++++++++++++++++++++++++++------------- 1 file changed, 26 insertions(+), 13 deletions(-) (limited to 'sys/kern') diff --git a/sys/kern/uipc_socket.c b/sys/kern/uipc_socket.c index 6606138..364f2db 100644 --- a/sys/kern/uipc_socket.c +++ b/sys/kern/uipc_socket.c @@ -506,20 +506,13 @@ int sodisconnect(so) struct socket *so; { - int s = splnet(); int error; - if ((so->so_state & SS_ISCONNECTED) == 0) { - error = ENOTCONN; - goto bad; - } - if (so->so_state & SS_ISDISCONNECTING) { - error = EALREADY; - goto bad; - } + if ((so->so_state & SS_ISCONNECTED) == 0) + return (ENOTCONN); + if (so->so_state & SS_ISDISCONNECTING) + return (EALREADY); error = (*so->so_proto->pr_usrreqs->pru_disconnect)(so); -bad: - splx(s); return (error); } @@ -1913,8 +1906,16 @@ static int filt_soread(struct knote *kn, long hint) { struct socket *so = kn->kn_fp->f_data; - int result; + int need_lock, result; + /* + * XXXRW: Conditional locking because filt_soread() can be called + * either from KNOTE() in the socket context where the socket buffer + * lock is already held, or from kqueue() itself. + */ + need_lock = !SOCKBUF_OWNED(&so->so_rcv); + if (need_lock) + SOCKBUF_LOCK(&so->so_rcv); kn->kn_data = so->so_rcv.sb_cc - so->so_rcv.sb_ctl; if (so->so_rcv.sb_state & SBS_CANTRCVMORE) { kn->kn_flags |= EV_EOF; @@ -1926,6 +1927,8 @@ filt_soread(struct knote *kn, long hint) result = (kn->kn_data >= kn->kn_sdata); else result = (so->so_rcv.sb_cc >= so->so_rcv.sb_lowat); + if (need_lock) + SOCKBUF_UNLOCK(&so->so_rcv); return (result); } @@ -1946,8 +1949,16 @@ static int filt_sowrite(struct knote *kn, long hint) { struct socket *so = kn->kn_fp->f_data; - int result; + int need_lock, result; + /* + * XXXRW: Conditional locking because filt_soread() can be called + * either from KNOTE() in the socket context where the socket buffer + * lock is already held, or from kqueue() itself. + */ + need_lock = !SOCKBUF_OWNED(&so->so_snd); + if (need_lock) + SOCKBUF_LOCK(&so->so_snd); kn->kn_data = sbspace(&so->so_snd); if (so->so_snd.sb_state & SBS_CANTSENDMORE) { kn->kn_flags |= EV_EOF; @@ -1962,6 +1973,8 @@ filt_sowrite(struct knote *kn, long hint) result = (kn->kn_data >= kn->kn_sdata); else result = (kn->kn_data >= so->so_snd.sb_lowat); + if (need_lock) + SOCKBUF_UNLOCK(&so->so_snd); return (result); } -- cgit v1.1