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Conditional acquisition of socket buffer mutexes when testing socket

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buffers with kqueue filters is no longer required: the kqueue framework
will guarantee that the mutex is held on entering the filter, either
due to a call from the socket code already holding the mutex, or by
explicitly acquiring it.  This removes the last of the conditional
socket locking.
This commit is contained in:
rwatson 2004-08-24 05:28:18 +00:00
parent 9b0c1e7ac1
commit d168fd3606
1 changed files with 16 additions and 35 deletions
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51
sys/kern/uipc_socket.c
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@ -2171,31 +2171,22 @@ filt_sordetach(struct knote *kn)
static int
filt_soread(struct knote *kn, long hint)
{
struct socket *so = kn->kn_fp->f_data;
int need_lock, result;
struct socket *so;
so = kn->kn_fp->f_data;
SOCKBUF_LOCK_ASSERT(&so->so_rcv);
/*
* 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;
kn->kn_fflags = so->so_error;
result = 1;
return (1);
} else if (so->so_error) /* temporary udp error */
result = 1;
return (1);
else if (kn->kn_sfflags & NOTE_LOWAT)
result = (kn->kn_data >= kn->kn_sdata);
return (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);
return (so->so_rcv.sb_cc >= so->so_rcv.sb_lowat);
}
static void
@ -2214,34 +2205,24 @@ filt_sowdetach(struct knote *kn)
static int
filt_sowrite(struct knote *kn, long hint)
{
struct socket *so = kn->kn_fp->f_data;
int need_lock, result;
struct socket *so;
/*
* 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);
so = kn->kn_fp->f_data;
SOCKBUF_LOCK_ASSERT(&so->so_snd);
kn->kn_data = sbspace(&so->so_snd);
if (so->so_snd.sb_state & SBS_CANTSENDMORE) {
kn->kn_flags |= EV_EOF;
kn->kn_fflags = so->so_error;
result = 1;
return (1);
} else if (so->so_error) /* temporary udp error */
result = 1;
return (1);
else if (((so->so_state & SS_ISCONNECTED) == 0) &&
(so->so_proto->pr_flags & PR_CONNREQUIRED))
result = 0;
return (0);
else if (kn->kn_sfflags & NOTE_LOWAT)
result = (kn->kn_data >= kn->kn_sdata);
return (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);
return (kn->kn_data >= so->so_snd.sb_lowat);
}
/*ARGSUSED*/