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Oops, fell into rpipe/wpipe trap: 

The end we want to do selwakeup() on is not necessarily same as the one
we send SIGIO to. Make pipeselwakeup() accept two parameters and update
callers accordingly. This change fixes behaviour for code, which does
select(2)s on the write end waiting for reader (watched on gv, the problem
manifestated itself as a too long delay before the document was displayed).

Clearly separate the resource free code for FreeBSD
and NetBSD case in pipeclose(), so that it's a bit clearer what's going on.
Also LK_DRAIN the lock before the memory is returned to pipe_pool.

Add missing wakeup() in pipe_write() for PIPE_WANTCLOSE case.
This commit is contained in:
jdolecek 2001-06-21 18:46:22 +00:00
parent 756d684c5a
commit ad2b5880f0
1 changed files with 30 additions and 30 deletions
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60
sys/kern/sys_pipe.c
View File

@ -1,4 +1,4 @@
/* $NetBSD: sys_pipe.c,v 1.2 2001/06/16 12:00:02 jdolecek Exp $ */
/* $NetBSD: sys_pipe.c,v 1.3 2001/06/21 18:46:22 jdolecek Exp $ */
/*
* Copyright (c) 1996 John S. Dyson
@ -188,7 +188,8 @@ static void pipe_free_kmem __P((struct pipe *cpipe));
static int pipe_create __P((struct pipe **cpipep));
static __inline int pipelock __P((struct pipe *cpipe, int catch));
static __inline void pipeunlock __P((struct pipe *cpipe));
static __inline void pipeselwakeup __P((struct pipe *cpipe));
static __inline void pipeselwakeup __P((struct pipe *selp,
struct pipe *sigp));
static int pipespace __P((struct pipe *cpipe, int size));
#ifdef __FreeBSD__
@ -522,30 +523,27 @@ pipeunlock(cpipe)
* 'sigpipe' side of pipe.
*/
static __inline void
pipeselwakeup(cpipe)
struct pipe *cpipe;
pipeselwakeup(selp, sigp)
struct pipe *selp, *sigp;
{
if (!cpipe)
return;
if (cpipe->pipe_state & PIPE_SEL) {
cpipe->pipe_state &= ~PIPE_SEL;
selwakeup(&cpipe->pipe_sel);
if (selp->pipe_state & PIPE_SEL) {
selp->pipe_state &= ~PIPE_SEL;
selwakeup(&selp->pipe_sel);
}
#ifdef __FreeBSD__
if ((cpipe->pipe_state & PIPE_ASYNC) && cpipe->pipe_sigio)
pgsigio(cpipe->pipe_sigio, SIGIO, 0);
KNOTE(&cpipe->pipe_sel.si_note, 0);
if (sigp && (sigp->pipe_state & PIPE_ASYNC) && sigp->pipe_sigio)
pgsigio(sigp->pipe_sigio, SIGIO, 0);
KNOTE(&selp->pipe_sel.si_note, 0);
#endif
#ifdef __NetBSD__
if (cpipe && (cpipe->pipe_state & PIPE_ASYNC)
&& cpipe->pipe_pgid != NO_PID){
if (sigp && (sigp->pipe_state & PIPE_ASYNC)
&& sigp->pipe_pgid != NO_PID){
struct proc *p;
if (cpipe->pipe_pgid < 0)
gsignal(-cpipe->pipe_pgid, SIGIO);
else if (cpipe->pipe_pgid > 0 && (p = pfind(cpipe->pipe_pgid)) != 0)
if (sigp->pipe_pgid < 0)
gsignal(-sigp->pipe_pgid, SIGIO);
else if (sigp->pipe_pgid > 0 && (p = pfind(sigp->pipe_pgid)) != 0)
psignal(p, SIGIO);
}
#endif /* NetBSD */
@ -686,7 +684,7 @@ pipe_read(fp, offset, uio, cred, flags)
/*
* We want to read more, wake up select/poll.
*/
pipeselwakeup(rpipe->pipe_peer);
pipeselwakeup(rpipe, rpipe->pipe_peer);
rpipe->pipe_state |= PIPE_WANTR;
error = tsleep(rpipe, PRIBIO | PCATCH, "piperd", 0);
@ -724,7 +722,7 @@ unlocked_error:
*/
if ((rpipe->pipe_buffer.size - rpipe->pipe_buffer.cnt) >= PIPE_BUF
&& (ocnt != rpipe->pipe_buffer.cnt || (rpipe->pipe_state & PIPE_SIGNALR))) {
pipeselwakeup(rpipe->pipe_peer);
pipeselwakeup(rpipe, rpipe->pipe_peer);
rpipe->pipe_state &= ~PIPE_SIGNALR;
}
@ -920,7 +918,7 @@ retry:
pipelock(wpipe, 0);
pipe_destroy_write_buffer(wpipe);
pipeunlock(wpipe);
pipeselwakeup(wpipe);
pipeselwakeup(wpipe, wpipe);
error = EPIPE;
goto error1;
}
@ -928,7 +926,7 @@ retry:
wpipe->pipe_state &= ~PIPE_WANTR;
wakeup(wpipe);
}
pipeselwakeup(wpipe);
pipeselwakeup(wpipe, wpipe);
error = tsleep(wpipe, PRIBIO | PCATCH, "pipdwt", 0);
}
@ -1124,7 +1122,7 @@ retry:
wpipe->pipe_state &= ~PIPE_WANTR;
wakeup(wpipe);
}
pipeselwakeup(wpipe);
pipeselwakeup(wpipe, wpipe);
error = tsleep(wpipe, PRIBIO | PCATCH, "pipdwt", 0);
}
@ -1138,7 +1136,7 @@ retry:
error:
/* XXX update uio ? */
if (error == EPIPE)
pipeselwakeup(wpipe);
pipeselwakeup(wpipe, wpipe);
wpipe->pipe_state &= ~PIPE_MOREW;
goto error1;
@ -1218,6 +1216,7 @@ pipe_write(fp, offset, uio, cred, flags)
&& (wpipe->pipe_state & PIPE_WANTCLOSE)) {
wpipe->pipe_state &=
~(PIPE_WANTCLOSE | PIPE_WANTR);
wakeup(wpipe);
}
return (error);
@ -1393,7 +1392,7 @@ pipe_write(fp, offset, uio, cred, flags)
* We have no more space and have something to offer,
* wake up select/poll.
*/
pipeselwakeup(wpipe);
pipeselwakeup(wpipe, wpipe);
wpipe->pipe_state |= PIPE_WANTW;
error = tsleep(wpipe, PRIBIO | PCATCH, "pipewr", 0);
@ -1441,7 +1440,7 @@ pipe_write(fp, offset, uio, cred, flags)
* is only done synchronously), so check wpipe->only pipe_buffer.cnt
*/
if (wpipe->pipe_buffer.cnt)
pipeselwakeup(wpipe);
pipeselwakeup(wpipe, wpipe);
/*
* Arrange for next read(2) to do a signal.
@ -1667,7 +1666,7 @@ pipeclose(cpipe)
if (!cpipe)
return;
pipeselwakeup(cpipe->pipe_peer);
pipeselwakeup(cpipe, cpipe);
/*
* If the other side is blocked, wake it up saying that
@ -1683,7 +1682,7 @@ pipeclose(cpipe)
* Disconnect from peer
*/
if ((ppipe = cpipe->pipe_peer) != NULL) {
pipeselwakeup(ppipe);
pipeselwakeup(ppipe, ppipe);
ppipe->pipe_state |= PIPE_EOF;
wakeup(ppipe);
@ -1695,16 +1694,17 @@ pipeclose(cpipe)
*/
#ifdef _FreeBSD__
mtx_lock(&vm_mtx);
#endif
pipe_free_kmem(cpipe);
#ifdef __FreeBSD__
/* XXX: erm, doesn't zalloc already have its own locks and
* not need the giant vm lock?
*/
zfree(pipe_zone, cpipe);
mtx_unlock(&vm_mtx);
#endif /* FreeBSD */
#ifdef __NetBSD__
pipe_free_kmem(cpipe);
(void) lockmgr(&cpipe->pipe_lock, LK_DRAIN, NULL);
pool_put(&pipe_pool, cpipe);
#endif
}