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| author | imp <imp@FreeBSD.org> | 2003-04-21 05:58:51 +0000 |
|---|---|---|
| committer | imp <imp@FreeBSD.org> | 2003-04-21 05:58:51 +0000 |
| commit | cf3cf85267793e75562a6705ade86e2e2f2ffd46 (patch) | |
| tree | 99bc8b116945a7fa927cae614e40521d1cd00148 /sys | |
| parent | 68750c77958aea54992841f17a2167facbff033f (diff) | |
| download | FreeBSD-src-cf3cf85267793e75562a6705ade86e2e2f2ffd46.zip FreeBSD-src-cf3cf85267793e75562a6705ade86e2e2f2ffd46.tar.gz | |
Fix /dev/devctl's implementation of poll. We should only be setting
the poll bits when there's actually something in the queue.
Otherwise, select always returned '2' when there were no items to be
read, and '3' when there were. This would preclude being able to read
in a threaded (libc_r) program, as well as checking to see if there
were pending events or not.
Diffstat (limited to 'sys')
| -rw-r--r-- | sys/kern/subr_bus.c | 16 |
1 files changed, 5 insertions, 11 deletions
diff --git a/sys/kern/subr_bus.c b/sys/kern/subr_bus.c index 6c59558..ecb1c7a 100644 --- a/sys/kern/subr_bus.c +++ b/sys/kern/subr_bus.c @@ -353,21 +353,15 @@ devpoll(dev_t dev, int events, d_thread_t *td) { int revents = 0; - if (events & (POLLIN | POLLRDNORM)) - revents |= events & (POLLIN | POLLRDNORM); - - if (events & (POLLOUT | POLLWRNORM)) - revents |= events & (POLLOUT | POLLWRNORM); - mtx_lock(&devsoftc.mtx); - if (events & POLLRDBAND) + if (events & (POLLIN | POLLRDNORM)) { if (!TAILQ_EMPTY(&devsoftc.devq)) - revents |= POLLRDBAND; + revents = events & (POLLIN | POLLRDNORM); + else + selrecord(td, &devsoftc.sel); + } mtx_unlock(&devsoftc.mtx); - if (revents == 0) - selrecord(td, &devsoftc.sel); - return (revents); } |
