diff options
| author | Warner Losh <imp@FreeBSD.org> | 2003-04-21 05:58:51 +0000 |
|---|---|---|
| committer | Warner Losh <imp@FreeBSD.org> | 2003-04-21 05:58:51 +0000 |
| commit | e22b0bf4b8d2885efa0dc4c1c5127de3008f7cd5 (patch) | |
| tree | 99bc8b116945a7fa927cae614e40521d1cd00148 /sys/kern/subr_bus.c | |
| parent | 61a0da1de58423828ee7cdfff28b6d19c43af56f (diff) | |
| download | src-e22b0bf4b8d2885efa0dc4c1c5127de3008f7cd5.tar.gz src-e22b0bf4b8d2885efa0dc4c1c5127de3008f7cd5.zip | |
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.
Notes
Notes:
svn path=/head/; revision=113789
Diffstat (limited to 'sys/kern/subr_bus.c')
| -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 6c5955858d40..ecb1c7a05a78 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); } |