diff options
| author | kib <kib@FreeBSD.org> | 2008-08-26 12:37:16 +0000 |
|---|---|---|
| committer | kib <kib@FreeBSD.org> | 2008-08-26 12:37:16 +0000 |
| commit | 05dac85e4b0f1f608662dcda515b72680edf8348 (patch) | |
| tree | e56e2d6943e7f9becd5ad8952f710e7110d719e6 /sys | |
| parent | 2d990eae0580f74b2aee49da3c6434c6224e084c (diff) | |
| download | FreeBSD-src-05dac85e4b0f1f608662dcda515b72680edf8348.zip FreeBSD-src-05dac85e4b0f1f608662dcda515b72680edf8348.tar.gz | |
Implement WNOWAIT flag for wait4(2). It specifies that process whose status
is returned shall be kept in the waitable state.
Add WSTOPPED as an alias for WUNTRACED.
Submitted by: Jukka Ukkonen <jau at iki fi>
PR: standards/116221
MFC after: 2 weeks
Diffstat (limited to 'sys')
| -rw-r--r-- | sys/kern/kern_exit.c | 16 | ||||
| -rw-r--r-- | sys/sys/wait.h | 5 |
2 files changed, 18 insertions, 3 deletions
diff --git a/sys/kern/kern_exit.c b/sys/kern/kern_exit.c index f0866ed..b536d99 100644 --- a/sys/kern/kern_exit.c +++ b/sys/kern/kern_exit.c @@ -690,7 +690,7 @@ kern_wait(struct thread *td, pid_t pid, int *status, int options, pid = -q->p_pgid; PROC_UNLOCK(q); } - if (options &~ (WUNTRACED|WNOHANG|WCONTINUED|WLINUXCLONE)) + if (options &~ (WUNTRACED|WNOHANG|WCONTINUED|WNOWAIT|WLINUXCLONE)) return (EINVAL); loop: if (q->p_flag & P_STATCHILD) { @@ -741,11 +741,23 @@ loop: sigqueue_take(p->p_ksi); PROC_UNLOCK(q); + PROC_UNLOCK(p); + + if (options & WNOWAIT) { + + /* + * Only poll, returning the status. + * Caller does not wish to release the proc + * struct just yet. + */ + sx_xunlock(&proctree_lock); + return (0); + } + /* * If we got the child via a ptrace 'attach', * we need to give it back to the old parent. */ - PROC_UNLOCK(p); if (p->p_oppid && (t = pfind(p->p_oppid)) != NULL) { PROC_LOCK(p); p->p_oppid = 0; diff --git a/sys/sys/wait.h b/sys/sys/wait.h index e5691db..0e23c23 100644 --- a/sys/sys/wait.h +++ b/sys/sys/wait.h @@ -72,11 +72,14 @@ * indicates that the caller should receive status about untraced children * which stop due to signals. If children are stopped and a wait without * this option is done, it is as though they were still running... nothing - * about them is returned. + * about them is returned. WNOWAIT only request information about zombie, + * leaving the proc around, available for later waits. */ #define WNOHANG 1 /* Don't hang in wait. */ #define WUNTRACED 2 /* Tell about stopped, untraced children. */ +#define WSTOPPED WUNTRACED /* SUS compatibility */ #define WCONTINUED 4 /* Report a job control continued process. */ +#define WNOWAIT 8 /* Poll only. Don't delete the proc entry. */ #if __BSD_VISIBLE #define WLINUXCLONE 0x80000000 /* Wait for kthread spawned from linux_clone. */ |
