diff options
| -rw-r--r-- | lib/libc/sys/wait.2 | 12 | ||||
| -rw-r--r-- | sys/kern/kern_exit.c | 16 | ||||
| -rw-r--r-- | sys/sys/wait.h | 5 |
3 files changed, 28 insertions, 5 deletions
diff --git a/lib/libc/sys/wait.2 b/lib/libc/sys/wait.2 index f4dfe9d..c492cd6 100644 --- a/lib/libc/sys/wait.2 +++ b/lib/libc/sys/wait.2 @@ -99,6 +99,7 @@ equals the absolute value of The .Fa status argument is defined below. +.Pp The .Fa options argument contains the bitwise OR of any of the following options. @@ -121,8 +122,15 @@ due to a .Dv SIGTTIN , SIGTTOU , SIGTSTP , or .Dv SIGSTOP -signal also have -their status reported. +signal also have their status reported. +The +.Dv WSTOPPED +option is an alias for +.Dv WUNTRACED . +The +.Dv WNOWAIT +option keeps the process whose status is returned in a waitable state. +The process may be waited for again after this call completes. .Pp If .Fa rusage 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. */ |
