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| author | joerg <joerg@FreeBSD.org> | 1997-09-13 19:43:24 +0000 |
|---|---|---|
| committer | joerg <joerg@FreeBSD.org> | 1997-09-13 19:43:24 +0000 |
| commit | 96e44a0ac22a5f2e1bc20b6742d1bf1b47bc8a2c (patch) | |
| tree | d14bcd255a98ba718e2d26e1c3fd0b7e63b57a99 /lib | |
| parent | b3004b96f00018abb27dfa6435afa6c1364781a4 (diff) | |
| download | FreeBSD-src-96e44a0ac22a5f2e1bc20b6742d1bf1b47bc8a2c.zip FreeBSD-src-96e44a0ac22a5f2e1bc20b6742d1bf1b47bc8a2c.tar.gz | |
Document SA_NOCLDWAIT.
Make all the SA_* flags go into a tagged list, to improve readability.
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/libc/sys/sigaction.2 | 55 |
1 files changed, 38 insertions, 17 deletions
diff --git a/lib/libc/sys/sigaction.2 b/lib/libc/sys/sigaction.2 index cf51196..3acdeaa 100644 --- a/lib/libc/sys/sigaction.2 +++ b/lib/libc/sys/sigaction.2 @@ -29,7 +29,8 @@ .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" -.\" @(#)sigaction.2 8.2 (Berkeley) 4/3/94 +.\" From: @(#)sigaction.2 8.2 (Berkeley) 4/3/94 +.\" $Id$ .\" .Dd April 3, 1994 .Dt SIGACTION 2 @@ -163,9 +164,10 @@ of the signal are ignored and discarded. .Pp Options may be specified by setting .Em sa_flags . -If the -.Dv SA_NOCLDSTOP -bit is set when installing a catching function +The meaning of the various bits is as follows: +.Bl -tag -offset indent -width SA_RESETHANDXX +.It Dv SA_NOCLDSTOP +If this bit is set when installing a catching function for the .Dv SIGCHLD signal, @@ -173,23 +175,34 @@ the .Dv SIGCHLD signal will be generated only when a child process exits, not when a child process stops. -Further, if the -.Dv SA_ONSTACK -bit is set in -.Em sa_flags , -the system will deliver the signal to the process on a +.It Dv SA_NOCLDWAIT +If this bit is set when calling +.Fn sigaction +for the +.Dv SIGCHLD +signal, the system will not create zombie processes when children of +the calling process exit. If the calling process subsequently issues +a +.Xr wait 2 +(or equivalent), it blocks until all of the calling process's child +processes terminate, and then returns a value of -1 with errno set to +.Dv ECHILD . +.It Dv SA_ONSTACK +If this bit is set, the system will deliver the signal to the process +on a .Em "signal stack" , specified with .Xr sigaltstack 2 . -If the -.Dv SA_NODEFER -bit is set, further occurrences of the delivered signal are not -masked during the execution of the handler. -If the -.Dv SA_RESETHAND -bit is set, the handler is reset back to +.It Dv SA_NODEFER +If this bit is set, further occurrences of the delivered signal are +not masked during the execution of the handler. +.It Dv SA_RESETHAND +If this bit is set, the handler is reset back to .Dv SIG_DFL at the moment the signal is delivered. +.\" Still missing: +.\" .It Dv SA_SIGINFO +.El .Pp If a signal is caught during the system calls listed below, the call may be forced to terminate @@ -369,7 +382,14 @@ The .Dv SA_NODEFER and .Dv SA_RESETHAND -are intended for backwards compatability with other operating systems. +flags are intended for backwards compatability with other operating +systems. The +.Dv SA_NOCLDSTOP , +and +.Dv SA_NOCLDWAIT +.\" and +.\" SA_SIGINFO +flags are featuring options commonly found in other operating systems. .Sh SEE ALSO .Xr kill 1 , .Xr kill 2 , @@ -382,6 +402,7 @@ are intended for backwards compatability with other operating systems. .Xr sigsetmask 2 , .Xr sigsuspend 2 , .Xr sigvec 2 , +.Xr wait 2 , .Xr setjmp 3 , .Xr siginterrupt 3 , .Xr sigsetops 3 , |
