1 files changed, 49 insertions, 11 deletions
diff --git a/lib/libc_r/man/pthread_sigmask.3 b/lib/libc_r/man/pthread_sigmask.3
index e3bc625974f..41aaf7c8c61 100644
--- a/lib/libc_r/man/pthread_sigmask.3
+++ b/lib/libc_r/man/pthread_sigmask.3
@@ -1,10 +1,11 @@
-.\" $OpenBSD: pthread_sigmask.3,v 1.3 1999/07/07 10:50:05 aaron Exp $
+.\" $OpenBSD: pthread_sigmask.3,v 1.4 2002/02/21 20:12:19 fgsch Exp $
+.\"
 .Dd March 21, 1999
 .Dt PTHREAD_SIGMASK 3
 .Os
 .Sh NAME
 .Nm pthread_sigmask
-.Nd manipulate the current thread's signal mask
+.Nd examine and/or change a thread's signal mask
 .Sh SYNOPSIS
 .Fd #include <pthread.h>
 .Fd #include <signal.h>
@@ -13,19 +14,56 @@
 .Sh DESCRIPTION
 The
 .Fn pthread_sigmask
-function is identical to
-.Xr sigprocmask 2 ,
-except that it only affects the signal mask of the calling thread.
+function examines and/or changes the calling thread's signal mask.
+.Pp
+If
+.Fa set
+is not
+.Dv NULL ,
+it specifies a set of signals to be modified, and
+.Fa how
+specifies what to set the signal mask to:
+.Bl -tag -width SIG_UNBLOCK
+.It Dv SIG_BLOCK
+Union of the current mask and
+.Fa set .
+.It Dv SIG_UNBLOCK
+Intersection of the current mask and the complement of
+.Fa set .
+.It Dv SIG_SETMASK
+.Fa set .
+.El
+.Pp
+If
+.Fa oset
+is not NULL, the previous signal mask is stored in the location pointed to by
+.Fa oset .
+.Pp
+.Dv SIGKILL
+and
+.Dv SIGSTOP
+cannot be blocked, and will be silently ignored if included in the signal mask.
 .Sh RETURN VALUES
-The return values of
+If successful,
+.Fn pthread_sigmask
+returns 0.
+Otherwise, an error is returned.
+.Sh ERRORS
 .Fn pthread_sigmask
-are the same as
-.Xr sigprocmask 2 .
+will fail if:
+.Bl -tag -width Er
+.It Bq Er EINVAL
+.Fa how
+is not one of the defined values.
+.El
 .Sh SEE ALSO
+.Xr sigaction 2 ,
+.Xr sigpending 2 ,
 .Xr sigprocmask 2 ,
+.Xr sigsetops 3 ,
+.Xr sigsuspend 2 ,
 .Xr pthreads 3
 .Sh STANDARDS
 .Fn pthread_sigmask
-conforms to ISO/IEC 9945-1 ANSI/IEEE
-.Pq Dq Tn POSIX
-Std 1003.1 Second Edition 1996-07-12.
+conforms to
+.St -p1003.1-96 .