Document more difference between parent and child.

Updates to ERRORS, and STANDARDS

ok jmc@

1 files changed, 27 insertions, 9 deletions

diff --git a/lib/libc/sys/fork.2 b/lib/libc/sys/fork.2
index 13d9638f82c..fab4fb8a539 100644
--- a/lib/libc/sys/fork.2
+++ b/lib/libc/sys/fork.2
@@ -1,4 +1,4 @@
-.\"	$OpenBSD: fork.2,v 1.15 2011/11/06 17:22:20 schwarze Exp $
+.\"	$OpenBSD: fork.2,v 1.16 2013/03/31 08:37:00 guenther Exp $
 .\"	$NetBSD: fork.2,v 1.6 1995/02/27 12:32:36 cgd Exp $
 .\"
 .\" Copyright (c) 1980, 1991, 1993
@@ -30,7 +30,7 @@
 .\"
 .\"	@(#)fork.2	8.1 (Berkeley) 6/4/93
 .\"
-.Dd $Mdocdate: November 6 2011 $
+.Dd $Mdocdate: March 31 2013 $
 .Dt FORK 2
 .Os
 .Sh NAME
@@ -48,11 +48,14 @@ The new process (child process) is an exact copy of the
 calling process (parent process) except for the following:
 .Bl -bullet -offset indent
 .It
-The child process has a unique process ID.
+The child process has a unique process ID,
+which also does not match any existing process group ID.
 .It
 The child process has a different parent
 process ID (i.e., the process ID of the parent process).
 .It
+The child process has a single thread.
+.It
 The child process has its own copy of the parent's descriptors.
 These descriptors reference the same underlying objects, so that,
 for instance, file pointers in file objects are shared between
@@ -67,12 +70,26 @@ This descriptor copying is also used by the shell to
 establish standard input and output for newly created processes
 as well as to set up pipes.
 .It
+The child process has no
+.Xr fcntl 2 Ns -style
+file locks.
+.It
 The child process' resource utilizations
 are set to 0; see
-.Xr setrlimit 2 .
+.Xr getrusage 2 .
 .It
 All interval timers are cleared; see
 .Xr setitimer 2 .
+.It
+The child process' semaphore undo values are set to 0; see
+.Xr semop 2 .
+.It
+The child process' pending signals set is empty.
+.It
+The child process has no memory locks; see
+.Xr mlock 2
+and
+.Xr mlockall 2 .
 .El
 .Pp
 In general, the child process should call
@@ -101,9 +118,10 @@ is set to indicate the error.
 will fail and no child process will be created if:
 .Bl -tag -width [EAGAIN]
 .It Bq Er EAGAIN
-The system-imposed limit on the total
-number of processes under execution would be exceeded.
-This limit is configuration-dependent.
+The system-imposed limits on the total
+number of processes or total number of threads
+under execution would be exceeded.
+These limits are configuration dependent.
 .It Bq Er EAGAIN
 The limit
 .Dv RLIMIT_NPROC
@@ -114,13 +132,13 @@ There is insufficient swap space for the new process.
 .El
 .Sh SEE ALSO
 .Xr execve 2 ,
-.Xr setrlimit 2 ,
+.Xr getrusage 2 ,
 .Xr wait 2
 .Sh STANDARDS
 The
 .Fn fork
 function conforms to
-.St -p1003.1-90 .
+.St -p1003.1-2008 .
 .Sh HISTORY
 The
 .Fn fork