From 03f3426d4da28916900a7b811e72b862c5411d0d Mon Sep 17 00:00:00 2001 From: Ben Pfaff Date: Sun, 11 Feb 2007 04:44:25 +0000 Subject: [PATCH] Clarify description of "wait" syscall. Thanks to Evan Kutter for describing the issue. --- doc/userprog.texi | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/doc/userprog.texi b/doc/userprog.texi index b50dc36..88d8bbd 100644 --- a/doc/userprog.texi +++ b/doc/userprog.texi @@ -619,10 +619,11 @@ the program cannot load or run for any reason. @end deftypefn @deftypefn {System Call} int wait (pid_t @var{pid}) -Waits for process @var{pid} to die and returns the status it passed to -@code{exit}. Returns -1 if @var{pid} -was terminated by the kernel (e.g.@: killed due to an exception). If -@var{pid} is does not refer to a child of the +If process @var{pid} is still alive, waits until it dies. +Then, returns the status that @var{pid} passed to @code{exit}, +or -1 if @var{pid} +was terminated by the kernel (e.g.@: killed due to an exception).= If +@var{pid} does not refer to a child of the calling thread, or if @code{wait} has already been successfully called for the given @var{pid}, returns -1 immediately, without waiting. -- 2.30.2