/* Emulate waitpid on systems that just have wait.
Copyright (C) 1994 Free Software Foundation, Inc.
This file is part of GNU DIFF.
GNU DIFF is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
GNU DIFF is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details. */
#include "vms.h"
#define WAITPID_CHILDREN 8
static pid_t waited_pid[WAITPID_CHILDREN];
static int waited_status[WAITPID_CHILDREN];
pid_t
waitpid (pid, stat_loc, options)
pid_t pid;
int *stat_loc;
int options;
{
int i;
pid_t p;
if (!options && (0 < pid || pid == -1))
{
/* If we have already waited for this child, return it immediately. */
for (i = 0; i < WAITPID_CHILDREN; i++)
{
p = waited_pid[i];
if (p && (p == pid || pid == -1))
{
waited_pid[i] = 0;
goto success;
}
}
/* The child has not returned yet; wait for it, accumulating status. */
for (i = 0; i < WAITPID_CHILDREN; i++)
if (! waited_pid[i])
{
p = wait (&waited_status[i]);
if (p < 0)
return p;
if (p == pid || pid == -1)
goto success;
waited_pid[i] = p;
}
}
/* We cannot emulate this wait call, e.g. because of too many children. */
abort ();
success:
if (stat_loc)
*stat_loc = waited_status[i];
return p;
}