freebsd-dev/contrib/cvs/lib/waitpid.c

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#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "system.h"
#include "wait.h"
#include <stdio.h>
struct unreaped {
pid_t pid;
int status;
};
static struct unreaped *unreaped;
static int n;
static struct unreaped *ualloc (oldptr, n)
struct unreaped *oldptr;
int n;
{
n *= sizeof (struct unreaped);
if (n == 0)
n = 1;
if (oldptr)
oldptr = (struct unreaped *) realloc ((char *) oldptr, n);
else
oldptr = (struct unreaped *) malloc (n);
if (oldptr == 0)
{
fprintf (stderr, "cannot allocate %d bytes\n", n);
exit (1);
}
return oldptr;
}
pid_t waitpid (pid, status, options)
pid_t pid;
int *status;
int options;
{
int i;
/* initialize */
if (unreaped == 0)
{
unreaped = ualloc (unreaped, 1);
unreaped[0].pid = 0;
n = 1;
}
for (i = 0; unreaped[i].pid; i++)
if (unreaped[i].pid == pid)
{
*status = unreaped[i].status;
while (unreaped[i].pid)
{
unreaped[i] = unreaped[i+1];
i++;
}
n--;
return pid;
}
while (1)
{
#ifdef HAVE_WAIT3
pid_t p = wait3 (status, options, (struct rusage *) 0);
#else
pid_t p = wait (status);
#endif
if (p == 0 || p == -1 || p == pid)
return p;
n++;
unreaped = ualloc (unreaped, n);
unreaped[n-1].pid = p;
unreaped[n-1].status = *status;
}
}