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#include "rc.h"
#include <errno.h>
#include "wait.h"
bool forked = FALSE;
typedef struct Pid Pid;
static struct Pid {
pid_t pid;
int stat;
bool alive;
Pid *n;
} *plist = NULL;
extern pid_t rc_fork() {
Pid *new;
struct Pid *p, *q;
pid_t pid = fork();
switch (pid) {
case -1:
uerror("fork");
rc_error(NULL);
/* NOTREACHED */
case 0:
forked = TRUE;
sigchk();
p = plist; q = 0;
while (p) {
if (q) efree(q);
q = p;
p = p->n;
}
if (q) efree(q);
plist = 0;
return 0;
default:
new = enew(Pid);
new->pid = pid;
new->alive = TRUE;
new->n = plist;
plist = new;
return pid;
}
}
extern pid_t rc_wait4(pid_t pid, int *stat, bool nointr) {
Pid *r, *prev;
/* Find the child on the list. */
for (r = plist, prev = NULL; r != NULL; prev = r, r = r->n)
if (r->pid == pid)
break;
/* Uh-oh, not there. */
if (r == NULL) {
errno = ECHILD; /* no children */
uerror("wait");
*stat = 0x100; /* exit(1) */
return -1;
}
/* If it's still alive, wait() for it. */
while (r->alive) {
int ret;
Pid *q;
ret = rc_wait(stat);
if (ret < 0) {
if (errno == ECHILD)
panic("lost child");
if (nointr)
continue;
else
return ret;
}
for (q = plist; q != NULL; q = q->n)
if (q->pid == ret) {
q->alive = FALSE;
q->stat = *stat;
break;
}
}
*stat = r->stat;
if (prev == NULL)
plist = r->n; /* remove element from head of list */
else
prev->n = r->n;
efree(r);
return pid;
}
extern List *sgetapids() {
List *r;
Pid *p;
for (r = NULL, p = plist; p != NULL; p = p->n) {
List *q;
if (!p->alive)
continue;
q = nnew(List);
q->w = nprint("%d", p->pid);
q->m = NULL;
q->n = r;
r = q;
}
return r;
}
extern void waitforall() {
int stat;
while (plist != NULL) {
pid_t pid = rc_wait4(plist->pid, &stat, FALSE);
if (pid > 0)
setstatus(pid, stat);
else {
set(FALSE);
if (errno == EINTR)
return;
}
sigchk();
}
}
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