/* wait till none of the processes in the stack starting at k is live */
int
waitstack(int k)
{
int npending, status, totstatus;
int i;
totstatus = 0;
npending = 0;
for(i=k ; i<nproc; ++i)
if(! procstack[i].done)
++npending;
enbint(SIG_IGN);
if(dbgflag > 1)
printf("waitstack(%d)\n", k);
while(npending>0 && proclive>0)
{
if(waitproc(&status) >= k)
--npending;
totstatus |= status;
}
if(nproc > k)
nproc = k;
enbint(intrupt);
return totstatus;
}
/*
* Check to see if any children have exited, and if so, read any unread
* input and then remove the child from the list of children.
*/
static void
reap(int dummy)
{
CHILD *pc;
int save_errno = errno;
int status = 0;
pid_t pid;
debugmsg(DM_CALL, "reap() called\n");
/*
* Reap every child that has exited. Break out of the
* loop as soon as we run out of children that have
* exited so far.
*/
for ( ; ; ) {
/*
* Do a non-blocking check for exiting processes
*/
pid = waitproc(&status, FALSE);
debugmsg(DM_MISC,
"reap() pid = %d status = %d activechildren=%d\n",
pid, status, activechildren);
/*
* See if a child really exited
*/
if (pid == 0)
break;
if (pid < 0) {
if (errno != ECHILD)
error("Wait failed: %s", SYSERR);
break;
}
/*
* Find the process (pid) and mark it as dead.
*/
for (pc = childlist; pc; pc = pc->c_next)
if (pc->c_pid == pid) {
needscan = TRUE;
pc->c_state = PSdead;
}
}
/*
* Reset signals
*/
(void) signal(SIGCHLD, reap);
debugmsg(DM_CALL, "reap() done\n");
errno = save_errno;
}
int
dosys(char *comstring, int nohalt, int nowait, char *prefix)
{
int status;
struct process *procp;
/* make sure there is room in the process stack */
if(nproc >= MAXPROC)
waitstack(MAXPROC-1);
/* make sure fewer than proclimit processes are running */
while(proclive >= proclimit)
{
enbint(SIG_IGN);
waitproc(&status);
enbint(intrupt);
}
if(prefix)
{
fputs(prefix, stdout);
fputs(comstring, stdout);
}
procp = procstack + nproc;
procp->pid = (forceshell || metas(comstring) ) ?
doshell(comstring,nohalt) : doexec(comstring);
if(procp->pid == -1)
fatal("fork failed");
procstack[nproc].nohalt = nohalt;
procstack[nproc].nowait = nowait;
procstack[nproc].done = NO;
++proclive;
++nproc;
if(nowait)
{
printf(" &%d\n", procp->pid);
fflush(stdout);
return 0;
}
if(prefix)
{
putchar('\n');
fflush(stdout);
}
return waitstack(nproc-1);
}
STATIC int
dowait(int flags, struct job *job)
{
int pid;
int status;
struct procstat *sp;
struct job *jp;
struct job *thisjob;
int done;
int stopped;
extern volatile char gotsig[];
TRACE(("dowait(%x) called\n", flags));
do {
pid = waitproc(flags & WBLOCK, job, &status);
TRACE(("wait returns pid %d, status %d\n", pid, status));
} while (pid == -1 && errno == EINTR && gotsig[SIGINT - 1] == 0);
if (pid <= 0)
return pid;
INTOFF;
thisjob = NULL;
for (jp = jobtab ; jp < jobtab + njobs ; jp++) {
if (jp->used) {
done = 1;
stopped = 1;
for (sp = jp->ps ; sp < jp->ps + jp->nprocs ; sp++) {
if (sp->pid == -1)
continue;
if (sp->pid == pid) {
TRACE(("Job %d: changing status of proc %d from 0x%x to 0x%x\n", jp - jobtab + 1, pid, sp->status, status));
sp->status = status;
thisjob = jp;
}
if (sp->status == -1)
stopped = 0;
else if (WIFSTOPPED(sp->status))
done = 0;
}
if (stopped) { /* stopped or done */
int state = done ? JOBDONE : JOBSTOPPED;
if (jp->state != state) {
TRACE(("Job %d: changing state from %d to %d\n", jp - jobtab + 1, jp->state, state));
jp->state = state;
#if JOBS
if (done)
set_curjob(jp, 0);
#endif
}
}
}
}
if (thisjob && thisjob->state != JOBRUNNING) {
int mode = 0;
if (!rootshell || !iflag)
mode = SHOW_SIGNALLED;
if ((job == thisjob && (flags & WNOFREE) == 0) ||
(job != thisjob && (flags & WNOFREE) != 0))
mode = SHOW_SIGNALLED | SHOW_NO_FREE;
if (mode)
showjob(out2, thisjob, mode);
else {
TRACE(("Not printing status, rootshell=%d, job=%p\n",
rootshell, job));
thisjob->changed = 1;
}
}
INTON;
return pid;
}
/*
#if defined HAVE_SELECT
*
* Wait for children to send output for us to read.
*
#else !HAVE_SELECT
*
* Wait up for children to exit.
*
#endif
*/
void
waitup(void)
{
#if defined(HAVE_SELECT)
int count;
CHILD *pc;
fd_set *rchildfdsp = NULL;
int rchildfdsn = 0;
size_t bytes;
debugmsg(DM_CALL, "waitup() start\n");
if (needscan)
childscan();
if (activechildren <= 0)
return;
/*
* Settup which children we want to select() on.
*/
for (pc = childlist; pc; pc = pc->c_next)
if (pc->c_readfd > rchildfdsn)
rchildfdsn = pc->c_readfd;
bytes = howmany(rchildfdsn+1, NFDBITS) * sizeof(fd_mask);
if ((rchildfdsp = (fd_set *)malloc(bytes)) == NULL)
return;
memset(rchildfdsp, 0, bytes);
for (pc = childlist; pc; pc = pc->c_next)
if (pc->c_readfd > 0) {
debugmsg(DM_MISC, "waitup() select on %d (%s)\n",
pc->c_readfd, pc->c_name);
FD_SET(pc->c_readfd, rchildfdsp);
}
/*
* Actually call select()
*/
/* XXX remove debugmsg() calls */
debugmsg(DM_MISC, "waitup() Call select(), activechildren=%d\n",
activechildren);
count = select(rchildfdsn+1, (SELECT_FD_TYPE *) rchildfdsp,
NULL, NULL, NULL);
debugmsg(DM_MISC, "waitup() select returned %d activechildren = %d\n",
count, activechildren);
/*
* select() will return count < 0 and errno == EINTR when
* there are no active children left.
*/
if (count < 0) {
if (errno != EINTR)
error("Select failed reading children input: %s",
SYSERR);
free(rchildfdsp);
return;
}
/*
* This should never happen.
*/
if (count == 0) {
error("Select returned an unexpected count of 0.");
free(rchildfdsp);
return;
}
/*
* Go through the list of children and read from each child
* which select() detected as ready for reading.
*/
for (pc = childlist; pc && count > 0; pc = pc->c_next) {
/*
* Make sure child still exists
*/
if (pc->c_name && kill(pc->c_pid, 0) < 0 &&
errno == ESRCH) {
debugmsg(DM_MISC,
"waitup() proc %d (%s) died unexpectedly!",
pc->c_pid, pc->c_name);
pc->c_state = PSdead;
needscan = TRUE;
}
if (pc->c_name == NULL ||
!FD_ISSET(pc->c_readfd, rchildfdsp))
continue;
readchild(pc);
--count;
}
free(rchildfdsp);
#else /* !defined(HAVE_SELECT) */
/*
* The non-select() version of waitproc()
*/
debugmsg(DM_CALL, "waitup() start\n");
if (waitproc(NULL, TRUE) > 0)
--activechildren;
#endif /* defined(HAVE_SELECT) */
debugmsg(DM_CALL, "waitup() end\n");
}