/* state change of children handled here */
static void sigchld_handler(int sig)
{
pid_t child_pid;
jobs **job;
int status;
/*
* There can be multiple SIGCHLD at once, not necessarily they will all be handled,
* so we reap all the children in non-blocking mode that takes care of the pending child
* whose SIGCHLD is not attended
*/
/* SIGCHLD should be blocked in critical section of modifying joblist */
/* thy shall NOT pass */
while ((child_pid = waitpid(-1, &status, WNOHANG|WUNTRACED|WCONTINUED)) > 0) {
if (WIFEXITED(status)) {
deljob(child_pid);
}
else if (WIFSIGNALED(status)) {
job = getjob(child_pid, 0);
if (NOTNULL(job)) {
shell_printf(SHELLPRINT_CHKSS | SHELLPRINT_CHKTERM,
TERMSTR_GREEN("SIGCHLD: ")"[%d] (%d) killed by signal %d\n",
(*job)->jid, (*job)->pid[0], WTERMSIG(status));
deljob(child_pid);
}
}
else if (WIFSTOPPED(status)) {
job = getjob(child_pid, 0);
if (NOTNULL(job)) {
(*job)->state = ST;
shell_printf(SHELLPRINT_CHKSS | SHELLPRINT_CHKTERM,
TERMSTR_GREEN("SIGCHLD : ")"[%d] (%d) stopped by signal %d\n",
(*job)->jid, (*job)->pid[0], WSTOPSIG(status));
}
}
else if (WIFCONTINUED(status)) {
job = getjob(child_pid, 0);
if (NOTNULL(job))
(*job)->state = BG;
}
}
/* thy shall pass */
}
/*
* the basic wait for foreground used by fg cmd and basic
* non bg cmd in the shell. Make sure SIGCHLD is blocked
* to avoid race conditions that make the joblist unreliable.
* No terminal control or printing if subshell
* */
void wait_fg(jobs **job)
{
int status, i;
/* thy shall NOT pass */
for (i=0; NOTNULL(job); i++) {
if (!subshell_flag && tcsetpgrp(TERMFD, (*job)->pid[0]) < 0)
perror("tcsetpgrp");
while (waitpid((*job)->pid[i], &status, WUNTRACED) == 0)
;
if (WIFEXITED(status)) {
if (!subshell_flag && tcsetpgrp(TERMFD, getpid()) < 0)
perror("tcsetpgrp");
if ((*job)->pid[i+1] == 0) {
deljob((*job)->pid[0]);
break;
}
}
else if (WIFSIGNALED(status)) {
if (!subshell_flag && tcsetpgrp(TERMFD, getpid()) < 0)
perror("tcsetpgrp");
shell_printf(SHELLPRINT_CHKSS | SHELLPRINT_CHKTERM,
"[%d] (%d) killed by signal %d\n", (*job)->jid, (*job)->pid[0],
WTERMSIG(status));
deljob((*job)->pid[0]);
break;
}
else if (WIFSTOPPED(status)) {
if (!subshell_flag && tcsetpgrp(TERMFD, getpid()) < 0)
perror("tcsetpgrp");
shell_printf(SHELLPRINT_CHKSS | SHELLPRINT_CHKTERM,
"[%d] (%d) stopped by signal %d\n", (*job)->jid,
(*job)->pid[0], WSTOPSIG(status));
(*job)->state = ST;
break;
}
}
/* thy shall pass */
}
STATIC void
freejob(struct job *jp)
{
struct procstat *ps;
int i;
INTOFF;
for (i = jp->nprocs, ps = jp->ps ; --i >= 0 ; ps++) {
if (ps->cmd != nullstr)
ckfree(ps->cmd);
}
if (jp->ps != &jp->ps0)
ckfree(jp->ps);
jp->used = 0;
#if JOBS
deljob(jp);
#endif
INTON;
}
