#ifndef MSDOS
-static void
-wait_for_termination_1 (pid_t pid, int interruptible)
+/* Wait for the subprocess with process id CHILD to terminate or change status.
+ CHILD must be a child process that has not been reaped.
+ If STATUS is non-null, store the waitpid-style exit status into *STATUS
+ and tell wait_reading_process_output that it needs to look around.
+ Use waitpid-style OPTIONS when waiting.
+ If INTERRUPTIBLE, this function is interruptible by a signal.
+
+ Return CHILD if successful, 0 if no status is available;
+ the latter is possible only when options & NOHANG. */
+static pid_t
+get_child_status (pid_t child, int *status, int options, bool interruptible)
{
- while (1)
+ pid_t pid;
+
+ /* Invoke waitpid only with a known process ID; do not invoke
+ waitpid with a nonpositive argument. Otherwise, Emacs might
+ reap an unwanted process by mistake. For example, invoking
+ waitpid (-1, ...) can mess up glib by reaping glib's subprocesses,
+ so that another thread running glib won't find them. */
+ eassert (0 < child);
+
+ while ((pid = waitpid (child, status, options)) < 0)
{
- int status;
- int wait_result = waitpid (pid, &status, 0);
- if (wait_result < 0)
- {
- if (errno != EINTR)
- break;
- }
- else
- {
- record_child_status_change (wait_result, status);
- break;
- }
+ /* Check that CHILD is a child process that has not been reaped,
+ and that STATUS and OPTIONS are valid. Otherwise abort,
+ as continuing after this internal error could cause Emacs to
+ become confused and kill innocent-victim processes. */
+ if (errno != EINTR)
+ emacs_abort ();
/* Note: the MS-Windows emulation of waitpid calls QUIT
internally. */
if (interruptible)
QUIT;
}
-}
-/* Wait for subprocess with process id `pid' to terminate and
- make sure it will get eliminated (not remain forever as a zombie) */
+ /* If successful and status is requested, tell wait_reading_process_output
+ that it needs to wake up and look around. */
+ if (pid && status && input_available_clear_time)
+ *input_available_clear_time = make_emacs_time (0, 0);
+ return pid;
+}
+
+/* Wait for the subprocess with process id CHILD to terminate.
+ CHILD must be a child process that has not been reaped.
+ If STATUS is non-null, store the waitpid-style exit status into *STATUS
+ and tell wait_reading_process_output that it needs to look around.
+ If INTERRUPTIBLE, this function is interruptible by a signal. */
void
-wait_for_termination (pid_t pid)
+wait_for_termination (pid_t child, int *status, bool interruptible)
{
- wait_for_termination_1 (pid, 0);
+ get_child_status (child, status, 0, interruptible);
}
-/* Like the above, but allow keyboard interruption. */
-void
-interruptible_wait_for_termination (pid_t pid)
+/* Report whether the subprocess with process id CHILD has changed status.
+ Termination counts as a change of status.
+ CHILD must be a child process that has not been reaped.
+ If STATUS is non-null, store the waitpid-style exit status into *STATUS
+ and tell wait_reading_process_output that it needs to look around.
+ Use waitpid-style OPTIONS to check status, but do not wait.
+
+ Return CHILD if successful, 0 if no status is available because
+ the process's state has not changed. */
+pid_t
+child_status_changed (pid_t child, int *status, int options)
{
- wait_for_termination_1 (pid, 1);
+ return get_child_status (child, status, WNOHANG | options, 0);
}
/*
void
sys_suspend (void)
{
-#if defined (SIGTSTP) && !defined (MSDOS)
-
- {
- pid_t pgrp = getpgrp ();
- EMACS_KILLPG (pgrp, SIGTSTP);
- }
-
-#else /* No SIGTSTP */
+#ifndef DOS_NT
+ kill (0, SIGTSTP);
+#else
/* On a system where suspending is not implemented,
instead fork a subshell and let it talk directly to the terminal
while we wait. */
sys_subshell ();
-#endif /* no SIGTSTP */
+#endif
}
/* Fork a subshell. */
char oldwd[MAXPATHLEN+1]; /* Fixed length is safe on MSDOS. */
#endif
pid_t pid;
+ int status;
struct save_signal saved_handlers[5];
Lisp_Object dir;
unsigned char *volatile str_volatile = 0;
#ifdef DOS_NT
pid = 0;
save_signal_handlers (saved_handlers);
- synch_process_alive = 1;
#else
pid = vfork ();
if (pid == -1)
/* Do this now if we did not do it before. */
#ifndef MSDOS
save_signal_handlers (saved_handlers);
- synch_process_alive = 1;
#endif
#ifndef DOS_NT
- wait_for_termination (pid);
+ wait_for_termination (pid, &status, 0);
#endif
restore_signal_handlers (saved_handlers);
- synch_process_alive = 0;
}
static void
/* When handling a signal, block nonfatal system signals that are caught
by Emacs. This makes race conditions less likely. */
sigaddset (&action->sa_mask, SIGALRM);
-#ifdef SIGCHLD
sigaddset (&action->sa_mask, SIGCHLD);
-#endif
#ifdef SIGDANGER
sigaddset (&action->sa_mask, SIGDANGER);
#endif
# ifdef SIGAIO
sys_siglist[SIGAIO] = "LAN I/O interrupt";
# endif
-# ifdef SIGALRM
sys_siglist[SIGALRM] = "Alarm clock";
-# endif
# ifdef SIGBUS
sys_siglist[SIGBUS] = "Bus error";
# endif
-# ifdef SIGCLD
- sys_siglist[SIGCLD] = "Child status changed";
-# endif
-# ifdef SIGCHLD
sys_siglist[SIGCHLD] = "Child status changed";
-# endif
# ifdef SIGCONT
sys_siglist[SIGCONT] = "Continued";
# endif
# ifdef SIGGRANT
sys_siglist[SIGGRANT] = "Monitor mode granted";
# endif
-# ifdef SIGHUP
sys_siglist[SIGHUP] = "Hangup";
-# endif
sys_siglist[SIGILL] = "Illegal instruction";
sys_siglist[SIGINT] = "Interrupt";
# ifdef SIGIO
# ifdef SIGIOT
sys_siglist[SIGIOT] = "IOT trap";
# endif
-# ifdef SIGKILL
sys_siglist[SIGKILL] = "Killed";
-# endif
# ifdef SIGLOST
sys_siglist[SIGLOST] = "Resource lost";
# endif
# ifdef SIGPHONE
sys_siglist[SIGWIND] = "SIGPHONE";
# endif
-# ifdef SIGPIPE
sys_siglist[SIGPIPE] = "Broken pipe";
-# endif
# ifdef SIGPOLL
sys_siglist[SIGPOLL] = "Pollable event occurred";
# endif
# ifdef SIGPWR
sys_siglist[SIGPWR] = "Power-fail restart";
# endif
-# ifdef SIGQUIT
sys_siglist[SIGQUIT] = "Quit";
-# endif
# ifdef SIGRETRACT
sys_siglist[SIGRETRACT] = "Need to relinquish monitor mode";
# endif
HCoop / bpt / emacs.git / blobdiff