-/*
- * timer.c --- daemon to provide a tagged interval timer service
- *
- * This little daemon runs forever waiting for signals. SIGIO (or SIGUSR1)
- * causes it to read an event spec from stdin; that is, a date followed by
- * colon followed by an event label. SIGALRM causes it to check its queue
- * for events attached to the current second; if one is found, its label
- * is written to stdout. SIGTERM causes it to terminate, printing a list
- * of pending events.
- *
- * This program is intended to be used with the lisp package called timer.el.
- * It was written anonymously in 1990. This version was documented and
- * rewritten for portability by esr@snark,thyrsus.com, Aug 7 1992.
- */
-#include <stdio.h>
-#include <signal.h>
-#include <fcntl.h> /* FASYNC */
-#include <sys/types.h> /* time_t */
-
-#include "../src/config.h"
-#ifdef USG
-#undef SIGIO
-#define SIGIO SIGUSR1
-#endif
-
-extern int errno;
-extern char *sys_errlist[], *malloc();
-extern time_t time();
-
-#define MAXEVENTS 256
-
-/*
- * The field separator for input. This character shouldn't be legal in a date,
- * and should be printable so event strings are readable by people. Was
- * originally ';', then got changed to bogus `\001'.
- */
-#define FS '@'
-
-struct event
-{
- char *token;
- time_t reply_at;
-}
-events[MAXEVENTS];
-
-char *pname; /* programme name for error messages */
-
-/* Accepts a string of two fields seperated by FS.
- * First field is string for getdate, saying when to wake-up.
- * Second field is a token to identify the request.
- */
-void schedule(str)
- char *str;
-{
- extern time_t getdate();
- extern char *strcpy();
- time_t now;
- register char *p;
- static struct event *ep;
-
-#ifdef DEBUG
- (void) fprintf(stderr, "Timer sees: %s", str);
-#endif /* DEBUG */
-
- /* check entry format */
- for(p = str; *p && *p != FS; p++)
- continue;
- if (!*p)
- {
- (void)fprintf(stderr, "%s: bad input format: %s", pname, str);
- return;
- }
- *p++ = 0;
-
- /* allocate an event slot */
- for(ep = events; ep < events + MAXEVENTS; ep++)
- if (ep->token == (char *)NULL)
- break;
- if (ep == events + MAXEVENTS)
- (void) fprintf(stderr, "%s: too many events: %s", pname, str);
-
- /* don't allow users to schedule events in past time */
- else if ((ep->reply_at = get_date(str, NULL)) - time(&now) < 0)
- (void)fprintf(stderr, "%s: bad time spec: %s%c%s", pname, str, FS, p);
-
- /* save the event description */
- else if ((ep->token = malloc((unsigned)strlen(p) + 1)) == NULL)
- (void)fprintf(stderr, "%s: malloc %s: %s%c%s",
- pname, sys_errlist[errno], str, FS, p);
- else
- {
- (void)strcpy(ep->token, p);
-
-#ifdef DEBUG
- (void) fprintf(stderr,
- "New event: %ld: %s", ep->reply_at, ep->token);
-#endif /* DEBUG */
- }
-}
-
-void
-notify()
-{
- time_t now, tdiff, waitfor = -1;
- register struct event *ep;
-
- now = time((time_t *)NULL);
-
- for(ep = events; ep < events + MAXEVENTS; ep++)
- if (ep->token)
- {
- /* any events ready to fire? */
- if (ep->reply_at <= now)
- {
-#ifdef DEBUG
- (void) fprintf(stderr,
- "Event %d firing: %ld @ %s",
- (ep - events), ep->reply_at, ep->token);
-#endif /* DEBUG */
- (void)fputs(ep->token, stdout);
- free(ep->token);
- ep->token = (char *)NULL;
- }
- else
- {
-#ifdef DEBUG
- (void) fprintf(stderr,
- "Event %d still waiting: %ld @ %s",
- (ep - events), ep->reply_at, ep->token);
-#endif /* DEBUG */
-
- /* next timeout should be the soonest of any remaining */
- if ((tdiff = ep->reply_at - now) < waitfor || waitfor < 0)
- waitfor = (long)tdiff;
- }
- }
-
- /* If there's no more events, SIGIO should be next wake-up */
- if (waitfor != -1)
- {
-#ifdef DEBUG
- (void) fprintf(stderr,
- "Setting %d-second alarm\n", waitfor);
-#endif /* DEBUG */
- (void)alarm(waitfor);
- }
-}
-
-void
-getevent()
-{
- extern char *fgets();
- struct event *ep;
- char buf[BUFSIZ];
-
- /* in principle the itimer should be disabled on entry to this function,
- but it really doesn't make any important difference if it isn't */
-
- if (fgets(buf, sizeof(buf), stdin) == NULL)
- exit(0);
-
- /* register the event */
- schedule(buf);
-
- /* Who knows what this interrupted, or if it said "now"? */
- notify();
-}
-
-void
-sigcatch(sig)
-/* dispatch on incoming signal, then restore it */
-{
- struct event *ep;
-
- switch(sig)
- {
- case SIGALRM:
-#ifdef DEBUG
- (void) fprintf(stderr, "Alarm signal received\n");
-#endif /* DEBUG */
- notify();
- break;
- case SIGIO:
- getevent();
- break;
- case SIGTERM:
- (void) fprintf(stderr, "Events still queued:\n");
- for (ep = events; ep < events + MAXEVENTS; ep++)
- if (ep->token)
- (void) fprintf(stderr, "%d = %ld @ %s",
- ep - events, ep->reply_at, ep->token);
- exit(0);
- break;
- }
-
- /* required on older UNIXes; harmless on newer ones */
- (void) signal(sig, sigcatch);
-}
-
-/*ARGSUSED*/
-int
-main(argc, argv)
- int argc;
- char **argv;
-{
- for (pname = argv[0] + strlen(argv[0]); *pname != '/' && pname != argv[0];
- pname--);
- if (*pname == '/') pname++;
-
- (void)signal(SIGIO, sigcatch);
- (void)signal(SIGALRM, sigcatch);
- (void)signal(SIGTERM, sigcatch);
-
-#ifndef USG
- (void)fcntl(0, F_SETFL, FASYNC);
-#endif /* USG */
-
- while (1) pause();
-}
-
-/* timer.c ends here */
+/* timer.c --- daemon to provide a tagged interval timer service
+
+ This little daemon runs forever waiting for commands to schedule events.
+ SIGALRM causes
+ it to check its queue for events attached to the current second; if
+ one is found, its label is written to stdout. SIGTERM causes it to
+ terminate, printing a list of pending events.
+
+ This program is intended to be used with the lisp package called
+ timer.el. The first such program was written anonymously in 1990.
+ This version was documented and rewritten for portability by
+ esr@snark.thyrsus.com, Aug 7 1992. */
+
+#include <stdio.h>
+#include <signal.h>
+#include <errno.h>
+#include <sys/types.h> /* time_t */
+
+#include <../src/config.h>
+#undef read
+
+#ifdef LINUX
+/* Perhaps this is correct unconditionally. */
+#undef signal
+#endif
+#ifdef _CX_UX
+/* I agree with the comment above, this probably should be unconditional (it
+ * is already unconditional in a couple of other files in this directory),
+ * but in the spirit of minimizing the effects of my port, I am making it
+ * conditional on _CX_UX.
+ */
+#undef signal
+#endif
+
+
+extern int errno;
+extern char *strerror ();
+extern time_t time ();
+
+/*
+ * The field separator for input. This character shouldn't occur in dates,
+ * and should be printable so event strings are readable by people.
+ */
+#define FS '@'
+
+struct event
+ {
+ char *token;
+ time_t reply_at;
+ };
+int events_size; /* How many slots have we allocated? */
+int num_events; /* How many are actually scheduled? */
+struct event *events; /* events[0 .. num_events-1] are the
+ valid events. */
+
+char *pname; /* program name for error messages */
+
+/* This buffer is used for reading commands.
+ We make it longer when necessary, but we never free it. */
+char *buf;
+/* This is the allocated size of buf. */
+int buf_size;
+
+/* Non-zero means don't handle an alarm now;
+ instead, just set alarm_deferred if an alarm happens.
+ We set this around parts of the program that call malloc and free. */
+int defer_alarms;
+
+/* Non-zero if an alarm came in during the reading of a command. */
+int alarm_deferred;
+\f
+/* Schedule one event, and arrange an alarm for it.
+ STR is a string of two fields separated by FS.
+ First field is string for get_date, saying when to wake-up.
+ Second field is a token to identify the request. */
+
+void
+schedule (str)
+ char *str;
+{
+ extern time_t get_date ();
+ extern char *strcpy ();
+ time_t now;
+ register char *p;
+ static struct event *ep;
+
+ /* check entry format */
+ for (p = str; *p && *p != FS; p++)
+ continue;
+ if (!*p)
+ {
+ fprintf (stderr, "%s: bad input format: %s\n", pname, str);
+ return;
+ }
+ *p++ = 0;
+
+ /* allocate an event slot */
+ ep = events + num_events;
+
+ /* If the event array is full, stretch it. After stretching, we know
+ that ep will be pointing to an available event spot. */
+ if (ep == events + events_size)
+ {
+ int old_size = events_size;
+
+ events_size *= 2;
+ events = ((struct event *)
+ realloc (events, events_size * sizeof (struct event)));
+ if (! events)
+ {
+ fprintf (stderr, "%s: virtual memory exhausted.\n", pname);
+ /* Since there is so much virtual memory, and running out
+ almost surely means something is very very wrong,
+ it is best to exit rather than continue. */
+ exit (1);
+ }
+
+ while (old_size < events_size)
+ events[old_size++].token = NULL;
+ }
+
+ /* Don't allow users to schedule events in past time. */
+ ep->reply_at = get_date (str, NULL);
+ if (ep->reply_at - time (&now) < 0)
+ {
+ fprintf (stderr, "%s: bad time spec: %s%c%s\n", pname, str, FS, p);
+ return;
+ }
+
+ /* save the event description */
+ ep->token = (char *) malloc ((unsigned) strlen (p) + 1);
+ if (! ep->token)
+ {
+ fprintf (stderr, "%s: malloc %s: %s%c%s\n",
+ pname, strerror (errno), str, FS, p);
+ return;
+ }
+
+ strcpy (ep->token, p);
+ num_events++;
+}
+\f
+/* Print the notification for the alarmed event just arrived if any,
+ and schedule an alarm for the next event if any. */
+
+void
+notify ()
+{
+ time_t now, tdiff, waitfor = -1;
+ register struct event *ep;
+
+ /* Inhibit interference with alarms while changing global vars. */
+ defer_alarms = 1;
+ alarm_deferred = 0;
+
+ now = time ((time_t *) NULL);
+
+ for (ep = events; ep < events + num_events; ep++)
+ /* Are any events ready to fire? */
+ if (ep->reply_at <= now)
+ {
+ fputs (ep->token, stdout);
+ putc ('\n', stdout);
+ fflush (stdout);
+ free (ep->token);
+
+ /* We now have a hole in the event array; fill it with the last
+ event. */
+ ep->token = events[num_events - 1].token;
+ ep->reply_at = events[num_events - 1].reply_at;
+ num_events--;
+
+ /* We ought to scan this event again. */
+ ep--;
+ }
+ else
+ {
+ /* next timeout should be the soonest of any remaining */
+ if ((tdiff = ep->reply_at - now) < waitfor || waitfor < 0)
+ waitfor = (long)tdiff;
+ }
+
+ /* If there are no more events, we needn't bother setting an alarm. */
+ if (num_events > 0)
+ alarm (waitfor);
+
+ /* Now check if there was another alarm
+ while we were handling an explicit request. */
+ defer_alarms = 0;
+ if (alarm_deferred)
+ notify ();
+ alarm_deferred = 0;
+}
+\f
+/* Read one command from command from standard input
+ and schedule the event for it. */
+
+void
+getevent ()
+{
+ int i;
+
+ /* In principle the itimer should be disabled on entry to this
+ function, but it really doesn't make any important difference
+ if it isn't. */
+
+ if (buf == 0)
+ {
+ buf_size = 80;
+ buf = (char *) malloc (buf_size);
+ }
+
+ /* Read a line from standard input, expanding buf if it is too short
+ to hold the line. */
+ for (i = 0; ; i++)
+ {
+ char c;
+ int nread;
+
+ if (i >= buf_size)
+ {
+ buf_size *= 2;
+ alarm_deferred = 0;
+ defer_alarms = 1;
+ buf = (char *) realloc (buf, buf_size);
+ defer_alarms = 0;
+ if (alarm_deferred)
+ notify ();
+ alarm_deferred = 0;
+ }
+
+ /* Read one character into c. */
+ while (1)
+ {
+ nread = read (fileno (stdin), &c, 1);
+
+ /* Retry after transient error. */
+ if (nread < 0
+ && (1
+#ifdef EINTR
+ || errno == EINTR
+#endif
+#ifdef EAGAIN
+ || errno == EAGAIN
+#endif
+ ))
+ continue;
+
+ /* Report serious errors. */
+ if (nread < 0)
+ {
+ perror ("read");
+ exit (1);
+ }
+
+ /* On eof, exit. */
+ if (nread == 0)
+ exit (0);
+
+ break;
+ }
+
+ if (c == '\n')
+ {
+ buf[i] = '\0';
+ break;
+ }
+
+ buf[i] = c;
+ }
+
+ /* Register the event. */
+ alarm_deferred = 0;
+ defer_alarms = 1;
+ schedule (buf);
+ defer_alarms = 0;
+ notify ();
+ alarm_deferred = 0;
+}
+
+/* Handle incoming signal SIG. */
+
+SIGTYPE
+sigcatch (sig)
+ int sig;
+{
+ struct event *ep;
+
+ /* required on older UNIXes; harmless on newer ones */
+ signal (sig, sigcatch);
+
+ switch (sig)
+ {
+ case SIGALRM:
+ if (defer_alarms)
+ alarm_deferred = 1;
+ else
+ notify ();
+ break;
+ case SIGTERM:
+ fprintf (stderr, "Events still queued:\n");
+ for (ep = events; ep < events + num_events; ep++)
+ fprintf (stderr, "%d = %ld @ %s\n",
+ ep - events, ep->reply_at, ep->token);
+ exit (0);
+ break;
+ }
+}
+
+/*ARGSUSED*/
+int
+main (argc, argv)
+ int argc;
+ char **argv;
+{
+ for (pname = argv[0] + strlen (argv[0]);
+ *pname != '/' && pname != argv[0];
+ pname--);
+ if (*pname == '/')
+ pname++;
+
+ events_size = 16;
+ events = ((struct event *) malloc (events_size * sizeof (*events)));
+ num_events = 0;
+
+ signal (SIGALRM, sigcatch);
+ signal (SIGTERM, sigcatch);
+
+ /* Loop reading commands from standard input
+ and scheduling alarms accordingly.
+ The alarms are handled asynchronously, while we wait for commands. */
+ while (1)
+ getevent ();
+}
+\f
+#ifndef HAVE_STRERROR
+char *
+strerror (errnum)
+ int errnum;
+{
+ extern char *sys_errlist[];
+ extern int sys_nerr;
+
+ if (errnum >= 0 && errnum < sys_nerr)
+ return sys_errlist[errnum];
+ return (char *) "Unknown error";
+}
+
+#endif /* ! HAVE_STRERROR */
+
+long *
+xmalloc (size)
+ int size;
+{
+ register long *val;
+
+ val = (long *) malloc (size);
+
+ if (!val && size)
+ {
+ fprintf (stderr, "timer: virtual memory exceeded\n");
+ exit (1);
+ }
+
+ return val;
+}
+
+/* timer.c ends here */
HCoop / bpt / emacs.git / blobdiff