/* subprocs.c --- choosing, spawning, and killing screenhacks.
- * xscreensaver, Copyright (c) 1991-2003 Jamie Zawinski <jwz@jwz.org>
+ * xscreensaver, Copyright (c) 1991-2006 Jamie Zawinski <jwz@jwz.org>
*
* Permission to use, copy, modify, distribute, and sell this software and its
* documentation for any purpose is hereby granted without fee, provided that
#endif
#include <sys/time.h> /* sys/resource.h needs this for timeval */
+#include <sys/param.h> /* for PATH_MAX */
#ifdef HAVE_SYS_WAIT_H
# include <sys/wait.h> /* for waitpid() and associated macros */
#define Widget void*
#include "xscreensaver.h"
+#include "exec.h"
#include "yarandom.h"
#include "visual.h" /* for id_to_visual() */
extern saver_info *global_si_kludge; /* I hate C so much... */
+/* Used when printing error/debugging messages from signal handlers.
+ */
+static const char *
+no_malloc_number_to_string (long num)
+{
+ static char string[128] = "";
+ int num_digits;
+ Bool negative_p = False;
+
+ num_digits = 0;
+
+ if (num == 0)
+ return "0";
+
+ if (num < 0)
+ {
+ negative_p = True;
+ num = -num;
+ }
+
+ while ((num > 0) && (num_digits < sizeof(string - 1)))
+ {
+ int digit;
+ digit = (int) num % 10;
+ num_digits++;
+ string[sizeof(string) - 1 - num_digits] = digit + '0';
+ num /= 10;
+ }
+
+ if (negative_p)
+ {
+ num_digits++;
+ string[sizeof(string) - 1 - num_digits] = '-';
+ }
+
+ return string + sizeof(string) - 1 - num_digits;
+}
+
+/* Like write(), but runs strlen() on the arg to get the length. */
+static int
+write_string (int fd, const char *str)
+{
+ return write (fd, str, strlen (str));
+}
+
+static int
+write_long (int fd, long n)
+{
+ const char *str = no_malloc_number_to_string (n);
+ return write_string (fd, str);
+}
+
+
/* RLIMIT_AS (called RLIMIT_VMEM on some systems) controls the maximum size
of a process's address space, i.e., the maximal brk(2) and mmap(2) values.
Setting this lets you put a cap on how much memory a process can allocate.
static struct screenhack_job *jobs = 0;
-/* for debugging -- nothing calls this, but it's useful to invoke from gdb. */
+/* for debugging -- nothing calls this, but it's useful to invoke from gdb.
+ */
+void show_job_list (void);
+
void
show_job_list (void)
{
saver_info *si = global_si_kludge; /* I hate C so much... */
if (si->prefs.debug_p)
- fprintf(stderr, "%s: got SIGCHLD%s\n", blurb(),
+ {
+ /* Don't call fprintf() from signal handlers, as it might malloc.
+ fprintf(stderr, "%s: got SIGCHLD%s\n", blurb(),
(block_sigchld_handler ? " (blocked)" : ""));
+ */
+ write_string (STDERR_FILENO, blurb());
+ write_string (STDERR_FILENO, ": got SIGCHLD");
+
+ if (block_sigchld_handler)
+ write_string (STDERR_FILENO, " (blocked)\n");
+ else
+ write_string (STDERR_FILENO, "\n");
+ }
if (block_sigchld_handler < 0)
abort();
#ifndef VMS
+
static void
await_dying_children (saver_info *si)
{
if (si->prefs.debug_p)
{
if (kid < 0 && errno)
- fprintf (stderr, "%s: waitpid(-1) ==> %ld (%d)\n", blurb(),
- (long) kid, errno);
- else
- fprintf (stderr, "%s: waitpid(-1) ==> %ld\n", blurb(),
- (long) kid);
+ {
+ /* Don't call fprintf() from signal handlers, as it might malloc.
+ fprintf (stderr, "%s: waitpid(-1) ==> %ld (%d)\n", blurb(),
+ (long) kid, errno);
+ */
+ write_string (STDERR_FILENO, blurb());
+ write_string (STDERR_FILENO, ": waitpid(-1) ==> ");
+ write_long (STDERR_FILENO, (long) kid);
+ write_string (STDERR_FILENO, " (");
+ write_long (STDERR_FILENO, (long) errno);
+ write_string (STDERR_FILENO, ")\n");
+ }
+ else
+ {
+ /* Don't call fprintf() from signal handlers, as it might malloc.
+ fprintf (stderr, "%s: waitpid(-1) ==> %ld\n", blurb(),
+ (long) kid);
+ */
+ write_string (STDERR_FILENO, blurb());
+ write_string (STDERR_FILENO, ": waitpid(-1) ==> ");
+ write_long (STDERR_FILENO, (long) kid);
+ write_string (STDERR_FILENO, "\n");
+ }
}
/* 0 means no more children to reap.
if (!job ||
(exit_status != 0 &&
(p->verbose_p || job->status != job_killed)))
- fprintf (stderr,
- "%s: %d: child pid %lu (%s) exited abnormally (code %d).\n",
- blurb(), screen_no, (unsigned long) kid, name, exit_status);
+ {
+ /* Don't call fprintf() from signal handlers, as it might malloc.
+ fprintf (stderr,
+ "%s: %d: child pid %lu (%s) exited abnormally (code %d).\n",
+ blurb(), screen_no, (unsigned long) kid, name, exit_status);
+ */
+ write_string (STDERR_FILENO, blurb());
+ write_string (STDERR_FILENO, ": ");
+ write_long (STDERR_FILENO, (long) screen_no);
+ write_string (STDERR_FILENO, ": child pid ");
+ write_long (STDERR_FILENO, (long) kid);
+ write_string (STDERR_FILENO, " (");
+ write_string (STDERR_FILENO, name);
+ write_string (STDERR_FILENO, ") exited abnormally (code ");
+ write_long (STDERR_FILENO, (long) exit_status);
+ write_string (STDERR_FILENO, ").\n");
+ }
else if (p->verbose_p)
- fprintf (stderr, "%s: %d: child pid %lu (%s) exited normally.\n",
- blurb(), screen_no, (unsigned long) kid, name);
+ {
+ /* Don't call fprintf() from signal handlers, as it might malloc.
+ fprintf (stderr, "%s: %d: child pid %lu (%s) exited normally.\n",
+ blurb(), screen_no, (unsigned long) kid, name);
+ */
+ write_string (STDERR_FILENO, blurb());
+ write_string (STDERR_FILENO, ": ");
+ write_long (STDERR_FILENO, (long) screen_no);
+ write_string (STDERR_FILENO, ": child pid ");
+ write_long (STDERR_FILENO, (long) kid);
+ write_string (STDERR_FILENO, " (");
+ write_string (STDERR_FILENO, name);
+ write_string (STDERR_FILENO, ") exited normally.\n");
+ }
if (job)
job->status = job_dead;
!job ||
job->status != job_killed ||
WTERMSIG (wait_status) != SIGTERM)
- fprintf (stderr, "%s: %d: child pid %lu (%s) terminated with %s.\n",
- blurb(), screen_no, (unsigned long) kid, name,
- signal_name (WTERMSIG(wait_status)));
+ {
+ /* Don't call fprintf() from signal handlers, as it might malloc.
+ fprintf (stderr, "%s: %d: child pid %lu (%s) terminated with %s.\n",
+ blurb(), screen_no, (unsigned long) kid, name,
+ signal_name (WTERMSIG(wait_status)));
+ */
+ write_string (STDERR_FILENO, blurb());
+ write_string (STDERR_FILENO, ": ");
+ write_long (STDERR_FILENO, (long) screen_no);
+ write_string (STDERR_FILENO, ": child pid ");
+ write_long (STDERR_FILENO, (long) kid);
+ write_string (STDERR_FILENO, " (");
+ write_string (STDERR_FILENO, name);
+ write_string (STDERR_FILENO, ") terminated with signal ");
+ write_long (STDERR_FILENO, WTERMSIG(wait_status));
+ write_string (STDERR_FILENO, ".\n");
+ }
if (job)
job->status = job_dead;
else if (WIFSTOPPED (wait_status))
{
if (p->verbose_p)
- fprintf (stderr, "%s: child pid %lu (%s) stopped with %s.\n",
- blurb(), (unsigned long) kid, name,
- signal_name (WSTOPSIG (wait_status)));
+ {
+ /* Don't call fprintf() from signal handlers, as it might malloc.
+ fprintf (stderr, "%s: child pid %lu (%s) stopped with %s.\n",
+ blurb(), (unsigned long) kid, name,
+ signal_name (WSTOPSIG (wait_status)));
+ */
+ write_string (STDERR_FILENO, blurb());
+ write_string (STDERR_FILENO, ": ");
+ write_long (STDERR_FILENO, (long) screen_no);
+ write_string (STDERR_FILENO, ": child pid ");
+ write_long (STDERR_FILENO, (long) kid);
+ write_string (STDERR_FILENO, " (");
+ write_string (STDERR_FILENO, name);
+ write_string (STDERR_FILENO, ") stopped with signal ");
+ write_long (STDERR_FILENO, WSTOPSIG(wait_status));
+ write_string (STDERR_FILENO, ".\n");
+ }
if (job)
job->status = job_stopped;
}
else
{
+ /* Don't call fprintf() from signal handlers, as it might malloc.
fprintf (stderr, "%s: child pid %lu (%s) died in a mysterious way!",
blurb(), (unsigned long) kid, name);
+ */
+ write_string (STDERR_FILENO, blurb());
+ write_string (STDERR_FILENO, ": ");
+ write_long (STDERR_FILENO, (long) screen_no);
+ write_string (STDERR_FILENO, ": child pid ");
+ write_long (STDERR_FILENO, (long) kid);
+ write_string (STDERR_FILENO, " (");
+ write_string (STDERR_FILENO, name);
+ write_string (STDERR_FILENO, ") died in a mysterious way!");
if (job)
job->status = job_dead;
}
fprintf (stderr, "\n");
*path = 0;
# if defined(HAVE_GETCWD)
- getcwd (path, sizeof(path));
+ if (! getcwd (path, sizeof(path)))
+ *path = 0;
# elif defined(HAVE_GETWD)
getwd (path);
# endif
}
+/* Executes the command in another process.
+ Command may be any single command acceptable to /bin/sh.
+ It may include wildcards, but no semicolons.
+ If successful, the pid of the other process is returned.
+ Otherwise, -1 is returned and an error may have been
+ printed to stderr.
+ */
+pid_t
+fork_and_exec (saver_screen_info *ssi, const char *command)
+{
+ saver_info *si = ssi->global;
+ saver_preferences *p = &si->prefs;
+ pid_t forked;
+
+ switch ((int) (forked = fork ()))
+ {
+ case -1:
+ {
+ char buf [255];
+ sprintf (buf, "%s: couldn't fork", blurb());
+ perror (buf);
+ break;
+ }
+
+ case 0:
+ close (ConnectionNumber (si->dpy)); /* close display fd */
+ limit_subproc_memory (p->inferior_memory_limit, p->verbose_p);
+ hack_subproc_environment (ssi); /* set $DISPLAY */
+
+ if (p->verbose_p)
+ fprintf (stderr, "%s: %d: spawning \"%s\" in pid %lu.\n",
+ blurb(), ssi->number, command,
+ (unsigned long) getpid ());
+
+ exec_command (p->shell, command, p->nice_inferior);
+
+ /* If that returned, we were unable to exec the subprocess.
+ Print an error message, if desired.
+ */
+ if (! p->ignore_uninstalled_p)
+ print_path_error (command);
+
+ exit (1); /* exits child fork */
+ break;
+
+ default: /* parent */
+ (void) make_job (forked, ssi->number, command);
+ break;
+ }
+
+ return forked;
+}
+
+
static void
spawn_screenhack_1 (saver_screen_info *ssi, Bool first_time_p)
{
screenhack *hack;
pid_t forked;
char buf [255];
- int new_hack;
+ int new_hack = -1;
int retry_count = 0;
Bool force = False;
{
new_hack = -1;
}
+ else if (p->mode == RANDOM_HACKS_SAME &&
+ ssi->number != 0)
+ {
+ /* Use the same hack that's running on screen 0.
+ (Assumes this function was called on screen 0 first.)
+ */
+ new_hack = si->screens[0].current_hack;
+ }
else /* (p->mode == RANDOM_HACKS) */
{
/* Select a random hack (but not the one we just ran.) */
if (!force &&
(!hack->enabled_p ||
+ !on_path_p (hack->command) ||
!select_visual_of_hack (ssi, hack)))
{
if (++retry_count > (p->screenhacks_count*4))
if (si->selection_mode < 0)
si->selection_mode = 0;
- switch ((int) (forked = fork ()))
+ forked = fork_and_exec (ssi, hack->command);
+ switch ((int) forked)
{
- case -1:
+ case -1: /* fork failed */
+ case 0: /* child fork (can't happen) */
sprintf (buf, "%s: couldn't fork", blurb());
perror (buf);
restore_real_vroot (si);
- saver_exit (si, 1, 0);
-
- case 0:
- close (ConnectionNumber (si->dpy)); /* close display fd */
- limit_subproc_memory (p->inferior_memory_limit, p->verbose_p);
- hack_subproc_environment (ssi); /* set $DISPLAY */
-
- if (p->verbose_p)
- fprintf (stderr, "%s: %d: spawning \"%s\" in pid %lu.\n",
- blurb(), ssi->number, hack->command,
- (unsigned long) getpid ());
-
- exec_command (p->shell, hack->command, p->nice_inferior);
-
- /* If that returned, we were unable to exec the subprocess.
- Print an error message, if desired.
- */
- if (! p->ignore_uninstalled_p)
- print_path_error (hack->command);
-
- exit (1); /* exits child fork */
+ saver_exit (si, 1, "couldn't fork");
break;
default:
ssi->pid = forked;
- (void) make_job (forked, ssi->number, hack->command);
break;
}
}
const char *odpy = DisplayString (si->dpy);
char *ndpy = (char *) malloc (strlen(odpy) + 20);
char *nssw = (char *) malloc (40);
- char *s;
+ char *s, *c;
strcpy (ndpy, "DISPLAY=");
s = ndpy + strlen(ndpy);
strcpy (s, odpy);
- while (*s && *s != ':') s++; /* skip to colon */
- while (*s == ':') s++; /* skip over colons */
+ /* We have to find the last colon since it is the boundary between
+ hostname & screen - IPv6 numeric format addresses may have many
+ colons before that point, and DECnet addresses always have two colons */
+ c = strrchr(s,':'); /* skip to last colon */
+ if (c != NULL) s = c+1;
while (isdigit(*s)) s++; /* skip over dpy number */
while (*s == '.') s++; /* skip over dot */
if (s[-1] != '.') *s++ = '.'; /* put on a dot */
close (out); /* don't need this one */
*buf = 0;
- fgets (buf, sizeof(buf)-1, f);
+ if (! fgets (buf, sizeof(buf)-1, f))
+ *buf = 0;
fclose (f);
/* Wait for the child to die. */
projects / xscreensaver / blobdiff