/* subprocs.c --- choosing, spawning, and killing screenhacks.
- * xscreensaver, Copyright (c) 1991-2002 Jamie Zawinski <jwz@jwz.org>
+ * xscreensaver, Copyright (c) 1991-2008 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 void
limit_subproc_memory (int address_space_limit, Bool verbose_p)
{
+
+/* This has caused way more problems than it has solved...
+ Let's just completely ignore the "memoryLimit" option now.
+ */
+#undef HAVE_SETRLIMIT
+
#if defined(HAVE_SETRLIMIT) && defined(RLIMIT_AS)
struct rlimit r;
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)
{
static int block_sigchld_handler = 0;
-void
+#ifdef HAVE_SIGACTION
+ sigset_t
+#else /* !HAVE_SIGACTION */
+ int
+#endif /* !HAVE_SIGACTION */
block_sigchld (void)
{
#ifdef HAVE_SIGACTION
+ struct sigaction sa;
sigset_t child_set;
+
+ memset (&sa, 0, sizeof (sa));
+ sa.sa_handler = SIG_IGN;
+ sigaction (SIGPIPE, &sa, NULL);
+
sigemptyset (&child_set);
sigaddset (&child_set, SIGCHLD);
sigprocmask (SIG_BLOCK, &child_set, 0);
-#endif /* HAVE_SIGACTION */
+
+#else /* !HAVE_SIGACTION */
+ signal (SIGPIPE, SIG_IGN);
+#endif /* !HAVE_SIGACTION */
block_sigchld_handler++;
+
+#ifdef HAVE_SIGACTION
+ return child_set;
+#else /* !HAVE_SIGACTION */
+ return 0;
+#endif /* !HAVE_SIGACTION */
}
void
unblock_sigchld (void)
{
#ifdef HAVE_SIGACTION
+ struct sigaction sa;
sigset_t child_set;
+
+ memset(&sa, 0, sizeof (sa));
+ sa.sa_handler = SIG_DFL;
+ sigaction(SIGPIPE, &sa, NULL);
+
sigemptyset(&child_set);
sigaddset(&child_set, SIGCHLD);
sigprocmask(SIG_UNBLOCK, &child_set, 0);
-#endif /* HAVE_SIGACTION */
+
+#else /* !HAVE_SIGACTION */
+ signal(SIGPIPE, SIG_DFL);
+#endif /* !HAVE_SIGACTION */
block_sigchld_handler--;
}
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;
/* No hacks at all */
new_hack = -1;
}
+ else if (p->screenhacks_count == 1)
+ {
+ /* Exactly one hack in the list */
+ new_hack = 0;
+ }
else if (si->selection_mode == -1)
{
/* Select the next hack, wrapping. */
{
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;
}
}
be the screen on which this particular hack is running -- not the display
specification which the driver itself is using, since the driver ignores
its screen number and manages all existing screens.
+
+ Likewise, store a window ID in $XSCREENSAVER_WINDOW -- this will allow
+ us to (eventually) run multiple hacks in Xinerama mode, where each hack
+ has the same $DISPLAY but a different piece of glass.
*/
saver_info *si = ssi->global;
const char *odpy = DisplayString (si->dpy);
- char *ndpy = (char *) malloc(strlen(odpy) + 20);
- char *s;
+ char *ndpy = (char *) malloc (strlen(odpy) + 20);
+ char *nssw = (char *) malloc (40);
+ 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 */
- sprintf(s, "%d", ssi->number); /* put on screen number */
+ sprintf(s, "%d", ssi->real_screen_number); /* put on screen number */
+
+ sprintf (nssw, "XSCREENSAVER_WINDOW=0x%lX",
+ (unsigned long) ssi->screensaver_window);
/* Allegedly, BSD 4.3 didn't have putenv(), but nobody runs such systems
any more, right? It's not Posix, but everyone seems to have it. */
#ifdef HAVE_PUTENV
if (putenv (ndpy))
abort ();
- /* do not free(ndpy) -- see above. */
+ if (putenv (nssw))
+ abort ();
+
+ /* don't free ndpy/nssw -- some implementations of putenv (BSD 4.4,
+ glibc 2.0) copy the argument, but some (libc4,5, glibc 2.1.2)
+ do not. So we must leak it (and/or the previous setting). Yay.
+ */
#endif /* HAVE_PUTENV */
}
execvp (av[0], av); /* shouldn't return. */
- if (errno != ENOENT || si->prefs.verbose_p)
+ if (errno != ENOENT /* || si->prefs.verbose_p */ )
{
- /* Ignore "no such file or directory" errors, unless verbose.
+ /* Ignore "no such file or directory" errors.
Issue all other exec errors, though. */
sprintf (buf, "%s: running %s", blurb(), av[0]);
perror (buf);
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