gst/gst.c: Use a pipe pair to receive status results from the forked child, and ignore the result from waitpid. Fixes...

Original commit message from CVS:
* gst/gst.c: (ensure_current_registry_forking):
Use a pipe pair to receive status results from the forked child, and
ignore the result from waitpid. Fixes #355499
This commit is contained in:
Jan Schmidt 2006-10-03 15:10:51 +00:00
parent 15b2ccbcc9
commit 438c525bbd
2 changed files with 52 additions and 32 deletions

View file

@ -1,3 +1,9 @@
2006-10-03 Jan Schmidt <thaytan@mad.scientist.com>
* gst/gst.c: (ensure_current_registry_forking):
Use a pipe pair to receive status results from the forked child, and
ignore the result from waitpid. Fixes #355499
2006-10-02 Wim Taymans <wim@fluendo.com>
* tests/check/gst/gstghostpad.c: (GST_START_TEST),

View file

@ -690,20 +690,35 @@ ensure_current_registry_forking (GstRegistry * default_registry,
{
#ifdef HAVE_FORK
pid_t pid;
int pfd[2];
/* We fork here, and let the child read and possibly rebuild the registry.
* After that, the parent will re-read the freshly generated registry. */
GST_DEBUG ("forking to update registry");
if (pipe (pfd) == -1) {
g_set_error (error, GST_CORE_ERROR, GST_CORE_ERROR_FAILED,
_("Error re-scanning registry %s: %s"),
", could not create pipes. Error", g_strerror (errno));
return FALSE;
}
pid = fork ();
if (pid == -1) {
GST_ERROR ("Failed to fork()");
g_set_error (error, GST_CORE_ERROR, GST_CORE_ERROR_FAILED,
_("Error re-scanning registry %s: %s"),
", failed to fork. Error", g_strerror (errno));
return FALSE;
}
if (pid == 0) {
gboolean res;
gchar res_byte;
/* this is the child. Close the read pipe */
close (pfd[0]);
/* this is the child */
GST_DEBUG ("child reading registry cache");
res =
scan_and_update_registry (default_registry, registry_file, TRUE, NULL);
@ -715,47 +730,46 @@ ensure_current_registry_forking (GstRegistry * default_registry,
/* make valgrind happy (yes, you can call it insane) */
g_free ((char *) registry_file);
_exit ((res) ? EXIT_SUCCESS : EXIT_FAILURE);
/* write a result byte to the pipe */
res_byte = res ? '1' : '0';
write (pfd[1], &res_byte, 1);
_exit (0);
} else {
/* parent */
int status;
pid_t ret;
int ret;
gchar res_byte;
GST_DEBUG ("parent waiting on child");
ret = waitpid (pid, &status, 0);
GST_DEBUG ("parent done waiting on child");
/* parent. Close write pipe */
close (pfd[1]);
/* Wait for result from the pipe */
GST_DEBUG ("Waiting for data from child");
ret = read (pfd[0], &res_byte, 1);
if (ret == -1) {
GST_ERROR ("error during waitpid: %s", g_strerror (errno));
g_set_error (error, GST_CORE_ERROR, GST_CORE_ERROR_FAILED,
_("Error re-scanning registry %s: %s"),
", waitpid returned error", g_strerror (errno));
", read returned error", g_strerror (errno));
close (pfd[0]);
return FALSE;
}
close (pfd[0]);
/* Wait to ensure the child is reaped, but ignore the result */
GST_DEBUG ("parent waiting on child");
waitpid (pid, NULL, 0);
GST_DEBUG ("parent done waiting on child");
if (ret == 0) {
GST_ERROR ("child did not exit normally, terminated by signal");
g_set_error (error, GST_CORE_ERROR, GST_CORE_ERROR_FAILED,
_("Error re-scanning registry %s"), ", child terminated by signal");
return FALSE;
}
if (!WIFEXITED (status)) {
if (WIFSIGNALED (status)) {
GST_ERROR ("child did not exit normally, terminated by signal %d",
WTERMSIG (status));
g_set_error (error, GST_CORE_ERROR, GST_CORE_ERROR_FAILED,
_("Error re-scanning registry %s: %d"),
", child terminated by signal", WTERMSIG (status));
} else {
GST_ERROR ("child did not exit normally, status: %d", status);
g_set_error (error, GST_CORE_ERROR, GST_CORE_ERROR_FAILED,
_("Error re-scanning registry %s: %d"),
", child did not exit normally, status", status);
}
return FALSE;
}
GST_DEBUG ("child exited normally with return value %d",
WEXITSTATUS (status));
if (WEXITSTATUS (status) == EXIT_SUCCESS) {
GST_DEBUG ("parent reading registry cache");
if (res_byte == '1') {
GST_DEBUG ("Child succeeded. Parent reading registry cache");
gst_registry_xml_read_cache (default_registry, registry_file);
} else {
GST_DEBUG ("parent re-scanning registry. Ignoring errors.");
GST_DEBUG ("Child failed. Parent re-scanning registry, ignoring errors.");
scan_and_update_registry (default_registry, registry_file, FALSE, NULL);
}
}