#include <sys/types.h>
#include <unistd.h>
#include <urcu/compiler.h>
-#include <lttng/ust-error.h>
#include <signal.h>
#include <common/common.h>
#include "health-sessiond.h"
#include "ust-app.h"
#include "ust-consumer.h"
-#include "ust-ctl.h"
+#include "lttng-ust-ctl.h"
+#include "lttng-ust-error.h"
#include "utils.h"
#include "session.h"
#include "lttng-sessiond.h"
* nullified. The session lock MUST be held unless the application is
* in the destroy path.
*
+ * Do not hold the registry lock while communicating with the consumerd, because
+ * doing so causes inter-process deadlocks between consumerd and sessiond with
+ * the metadata request notification.
+ *
* Return 0 on success else a negative value.
*/
static int close_metadata(struct ust_registry_session *registry,
{
int ret;
struct consumer_socket *socket;
+ uint64_t metadata_key;
+ bool registry_was_already_closed;
assert(registry);
assert(consumer);
rcu_read_lock();
pthread_mutex_lock(®istry->lock);
+ metadata_key = registry->metadata_key;
+ registry_was_already_closed = registry->metadata_closed;
+ if (metadata_key != 0) {
+ /*
+ * Metadata closed. Even on error this means that the consumer
+ * is not responding or not found so either way a second close
+ * should NOT be emit for this registry.
+ */
+ registry->metadata_closed = 1;
+ }
+ pthread_mutex_unlock(®istry->lock);
- if (!registry->metadata_key || registry->metadata_closed) {
+ if (metadata_key == 0 || registry_was_already_closed) {
ret = 0;
goto end;
}
consumer);
if (!socket) {
ret = -1;
- goto error;
+ goto end;
}
- ret = consumer_close_metadata(socket, registry->metadata_key);
+ ret = consumer_close_metadata(socket, metadata_key);
if (ret < 0) {
- goto error;
+ goto end;
}
-error:
- /*
- * Metadata closed. Even on error this means that the consumer is not
- * responding or not found so either way a second close should NOT be emit
- * for this registry.
- */
- registry->metadata_closed = 1;
end:
- pthread_mutex_unlock(®istry->lock);
rcu_read_unlock();
return ret;
}
/* Init most of the default value by allocating and zeroing */
ua_event = zmalloc(sizeof(struct ust_app_event));
if (ua_event == NULL) {
- PERROR("malloc");
+ PERROR("Failed to allocate ust_app_event structure");
goto error;
}
ua_event = alloc_ust_app_event(uevent->attr.name, &uevent->attr);
if (ua_event == NULL) {
- /* Only malloc can failed so something is really wrong */
+ /* Only failure mode of alloc_ust_app_event(). */
ret = -ENOMEM;
goto end;
}
if (session_was_created) {
destroy_app_session(app, ua_sess);
}
- goto error_rcu_unlock;
+ /* Continue to the next application. */
}
}