X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=liblttng-ust%2Flttng-events.c;h=68c024c4647e9206f6b9bec37d17f63e40425be8;hb=f135e0eefb40f8093b404bfe9a51af3005447fd9;hp=9380e9ceb688b9b46df58122d7cc3a47c14421b3;hpb=246be17ec5a99beae7cc40eede54b4958958d8fb;p=lttng-ust.git

diff --git a/liblttng-ust/lttng-events.c b/liblttng-ust/lttng-events.c
index 9380e9ce..68c024c4 100644
--- a/liblttng-ust/lttng-events.c
+++ b/liblttng-ust/lttng-events.c
@@ -54,29 +54,23 @@
 #include "tracepoint-internal.h"
 #include "lttng-tracer.h"
 #include "lttng-tracer-core.h"
+#include "lttng-ust-baddr.h"
 #include "wait.h"
 #include "../libringbuffer/shm.h"
 #include "jhash.h"
 
 /*
- * The sessions mutex is the centralized mutex across UST tracing
- * control and probe registration. All operations within this file are
- * called by the communication thread, under ust_lock protection.
+ * All operations within this file are called by the communication
+ * thread, under ust_lock protection.
  */
-static pthread_mutex_t sessions_mutex = PTHREAD_MUTEX_INITIALIZER;
 
-void ust_lock(void)
-{
-	pthread_mutex_lock(&sessions_mutex);
-}
+static CDS_LIST_HEAD(sessions);
 
-void ust_unlock(void)
+struct cds_list_head *_lttng_get_sessions(void)
 {
-	pthread_mutex_unlock(&sessions_mutex);
+	return &sessions;
 }
 
-static CDS_LIST_HEAD(sessions);
-
 static void _lttng_event_destroy(struct lttng_event *event);
 
 static
@@ -106,8 +100,6 @@ int lttng_loglevel_match(int loglevel,
 		enum lttng_ust_loglevel_type req_type,
 		int req_loglevel)
 {
-	if (req_type == LTTNG_UST_LOGLEVEL_ALL)
-		return 1;
 	if (!has_loglevel)
 		loglevel = TRACE_DEFAULT;
 	switch (req_type) {
@@ -251,8 +243,6 @@ int lttng_session_enable(struct lttng_session *session)
 
 	/* Set transient enabler state to "enabled" */
 	session->tstate = 1;
-	/* We need to sync enablers with session before activation. */
-	lttng_session_sync_enablers(session);
 
 	/*
 	 * Snapshot the number of events per channel to know the type of header
@@ -290,6 +280,9 @@ int lttng_session_enable(struct lttng_session *session)
 		}
 	}
 
+	/* We need to sync enablers with session before activation. */
+	lttng_session_sync_enablers(session);
+
 	/* Set atomically the state to "active" */
 	CMM_ACCESS_ONCE(session->active) = 1;
 	CMM_ACCESS_ONCE(session->been_active) = 1;
@@ -676,19 +669,31 @@ int lttng_fix_pending_events(void)
 }
 
 /*
- * Called after session enable: For each session, execute pending statedumps.
+ * For each session of the owner thread, execute pending statedump.
+ * Only dump state for the sessions owned by the caller thread, because
+ * we don't keep ust_lock across the entire iteration.
  */
-int lttng_handle_pending_statedumps(t_statedump_func_ptr statedump_func_ptr)
+void lttng_handle_pending_statedump(void *owner)
 {
 	struct lttng_session *session;
 
+	/* Execute state dump */
+	lttng_ust_baddr_statedump(owner);
+
+	/* Clear pending state dump */
+	if (ust_lock()) {
+		goto end;
+	}
 	cds_list_for_each_entry(session, &sessions, node) {
-		if (session->statedump_pending) {
-			session->statedump_pending = 0;
-			statedump_func_ptr(session);
-		}
+		if (session->owner != owner)
+			continue;
+		if (!session->statedump_pending)
+			continue;
+		session->statedump_pending = 0;
 	}
-	return 0;
+end:
+	ust_unlock();
+	return;
 }
 
 /*
@@ -736,7 +741,16 @@ struct lttng_enabler *lttng_enabler_create(enum lttng_enabler_type type,
 		sizeof(enabler->event_param));
 	enabler->chan = chan;
 	/* ctx left NULL */
-	enabler->enabled = 1;
+	/*
+	 * The "disable" event create comm field has been added to fix a
+	 * race between event creation (of a started trace) and enabling
+	 * filtering. New session daemon always set the "disable" field
+	 * to 1, and are aware that they need to explicitly enable the
+	 * event. Older session daemon (within same ABI) leave it at 0,
+	 * and therefore we need to enable it here, keeping the original
+	 * racy behavior.
+	 */
+	enabler->enabled = !event_param->disabled;
 	cds_list_add(&enabler->node, &enabler->chan->session->enablers_head);
 	lttng_session_lazy_sync_enablers(enabler->chan->session);
 	return enabler;