X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=src%2Fbin%2Flttng-relayd%2Fctf-trace.cpp;h=4ee745a10c9102b42e01f32a6e16ffbf699a12cd;hb=c9e313bc594f40a86eed237dce222c0fc99c957f;hp=7a3cbdea0ebde00f0613ccff1cb42553d2d6d798;hpb=ac497a37018f3c253d2e50397294f58d33f7f24f;p=lttng-tools.git

diff --git a/src/bin/lttng-relayd/ctf-trace.cpp b/src/bin/lttng-relayd/ctf-trace.cpp
index 7a3cbdea0..4ee745a10 100644
--- a/src/bin/lttng-relayd/ctf-trace.cpp
+++ b/src/bin/lttng-relayd/ctf-trace.cpp
@@ -9,13 +9,13 @@
 
 #define _LGPL_SOURCE
 
-#include <common/common.h>
-#include <common/utils.h>
+#include <common/common.hpp>
+#include <common/utils.hpp>
 #include <urcu/rculist.h>
 
-#include "ctf-trace.h"
-#include "lttng-relayd.h"
-#include "stream.h"
+#include "ctf-trace.hpp"
+#include "lttng-relayd.hpp"
+#include "stream.hpp"
 
 static uint64_t last_relay_ctf_trace_id;
 static pthread_mutex_t last_relay_ctf_trace_id_lock = PTHREAD_MUTEX_INITIALIZER;
@@ -41,6 +41,8 @@ static void ctf_trace_destroy(struct ctf_trace *trace)
 	 * control side.
 	 */
 	LTTNG_ASSERT(cds_list_empty(&trace->stream_list));
+	ASSERT_RCU_READ_LOCKED();
+
 	session_put(trace->session);
 	trace->session = NULL;
 	free(trace->path);
@@ -62,11 +64,26 @@ static void ctf_trace_release(struct urcu_ref *ref)
 }
 
 /*
- * Should be called with RCU read-side lock held.
+ * The caller must either:
+ * - hold the RCU read side lock, or
+ * - guarantee the existence of the object by already holding a reference to
+ *   the object.
  */
 bool ctf_trace_get(struct ctf_trace *trace)
 {
-	return urcu_ref_get_unless_zero(&trace->ref);
+	const bool ref = urcu_ref_get_unless_zero(&trace->ref);
+
+	if (!ref) {
+		/*
+		 * The ref count is already zero. It means the object is being
+		 * torn down concurently.
+		 * This is only acceptable if we hold the RCU read-side lock,
+		 * else it's a logic error.
+		 */
+		ASSERT_RCU_READ_LOCKED();
+	}
+
+	return ref;
 }
 
 /*