X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;ds=sidebyside;f=include%2Flttng%2Ftracepoint.h;h=fb635c111327e86a20a6898d364f3e175acb9a85;hb=5f733922ed1e2db5b397292ede81303a9e538a08;hp=8b08914418f0c98b047c46d53ed77637fb838073;hpb=6ddc916dfa930b6b9018ffd53a76faeb61b81ebd;p=lttng-ust.git

diff --git a/include/lttng/tracepoint.h b/include/lttng/tracepoint.h
index 8b089144..fb635c11 100644
--- a/include/lttng/tracepoint.h
+++ b/include/lttng/tracepoint.h
@@ -13,6 +13,14 @@
  *
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
  */
 
 #include <lttng/tracepoint-types.h>
@@ -145,7 +153,7 @@ void __tracepoint_cb_##_provider##___##_name(_TP_ARGS_PROTO(__VA_ARGS__))		\
 {											\
 	struct tracepoint_probe *__tp_probe;						\
 											\
-	if (!TP_RCU_LINK_TEST())							\
+	if (caa_unlikely(!TP_RCU_LINK_TEST()))						\
 		return;									\
 	tp_rcu_read_lock_bp();								\
 	__tp_probe = tp_rcu_dereference_bp(__tracepoint_##_provider##___##_name.probes); \
@@ -205,8 +213,87 @@ struct tracepoint_dlopen {
 
 extern struct tracepoint_dlopen tracepoint_dlopen;
 
+#if defined(TRACEPOINT_DEFINE) || defined(TRACEPOINT_CREATE_PROBES)
+
+/*
+ * These weak symbols, the constructor, and destructor take care of
+ * registering only _one_ instance of the tracepoints per shared-ojbect
+ * (or for the whole main program).
+ */
+int __tracepoint_registered
+	__attribute__((weak, visibility("hidden")));
+int __tracepoint_ptrs_registered
+	__attribute__((weak, visibility("hidden")));
+struct tracepoint_dlopen tracepoint_dlopen
+	__attribute__((weak, visibility("hidden")));
+
+static void lttng_ust_notrace __attribute__((constructor))
+__tracepoints__init(void);
+static void
+__tracepoints__init(void)
+{
+	if (__tracepoint_registered++)
+		return;
+
+	if (!tracepoint_dlopen.liblttngust_handle)
+		tracepoint_dlopen.liblttngust_handle =
+			dlopen("liblttng-ust-tracepoint.so.0", RTLD_NOW | RTLD_GLOBAL);
+	if (!tracepoint_dlopen.liblttngust_handle)
+		return;
+	tracepoint_dlopen.tracepoint_register_lib =
+		URCU_FORCE_CAST(int (*)(struct tracepoint * const *, int),
+				dlsym(tracepoint_dlopen.liblttngust_handle,
+					"tracepoint_register_lib"));
+	tracepoint_dlopen.tracepoint_unregister_lib =
+		URCU_FORCE_CAST(int (*)(struct tracepoint * const *),
+				dlsym(tracepoint_dlopen.liblttngust_handle,
+					"tracepoint_unregister_lib"));
+#ifndef _LGPL_SOURCE
+	tracepoint_dlopen.rcu_read_lock_sym_bp =
+		URCU_FORCE_CAST(void (*)(void),
+				dlsym(tracepoint_dlopen.liblttngust_handle,
+					"tp_rcu_read_lock_bp"));
+	tracepoint_dlopen.rcu_read_unlock_sym_bp =
+		URCU_FORCE_CAST(void (*)(void),
+				dlsym(tracepoint_dlopen.liblttngust_handle,
+					"tp_rcu_read_unlock_bp"));
+	tracepoint_dlopen.rcu_dereference_sym_bp =
+		URCU_FORCE_CAST(void *(*)(void *p),
+				dlsym(tracepoint_dlopen.liblttngust_handle,
+					"tp_rcu_dereference_sym_bp"));
+#endif
+}
+
+static void lttng_ust_notrace __attribute__((destructor))
+__tracepoints__destroy(void);
+static void
+__tracepoints__destroy(void)
+{
+	int ret;
+
+	if (--__tracepoint_registered)
+		return;
+	if (tracepoint_dlopen.liblttngust_handle && !__tracepoint_ptrs_registered) {
+		ret = dlclose(tracepoint_dlopen.liblttngust_handle);
+		assert(!ret);
+		memset(&tracepoint_dlopen, 0, sizeof(tracepoint_dlopen));
+	}
+}
+
+#endif
+
 #ifdef TRACEPOINT_DEFINE
 
+/*
+ * These weak symbols, the constructor, and destructor take care of
+ * registering only _one_ instance of the tracepoints per shared-ojbect
+ * (or for the whole main program).
+ */
+extern struct tracepoint * const __start___tracepoints_ptrs[]
+	__attribute__((weak, visibility("hidden")));
+extern struct tracepoint * const __stop___tracepoints_ptrs[]
+	__attribute__((weak, visibility("hidden")));
+
 /*
  * When TRACEPOINT_PROBE_DYNAMIC_LINKAGE is defined, we do not emit a
  * unresolved symbol that requires the provider to be linked in. When
@@ -247,71 +334,35 @@ extern struct tracepoint_dlopen tracepoint_dlopen;
 		__attribute__((used, section("__tracepoints_ptrs"))) =		\
 			&__tracepoint_##_provider##___##_name;
 
-/*
- * These weak symbols, the constructor, and destructor take care of
- * registering only _one_ instance of the tracepoints per shared-ojbect
- * (or for the whole main program).
- */
-extern struct tracepoint * const __start___tracepoints_ptrs[]
-	__attribute__((weak, visibility("hidden")));
-extern struct tracepoint * const __stop___tracepoints_ptrs[]
-	__attribute__((weak, visibility("hidden")));
-int __tracepoint_registered
-	__attribute__((weak, visibility("hidden")));
-struct tracepoint_dlopen tracepoint_dlopen
-	__attribute__((weak, visibility("hidden")));
-
 static void lttng_ust_notrace __attribute__((constructor))
-__tracepoints__init(void);
+__tracepoints__ptrs_init(void);
 static void
-__tracepoints__init(void)
+__tracepoints__ptrs_init(void)
 {
-	if (__tracepoint_registered++)
+	if (__tracepoint_ptrs_registered++)
 		return;
-
-	tracepoint_dlopen.liblttngust_handle =
-		dlopen("liblttng-ust-tracepoint.so.0", RTLD_NOW | RTLD_GLOBAL);
+	if (!tracepoint_dlopen.liblttngust_handle)
+		tracepoint_dlopen.liblttngust_handle =
+			dlopen("liblttng-ust-tracepoint.so.0", RTLD_NOW | RTLD_GLOBAL);
 	if (!tracepoint_dlopen.liblttngust_handle)
 		return;
-	tracepoint_dlopen.tracepoint_register_lib =
-		URCU_FORCE_CAST(int (*)(struct tracepoint * const *, int),
-				dlsym(tracepoint_dlopen.liblttngust_handle,
-					"tracepoint_register_lib"));
-	tracepoint_dlopen.tracepoint_unregister_lib =
-		URCU_FORCE_CAST(int (*)(struct tracepoint * const *),
-				dlsym(tracepoint_dlopen.liblttngust_handle,
-					"tracepoint_unregister_lib"));
-#ifndef _LGPL_SOURCE
-	tracepoint_dlopen.rcu_read_lock_sym_bp =
-		URCU_FORCE_CAST(void (*)(void),
-				dlsym(tracepoint_dlopen.liblttngust_handle,
-					"tp_rcu_read_lock_bp"));
-	tracepoint_dlopen.rcu_read_unlock_sym_bp =
-		URCU_FORCE_CAST(void (*)(void),
-				dlsym(tracepoint_dlopen.liblttngust_handle,
-					"tp_rcu_read_unlock_bp"));
-	tracepoint_dlopen.rcu_dereference_sym_bp =
-		URCU_FORCE_CAST(void *(*)(void *p),
-				dlsym(tracepoint_dlopen.liblttngust_handle,
-					"tp_rcu_dereference_sym_bp"));
-#endif
 	tracepoint_dlopen.tracepoint_register_lib(__start___tracepoints_ptrs,
 				__stop___tracepoints_ptrs -
 				__start___tracepoints_ptrs);
 }
 
 static void lttng_ust_notrace __attribute__((destructor))
-__tracepoints__destroy(void);
+__tracepoints__ptrs_destroy(void);
 static void
-__tracepoints__destroy(void)
+__tracepoints__ptrs_destroy(void)
 {
 	int ret;
 
-	if (--__tracepoint_registered)
+	if (--__tracepoint_ptrs_registered)
 		return;
 	if (tracepoint_dlopen.tracepoint_unregister_lib)
 		tracepoint_dlopen.tracepoint_unregister_lib(__start___tracepoints_ptrs);
-	if (tracepoint_dlopen.liblttngust_handle) {
+	if (tracepoint_dlopen.liblttngust_handle && !__tracepoint_registered) {
 		ret = dlclose(tracepoint_dlopen.liblttngust_handle);
 		assert(!ret);
 		memset(&tracepoint_dlopen, 0, sizeof(tracepoint_dlopen));