X-Git-Url: http://git.lttng.org./?a=blobdiff_plain;f=include%2Flttng%2Ftracepoint.h;h=ed20594497ab65bab366b594bb965e740d3e9b29;hb=3227b2b93e5eafe5e9ab5fcbad718eb36cd4a383;hp=63759a20ee3da5f7a7e0beb6f08219c8567abe55;hpb=1a20609484df56e378318d65f07f39dcd8ec1db2;p=lttng-ust.git

diff --git a/include/lttng/tracepoint.h b/include/lttng/tracepoint.h
index 63759a20..ed205944 100644
--- a/include/lttng/tracepoint.h
+++ b/include/lttng/tracepoint.h
@@ -28,6 +28,7 @@
 #include <lttng/tracepoint-types.h>
 #include <lttng/tracepoint-rcu.h>
 #include <urcu/compiler.h>
+#include <urcu/system.h>
 #include <dlfcn.h>	/* for dlopen */
 #include <string.h>	/* for memset */
 #include <lttng/ust-config.h>	/* for sdt */
@@ -36,19 +37,26 @@
 #ifdef LTTNG_UST_HAVE_SDT_INTEGRATION
 #define SDT_USE_VARIADIC
 #include <sys/sdt.h>
+#define LTTNG_STAP_PROBEV STAP_PROBEV
 #else
-#define STAP_PROBEV(...)
+#define LTTNG_STAP_PROBEV(...)
 #endif
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
+#define tracepoint_enabled(provider, name) \
+	caa_unlikely(CMM_LOAD_SHARED(__tracepoint_##provider##___##name.state))
+
+#define do_tracepoint(provider, name, ...) \
+	__tracepoint_cb_##provider##___##name(__VA_ARGS__)
+
 #define tracepoint(provider, name, ...)					    \
 	do {								    \
-		STAP_PROBEV(provider, name, ## __VA_ARGS__);		    \
-		if (caa_unlikely(__tracepoint_##provider##___##name.state)) \
-			__tracepoint_cb_##provider##___##name(__VA_ARGS__); \
+		LTTNG_STAP_PROBEV(provider, name, ## __VA_ARGS__);	    \
+		if (tracepoint_enabled(provider, name)) 		    \
+			do_tracepoint(provider, name, __VA_ARGS__);	    \
 	} while (0)
 
 #define TP_ARGS(...)       __VA_ARGS__
@@ -219,6 +227,21 @@ struct lttng_ust_tracepoint_dlopen {
 
 extern struct lttng_ust_tracepoint_dlopen tracepoint_dlopen;
 
+/* Disable tracepoint destructors. */
+int __tracepoints__disable_destructors __attribute__((weak));
+
+/*
+ * Programs that have threads that survive after they exit, and
+ * therefore call library destructors, should disable the tracepoint
+ * destructors by calling tracepoint_disable_destructors(). This will
+ * leak the tracepoint instrumentation library shared object, leaving
+ * its teardown to the operating system process teardown.
+ */
+static inline void tracepoint_disable_destructors(void)
+{
+	__tracepoints__disable_destructors = 1;
+}
+
 #if defined(TRACEPOINT_DEFINE) || defined(TRACEPOINT_CREATE_PROBES)
 
 /*
@@ -293,7 +316,9 @@ __tracepoints__destroy(void)
 
 	if (--__tracepoint_registered)
 		return;
-	if (tracepoint_dlopen.liblttngust_handle && !__tracepoint_ptrs_registered) {
+	if (!__tracepoints__disable_destructors
+			&& tracepoint_dlopen.liblttngust_handle
+			&& !__tracepoint_ptrs_registered) {
 		ret = dlclose(tracepoint_dlopen.liblttngust_handle);
 		if (ret) {
 			fprintf(stderr, "Error (%d) in dlclose\n", ret);
@@ -398,7 +423,9 @@ __tracepoints__ptrs_destroy(void)
 		return;
 	if (tracepoint_dlopen.tracepoint_unregister_lib)
 		tracepoint_dlopen.tracepoint_unregister_lib(__start___tracepoints_ptrs);
-	if (tracepoint_dlopen.liblttngust_handle && !__tracepoint_registered) {
+	if (!__tracepoints__disable_destructors
+			&& tracepoint_dlopen.liblttngust_handle
+			&& !__tracepoint_ptrs_registered) {
 		ret = dlclose(tracepoint_dlopen.liblttngust_handle);
 		if (ret) {
 			fprintf(stderr, "Error (%d) in dlclose\n", ret);
@@ -422,6 +449,50 @@ __tracepoints__ptrs_destroy(void)
 
 /* The following declarations must be outside re-inclusion protection. */
 
+#ifndef TRACEPOINT_ENUM
+
+/*
+ * Tracepoint Enumerations
+ *
+ * The enumeration is a mapping between an integer, or range of integers, and
+ * a string. It can be used to have a more compact trace in cases where the
+ * possible values for a field are limited:
+ *
+ * An example:
+ *
+ * TRACEPOINT_ENUM(someproject_component, enumname,
+ *	TP_ENUM_VALUES(
+ *		ctf_enum_value("even", 0)
+ *		ctf_enum_value("uneven", 1)
+ *		ctf_enum_range("twoto4", 2, 4)
+ *		ctf_enum_value("five", 5)
+ *	)
+ * )
+ *
+ * Where "someproject_component" is the name of the component this enumeration
+ * belongs to and "enumname" identifies this enumeration. Inside the
+ * TP_ENUM_VALUES macro is the actual mapping. Each string value can map
+ * to either a single value with ctf_enum_value or a range of values
+ * with ctf_enum_range.
+ *
+ * Enumeration ranges may overlap, but the behavior is implementation-defined,
+ * each trace reader will handle overlapping as it wishes.
+ *
+ * That enumeration can then be used in a field inside the TP_FIELD macro using
+ * the following line:
+ *
+ * ctf_enum(someproject_component, enumname, enumtype, enumfield, enumval)
+ *
+ * Where "someproject_component" and "enumname" match those in the
+ * TRACEPOINT_ENUM, "enumtype" is a signed or unsigned integer type
+ * backing the enumeration, "enumfield" is the name of the field and
+ * "enumval" is the value.
+ */
+
+#define TRACEPOINT_ENUM(provider, name, values)
+
+#endif /* #ifndef TRACEPOINT_ENUM */
+
 #ifndef TRACEPOINT_EVENT
 
 /*
@@ -445,6 +516,9 @@ __tracepoints__ptrs_destroy(void)
  *         * Integer, printed with 0x base 16 * 
  *         ctf_integer_hex(unsigned long, field_d, arg1)
  *
+ *         * Enumeration *
+ *         ctf_enum(someproject_component, enum_name, int, field_e, arg0)
+ *
  *         * Array Sequence, printed as UTF8-encoded array of bytes * 
  *         ctf_array_text(char, field_b, string, FIXED_LEN)
  *         ctf_sequence_text(char, field_c, string, size_t, strlen)