X-Git-Url: https://git.lttng.org/?a=blobdiff_plain;f=include%2Fust%2Ftracepoint.h;h=e39a3849bc8b928bc7aaff2e5d4f5192eb300a5b;hb=d4419b81b243bc3a6bdd4a09b3ca2216d044a1c7;hp=3c959cb84c8d9ebd63cad8c247dcee91266588d3;hpb=d75775a692da014abaa64e9f8bddb3c604a83bf6;p=lttng-ust.git diff --git a/include/ust/tracepoint.h b/include/ust/tracepoint.h index 3c959cb8..e39a3849 100644 --- a/include/ust/tracepoint.h +++ b/include/ust/tracepoint.h @@ -28,6 +28,10 @@ #include #include +#ifdef __cplusplus +extern "C" { +#endif + struct tracepoint_probe { void *func; void *data; @@ -45,28 +49,6 @@ struct tracepoint { */ #define tracepoint(name, args...) __trace_##name(args) -/* - * Library should be made known to libust by declaring TRACEPOINT_LIB in - * the source file. (Usually at the end of the file, in the outermost - * scope). - */ -#define TRACEPOINT_LIB \ - extern struct tracepoint * const __start___tracepoints_ptrs[] __attribute__((weak, visibility("hidden"))); \ - extern struct tracepoint * const __stop___tracepoints_ptrs[] __attribute__((weak, visibility("hidden"))); \ - static struct tracepoint * __tracepoint_ptr_dummy \ - __attribute__((used, section("__tracepoints_ptrs"))); \ - static void __attribute__((constructor)) __tracepoints__init(void) \ - { \ - tracepoint_register_lib(__start___tracepoints_ptrs, \ - __stop___tracepoints_ptrs - \ - __start___tracepoints_ptrs); \ - } \ - \ - static void __attribute__((destructor)) __tracepoints__destroy(void) \ - { \ - tracepoint_unregister_lib(__start___tracepoints_ptrs); \ - } - /* * it_func[0] is never NULL because there is at least one element in the array * when the array itself is non NULL. @@ -83,7 +65,7 @@ struct tracepoint { do { \ __tp_it_func = __tp_it_probe_ptr->func; \ __tp_cb_data = __tp_it_probe_ptr->data; \ - ((void(*)(proto))__tp_it_func)(args); \ + URCU_FORCE_CAST(void(*)(proto), __tp_it_func)(args); \ } while ((++__tp_it_probe_ptr)->func); \ } \ rcu_read_unlock(); \ @@ -95,7 +77,7 @@ struct tracepoint { #define __CHECK_TRACE(name, proto, args) \ do { \ - if (unlikely(__tracepoint_##name.state)) \ + if (caa_unlikely(__tracepoint_##name.state)) \ __DO_TRACE(&__tracepoint_##name, \ TP_PROTO(proto), TP_ARGS(args)); \ } while (0) @@ -117,7 +99,6 @@ struct tracepoint { { \ return __tracepoint_probe_register(#name, (void *)probe,\ data); \ - \ } \ static inline int \ __unregister_trace_##name(void (*probe)(data_proto), void *data)\ @@ -182,18 +163,39 @@ int __tracepoint_probe_register(const char *name, void *probe, void *data); extern int __tracepoint_probe_unregister(const char *name, void *probe, void *data); -struct tracepoint_lib { - struct tracepoint * const *tracepoints_start; - int tracepoints_count; - struct cds_list_head list; -}; - extern int tracepoint_register_lib(struct tracepoint * const *tracepoints_start, int tracepoints_count); extern int tracepoint_unregister_lib(struct tracepoint * const *tracepoints_start); +/* + * 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"))); + +static void __attribute__((constructor)) __tracepoints__init(void) +{ + if (__tracepoint_registered++) + return; + tracepoint_register_lib(__start___tracepoints_ptrs, + __stop___tracepoints_ptrs - + __start___tracepoints_ptrs); +} + +static void __attribute__((destructor)) __tracepoints__destroy(void) +{ + if (--__tracepoint_registered) + return; + tracepoint_unregister_lib(__start___tracepoints_ptrs); +} #ifndef TRACEPOINT_EVENT /* @@ -201,7 +203,7 @@ int tracepoint_unregister_lib(struct tracepoint * const *tracepoints_start); * * In short, an example: * - * TRACEPOINT_EVENT(< [com_company_]project_[component_]_event >, + * TRACEPOINT_EVENT(< [com_company_]project_[component_]event >, * TP_PROTO(int arg0, void *arg1, char *string, size_t strlen, * long *arg4, size_t arg4_len), * TP_ARGS(arg0, arg1, string, strlen, arg4, arg4_len), @@ -233,6 +235,7 @@ int tracepoint_unregister_lib(struct tracepoint * const *tracepoints_start); * * Firstly, name your tracepoint via TRACEPOINT_EVENT(name, * + * The name should be a proper C99 identifier. * The "name" MUST follow these rules to ensure no namespace clash * occurs: * @@ -246,8 +249,10 @@ int tracepoint_unregister_lib(struct tracepoint * const *tracepoints_start); * project_event * * Where "project" is the name of the project, - * "component" is the name of the project component where the - * tracepoint is located (optional), + * "component" is the name of the project component (which may + * include several levels of sub-components, e.g. + * ...component_subcomponent_...) where the tracepoint is located + * (optional), * "event" is the name of the tracepoint event. * * For projects issued from a single company wishing to advertise that @@ -261,8 +266,10 @@ int tracepoint_unregister_lib(struct tracepoint * const *tracepoints_start); * * Where "company" is the name of the company, * "project" is the name of the project, - * "component" is the name of the project component where the - * tracepoint is located (optional), + * "component" is the name of the project component (which may + * include several levels of sub-components, e.g. + * ...component_subcomponent_...) where the tracepoint is located + * (optional), * "event" is the name of the tracepoint event. * * @@ -324,6 +331,13 @@ int tracepoint_unregister_lib(struct tracepoint * const *tracepoints_start); * ctf_integer(int, next_prio, next->prio) * ) * ) + * + * Do _NOT_ add comma (,) nor semicolon (;) after the TRACEPOINT_EVENT + * declaration. + * + * The TRACEPOINT_SYSTEM must be defined when declaring a + * TRACEPOINT_EVENT. See ust/tracepoint-event.h for information about + * usage of other macros controlling TRACEPOINT_EVENT. */ #define TRACEPOINT_EVENT(name, proto, args, fields) \ @@ -345,4 +359,65 @@ int tracepoint_unregister_lib(struct tracepoint * const *tracepoints_start); #endif /* #ifndef TRACEPOINT_EVENT */ +#ifndef TRACEPOINT_LOGLEVEL + +/* + * Tracepoint Loglevel Declaration Facility + * + * This is a place-holder the tracepoint loglevel declaration, + * overridden by the tracer implementation. + * + * Typical use of these loglevels: + * + * 1) Declare the mapping between loglevel names and an integer values + * within TRACEPOINT_LOGLEVEL_ENUM, using TP_LOGLEVEL for each tuple. + * Do _NOT_ add comma (,) nor semicolon (;) between the + * TRACEPOINT_LOGLEVEL_ENUM entries. Do _NOT_ add comma (,) nor + * semicolon (;) after the TRACEPOINT_LOGLEVEL_ENUM declaration. The + * name should be a proper C99 identifier. + * + * TRACEPOINT_LOGLEVEL_ENUM( + * TP_LOGLEVEL( < loglevel_name >, < value > ) + * TP_LOGLEVEL( < loglevel_name >, < value > ) + * ... + * ) + * + * e.g.: + * + * TRACEPOINT_LOGLEVEL_ENUM( + * TP_LOGLEVEL(LOG_EMERG, 0) + * TP_LOGLEVEL(LOG_ALERT, 1) + * TP_LOGLEVEL(LOG_CRIT, 2) + * TP_LOGLEVEL(LOG_ERR, 3) + * TP_LOGLEVEL(LOG_WARNING, 4) + * TP_LOGLEVEL(LOG_NOTICE, 5) + * TP_LOGLEVEL(LOG_INFO, 6) + * TP_LOGLEVEL(LOG_DEBUG, 7) + * ) + * + * 2) Then, declare tracepoint loglevels for tracepoints. A + * TRACEPOINT_EVENT should be declared prior to the the + * TRACEPOINT_LOGLEVEL for a given tracepoint name. The first field + * is the name of the tracepoint, the second field is the loglevel + * name. + * + * TRACEPOINT_LOGLEVEL(< [com_company_]project_[component_]event >, + * < loglevel_name >) + * + * The TRACEPOINT_SYSTEM must be defined when declaring a + * TRACEPOINT_LOGLEVEL_ENUM and TRACEPOINT_LOGLEVEL. The tracepoint + * loglevel enumeration apply to the entire TRACEPOINT_SYSTEM. Only one + * tracepoint loglevel enumeration should be declared per tracepoint + * system. + */ + +#define TRACEPOINT_LOGLEVEL_ENUM() +#define TRACEPOINT_LOGLEVEL(name, loglevel) + +#endif /* #ifndef TRACEPOINT_LOGLEVEL */ + +#ifdef __cplusplus +} +#endif + #endif /* _UST_TRACEPOINT_H */