TRACEPOINT_EVENT API

[lttng-ust.git] / include / ust / tracepoint.h

diff --git a/include/ust/tracepoint.h b/include/ust/tracepoint.h
index 3d61f72883c762cc44ad64fb5c4c005d281d2084..18ee28b064e9e39e3519f43d8514daec9562256b 100644 (file)
--- a/include/ust/tracepoint.h
+++ b/include/ust/tracepoint.h
@@ -199,17 +199,48 @@ int tracepoint_unregister_lib(struct tracepoint * const *tracepoints_start);
 /*
  * For use with the TRACEPOINT_EVENT macro:
  *
- * We define a tracepoint, its arguments, its printf format
- * and its 'fast binary record' layout.
+ * We define a tracepoint, its arguments, and its 'fast binary record'
+ * layout.
  *
- * Firstly, name your tracepoint via TRACEPOINT_EVENT(name : the
- * 'subsystem_event' notation is fine.
+ * Firstly, name your tracepoint via TRACEPOINT_EVENT(name,
  *
- * Think about this whole construct as the
- * 'trace_sched_switch() function' from now on.
+ * The "name" MUST follow these rules to ensure no namespace clash
+ * occurs:
  *
+ * For projects (applications and libraries) for which an entity
+ * specific to the project controls the source code and thus its
+ * tracepoints (typically with a scope larger than a single company):
  *
- *  TRACEPOINT_EVENT(sched_switch,
+ * either:
+ *   project_component_event
+ * or:
+ *   project_event
+ *
+ * Where "project" is the name of the project,
+ *       "component" is the name of the project component 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
+ * the company controls the source code and thus the tracepoints, the
+ * "com_" prefix should be used:
+ *
+ * either:
+ *   com_company_project_component_event
+ * or:
+ *   com_company_project_event
+ *
+ * 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),
+ *       "event" is the name of the tracepoint event.
+ *
+ *
+ * As an example, let's consider a user-space application "someproject"
+ * that would have an internal thread scheduler:
+ *
+ *  TRACEPOINT_EVENT(someproject_sched_switch,
  *
  *     *
  *     * A function has a regular function arguments
@@ -236,7 +267,7 @@ int tracepoint_unregister_lib(struct tracepoint * const *tracepoints_start);
  *     * be saved into the ring buffer. These are the fields
  *     * that will be exposed to readers.
  *     *
- *     * tp_field(pid_t, prev_pid, prev->pid) is equivalent
+ *     * ctf_integer(pid_t, prev_pid, prev->pid) is equivalent
  *     * to a standard declaraton:
  *     *
  *     *       pid_t prev_pid;
@@ -245,7 +276,7 @@ int tracepoint_unregister_lib(struct tracepoint * const *tracepoints_start);
  *     *
  *     *       prev_pid = prev->pid;
  *     *
- *     * tp_array(char, prev_comm, TASK_COMM_LEN, prev->comm) is
+ *     * ctf_array(char, prev_comm, prev->comm, TASK_COMM_LEN) is
  *     * equivalent to:
  *     *
  *     *       char prev_comm[TASK_COMM_LEN];
@@ -256,14 +287,14 @@ int tracepoint_unregister_lib(struct tracepoint * const *tracepoints_start);
  *     *
  *
  *     TP_FIELDS(
- *             tp_array(char,  prev_comm, TASK_COMM_LEN, prev->comm)
- *             tp_field(pid_t, prev_pid,  prev->pid)
- *             tp_field(int,   prev_prio, prev->prio)
- *             tp_array(char,  next_comm, TASK_COMM_LEN, next->comm)
- *             tp_field(pid_t, next_pid,  next->pid)
- *             tp_field(int,   next_prio, next->prio)
+ *             ctf_array(char, prev_comm, prev->comm, TASK_COMM_LEN)
+ *             ctf_integer(pid_t, prev_pid,  prev->pid)
+ *             ctf_integer(int, prev_prio, prev->prio)
+ *             ctf_array(char, next_comm, next->comm, TASK_COMM_LEN)
+ *             ctf_integer(pid_t, next_pid,  next->pid)
+ *             ctf_integer(int, next_prio, next->prio)
  *     )
- * );
+ * )
  */
 
 #define TRACEPOINT_EVENT(name, proto, args, fields)                    \
@@ -283,45 +314,6 @@ int tracepoint_unregister_lib(struct tracepoint * const *tracepoints_start);
 #define TRACEPOINT_EVENT_INSTANCE_NOARGS(template, name)               \
        _DECLARE_TRACEPOINT_NOARGS(name)
 
-
-
-#define TRACEPOINT_EVENT_LIB                                           \
-       extern struct trace_event * const __start___trace_events_ptrs[] \
-       __attribute__((weak, visibility("hidden")));                    \
-       extern struct trace_event * const __stop___trace_events_ptrs[]  \
-       __attribute__((weak, visibility("hidden")));                    \
-       static struct trace_event * __event_ptrs_dummy                  \
-       __attribute__((used, section("__trace_events_ptrs")));          \
-       static void __attribute__((constructor))                        \
-       __trace_events__init(void)                                      \
-       {                                                               \
-               trace_event_register_lib(__start___trace_events_ptrs,   \
-                                        __stop___trace_events_ptrs -   \
-                                        __start___trace_events_ptrs);  \
-       }                                                               \
-                                                                       \
-       static void __attribute__((destructor))                         \
-       __trace_event__destroy(void)                                    \
-       {                                                               \
-               trace_event_unregister_lib(__start___trace_events_ptrs);\
-       }
-
-struct trace_event {
-       const char *name;
-};
-
-struct trace_event_lib {
-       struct trace_event * const *trace_events_start;
-       int trace_events_count;
-       struct cds_list_head list;
-};
-
-extern
-int trace_event_register_lib(struct trace_event * const *start_trace_events,
-                            int trace_event_count);
-extern
-int trace_event_unregister_lib(struct trace_event * const *start_trace_events);
-
 #endif /* #ifndef TRACEPOINT_EVENT */
 
 #endif /* _UST_TRACEPOINT_H */