+static void __attribute__((destructor)) __tracepoints__destroy(void)
+{
+ if (--__tracepoint_registered)
+ return;
+ tracepoint_unregister_lib(__start___tracepoints_ptrs);
+}
+
+#ifndef TRACEPOINT_EVENT
+/*
+ * Usage of the TRACEPOINT_EVENT macro:
+ *
+ * In short, an example:
+ *
+ * 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),
+ * TP_FIELDS(
+ *
+ * * Integer, printed in base 10 *
+ * ctf_integer(int, field_a, arg0)
+ *
+ * * Integer, printed with 0x base 16 *
+ * ctf_integer_hex(unsigned long, field_d, arg1)
+ *
+ * * 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)
+ *
+ * * String, printed as UTF8-encoded string *
+ * ctf_string(field_e, string)
+ *
+ * * Array sequence of signed integer values *
+ * ctf_array(long, field_f, arg4, FIXED_LEN4)
+ * ctf_sequence(long, field_g, arg4, size_t, arg4_len)
+ * )
+ * )
+ *
+ * In more detail:
+ *
+ * We define a tracepoint, its arguments, and its 'fast binary record'
+ * layout.
+ *
+ * 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:
+ *
+ * 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):
+ *
+ * either:
+ * project_component_event
+ * or:
+ * project_event
+ *
+ * Where "project" is the name of the project,
+ * "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
+ * 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 (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.
+ *
+ *
+ * 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
+ * * prototype, declare it via TP_PROTO():
+ * *
+ *
+ * TP_PROTO(struct rq *rq, struct task_struct *prev,
+ * struct task_struct *next),
+ *
+ * *
+ * * Define the call signature of the 'function'.
+ * * (Design sidenote: we use this instead of a
+ * * TP_PROTO1/TP_PROTO2/TP_PROTO3 ugliness.)
+ * *
+ *
+ * TP_ARGS(rq, prev, next),
+ *
+ * *
+ * * Fast binary tracing: define the trace record via
+ * * TP_FIELDS(). You can think about it like a
+ * * regular C structure local variable definition.
+ * *
+ * * This is how the trace record is structured and will
+ * * be saved into the ring buffer. These are the fields
+ * * that will be exposed to readers.
+ * *
+ * * ctf_integer(pid_t, prev_pid, prev->pid) is equivalent
+ * * to a standard declaraton:
+ * *
+ * * pid_t prev_pid;
+ * *
+ * * followed by an assignment:
+ * *
+ * * prev_pid = prev->pid;
+ * *
+ * * ctf_array(char, prev_comm, prev->comm, TASK_COMM_LEN) is
+ * * equivalent to:
+ * *
+ * * char prev_comm[TASK_COMM_LEN];
+ * *
+ * * followed by an assignment:
+ * *
+ * * memcpy(prev_comm, prev->comm, TASK_COMM_LEN);
+ * *
+ *
+ * TP_FIELDS(
+ * 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)
+ * )
+ * )
+ *
+ * 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.
+ */