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

#ifndef _LTTNG_TRACEPOINT_H
#define _LTTNG_TRACEPOINT_H

/*
 * Copyright (c) 2011 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
 *
 * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
 * OR IMPLIED.  ANY USE IS AT YOUR OWN RISK.
 *
 * Permission is hereby granted to use or copy this program
 * for any purpose,  provided the above notices are retained on all copies.
 * Permission to modify the code and to distribute modified code is granted,
 * provided the above notices are retained, and a notice that the code was
 * modified is included with the above copyright notice.
 */

#include <urcu-bp.h>
#include <tracepoint-types.h>
#include <urcu/compiler.h>

#ifdef __cplusplus
extern "C" {
#endif

#define tracepoint(provider, name, ...)					    \
	do {								    \
		if (caa_unlikely(__tracepoint_##provider##___##name.state)) \
			__tracepoint_cb_##provider##___##name(__VA_ARGS__); \
	} while (0)

#define TP_ARGS(...)       __VA_ARGS__

/*
 * TP_ARGS takes tuples of type, argument separated by a comma.
 * It can take up to 10 tuples (which means that less than 10 tuples is
 * fine too).
 * Each tuple is also separated by a comma.
 */
#define _TP_COMBINE_TOKENS1(_tokena, _tokenb)       _tokena##_tokenb
#define _TP_COMBINE_TOKENS(_tokena, _tokenb)        _TP_COMBINE_TOKENS1(_tokena, _tokenb)

/* _TP_EXVAR* extract the var names. */
#define _TP_EXVAR0()
#define _TP_EXVAR2(a,b)						b
#define _TP_EXVAR4(a,b,c,d)					b,d
#define _TP_EXVAR6(a,b,c,d,e,f)					b,d,f
#define _TP_EXVAR8(a,b,c,d,e,f,g,h)				b,d,f,h
#define _TP_EXVAR10(a,b,c,d,e,f,g,h,i,j)			b,d,f,h,j
#define _TP_EXVAR12(a,b,c,d,e,f,g,h,i,j,k,l)			b,d,f,h,j,l
#define _TP_EXVAR14(a,b,c,d,e,f,g,h,i,j,k,l,m,n)		b,d,f,h,j,l,n
#define _TP_EXVAR16(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p)		b,d,f,h,j,l,n,p
#define _TP_EXVAR18(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r)	b,d,f,h,j,l,n,p,r
#define _TP_EXVAR20(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t)	b,d,f,h,j,l,n,p,r,t

#define _TP_EXDATA_VAR0()						__tp_data
#define _TP_EXDATA_VAR2(a,b)						__tp_data,b
#define _TP_EXDATA_VAR4(a,b,c,d)					__tp_data,b,d
#define _TP_EXDATA_VAR6(a,b,c,d,e,f)					__tp_data,b,d,f
#define _TP_EXDATA_VAR8(a,b,c,d,e,f,g,h)				__tp_data,b,d,f,h
#define _TP_EXDATA_VAR10(a,b,c,d,e,f,g,h,i,j)				__tp_data,b,d,f,h,j
#define _TP_EXDATA_VAR12(a,b,c,d,e,f,g,h,i,j,k,l)			__tp_data,b,d,f,h,j,l
#define _TP_EXDATA_VAR14(a,b,c,d,e,f,g,h,i,j,k,l,m,n)			__tp_data,b,d,f,h,j,l,n
#define _TP_EXDATA_VAR16(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p)		__tp_data,b,d,f,h,j,l,n,p
#define _TP_EXDATA_VAR18(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r)		__tp_data,b,d,f,h,j,l,n,p,r
#define _TP_EXDATA_VAR20(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t)	__tp_data,b,d,f,h,j,l,n,p,r,t

/* _TP_EXPROTO* extract tuples of type, var */
#define _TP_EXPROTO0()
#define _TP_EXPROTO2(a,b)					a b
#define _TP_EXPROTO4(a,b,c,d)					a b,c d
#define _TP_EXPROTO6(a,b,c,d,e,f)				a b,c d,e f
#define _TP_EXPROTO8(a,b,c,d,e,f,g,h)				a b,c d,e f,g h
#define _TP_EXPROTO10(a,b,c,d,e,f,g,h,i,j)			a b,c d,e f,g h,i j
#define _TP_EXPROTO12(a,b,c,d,e,f,g,h,i,j,k,l)			a b,c d,e f,g h,i j,k l
#define _TP_EXPROTO14(a,b,c,d,e,f,g,h,i,j,k,l,m,n)		a b,c d,e f,g h,i j,k l,m n
#define _TP_EXPROTO16(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p)		a b,c d,e f,g h,i j,k l,m n,o p
#define _TP_EXPROTO18(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r)	a b,c d,e f,g h,i j,k l,m n,o p,q r
#define _TP_EXPROTO20(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t)	a b,c d,e f,g h,i j,k l,m n,o p,q r,s t

#define _TP_EXDATA_PROTO0()						void *__tp_data
#define _TP_EXDATA_PROTO2(a,b)						void *__tp_data,a b
#define _TP_EXDATA_PROTO4(a,b,c,d)					void *__tp_data,a b,c d
#define _TP_EXDATA_PROTO6(a,b,c,d,e,f)					void *__tp_data,a b,c d,e f
#define _TP_EXDATA_PROTO8(a,b,c,d,e,f,g,h)				void *__tp_data,a b,c d,e f,g h
#define _TP_EXDATA_PROTO10(a,b,c,d,e,f,g,h,i,j)				void *__tp_data,a b,c d,e f,g h,i j
#define _TP_EXDATA_PROTO12(a,b,c,d,e,f,g,h,i,j,k,l)			void *__tp_data,a b,c d,e f,g h,i j,k l
#define _TP_EXDATA_PROTO14(a,b,c,d,e,f,g,h,i,j,k,l,m,n)			void *__tp_data,a b,c d,e f,g h,i j,k l,m n
#define _TP_EXDATA_PROTO16(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p)		void *__tp_data,a b,c d,e f,g h,i j,k l,m n,o p
#define _TP_EXDATA_PROTO18(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r)		void *__tp_data,a b,c d,e f,g h,i j,k l,m n,o p,q r
#define _TP_EXDATA_PROTO20(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t)	void *__tp_data,a b,c d,e f,g h,i j,k l,m n,o p,q r,s t

/* Preprocessor trick to count arguments. Inspired from sdt.h. */
#define _TP_NARGS(...)			__TP_NARGS(__VA_ARGS__, 20,19,18,17,16,15,14,13,12,11,10,9,8,7,6,5,4,3,2,1,0)
#define __TP_NARGS(_0,_1,_2,_3,_4,_5,_6,_7,_8,_9,_10,_11,_12,_13,_14,_15,_16,_17,_18,_19,_20, N, ...)	N
#define _TP_PROTO_N(N, ...)		_TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXPROTO, N)(__VA_ARGS__))
#define _TP_VAR_N(N, ...)		_TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXVAR, N)(__VA_ARGS__))
#define _TP_DATA_PROTO_N(N, ...)	_TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXDATA_PROTO, N)(__VA_ARGS__))
#define _TP_DATA_VAR_N(N, ...)		_TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXDATA_VAR, N)(__VA_ARGS__))
#define _TP_ARGS_PROTO(...)		_TP_PROTO_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
#define _TP_ARGS_VAR(...)		_TP_VAR_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
#define _TP_ARGS_DATA_PROTO(...)	_TP_DATA_PROTO_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
#define _TP_ARGS_DATA_VAR(...)		_TP_DATA_VAR_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
#define _TP_PARAMS(...)			__VA_ARGS__

#define _DECLARE_TRACEPOINT(provider, name, ...)			 		\
extern struct tracepoint __tracepoint_##provider##___##name;				\
static inline void __tracepoint_cb_##provider##___##name(_TP_ARGS_PROTO(__VA_ARGS__))	\
{											\
	struct tracepoint_probe *__tp_probe;						\
											\
	rcu_read_lock_bp();								\
	__tp_probe = rcu_dereference(__tracepoint_##provider##___##name.probes);	\
	if (caa_unlikely(!__tp_probe))							\
		goto end;								\
	do {										\
		void *__tp_cb =	__tp_probe->func;					\
		void *__tp_data = __tp_probe->data;					\
											\
		URCU_FORCE_CAST(void (*)(_TP_ARGS_DATA_PROTO(__VA_ARGS__)), __tp_cb)	\
				(_TP_ARGS_DATA_VAR(__VA_ARGS__));			\
	} while ((++__tp_probe)->func);							\
end:											\
	rcu_read_unlock_bp();								\
}											\
static inline void __tracepoint_register_##provider##___##name(char *name,		\
		void *func, void *data)							\
{											\
	__tracepoint_probe_register(name, func, data);					\
}											\
static inline void __tracepoint_unregister_##provider##___##name(char *name,		\
		void *func, void *data)							\
{											\
	__tracepoint_probe_unregister(name, func, data);				\
}

/*
 * Note: to allow PIC code, we need to allow the linker to update the pointers
 * in the __tracepoints_ptrs section.
 * Therefore, this section is _not_ const (read-only).
 */
#define _DEFINE_TRACEPOINT(provider, name)					\
	static const char __tp_strtab_##provider##___##name[]			\
		__attribute__((section("__tracepoints_strings"))) =		\
			#provider ":" #name;					\
	struct tracepoint __tracepoint_##provider##___##name			\
		__attribute__((section("__tracepoints"))) =			\
			{ __tp_strtab_##provider##___##name, 0, NULL };		\
	static struct tracepoint * __tracepoint_ptr_##provider##___##name	\
		__attribute__((used, section("__tracepoints_ptrs"))) =		\
			&__tracepoint_##provider##___##name;

extern int __tracepoint_probe_register(const char *name, void *func, void *data);
extern int __tracepoint_probe_unregister(const char *name, void *func, void *data);
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);
}

#ifdef __cplusplus
}
#endif

#endif /* _LTTNG_TRACEPOINT_H */

/* The following declarations must be outside re-inclusion protection. */

#ifndef TRACEPOINT_EVENT

/*
 * How to use the TRACEPOINT_EVENT macro:
 *
 * An example:
 * 
 * TRACEPOINT_EVENT(someproject_component, event_name,
 *
 *     * TP_ARGS takes from 0 to 10 "type, field_name" pairs *
 *
 *     TP_ARGS(int, arg0, void *, arg1, char *, string, size_t, strlen,
 *             long *, arg4, size_t, arg4_len),
 *
 *	* TP_FIELDS describes the event payload layout in the trace *
 *
 *     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)
 *     )
 * )
 *
 * More detailed explanation:
 *
 * The name of the tracepoint is expressed as a tuple with the provider
 * and name arguments.
 *
 * The provider and name should be a proper C99 identifier.
 * The "provider" and "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.
 *
 * the provider:event identifier is limited to 127 characters.
 */

#define TRACEPOINT_EVENT(provider, name, args, fields)			\
	_DECLARE_TRACEPOINT(provider, name, _TP_PARAMS(args))

#define TRACEPOINT_EVENT_CLASS(provider, name, args, fields)

#define TRACEPOINT_EVENT_INSTANCE(provider, _template, name, args)	\
	_DECLARE_TRACEPOINT(provider, name, _TP_PARAMS(args))

#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_PROVIDER must be defined when declaring a
 * TRACEPOINT_LOGLEVEL_ENUM and TRACEPOINT_LOGLEVEL. The tracepoint
 * loglevel enumeration apply to the entire TRACEPOINT_PROVIDER. Only one
 * tracepoint loglevel enumeration should be declared per tracepoint
 * provider.
 */

#define TRACEPOINT_LOGLEVEL_ENUM()
#define TRACEPOINT_LOGLEVEL(name, loglevel)

#endif /* #ifndef TRACEPOINT_LOGLEVEL */
Commit	Line	Data
	1	#ifndef _LTTNG_TRACEPOINT_H
	2	#define _LTTNG_TRACEPOINT_H
	3
	4	/*
	5	* Copyright (c) 2011 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
	6	*
	7	* THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
	8	* OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
	9	*
	10	* Permission is hereby granted to use or copy this program
	11	* for any purpose, provided the above notices are retained on all copies.
	12	* Permission to modify the code and to distribute modified code is granted,
	13	* provided the above notices are retained, and a notice that the code was
	14	* modified is included with the above copyright notice.
	15	*/
	16
	17	#include <urcu-bp.h>
	18	#include <tracepoint-types.h>
	19	#include <urcu/compiler.h>
	20
	21	#ifdef __cplusplus
	22	extern "C" {
	23	#endif
	24
	25	#define tracepoint(provider, name, ...) \
	26	do { \
	27	if (caa_unlikely(__tracepoint_##provider##___##name.state)) \
	28	__tracepoint_cb_##provider##___##name(__VA_ARGS__); \
	29	} while (0)
	30
	31	#define TP_ARGS(...) __VA_ARGS__
	32
	33	/*
	34	* TP_ARGS takes tuples of type, argument separated by a comma.
	35	* It can take up to 10 tuples (which means that less than 10 tuples is
	36	* fine too).
	37	* Each tuple is also separated by a comma.
	38	*/
	39	#define _TP_COMBINE_TOKENS1(_tokena, _tokenb) _tokena##_tokenb
	40	#define _TP_COMBINE_TOKENS(_tokena, _tokenb) _TP_COMBINE_TOKENS1(_tokena, _tokenb)
	41
	42	/* _TP_EXVAR* extract the var names. */
	43	#define _TP_EXVAR0()
	44	#define _TP_EXVAR2(a,b) b
	45	#define _TP_EXVAR4(a,b,c,d) b,d
	46	#define _TP_EXVAR6(a,b,c,d,e,f) b,d,f
	47	#define _TP_EXVAR8(a,b,c,d,e,f,g,h) b,d,f,h
	48	#define _TP_EXVAR10(a,b,c,d,e,f,g,h,i,j) b,d,f,h,j
	49	#define _TP_EXVAR12(a,b,c,d,e,f,g,h,i,j,k,l) b,d,f,h,j,l
	50	#define _TP_EXVAR14(a,b,c,d,e,f,g,h,i,j,k,l,m,n) b,d,f,h,j,l,n
	51	#define _TP_EXVAR16(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p) b,d,f,h,j,l,n,p
	52	#define _TP_EXVAR18(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r) b,d,f,h,j,l,n,p,r
	53	#define _TP_EXVAR20(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t) b,d,f,h,j,l,n,p,r,t
	54
	55	#define _TP_EXDATA_VAR0() __tp_data
	56	#define _TP_EXDATA_VAR2(a,b) __tp_data,b
	57	#define _TP_EXDATA_VAR4(a,b,c,d) __tp_data,b,d
	58	#define _TP_EXDATA_VAR6(a,b,c,d,e,f) __tp_data,b,d,f
	59	#define _TP_EXDATA_VAR8(a,b,c,d,e,f,g,h) __tp_data,b,d,f,h
	60	#define _TP_EXDATA_VAR10(a,b,c,d,e,f,g,h,i,j) __tp_data,b,d,f,h,j
	61	#define _TP_EXDATA_VAR12(a,b,c,d,e,f,g,h,i,j,k,l) __tp_data,b,d,f,h,j,l
	62	#define _TP_EXDATA_VAR14(a,b,c,d,e,f,g,h,i,j,k,l,m,n) __tp_data,b,d,f,h,j,l,n
	63	#define _TP_EXDATA_VAR16(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p) __tp_data,b,d,f,h,j,l,n,p
	64	#define _TP_EXDATA_VAR18(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r) __tp_data,b,d,f,h,j,l,n,p,r
	65	#define _TP_EXDATA_VAR20(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t) __tp_data,b,d,f,h,j,l,n,p,r,t
	66
	67	/* _TP_EXPROTO* extract tuples of type, var */
	68	#define _TP_EXPROTO0()
	69	#define _TP_EXPROTO2(a,b) a b
	70	#define _TP_EXPROTO4(a,b,c,d) a b,c d
	71	#define _TP_EXPROTO6(a,b,c,d,e,f) a b,c d,e f
	72	#define _TP_EXPROTO8(a,b,c,d,e,f,g,h) a b,c d,e f,g h
	73	#define _TP_EXPROTO10(a,b,c,d,e,f,g,h,i,j) a b,c d,e f,g h,i j
	74	#define _TP_EXPROTO12(a,b,c,d,e,f,g,h,i,j,k,l) a b,c d,e f,g h,i j,k l
	75	#define _TP_EXPROTO14(a,b,c,d,e,f,g,h,i,j,k,l,m,n) a b,c d,e f,g h,i j,k l,m n
	76	#define _TP_EXPROTO16(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p) a b,c d,e f,g h,i j,k l,m n,o p
	77	#define _TP_EXPROTO18(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r) a b,c d,e f,g h,i j,k l,m n,o p,q r
	78	#define _TP_EXPROTO20(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t) a b,c d,e f,g h,i j,k l,m n,o p,q r,s t
	79
	80	#define _TP_EXDATA_PROTO0() void *__tp_data
	81	#define _TP_EXDATA_PROTO2(a,b) void *__tp_data,a b
	82	#define _TP_EXDATA_PROTO4(a,b,c,d) void *__tp_data,a b,c d
	83	#define _TP_EXDATA_PROTO6(a,b,c,d,e,f) void *__tp_data,a b,c d,e f
	84	#define _TP_EXDATA_PROTO8(a,b,c,d,e,f,g,h) void *__tp_data,a b,c d,e f,g h
	85	#define _TP_EXDATA_PROTO10(a,b,c,d,e,f,g,h,i,j) void *__tp_data,a b,c d,e f,g h,i j
	86	#define _TP_EXDATA_PROTO12(a,b,c,d,e,f,g,h,i,j,k,l) void *__tp_data,a b,c d,e f,g h,i j,k l
	87	#define _TP_EXDATA_PROTO14(a,b,c,d,e,f,g,h,i,j,k,l,m,n) void *__tp_data,a b,c d,e f,g h,i j,k l,m n
	88	#define _TP_EXDATA_PROTO16(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p) void *__tp_data,a b,c d,e f,g h,i j,k l,m n,o p
	89	#define _TP_EXDATA_PROTO18(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r) void *__tp_data,a b,c d,e f,g h,i j,k l,m n,o p,q r
	90	#define _TP_EXDATA_PROTO20(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t) void *__tp_data,a b,c d,e f,g h,i j,k l,m n,o p,q r,s t
	91
	92	/* Preprocessor trick to count arguments. Inspired from sdt.h. */
	93	#define _TP_NARGS(...) __TP_NARGS(__VA_ARGS__, 20,19,18,17,16,15,14,13,12,11,10,9,8,7,6,5,4,3,2,1,0)
	94	#define __TP_NARGS(_0,_1,_2,_3,_4,_5,_6,_7,_8,_9,_10,_11,_12,_13,_14,_15,_16,_17,_18,_19,_20, N, ...) N
	95	#define _TP_PROTO_N(N, ...) _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXPROTO, N)(__VA_ARGS__))
	96	#define _TP_VAR_N(N, ...) _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXVAR, N)(__VA_ARGS__))
	97	#define _TP_DATA_PROTO_N(N, ...) _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXDATA_PROTO, N)(__VA_ARGS__))
	98	#define _TP_DATA_VAR_N(N, ...) _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXDATA_VAR, N)(__VA_ARGS__))
	99	#define _TP_ARGS_PROTO(...) _TP_PROTO_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
	100	#define _TP_ARGS_VAR(...) _TP_VAR_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
	101	#define _TP_ARGS_DATA_PROTO(...) _TP_DATA_PROTO_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
	102	#define _TP_ARGS_DATA_VAR(...) _TP_DATA_VAR_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
	103	#define _TP_PARAMS(...) __VA_ARGS__
	104
	105	#define _DECLARE_TRACEPOINT(provider, name, ...) \
	106	extern struct tracepoint __tracepoint_##provider##___##name; \
	107	static inline void __tracepoint_cb_##provider##___##name(_TP_ARGS_PROTO(__VA_ARGS__)) \
	108	{ \
	109	struct tracepoint_probe *__tp_probe; \
	110	\
	111	rcu_read_lock_bp(); \
	112	__tp_probe = rcu_dereference(__tracepoint_##provider##___##name.probes); \
	113	if (caa_unlikely(!__tp_probe)) \
	114	goto end; \
	115	do { \
	116	void *__tp_cb = __tp_probe->func; \
	117	void *__tp_data = __tp_probe->data; \
	118	\
	119	URCU_FORCE_CAST(void (*)(_TP_ARGS_DATA_PROTO(__VA_ARGS__)), __tp_cb) \
	120	(_TP_ARGS_DATA_VAR(__VA_ARGS__)); \
	121	} while ((++__tp_probe)->func); \
	122	end: \
	123	rcu_read_unlock_bp(); \
	124	} \
	125	static inline void __tracepoint_register_##provider##___##name(char *name, \
	126	void func, void data) \
	127	{ \
	128	__tracepoint_probe_register(name, func, data); \
	129	} \
	130	static inline void __tracepoint_unregister_##provider##___##name(char *name, \
	131	void func, void data) \
	132	{ \
	133	__tracepoint_probe_unregister(name, func, data); \
	134	}
	135
	136	/*
	137	* Note: to allow PIC code, we need to allow the linker to update the pointers
	138	* in the __tracepoints_ptrs section.
	139	* Therefore, this section is _not_ const (read-only).
	140	*/
	141	#define _DEFINE_TRACEPOINT(provider, name) \
	142	static const char __tp_strtab_##provider##___##name[] \
	143	__attribute__((section("__tracepoints_strings"))) = \
	144	#provider ":" #name; \
	145	struct tracepoint __tracepoint_##provider##___##name \
	146	__attribute__((section("__tracepoints"))) = \
	147	{ __tp_strtab_##provider##___##name, 0, NULL }; \
	148	static struct tracepoint * __tracepoint_ptr_##provider##___##name \
	149	__attribute__((used, section("__tracepoints_ptrs"))) = \
	150	&__tracepoint_##provider##___##name;
	151
	152	extern int __tracepoint_probe_register(const char name, void func, void *data);
	153	extern int __tracepoint_probe_unregister(const char name, void func, void *data);
	154	extern int tracepoint_register_lib(struct tracepoint * const *tracepoints_start,
	155	int tracepoints_count);
	156	extern int tracepoint_unregister_lib(struct tracepoint * const *tracepoints_start);
	157
	158	/*
	159	* These weak symbols, the constructor, and destructor take care of
	160	* registering only _one_ instance of the tracepoints per shared-ojbect
	161	* (or for the whole main program).
	162	*/
	163	extern struct tracepoint * const __start___tracepoints_ptrs[]
	164	__attribute__((weak, visibility("hidden")));
	165	extern struct tracepoint * const __stop___tracepoints_ptrs[]
	166	__attribute__((weak, visibility("hidden")));
	167	int __tracepoint_registered
	168	__attribute__((weak, visibility("hidden")));
	169
	170	static void __attribute__((constructor)) __tracepoints__init(void)
	171	{
	172	if (__tracepoint_registered++)
	173	return;
	174	tracepoint_register_lib(__start___tracepoints_ptrs,
	175	__stop___tracepoints_ptrs -
	176	__start___tracepoints_ptrs);
	177	}
	178
	179	static void __attribute__((destructor)) __tracepoints__destroy(void)
	180	{
	181	if (--__tracepoint_registered)
	182	return;
	183	tracepoint_unregister_lib(__start___tracepoints_ptrs);
	184	}
	185
	186	#ifdef __cplusplus
	187	}
	188	#endif
	189
	190	#endif /* _LTTNG_TRACEPOINT_H */
	191
	192	/* The following declarations must be outside re-inclusion protection. */
	193
	194	#ifndef TRACEPOINT_EVENT
	195
	196	/*
	197	* How to use the TRACEPOINT_EVENT macro:
	198	*
	199	* An example:
	200	*
	201	* TRACEPOINT_EVENT(someproject_component, event_name,
	202	*
	203	* * TP_ARGS takes from 0 to 10 "type, field_name" pairs *
	204	*
	205	* TP_ARGS(int, arg0, void , arg1, char , string, size_t, strlen,
	206	* long *, arg4, size_t, arg4_len),
	207	*
	208	* * TP_FIELDS describes the event payload layout in the trace *
	209	*
	210	* TP_FIELDS(
	211	* * Integer, printed in base 10 *
	212	* ctf_integer(int, field_a, arg0)
	213	*
	214	* * Integer, printed with 0x base 16 *
	215	* ctf_integer_hex(unsigned long, field_d, arg1)
	216	*
	217	* * Array Sequence, printed as UTF8-encoded array of bytes *
	218	* ctf_array_text(char, field_b, string, FIXED_LEN)
	219	* ctf_sequence_text(char, field_c, string, size_t, strlen)
	220	*
	221	* * String, printed as UTF8-encoded string *
	222	* ctf_string(field_e, string)
	223	*
	224	* * Array sequence of signed integer values *
	225	* ctf_array(long, field_f, arg4, FIXED_LEN4)
	226	* ctf_sequence(long, field_g, arg4, size_t, arg4_len)
	227	* )
	228	* )
	229	*
	230	* More detailed explanation:
	231	*
	232	* The name of the tracepoint is expressed as a tuple with the provider
	233	* and name arguments.
	234	*
	235	* The provider and name should be a proper C99 identifier.
	236	* The "provider" and "name" MUST follow these rules to ensure no
	237	* namespace clash occurs:
	238	*
	239	* For projects (applications and libraries) for which an entity
	240	* specific to the project controls the source code and thus its
	241	* tracepoints (typically with a scope larger than a single company):
	242	*
	243	* either:
	244	* project_component, event
	245	* or:
	246	* project, event
	247	*
	248	* Where "project" is the name of the project,
	249	* "component" is the name of the project component (which may
	250	* include several levels of sub-components, e.g.
	251	* ...component_subcomponent_...) where the tracepoint is located
	252	* (optional),
	253	* "event" is the name of the tracepoint event.
	254	*
	255	* For projects issued from a single company wishing to advertise that
	256	* the company controls the source code and thus the tracepoints, the
	257	* "com_" prefix should be used:
	258	*
	259	* either:
	260	* com_company_project_component, event
	261	* or:
	262	* com_company_project, event
	263	*
	264	* Where "company" is the name of the company,
	265	* "project" is the name of the project,
	266	* "component" is the name of the project component (which may
	267	* include several levels of sub-components, e.g.
	268	* ...component_subcomponent_...) where the tracepoint is located
	269	* (optional),
	270	* "event" is the name of the tracepoint event.
	271	*
	272	* the provider:event identifier is limited to 127 characters.
	273	*/
	274
	275	#define TRACEPOINT_EVENT(provider, name, args, fields) \
	276	_DECLARE_TRACEPOINT(provider, name, _TP_PARAMS(args))
	277
	278	#define TRACEPOINT_EVENT_CLASS(provider, name, args, fields)
	279
	280	#define TRACEPOINT_EVENT_INSTANCE(provider, _template, name, args) \
	281	_DECLARE_TRACEPOINT(provider, name, _TP_PARAMS(args))
	282
	283	#endif /* #ifndef TRACEPOINT_EVENT */
	284
	285	#ifndef TRACEPOINT_LOGLEVEL
	286
	287	/*
	288	* Tracepoint Loglevel Declaration Facility
	289	*
	290	* This is a place-holder the tracepoint loglevel declaration,
	291	* overridden by the tracer implementation.
	292	*
	293	* Typical use of these loglevels:
	294	*
	295	* 1) Declare the mapping between loglevel names and an integer values
	296	* within TRACEPOINT_LOGLEVEL_ENUM, using TP_LOGLEVEL for each tuple.
	297	* Do _NOT_ add comma (,) nor semicolon (;) between the
	298	* TRACEPOINT_LOGLEVEL_ENUM entries. Do _NOT_ add comma (,) nor
	299	* semicolon (;) after the TRACEPOINT_LOGLEVEL_ENUM declaration. The
	300	* name should be a proper C99 identifier.
	301	*
	302	* TRACEPOINT_LOGLEVEL_ENUM(
	303	* TP_LOGLEVEL( < loglevel_name >, < value > )
	304	* TP_LOGLEVEL( < loglevel_name >, < value > )
	305	* ...
	306	* )
	307	*
	308	* e.g.:
	309	*
	310	* TRACEPOINT_LOGLEVEL_ENUM(
	311	* TP_LOGLEVEL(LOG_EMERG, 0)
	312	* TP_LOGLEVEL(LOG_ALERT, 1)
	313	* TP_LOGLEVEL(LOG_CRIT, 2)
	314	* TP_LOGLEVEL(LOG_ERR, 3)
	315	* TP_LOGLEVEL(LOG_WARNING, 4)
	316	* TP_LOGLEVEL(LOG_NOTICE, 5)
	317	* TP_LOGLEVEL(LOG_INFO, 6)
	318	* TP_LOGLEVEL(LOG_DEBUG, 7)
	319	* )
	320	*
	321	* 2) Then, declare tracepoint loglevels for tracepoints. A
	322	* TRACEPOINT_EVENT should be declared prior to the the
	323	* TRACEPOINT_LOGLEVEL for a given tracepoint name. The first field
	324	* is the name of the tracepoint, the second field is the loglevel
	325	* name.
	326	*
	327	* TRACEPOINT_LOGLEVEL(< [com_company_]project[_component] >, < event >,
	328	* < loglevel_name >)
	329	*
	330	* The TRACEPOINT_PROVIDER must be defined when declaring a
	331	* TRACEPOINT_LOGLEVEL_ENUM and TRACEPOINT_LOGLEVEL. The tracepoint
	332	* loglevel enumeration apply to the entire TRACEPOINT_PROVIDER. Only one
	333	* tracepoint loglevel enumeration should be declared per tracepoint
	334	* provider.
	335	*/
	336
	337	#define TRACEPOINT_LOGLEVEL_ENUM()
	338	#define TRACEPOINT_LOGLEVEL(name, loglevel)
	339
	340	#endif /* #ifndef TRACEPOINT_LOGLEVEL */