[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>
#include <dlfcn.h>	/* for dlopen */

#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;						\
											\
	if (!rcu_read_lock_bp)								\
		return;									\
	rcu_read_lock_bp();								\
	__tp_probe = rcu_dereference_bp(__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);				\
}

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

#ifdef TRACEPOINT_DEFINE

/*
 * 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;

static int (*tracepoint_register_lib)(struct tracepoint * const *tracepoints_start,
		int tracepoints_count);
static int (*tracepoint_unregister_lib)(struct tracepoint * const *tracepoints_start);
static void *liblttngust_handle;

/*
 * 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;

	liblttngust_handle = dlopen("liblttng-ust.so", RTLD_NOW | RTLD_GLOBAL);
	if (!liblttngust_handle)
		return;
	tracepoint_register_lib =
		URCU_FORCE_CAST(int (*)(struct tracepoint * const *, int),
				dlsym(liblttngust_handle,
					"tracepoint_register_lib"));
	tracepoint_unregister_lib =
		URCU_FORCE_CAST(int (*)(struct tracepoint * const *),
				dlsym(liblttngust_handle,
					"tracepoint_unregister_lib"));
	tracepoint_register_lib(__start___tracepoints_ptrs,
				__stop___tracepoints_ptrs -
				__start___tracepoints_ptrs);
}

static void __attribute__((destructor)) __tracepoints__destroy(void)
{
	int ret;
	if (--__tracepoint_registered)
		return;
	if (tracepoint_unregister_lib)
		tracepoint_unregister_lib(__start___tracepoints_ptrs);
	if (liblttngust_handle) {
		tracepoint_unregister_lib = NULL;
		tracepoint_register_lib = NULL;
		ret = dlclose(liblttngust_handle);
		assert(!ret);
	}
}

#else /* TRACEPOINT_DEFINE */

#define _DEFINE_TRACEPOINT(provider, name)

#endif /* #else TRACEPOINT_DEFINE */

#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(provider, name)

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

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

#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
 *    tp_loglevel entries contained within TRACEPOINT_LOGLEVEL_ENUM().
 *    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(provider, name, loglevel)

#endif /* #ifndef TRACEPOINT_LOGLEVEL */
Commit	Line	Data
b728d87e MD	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>
deb6e540	20	#include <dlfcn.h> /* for dlopen */
b728d87e MD	21
	22	#ifdef __cplusplus
	23	extern "C" {
	24	#endif
	25
23c8854a MD	26	#define tracepoint(provider, name, ...) \
	27	do { \
	28	if (caa_unlikely(__tracepoint_##provider##___##name.state)) \
	29	__tracepoint_cb_##provider##___##name(__VA_ARGS__); \
b728d87e MD	30	} while (0)
	31
	32	#define TP_ARGS(...) __VA_ARGS__
	33
	34	/*
	35	* TP_ARGS takes tuples of type, argument separated by a comma.
	36	* It can take up to 10 tuples (which means that less than 10 tuples is
	37	* fine too).
	38	* Each tuple is also separated by a comma.
	39	*/
	40	#define _TP_COMBINE_TOKENS1(_tokena, _tokenb) _tokena##_tokenb
	41	#define _TP_COMBINE_TOKENS(_tokena, _tokenb) _TP_COMBINE_TOKENS1(_tokena, _tokenb)
	42
23c8854a	43	/* _TP_EXVAR* extract the var names. */
b728d87e MD	44	#define _TP_EXVAR0()
	45	#define _TP_EXVAR2(a,b) b
	46	#define _TP_EXVAR4(a,b,c,d) b,d
	47	#define _TP_EXVAR6(a,b,c,d,e,f) b,d,f
	48	#define _TP_EXVAR8(a,b,c,d,e,f,g,h) b,d,f,h
	49	#define _TP_EXVAR10(a,b,c,d,e,f,g,h,i,j) b,d,f,h,j
	50	#define _TP_EXVAR12(a,b,c,d,e,f,g,h,i,j,k,l) b,d,f,h,j,l
	51	#define _TP_EXVAR14(a,b,c,d,e,f,g,h,i,j,k,l,m,n) b,d,f,h,j,l,n
	52	#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
	53	#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
	54	#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
	55
	56	#define _TP_EXDATA_VAR0() __tp_data
	57	#define _TP_EXDATA_VAR2(a,b) __tp_data,b
	58	#define _TP_EXDATA_VAR4(a,b,c,d) __tp_data,b,d
	59	#define _TP_EXDATA_VAR6(a,b,c,d,e,f) __tp_data,b,d,f
	60	#define _TP_EXDATA_VAR8(a,b,c,d,e,f,g,h) __tp_data,b,d,f,h
	61	#define _TP_EXDATA_VAR10(a,b,c,d,e,f,g,h,i,j) __tp_data,b,d,f,h,j
	62	#define _TP_EXDATA_VAR12(a,b,c,d,e,f,g,h,i,j,k,l) __tp_data,b,d,f,h,j,l
	63	#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
	64	#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
	65	#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
	66	#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
	67
	68	/* _TP_EXPROTO* extract tuples of type, var */
	69	#define _TP_EXPROTO0()
	70	#define _TP_EXPROTO2(a,b) a b
	71	#define _TP_EXPROTO4(a,b,c,d) a b,c d
	72	#define _TP_EXPROTO6(a,b,c,d,e,f) a b,c d,e f
	73	#define _TP_EXPROTO8(a,b,c,d,e,f,g,h) a b,c d,e f,g h
	74	#define _TP_EXPROTO10(a,b,c,d,e,f,g,h,i,j) a b,c d,e f,g h,i j
	75	#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
	76	#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
	77	#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
	78	#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
	79	#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
	80
	81	#define _TP_EXDATA_PROTO0() void *__tp_data
	82	#define _TP_EXDATA_PROTO2(a,b) void *__tp_data,a b
	83	#define _TP_EXDATA_PROTO4(a,b,c,d) void *__tp_data,a b,c d
	84	#define _TP_EXDATA_PROTO6(a,b,c,d,e,f) void *__tp_data,a b,c d,e f
	85	#define _TP_EXDATA_PROTO8(a,b,c,d,e,f,g,h) void *__tp_data,a b,c d,e f,g h
	86	#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
	87	#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
	88	#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
	89	#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
	90	#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
	91	#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
	92
	93	/* Preprocessor trick to count arguments. Inspired from sdt.h. */
	94	#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)
	95	#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
23c8854a MD	96	#define _TP_PROTO_N(N, ...) _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXPROTO, N)(__VA_ARGS__))
	97	#define _TP_VAR_N(N, ...) _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXVAR, N)(__VA_ARGS__))
	98	#define _TP_DATA_PROTO_N(N, ...) _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXDATA_PROTO, N)(__VA_ARGS__))
	99	#define _TP_DATA_VAR_N(N, ...) _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXDATA_VAR, N)(__VA_ARGS__))
b728d87e	100	#define _TP_ARGS_PROTO(...) _TP_PROTO_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
23c8854a	101	#define _TP_ARGS_VAR(...) _TP_VAR_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
b728d87e	102	#define _TP_ARGS_DATA_PROTO(...) _TP_DATA_PROTO_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
23c8854a	103	#define _TP_ARGS_DATA_VAR(...) _TP_DATA_VAR_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
b728d87e MD	104	#define _TP_PARAMS(...) __VA_ARGS__
	105
	106	#define _DECLARE_TRACEPOINT(provider, name, ...) \
23c8854a MD	107	extern struct tracepoint __tracepoint_##provider##___##name; \
23c8854a MD	108	static inline void __tracepoint_cb_##provider##___##name(_TP_ARGS_PROTO(__VA_ARGS__)) \
b728d87e MD	109	{ \
	110	struct tracepoint_probe *__tp_probe; \
	111	\
deb6e540 MD	112	if (!rcu_read_lock_bp) \
deb6e540 MD	113	return; \
b728d87e	114	rcu_read_lock_bp(); \
deb6e540	115	__tp_probe = rcu_dereference_bp(__tracepoint_##provider##___##name.probes); \
23c8854a	116	if (caa_unlikely(!__tp_probe)) \
b728d87e MD	117	goto end; \
b728d87e MD	118	do { \
23c8854a MD	119	void *__tp_cb = __tp_probe->func; \
23c8854a MD	120	void *__tp_data = __tp_probe->data; \
b728d87e	121	\
23c8854a MD	122	URCU_FORCE_CAST(void (*)(_TP_ARGS_DATA_PROTO(__VA_ARGS__)), __tp_cb) \
	123	(_TP_ARGS_DATA_VAR(__VA_ARGS__)); \
	124	} while ((++__tp_probe)->func); \
b728d87e MD	125	end: \
	126	rcu_read_unlock_bp(); \
	127	} \
23c8854a MD	128	static inline void __tracepoint_register_##provider##___##name(char *name, \
23c8854a MD	129	void func, void data) \
b728d87e	130	{ \
23c8854a	131	__tracepoint_probe_register(name, func, data); \
b728d87e	132	} \
23c8854a MD	133	static inline void __tracepoint_unregister_##provider##___##name(char *name, \
23c8854a MD	134	void func, void data) \
b728d87e	135	{ \
23c8854a	136	__tracepoint_probe_unregister(name, func, data); \
b728d87e MD	137	}
b728d87e MD	138
deb6e540 MD	139	extern int __tracepoint_probe_register(const char name, void func, void *data);
	140	extern int __tracepoint_probe_unregister(const char name, void func, void *data);
	141
	142	#ifdef TRACEPOINT_DEFINE
	143
b728d87e MD	144	/*
	145	* Note: to allow PIC code, we need to allow the linker to update the pointers
	146	* in the __tracepoints_ptrs section.
	147	* Therefore, this section is _not_ const (read-only).
	148	*/
	149	#define _DEFINE_TRACEPOINT(provider, name) \
	150	static const char __tp_strtab_##provider##___##name[] \
	151	__attribute__((section("__tracepoints_strings"))) = \
	152	#provider ":" #name; \
	153	struct tracepoint __tracepoint_##provider##___##name \
	154	__attribute__((section("__tracepoints"))) = \
	155	{ __tp_strtab_##provider##___##name, 0, NULL }; \
	156	static struct tracepoint * __tracepoint_ptr_##provider##___##name \
	157	__attribute__((used, section("__tracepoints_ptrs"))) = \
	158	&__tracepoint_##provider##___##name;
	159
deb6e540	160	static int (tracepoint_register_lib)(struct tracepoint const *tracepoints_start,
b728d87e	161	int tracepoints_count);
deb6e540 MD	162	static int (tracepoint_unregister_lib)(struct tracepoint const *tracepoints_start);
deb6e540 MD	163	static void *liblttngust_handle;
b728d87e MD	164
	165	/*
	166	* These weak symbols, the constructor, and destructor take care of
	167	* registering only _one_ instance of the tracepoints per shared-ojbect
	168	* (or for the whole main program).
	169	*/
	170	extern struct tracepoint * const __start___tracepoints_ptrs[]
	171	__attribute__((weak, visibility("hidden")));
	172	extern struct tracepoint * const __stop___tracepoints_ptrs[]
	173	__attribute__((weak, visibility("hidden")));
	174	int __tracepoint_registered
	175	__attribute__((weak, visibility("hidden")));
	176
	177	static void __attribute__((constructor)) __tracepoints__init(void)
	178	{
	179	if (__tracepoint_registered++)
	180	return;
deb6e540 MD	181
	182	liblttngust_handle = dlopen("liblttng-ust.so", RTLD_NOW \| RTLD_GLOBAL);
	183	if (!liblttngust_handle)
	184	return;
93ffe366 MD	185	tracepoint_register_lib =
	186	URCU_FORCE_CAST(int ()(struct tracepoint const *, int),
	187	dlsym(liblttngust_handle,
	188	"tracepoint_register_lib"));
	189	tracepoint_unregister_lib =
	190	URCU_FORCE_CAST(int ()(struct tracepoint const *),
	191	dlsym(liblttngust_handle,
	192	"tracepoint_unregister_lib"));
b728d87e MD	193	tracepoint_register_lib(__start___tracepoints_ptrs,
	194	__stop___tracepoints_ptrs -
	195	__start___tracepoints_ptrs);
	196	}
	197
	198	static void __attribute__((destructor)) __tracepoints__destroy(void)
	199	{
deb6e540	200	int ret;
b728d87e MD	201	if (--__tracepoint_registered)
b728d87e MD	202	return;
deb6e540 MD	203	if (tracepoint_unregister_lib)
	204	tracepoint_unregister_lib(__start___tracepoints_ptrs);
	205	if (liblttngust_handle) {
	206	tracepoint_unregister_lib = NULL;
	207	tracepoint_register_lib = NULL;
	208	ret = dlclose(liblttngust_handle);
	209	assert(!ret);
	210	}
b728d87e MD	211	}
b728d87e MD	212
deb6e540 MD	213	#else /* TRACEPOINT_DEFINE */
	214
	215	#define _DEFINE_TRACEPOINT(provider, name)
	216
	217	#endif /* #else TRACEPOINT_DEFINE */
	218
b728d87e MD	219	#ifdef __cplusplus
	220	}
	221	#endif
	222
	223	#endif /* _LTTNG_TRACEPOINT_H */
	224
	225	/* The following declarations must be outside re-inclusion protection. */
	226
	227	#ifndef TRACEPOINT_EVENT
	228
	229	/*
	230	* How to use the TRACEPOINT_EVENT macro:
	231	*
	232	* An example:
	233	*
	234	* TRACEPOINT_EVENT(someproject_component, event_name,
	235	*
	236	* * TP_ARGS takes from 0 to 10 "type, field_name" pairs *
	237	*
	238	* TP_ARGS(int, arg0, void , arg1, char , string, size_t, strlen,
	239	* long *, arg4, size_t, arg4_len),
	240	*
	241	* * TP_FIELDS describes the event payload layout in the trace *
	242	*
	243	* TP_FIELDS(
	244	* * Integer, printed in base 10 *
	245	* ctf_integer(int, field_a, arg0)
	246	*
	247	* * Integer, printed with 0x base 16 *
	248	* ctf_integer_hex(unsigned long, field_d, arg1)
	249	*
	250	* * Array Sequence, printed as UTF8-encoded array of bytes *
	251	* ctf_array_text(char, field_b, string, FIXED_LEN)
	252	* ctf_sequence_text(char, field_c, string, size_t, strlen)
	253	*
	254	* * String, printed as UTF8-encoded string *
	255	* ctf_string(field_e, string)
	256	*
	257	* * Array sequence of signed integer values *
	258	* ctf_array(long, field_f, arg4, FIXED_LEN4)
	259	* ctf_sequence(long, field_g, arg4, size_t, arg4_len)
	260	* )
	261	* )
	262	*
	263	* More detailed explanation:
	264	*
	265	* The name of the tracepoint is expressed as a tuple with the provider
	266	* and name arguments.
	267	*
	268	* The provider and name should be a proper C99 identifier.
	269	* The "provider" and "name" MUST follow these rules to ensure no
	270	* namespace clash occurs:
	271	*
	272	* For projects (applications and libraries) for which an entity
	273	* specific to the project controls the source code and thus its
	274	* tracepoints (typically with a scope larger than a single company):
	275	*
	276	* either:
	277	* project_component, event
	278	* or:
	279	* project, event
	280	*
	281	* Where "project" is the name of the project,
	282	* "component" is the name of the project component (which may
283	* include several levels of sub-components, e.g.
284	* ...component_subcomponent_...) where the tracepoint is located
285	* (optional),
286	* "event" is the name of the tracepoint event.
287	*
288	* For projects issued from a single company wishing to advertise that
289	* the company controls the source code and thus the tracepoints, the
290	* "com_" prefix should be used:
291	*
292	* either:
293	* com_company_project_component, event
294	* or:
295	* com_company_project, event
296	*
297	* Where "company" is the name of the company,
298	* "project" is the name of the project,
299	* "component" is the name of the project component (which may
300	* include several levels of sub-components, e.g.
301	* ...component_subcomponent_...) where the tracepoint is located
302	* (optional),
303	* "event" is the name of the tracepoint event.
304	*
305	* the provider:event identifier is limited to 127 characters.
306	*/
307
b728d87e	308	#define TRACEPOINT_EVENT(provider, name, args, fields) \
deb6e540 MD	309	_DECLARE_TRACEPOINT(provider, name, _TP_PARAMS(args)) \
deb6e540 MD	310	_DEFINE_TRACEPOINT(provider, name)
b728d87e MD	311
	312	#define TRACEPOINT_EVENT_CLASS(provider, name, args, fields)
	313
	314	#define TRACEPOINT_EVENT_INSTANCE(provider, _template, name, args) \
deb6e540 MD	315	_DECLARE_TRACEPOINT(provider, name, _TP_PARAMS(args)) \
deb6e540 MD	316	_DEFINE_TRACEPOINT(provider, name)
b728d87e MD	317
	318	#endif /* #ifndef TRACEPOINT_EVENT */
	319
	320	#ifndef TRACEPOINT_LOGLEVEL
	321
	322	/*
	323	* Tracepoint Loglevel Declaration Facility
	324	*
	325	* This is a place-holder the tracepoint loglevel declaration,
	326	* overridden by the tracer implementation.
	327	*
	328	* Typical use of these loglevels:
	329	*
	330	* 1) Declare the mapping between loglevel names and an integer values
8e90eb06 MD	331	* within TRACEPOINT_LOGLEVEL_ENUM(), using tp_loglevel() for each
	332	* tuple. Do _NOT_ add comma (,) nor semicolon (;) between the
	333	* tp_loglevel entries contained within TRACEPOINT_LOGLEVEL_ENUM().
	334	* Do _NOT_ add comma (,) nor semicolon (;) after the
	335	* TRACEPOINT_LOGLEVEL_ENUM() declaration. The name should be a
	336	* proper C99 identifier.
b728d87e MD	337	*
b728d87e MD	338	* TRACEPOINT_LOGLEVEL_ENUM(
8e90eb06 MD	339	* tp_loglevel( < loglevel_name >, < value > )
8e90eb06 MD	340	* tp_loglevel( < loglevel_name >, < value > )
b728d87e MD	341	* ...
	342	* )
	343	*
	344	* e.g.:
	345	*
	346	* TRACEPOINT_LOGLEVEL_ENUM(
8e90eb06 MD	347	* tp_loglevel(LOG_EMERG, 0)
	348	* tp_loglevel(LOG_ALERT, 1)
	349	* tp_loglevel(LOG_CRIT, 2)
	350	* tp_loglevel(LOG_ERR, 3)
	351	* tp_loglevel(LOG_WARNING, 4)
	352	* tp_loglevel(LOG_NOTICE, 5)
	353	* tp_loglevel(LOG_INFO, 6)
	354	* tp_loglevel(LOG_DEBUG, 7)
b728d87e MD	355	* )
	356	*
	357	* 2) Then, declare tracepoint loglevels for tracepoints. A
	358	* TRACEPOINT_EVENT should be declared prior to the the
	359	* TRACEPOINT_LOGLEVEL for a given tracepoint name. The first field
	360	* is the name of the tracepoint, the second field is the loglevel
	361	* name.
	362	*
	363	* TRACEPOINT_LOGLEVEL(< [com_company_]project[_component] >, < event >,
	364	* < loglevel_name >)
	365	*
	366	* The TRACEPOINT_PROVIDER must be defined when declaring a
	367	* TRACEPOINT_LOGLEVEL_ENUM and TRACEPOINT_LOGLEVEL. The tracepoint
	368	* loglevel enumeration apply to the entire TRACEPOINT_PROVIDER. Only one
	369	* tracepoint loglevel enumeration should be declared per tracepoint
	370	* provider.
	371	*/
	372
05ceaafd MD	373	#define TRACEPOINT_LOGLEVEL_ENUM(...)
05ceaafd MD	374	#define TRACEPOINT_LOGLEVEL(provider, name, loglevel)
b728d87e MD	375
b728d87e MD	376	#endif /* #ifndef TRACEPOINT_LOGLEVEL */