[deliverable/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 <lttng/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_TOKENS(_tokena, _tokenb)				\
		_tokena##_tokenb
#define _TP_COMBINE_TOKENS(_tokena, _tokenb)				\
		__TP_COMBINE_TOKENS(_tokena, _tokenb)
#define __TP_COMBINE_TOKENS3(_tokena, _tokenb, _tokenc)			\
		_tokena##_tokenb##_tokenc
#define _TP_COMBINE_TOKENS3(_tokena, _tokenb, _tokenc)			\
		__TP_COMBINE_TOKENS3(_tokena, _tokenb, _tokenc)
#define __TP_COMBINE_TOKENS4(_tokena, _tokenb, _tokenc, _tokend)	\
		_tokena##_tokenb##_tokenc##_tokend
#define _TP_COMBINE_TOKENS4(_tokena, _tokenb, _tokenc, _tokend)		\
		__TP_COMBINE_TOKENS4(_tokena, _tokenb, _tokenc, _tokend)

/* _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__

#ifdef _LGPL_SOURCE
#define _TP_RCU_LINK_TEST()	1
#else
#define _TP_RCU_LINK_TEST()	rcu_read_lock_bp
#endif

#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 (!_TP_RCU_LINK_TEST())							\
		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>
8fce9e2b	18	#include <lttng/tracepoint-types.h>
b728d87e	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	*/
df854e41 MD	40	#define __TP_COMBINE_TOKENS(_tokena, _tokenb) \
	41	_tokena##_tokenb
	42	#define _TP_COMBINE_TOKENS(_tokena, _tokenb) \
	43	__TP_COMBINE_TOKENS(_tokena, _tokenb)
	44	#define __TP_COMBINE_TOKENS3(_tokena, _tokenb, _tokenc) \
	45	_tokena##_tokenb##_tokenc
	46	#define _TP_COMBINE_TOKENS3(_tokena, _tokenb, _tokenc) \
	47	__TP_COMBINE_TOKENS3(_tokena, _tokenb, _tokenc)
	48	#define __TP_COMBINE_TOKENS4(_tokena, _tokenb, _tokenc, _tokend) \
	49	_tokena##_tokenb##_tokenc##_tokend
	50	#define _TP_COMBINE_TOKENS4(_tokena, _tokenb, _tokenc, _tokend) \
	51	__TP_COMBINE_TOKENS4(_tokena, _tokenb, _tokenc, _tokend)
b728d87e	52
23c8854a	53	/* _TP_EXVAR* extract the var names. */
b728d87e MD	54	#define _TP_EXVAR0()
	55	#define _TP_EXVAR2(a,b) b
	56	#define _TP_EXVAR4(a,b,c,d) b,d
	57	#define _TP_EXVAR6(a,b,c,d,e,f) b,d,f
	58	#define _TP_EXVAR8(a,b,c,d,e,f,g,h) b,d,f,h
	59	#define _TP_EXVAR10(a,b,c,d,e,f,g,h,i,j) b,d,f,h,j
	60	#define _TP_EXVAR12(a,b,c,d,e,f,g,h,i,j,k,l) b,d,f,h,j,l
	61	#define _TP_EXVAR14(a,b,c,d,e,f,g,h,i,j,k,l,m,n) b,d,f,h,j,l,n
	62	#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
	63	#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
	64	#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
	65
	66	#define _TP_EXDATA_VAR0() __tp_data
	67	#define _TP_EXDATA_VAR2(a,b) __tp_data,b
	68	#define _TP_EXDATA_VAR4(a,b,c,d) __tp_data,b,d
	69	#define _TP_EXDATA_VAR6(a,b,c,d,e,f) __tp_data,b,d,f
	70	#define _TP_EXDATA_VAR8(a,b,c,d,e,f,g,h) __tp_data,b,d,f,h
	71	#define _TP_EXDATA_VAR10(a,b,c,d,e,f,g,h,i,j) __tp_data,b,d,f,h,j
	72	#define _TP_EXDATA_VAR12(a,b,c,d,e,f,g,h,i,j,k,l) __tp_data,b,d,f,h,j,l
	73	#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
	74	#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
	75	#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
	76	#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
	77
	78	/* _TP_EXPROTO* extract tuples of type, var */
	79	#define _TP_EXPROTO0()
	80	#define _TP_EXPROTO2(a,b) a b
	81	#define _TP_EXPROTO4(a,b,c,d) a b,c d
	82	#define _TP_EXPROTO6(a,b,c,d,e,f) a b,c d,e f
	83	#define _TP_EXPROTO8(a,b,c,d,e,f,g,h) a b,c d,e f,g h
	84	#define _TP_EXPROTO10(a,b,c,d,e,f,g,h,i,j) a b,c d,e f,g h,i j
	85	#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
	86	#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
	87	#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
	88	#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
	89	#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
	90
	91	#define _TP_EXDATA_PROTO0() void *__tp_data
	92	#define _TP_EXDATA_PROTO2(a,b) void *__tp_data,a b
	93	#define _TP_EXDATA_PROTO4(a,b,c,d) void *__tp_data,a b,c d
	94	#define _TP_EXDATA_PROTO6(a,b,c,d,e,f) void *__tp_data,a b,c d,e f
	95	#define _TP_EXDATA_PROTO8(a,b,c,d,e,f,g,h) void *__tp_data,a b,c d,e f,g h
	96	#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
	97	#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
	98	#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
	99	#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
	100	#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
	101	#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
	102
	103	/* Preprocessor trick to count arguments. Inspired from sdt.h. */
	104	#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)
	105	#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	106	#define _TP_PROTO_N(N, ...) _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXPROTO, N)(__VA_ARGS__))
	107	#define _TP_VAR_N(N, ...) _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXVAR, N)(__VA_ARGS__))
	108	#define _TP_DATA_PROTO_N(N, ...) _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXDATA_PROTO, N)(__VA_ARGS__))
	109	#define _TP_DATA_VAR_N(N, ...) _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXDATA_VAR, N)(__VA_ARGS__))
b728d87e	110	#define _TP_ARGS_PROTO(...) _TP_PROTO_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
23c8854a	111	#define _TP_ARGS_VAR(...) _TP_VAR_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
b728d87e	112	#define _TP_ARGS_DATA_PROTO(...) _TP_DATA_PROTO_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
23c8854a	113	#define _TP_ARGS_DATA_VAR(...) _TP_DATA_VAR_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
b728d87e MD	114	#define _TP_PARAMS(...) __VA_ARGS__
b728d87e MD	115
5cd29ace MD	116	#ifdef _LGPL_SOURCE
	117	#define _TP_RCU_LINK_TEST() 1
	118	#else
	119	#define _TP_RCU_LINK_TEST() rcu_read_lock_bp
	120	#endif
	121
b728d87e	122	#define _DECLARE_TRACEPOINT(provider, name, ...) \
23c8854a MD	123	extern struct tracepoint __tracepoint_##provider##___##name; \
23c8854a MD	124	static inline void __tracepoint_cb_##provider##___##name(_TP_ARGS_PROTO(__VA_ARGS__)) \
b728d87e MD	125	{ \
	126	struct tracepoint_probe *__tp_probe; \
	127	\
5cd29ace	128	if (!_TP_RCU_LINK_TEST()) \
deb6e540	129	return; \
b728d87e	130	rcu_read_lock_bp(); \
deb6e540	131	__tp_probe = rcu_dereference_bp(__tracepoint_##provider##___##name.probes); \
23c8854a	132	if (caa_unlikely(!__tp_probe)) \
b728d87e MD	133	goto end; \
b728d87e MD	134	do { \
23c8854a MD	135	void *__tp_cb = __tp_probe->func; \
23c8854a MD	136	void *__tp_data = __tp_probe->data; \
b728d87e	137	\
23c8854a MD	138	URCU_FORCE_CAST(void (*)(_TP_ARGS_DATA_PROTO(__VA_ARGS__)), __tp_cb) \
	139	(_TP_ARGS_DATA_VAR(__VA_ARGS__)); \
	140	} while ((++__tp_probe)->func); \
b728d87e MD	141	end: \
	142	rcu_read_unlock_bp(); \
	143	} \
23c8854a MD	144	static inline void __tracepoint_register_##provider##___##name(char *name, \
23c8854a MD	145	void func, void data) \
b728d87e	146	{ \
23c8854a	147	__tracepoint_probe_register(name, func, data); \
b728d87e	148	} \
23c8854a MD	149	static inline void __tracepoint_unregister_##provider##___##name(char *name, \
23c8854a MD	150	void func, void data) \
b728d87e	151	{ \
23c8854a	152	__tracepoint_probe_unregister(name, func, data); \
b728d87e MD	153	}
b728d87e MD	154
deb6e540 MD	155	extern int __tracepoint_probe_register(const char name, void func, void *data);
	156	extern int __tracepoint_probe_unregister(const char name, void func, void *data);
	157
	158	#ifdef TRACEPOINT_DEFINE
	159
b728d87e MD	160	/*
	161	* Note: to allow PIC code, we need to allow the linker to update the pointers
	162	* in the __tracepoints_ptrs section.
	163	* Therefore, this section is _not_ const (read-only).
	164	*/
	165	#define _DEFINE_TRACEPOINT(provider, name) \
	166	static const char __tp_strtab_##provider##___##name[] \
	167	__attribute__((section("__tracepoints_strings"))) = \
	168	#provider ":" #name; \
	169	struct tracepoint __tracepoint_##provider##___##name \
	170	__attribute__((section("__tracepoints"))) = \
	171	{ __tp_strtab_##provider##___##name, 0, NULL }; \
	172	static struct tracepoint * __tracepoint_ptr_##provider##___##name \
	173	__attribute__((used, section("__tracepoints_ptrs"))) = \
	174	&__tracepoint_##provider##___##name;
	175
deb6e540	176	static int (tracepoint_register_lib)(struct tracepoint const *tracepoints_start,
b728d87e	177	int tracepoints_count);
deb6e540 MD	178	static int (tracepoint_unregister_lib)(struct tracepoint const *tracepoints_start);
deb6e540 MD	179	static void *liblttngust_handle;
b728d87e MD	180
	181	/*
	182	* These weak symbols, the constructor, and destructor take care of
	183	* registering only _one_ instance of the tracepoints per shared-ojbect
	184	* (or for the whole main program).
	185	*/
	186	extern struct tracepoint * const __start___tracepoints_ptrs[]
	187	__attribute__((weak, visibility("hidden")));
	188	extern struct tracepoint * const __stop___tracepoints_ptrs[]
	189	__attribute__((weak, visibility("hidden")));
	190	int __tracepoint_registered
	191	__attribute__((weak, visibility("hidden")));
	192
	193	static void __attribute__((constructor)) __tracepoints__init(void)
	194	{
	195	if (__tracepoint_registered++)
	196	return;
deb6e540 MD	197
	198	liblttngust_handle = dlopen("liblttng-ust.so", RTLD_NOW \| RTLD_GLOBAL);
	199	if (!liblttngust_handle)
	200	return;
93ffe366 MD	201	tracepoint_register_lib =
	202	URCU_FORCE_CAST(int ()(struct tracepoint const *, int),
	203	dlsym(liblttngust_handle,
	204	"tracepoint_register_lib"));
	205	tracepoint_unregister_lib =
	206	URCU_FORCE_CAST(int ()(struct tracepoint const *),
	207	dlsym(liblttngust_handle,
	208	"tracepoint_unregister_lib"));
b728d87e MD	209	tracepoint_register_lib(__start___tracepoints_ptrs,
	210	__stop___tracepoints_ptrs -
	211	__start___tracepoints_ptrs);
	212	}
	213
	214	static void __attribute__((destructor)) __tracepoints__destroy(void)
	215	{
deb6e540	216	int ret;
b728d87e MD	217	if (--__tracepoint_registered)
b728d87e MD	218	return;
deb6e540 MD	219	if (tracepoint_unregister_lib)
	220	tracepoint_unregister_lib(__start___tracepoints_ptrs);
	221	if (liblttngust_handle) {
	222	tracepoint_unregister_lib = NULL;
	223	tracepoint_register_lib = NULL;
	224	ret = dlclose(liblttngust_handle);
	225	assert(!ret);
	226	}
b728d87e MD	227	}
b728d87e MD	228
deb6e540 MD	229	#else /* TRACEPOINT_DEFINE */
	230
	231	#define _DEFINE_TRACEPOINT(provider, name)
	232
	233	#endif /* #else TRACEPOINT_DEFINE */
	234
b728d87e MD	235	#ifdef __cplusplus
	236	}
	237	#endif
	238
	239	#endif /* _LTTNG_TRACEPOINT_H */
	240
	241	/* The following declarations must be outside re-inclusion protection. */
	242
	243	#ifndef TRACEPOINT_EVENT
	244
	245	/*
	246	* How to use the TRACEPOINT_EVENT macro:
	247	*
	248	* An example:
	249	*
	250	* TRACEPOINT_EVENT(someproject_component, event_name,
	251	*
	252	* * TP_ARGS takes from 0 to 10 "type, field_name" pairs *
	253	*
	254	* TP_ARGS(int, arg0, void , arg1, char , string, size_t, strlen,
	255	* long *, arg4, size_t, arg4_len),
	256	*
	257	* * TP_FIELDS describes the event payload layout in the trace *
	258	*
	259	* TP_FIELDS(
	260	* * Integer, printed in base 10 *
	261	* ctf_integer(int, field_a, arg0)
	262	*
	263	* * Integer, printed with 0x base 16 *
	264	* ctf_integer_hex(unsigned long, field_d, arg1)
	265	*
	266	* * Array Sequence, printed as UTF8-encoded array of bytes *
	267	* ctf_array_text(char, field_b, string, FIXED_LEN)
	268	* ctf_sequence_text(char, field_c, string, size_t, strlen)
	269	*
	270	* * String, printed as UTF8-encoded string *
	271	* ctf_string(field_e, string)
	272	*
	273	* * Array sequence of signed integer values *
	274	* ctf_array(long, field_f, arg4, FIXED_LEN4)
	275	* ctf_sequence(long, field_g, arg4, size_t, arg4_len)
	276	* )
	277	* )
	278	*
	279	* More detailed explanation:
	280	*
	281	* The name of the tracepoint is expressed as a tuple with the provider
	282	* and name arguments.
	283	*
	284	* The provider and name should be a proper C99 identifier.
	285	* The "provider" and "name" MUST follow these rules to ensure no
	286	* namespace clash occurs:
	287	*
	288	* For projects (applications and libraries) for which an entity
	289	* specific to the project controls the source code and thus its
	290	* tracepoints (typically with a scope larger than a single company):
	291	*
	292	* either:
	293	* project_component, event
	294	* or:
	295	* project, event
	296	*
	297	* Where "project" is the name of the project,
	298	* "component" is the name of the project component (which may
299	* include several levels of sub-components, e.g.
300	* ...component_subcomponent_...) where the tracepoint is located
301	* (optional),
302	* "event" is the name of the tracepoint event.
303	*
304	* For projects issued from a single company wishing to advertise that
305	* the company controls the source code and thus the tracepoints, the
306	* "com_" prefix should be used:
307	*
308	* either:
309	* com_company_project_component, event
310	* or:
311	* com_company_project, event
312	*
313	* Where "company" is the name of the company,
314	* "project" is the name of the project,
315	* "component" is the name of the project component (which may
316	* include several levels of sub-components, e.g.
317	* ...component_subcomponent_...) where the tracepoint is located
318	* (optional),
319	* "event" is the name of the tracepoint event.
320	*
321	* the provider:event identifier is limited to 127 characters.
322	*/
323
b728d87e	324	#define TRACEPOINT_EVENT(provider, name, args, fields) \
deb6e540 MD	325	_DECLARE_TRACEPOINT(provider, name, _TP_PARAMS(args)) \
deb6e540 MD	326	_DEFINE_TRACEPOINT(provider, name)
b728d87e MD	327
	328	#define TRACEPOINT_EVENT_CLASS(provider, name, args, fields)
	329
	330	#define TRACEPOINT_EVENT_INSTANCE(provider, _template, name, args) \
deb6e540 MD	331	_DECLARE_TRACEPOINT(provider, name, _TP_PARAMS(args)) \
deb6e540 MD	332	_DEFINE_TRACEPOINT(provider, name)
b728d87e MD	333
	334	#endif /* #ifndef TRACEPOINT_EVENT */
	335
	336	#ifndef TRACEPOINT_LOGLEVEL
	337
	338	/*
	339	* Tracepoint Loglevel Declaration Facility
	340	*
	341	* This is a place-holder the tracepoint loglevel declaration,
	342	* overridden by the tracer implementation.
	343	*
	344	* Typical use of these loglevels:
	345	*
	346	* 1) Declare the mapping between loglevel names and an integer values
8e90eb06 MD	347	* within TRACEPOINT_LOGLEVEL_ENUM(), using tp_loglevel() for each
	348	* tuple. Do _NOT_ add comma (,) nor semicolon (;) between the
	349	* tp_loglevel entries contained within TRACEPOINT_LOGLEVEL_ENUM().
	350	* Do _NOT_ add comma (,) nor semicolon (;) after the
	351	* TRACEPOINT_LOGLEVEL_ENUM() declaration. The name should be a
	352	* proper C99 identifier.
b728d87e MD	353	*
b728d87e MD	354	* TRACEPOINT_LOGLEVEL_ENUM(
8e90eb06 MD	355	* tp_loglevel( < loglevel_name >, < value > )
8e90eb06 MD	356	* tp_loglevel( < loglevel_name >, < value > )
b728d87e MD	357	* ...
	358	* )
	359	*
	360	* e.g.:
	361	*
	362	* TRACEPOINT_LOGLEVEL_ENUM(
8e90eb06 MD	363	* tp_loglevel(LOG_EMERG, 0)
	364	* tp_loglevel(LOG_ALERT, 1)
	365	* tp_loglevel(LOG_CRIT, 2)
	366	* tp_loglevel(LOG_ERR, 3)
	367	* tp_loglevel(LOG_WARNING, 4)
	368	* tp_loglevel(LOG_NOTICE, 5)
	369	* tp_loglevel(LOG_INFO, 6)
	370	* tp_loglevel(LOG_DEBUG, 7)
b728d87e MD	371	* )
	372	*
	373	* 2) Then, declare tracepoint loglevels for tracepoints. A
	374	* TRACEPOINT_EVENT should be declared prior to the the
	375	* TRACEPOINT_LOGLEVEL for a given tracepoint name. The first field
	376	* is the name of the tracepoint, the second field is the loglevel
	377	* name.
	378	*
	379	* TRACEPOINT_LOGLEVEL(< [com_company_]project[_component] >, < event >,
	380	* < loglevel_name >)
	381	*
	382	* The TRACEPOINT_PROVIDER must be defined when declaring a
	383	* TRACEPOINT_LOGLEVEL_ENUM and TRACEPOINT_LOGLEVEL. The tracepoint
	384	* loglevel enumeration apply to the entire TRACEPOINT_PROVIDER. Only one
	385	* tracepoint loglevel enumeration should be declared per tracepoint
	386	* provider.
	387	*/
	388
05ceaafd MD	389	#define TRACEPOINT_LOGLEVEL_ENUM(...)
05ceaafd MD	390	#define TRACEPOINT_LOGLEVEL(provider, name, loglevel)
b728d87e MD	391
b728d87e MD	392	#endif /* #ifndef TRACEPOINT_LOGLEVEL */