[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 <lttng/tracepoint-types.h>
#include <lttng/tracepoint-rcu.h>
#include <urcu/compiler.h>
#include <dlfcn.h>	/* for dlopen */
#include <assert.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_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__

#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;									\
	tp_rcu_read_lock_bp();								\
	__tp_probe = tp_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:											\
	tp_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-tracepoint.so.0", 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"));
#ifndef _LGPL_SOURCE
	tp_rcu_read_lock_bp =
		URCU_FORCE_CAST(void (*)(void),
				dlsym(liblttngust_handle,
					"tp_rcu_read_lock_bp"));
	tp_rcu_read_unlock_bp =
		URCU_FORCE_CAST(void (*)(void),
				dlsym(liblttngust_handle,
					"tp_rcu_read_unlock_bp"));
	tp_rcu_dereference_sym_bp =
		URCU_FORCE_CAST(void *(*)(void *p),
				dlsym(liblttngust_handle,
					"tp_rcu_dereference_sym_bp"));
#endif
	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 Loglevels
 *
 * Typical use of these loglevels:
 *
 * The loglevels go from 0 to 15. Higher numbers imply the most
 * verbosity (higher event throughput expected.
 *
 * Loglevels 0 through 6, and loglevel 15, match syslog(3) loglevels
 * semantic. Loglevels 7 through 14 offer more fine-grained selection of
 * traced information.
 *
 * TRACE_EMERG    0
 * system is unusable
 *
 * TRACE_ALERT    1
 * action must be taken immediately
 *
 * TRACE_CRIT     2
 * critical conditions
 *
 * TRACE_ERR      3
 * error conditions
 *
 * TRACE_WARNING  4
 * warning conditions
 *
 * TRACE_NOTICE   5
 * normal, but significant, condition
 *
 * TRACE_INFO     6
 * informational message
 *
 * TRACE_DEBUG_SYSTEM   7
 * information has system-level scope
 *
 * TRACE_PROCESS  8
 * information has process-level scope
 *
 * TRACE_MODULE   9
 * information has module (executable/library) scope
 *
 * TRACE_UNIT     10
 * information has compilation unit scope
 *
 * TRACE_CLASS    11
 * information has class-level scope
 *
 * TRACE_OBJECT   12
 * information has object-level scope
 *
 * TRACE_FUNCTION 13
 * information has function-level scope
 *
 * TRACE_PRINTF   14
 * tracepoint_printf message
 *
 * TRACE_DEBUG    15
 * debug-level message
 *
 * 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 already declared before declaring a
 * TRACEPOINT_LOGLEVEL.
 */

#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
8fce9e2b	17	#include <lttng/tracepoint-types.h>
40b2b5a4	18	#include <lttng/tracepoint-rcu.h>
b728d87e	19	#include <urcu/compiler.h>
deb6e540	20	#include <dlfcn.h> /* for dlopen */
40b2b5a4	21	#include <assert.h>
b728d87e MD	22
	23	#ifdef __cplusplus
	24	extern "C" {
	25	#endif
	26
23c8854a MD	27	#define tracepoint(provider, name, ...) \
	28	do { \
	29	if (caa_unlikely(__tracepoint_##provider##___##name.state)) \
	30	__tracepoint_cb_##provider##___##name(__VA_ARGS__); \
b728d87e MD	31	} while (0)
	32
	33	#define TP_ARGS(...) __VA_ARGS__
	34
	35	/*
	36	* TP_ARGS takes tuples of type, argument separated by a comma.
	37	* It can take up to 10 tuples (which means that less than 10 tuples is
	38	* fine too).
	39	* Each tuple is also separated by a comma.
	40	*/
df854e41 MD	41	#define __TP_COMBINE_TOKENS(_tokena, _tokenb) \
	42	_tokena##_tokenb
	43	#define _TP_COMBINE_TOKENS(_tokena, _tokenb) \
	44	__TP_COMBINE_TOKENS(_tokena, _tokenb)
	45	#define __TP_COMBINE_TOKENS3(_tokena, _tokenb, _tokenc) \
	46	_tokena##_tokenb##_tokenc
	47	#define _TP_COMBINE_TOKENS3(_tokena, _tokenb, _tokenc) \
	48	__TP_COMBINE_TOKENS3(_tokena, _tokenb, _tokenc)
	49	#define __TP_COMBINE_TOKENS4(_tokena, _tokenb, _tokenc, _tokend) \
	50	_tokena##_tokenb##_tokenc##_tokend
	51	#define _TP_COMBINE_TOKENS4(_tokena, _tokenb, _tokenc, _tokend) \
	52	__TP_COMBINE_TOKENS4(_tokena, _tokenb, _tokenc, _tokend)
b728d87e	53
23c8854a	54	/* _TP_EXVAR* extract the var names. */
b728d87e MD	55	#define _TP_EXVAR0()
	56	#define _TP_EXVAR2(a,b) b
	57	#define _TP_EXVAR4(a,b,c,d) b,d
	58	#define _TP_EXVAR6(a,b,c,d,e,f) b,d,f
	59	#define _TP_EXVAR8(a,b,c,d,e,f,g,h) b,d,f,h
	60	#define _TP_EXVAR10(a,b,c,d,e,f,g,h,i,j) b,d,f,h,j
	61	#define _TP_EXVAR12(a,b,c,d,e,f,g,h,i,j,k,l) b,d,f,h,j,l
	62	#define _TP_EXVAR14(a,b,c,d,e,f,g,h,i,j,k,l,m,n) b,d,f,h,j,l,n
	63	#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
	64	#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
	65	#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
	66
	67	#define _TP_EXDATA_VAR0() __tp_data
	68	#define _TP_EXDATA_VAR2(a,b) __tp_data,b
	69	#define _TP_EXDATA_VAR4(a,b,c,d) __tp_data,b,d
	70	#define _TP_EXDATA_VAR6(a,b,c,d,e,f) __tp_data,b,d,f
	71	#define _TP_EXDATA_VAR8(a,b,c,d,e,f,g,h) __tp_data,b,d,f,h
	72	#define _TP_EXDATA_VAR10(a,b,c,d,e,f,g,h,i,j) __tp_data,b,d,f,h,j
	73	#define _TP_EXDATA_VAR12(a,b,c,d,e,f,g,h,i,j,k,l) __tp_data,b,d,f,h,j,l
	74	#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
	75	#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
	76	#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
	77	#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
	78
	79	/* _TP_EXPROTO* extract tuples of type, var */
	80	#define _TP_EXPROTO0()
	81	#define _TP_EXPROTO2(a,b) a b
	82	#define _TP_EXPROTO4(a,b,c,d) a b,c d
	83	#define _TP_EXPROTO6(a,b,c,d,e,f) a b,c d,e f
	84	#define _TP_EXPROTO8(a,b,c,d,e,f,g,h) a b,c d,e f,g h
	85	#define _TP_EXPROTO10(a,b,c,d,e,f,g,h,i,j) a b,c d,e f,g h,i j
	86	#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
	87	#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
	88	#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
	89	#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
	90	#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
	91
	92	#define _TP_EXDATA_PROTO0() void *__tp_data
	93	#define _TP_EXDATA_PROTO2(a,b) void *__tp_data,a b
	94	#define _TP_EXDATA_PROTO4(a,b,c,d) void *__tp_data,a b,c d
	95	#define _TP_EXDATA_PROTO6(a,b,c,d,e,f) void *__tp_data,a b,c d,e f
	96	#define _TP_EXDATA_PROTO8(a,b,c,d,e,f,g,h) void *__tp_data,a b,c d,e f,g h
	97	#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
	98	#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
	99	#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
	100	#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
	101	#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
	102	#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
	103
	104	/* Preprocessor trick to count arguments. Inspired from sdt.h. */
	105	#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)
	106	#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	107	#define _TP_PROTO_N(N, ...) _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXPROTO, N)(__VA_ARGS__))
	108	#define _TP_VAR_N(N, ...) _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXVAR, N)(__VA_ARGS__))
	109	#define _TP_DATA_PROTO_N(N, ...) _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXDATA_PROTO, N)(__VA_ARGS__))
	110	#define _TP_DATA_VAR_N(N, ...) _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXDATA_VAR, N)(__VA_ARGS__))
b728d87e	111	#define _TP_ARGS_PROTO(...) _TP_PROTO_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
23c8854a	112	#define _TP_ARGS_VAR(...) _TP_VAR_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
b728d87e	113	#define _TP_ARGS_DATA_PROTO(...) _TP_DATA_PROTO_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
23c8854a	114	#define _TP_ARGS_DATA_VAR(...) _TP_DATA_VAR_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
b728d87e MD	115	#define _TP_PARAMS(...) __VA_ARGS__
	116
	117	#define _DECLARE_TRACEPOINT(provider, name, ...) \
23c8854a MD	118	extern struct tracepoint __tracepoint_##provider##___##name; \
23c8854a MD	119	static inline void __tracepoint_cb_##provider##___##name(_TP_ARGS_PROTO(__VA_ARGS__)) \
b728d87e MD	120	{ \
	121	struct tracepoint_probe *__tp_probe; \
	122	\
40b2b5a4	123	if (!TP_RCU_LINK_TEST()) \
deb6e540	124	return; \
40b2b5a4 MD	125	tp_rcu_read_lock_bp(); \
40b2b5a4 MD	126	__tp_probe = tp_rcu_dereference_bp(__tracepoint_##provider##___##name.probes); \
23c8854a	127	if (caa_unlikely(!__tp_probe)) \
b728d87e MD	128	goto end; \
b728d87e MD	129	do { \
23c8854a MD	130	void *__tp_cb = __tp_probe->func; \
23c8854a MD	131	void *__tp_data = __tp_probe->data; \
b728d87e	132	\
23c8854a MD	133	URCU_FORCE_CAST(void (*)(_TP_ARGS_DATA_PROTO(__VA_ARGS__)), __tp_cb) \
	134	(_TP_ARGS_DATA_VAR(__VA_ARGS__)); \
	135	} while ((++__tp_probe)->func); \
b728d87e	136	end: \
40b2b5a4	137	tp_rcu_read_unlock_bp(); \
b728d87e	138	} \
23c8854a MD	139	static inline void __tracepoint_register_##provider##___##name(char *name, \
23c8854a MD	140	void func, void data) \
b728d87e	141	{ \
23c8854a	142	__tracepoint_probe_register(name, func, data); \
b728d87e	143	} \
23c8854a MD	144	static inline void __tracepoint_unregister_##provider##___##name(char *name, \
23c8854a MD	145	void func, void data) \
b728d87e	146	{ \
23c8854a	147	__tracepoint_probe_unregister(name, func, data); \
b728d87e MD	148	}
b728d87e MD	149
deb6e540 MD	150	extern int __tracepoint_probe_register(const char name, void func, void *data);
	151	extern int __tracepoint_probe_unregister(const char name, void func, void *data);
	152
	153	#ifdef TRACEPOINT_DEFINE
	154
b728d87e MD	155	/*
	156	* Note: to allow PIC code, we need to allow the linker to update the pointers
	157	* in the __tracepoints_ptrs section.
	158	* Therefore, this section is _not_ const (read-only).
	159	*/
	160	#define _DEFINE_TRACEPOINT(provider, name) \
	161	static const char __tp_strtab_##provider##___##name[] \
	162	__attribute__((section("__tracepoints_strings"))) = \
	163	#provider ":" #name; \
	164	struct tracepoint __tracepoint_##provider##___##name \
	165	__attribute__((section("__tracepoints"))) = \
	166	{ __tp_strtab_##provider##___##name, 0, NULL }; \
	167	static struct tracepoint * __tracepoint_ptr_##provider##___##name \
	168	__attribute__((used, section("__tracepoints_ptrs"))) = \
	169	&__tracepoint_##provider##___##name;
	170
deb6e540	171	static int (tracepoint_register_lib)(struct tracepoint const *tracepoints_start,
b728d87e	172	int tracepoints_count);
deb6e540 MD	173	static int (tracepoint_unregister_lib)(struct tracepoint const *tracepoints_start);
deb6e540 MD	174	static void *liblttngust_handle;
b728d87e MD	175
	176	/*
	177	* These weak symbols, the constructor, and destructor take care of
	178	* registering only _one_ instance of the tracepoints per shared-ojbect
	179	* (or for the whole main program).
	180	*/
	181	extern struct tracepoint * const __start___tracepoints_ptrs[]
	182	__attribute__((weak, visibility("hidden")));
	183	extern struct tracepoint * const __stop___tracepoints_ptrs[]
	184	__attribute__((weak, visibility("hidden")));
	185	int __tracepoint_registered
	186	__attribute__((weak, visibility("hidden")));
	187
	188	static void __attribute__((constructor)) __tracepoints__init(void)
	189	{
	190	if (__tracepoint_registered++)
	191	return;
deb6e540	192
8792fbae	193	liblttngust_handle = dlopen("liblttng-ust-tracepoint.so.0", RTLD_NOW \| RTLD_GLOBAL);
deb6e540 MD	194	if (!liblttngust_handle)
deb6e540 MD	195	return;
93ffe366 MD	196	tracepoint_register_lib =
	197	URCU_FORCE_CAST(int ()(struct tracepoint const *, int),
	198	dlsym(liblttngust_handle,
	199	"tracepoint_register_lib"));
	200	tracepoint_unregister_lib =
	201	URCU_FORCE_CAST(int ()(struct tracepoint const *),
	202	dlsym(liblttngust_handle,
	203	"tracepoint_unregister_lib"));
40b2b5a4 MD	204	#ifndef _LGPL_SOURCE
	205	tp_rcu_read_lock_bp =
	206	URCU_FORCE_CAST(void (*)(void),
	207	dlsym(liblttngust_handle,
	208	"tp_rcu_read_lock_bp"));
	209	tp_rcu_read_unlock_bp =
	210	URCU_FORCE_CAST(void (*)(void),
	211	dlsym(liblttngust_handle,
	212	"tp_rcu_read_unlock_bp"));
	213	tp_rcu_dereference_sym_bp =
	214	URCU_FORCE_CAST(void ()(void *p),
	215	dlsym(liblttngust_handle,
	216	"tp_rcu_dereference_sym_bp"));
	217	#endif
b728d87e MD	218	tracepoint_register_lib(__start___tracepoints_ptrs,
	219	__stop___tracepoints_ptrs -
	220	__start___tracepoints_ptrs);
	221	}
	222
	223	static void __attribute__((destructor)) __tracepoints__destroy(void)
	224	{
deb6e540	225	int ret;
b728d87e MD	226	if (--__tracepoint_registered)
b728d87e MD	227	return;
deb6e540 MD	228	if (tracepoint_unregister_lib)
	229	tracepoint_unregister_lib(__start___tracepoints_ptrs);
	230	if (liblttngust_handle) {
	231	tracepoint_unregister_lib = NULL;
	232	tracepoint_register_lib = NULL;
	233	ret = dlclose(liblttngust_handle);
	234	assert(!ret);
	235	}
b728d87e MD	236	}
b728d87e MD	237
deb6e540 MD	238	#else /* TRACEPOINT_DEFINE */
	239
	240	#define _DEFINE_TRACEPOINT(provider, name)
	241
	242	#endif /* #else TRACEPOINT_DEFINE */
	243
b728d87e MD	244	#ifdef __cplusplus
	245	}
	246	#endif
	247
	248	#endif /* _LTTNG_TRACEPOINT_H */
	249
	250	/* The following declarations must be outside re-inclusion protection. */
	251
	252	#ifndef TRACEPOINT_EVENT
	253
	254	/*
	255	* How to use the TRACEPOINT_EVENT macro:
	256	*
	257	* An example:
	258	*
	259	* TRACEPOINT_EVENT(someproject_component, event_name,
	260	*
	261	* * TP_ARGS takes from 0 to 10 "type, field_name" pairs *
	262	*
	263	* TP_ARGS(int, arg0, void , arg1, char , string, size_t, strlen,
	264	* long *, arg4, size_t, arg4_len),
	265	*
	266	* * TP_FIELDS describes the event payload layout in the trace *
	267	*
	268	* TP_FIELDS(
	269	* * Integer, printed in base 10 *
	270	* ctf_integer(int, field_a, arg0)
	271	*
	272	* * Integer, printed with 0x base 16 *
	273	* ctf_integer_hex(unsigned long, field_d, arg1)
	274	*
	275	* * Array Sequence, printed as UTF8-encoded array of bytes *
	276	* ctf_array_text(char, field_b, string, FIXED_LEN)
	277	* ctf_sequence_text(char, field_c, string, size_t, strlen)
	278	*
	279	* * String, printed as UTF8-encoded string *
	280	* ctf_string(field_e, string)
	281	*
	282	* * Array sequence of signed integer values *
	283	* ctf_array(long, field_f, arg4, FIXED_LEN4)
	284	* ctf_sequence(long, field_g, arg4, size_t, arg4_len)
	285	* )
	286	* )
	287	*
	288	* More detailed explanation:
	289	*
	290	* The name of the tracepoint is expressed as a tuple with the provider
	291	* and name arguments.
	292	*
	293	* The provider and name should be a proper C99 identifier.
	294	* The "provider" and "name" MUST follow these rules to ensure no
	295	* namespace clash occurs:
	296	*
	297	* For projects (applications and libraries) for which an entity
	298	* specific to the project controls the source code and thus its
	299	* tracepoints (typically with a scope larger than a single company):
	300	*
	301	* either:
	302	* project_component, event
	303	* or:
	304	* project, event
	305	*
	306	* Where "project" is the name of the project,
	307	* "component" is the name of the project component (which may
308	* include several levels of sub-components, e.g.
309	* ...component_subcomponent_...) where the tracepoint is located
310	* (optional),
311	* "event" is the name of the tracepoint event.
312	*
313	* For projects issued from a single company wishing to advertise that
314	* the company controls the source code and thus the tracepoints, the
315	* "com_" prefix should be used:
316	*
317	* either:
318	* com_company_project_component, event
319	* or:
320	* com_company_project, event
321	*
322	* Where "company" is the name of the company,
323	* "project" is the name of the project,
324	* "component" is the name of the project component (which may
325	* include several levels of sub-components, e.g.
326	* ...component_subcomponent_...) where the tracepoint is located
327	* (optional),
328	* "event" is the name of the tracepoint event.
329	*
330	* the provider:event identifier is limited to 127 characters.
331	*/
332
b728d87e	333	#define TRACEPOINT_EVENT(provider, name, args, fields) \
deb6e540 MD	334	_DECLARE_TRACEPOINT(provider, name, _TP_PARAMS(args)) \
deb6e540 MD	335	_DEFINE_TRACEPOINT(provider, name)
b728d87e MD	336
	337	#define TRACEPOINT_EVENT_CLASS(provider, name, args, fields)
	338
	339	#define TRACEPOINT_EVENT_INSTANCE(provider, _template, name, args) \
deb6e540 MD	340	_DECLARE_TRACEPOINT(provider, name, _TP_PARAMS(args)) \
deb6e540 MD	341	_DEFINE_TRACEPOINT(provider, name)
b728d87e MD	342
	343	#endif /* #ifndef TRACEPOINT_EVENT */
	344
	345	#ifndef TRACEPOINT_LOGLEVEL
	346
	347	/*
75c5ad79	348	* Tracepoint Loglevels
b728d87e MD	349	*
	350	* Typical use of these loglevels:
	351	*
75c5ad79 MD	352	* The loglevels go from 0 to 15. Higher numbers imply the most
	353	* verbosity (higher event throughput expected.
	354	*
	355	* Loglevels 0 through 6, and loglevel 15, match syslog(3) loglevels
	356	* semantic. Loglevels 7 through 14 offer more fine-grained selection of
	357	* traced information.
	358	*
	359	* TRACE_EMERG 0
	360	* system is unusable
	361	*
	362	* TRACE_ALERT 1
	363	* action must be taken immediately
	364	*
	365	* TRACE_CRIT 2
	366	* critical conditions
	367	*
	368	* TRACE_ERR 3
	369	* error conditions
	370	*
	371	* TRACE_WARNING 4
	372	* warning conditions
	373	*
	374	* TRACE_NOTICE 5
	375	* normal, but significant, condition
	376	*
	377	* TRACE_INFO 6
	378	* informational message
	379	*
	380	* TRACE_DEBUG_SYSTEM 7
	381	* information has system-level scope
	382	*
	383	* TRACE_PROCESS 8
	384	* information has process-level scope
	385	*
	386	* TRACE_MODULE 9
	387	* information has module (executable/library) scope
	388	*
	389	* TRACE_UNIT 10
	390	* information has compilation unit scope
	391	*
	392	* TRACE_CLASS 11
	393	* information has class-level scope
	394	*
	395	* TRACE_OBJECT 12
	396	* information has object-level scope
	397	*
	398	* TRACE_FUNCTION 13
	399	* information has function-level scope
	400	*
	401	* TRACE_PRINTF 14
	402	* tracepoint_printf message
	403	*
	404	* TRACE_DEBUG 15
	405	* debug-level message
	406	*
	407	* Declare tracepoint loglevels for tracepoints. A TRACEPOINT_EVENT
	408	* should be declared prior to the the TRACEPOINT_LOGLEVEL for a given
	409	* tracepoint name. The first field is the name of the tracepoint, the
	410	* second field is the loglevel name.
b728d87e MD	411	*
	412	* TRACEPOINT_LOGLEVEL(< [com_company_]project[_component] >, < event >,
	413	* < loglevel_name >)
	414	*
75c5ad79 MD	415	* The TRACEPOINT_PROVIDER must be already declared before declaring a
75c5ad79 MD	416	* TRACEPOINT_LOGLEVEL.
b728d87e MD	417	*/
b728d87e MD	418
05ceaafd MD	419	#define TRACEPOINT_LOGLEVEL_ENUM(...)
05ceaafd MD	420	#define TRACEPOINT_LOGLEVEL(provider, name, loglevel)
b728d87e MD	421
b728d87e MD	422	#endif /* #ifndef TRACEPOINT_LOGLEVEL */