Update hardcoded loglevel
[lttng-ust.git] / include / lttng / tracepoint.h
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 <lttng/tracepoint-types.h>
18 #include <lttng/tracepoint-rcu.h>
19 #include <urcu/compiler.h>
20 #include <dlfcn.h> /* for dlopen */
21 #include <assert.h>
22
23 #ifdef __cplusplus
24 extern "C" {
25 #endif
26
27 #define tracepoint(provider, name, ...) \
28 do { \
29 if (caa_unlikely(__tracepoint_##provider##___##name.state)) \
30 __tracepoint_cb_##provider##___##name(__VA_ARGS__); \
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 */
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)
53
54 /* _TP_EXVAR* extract the var names. */
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
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__))
111 #define _TP_ARGS_PROTO(...) _TP_PROTO_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
112 #define _TP_ARGS_VAR(...) _TP_VAR_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
113 #define _TP_ARGS_DATA_PROTO(...) _TP_DATA_PROTO_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
114 #define _TP_ARGS_DATA_VAR(...) _TP_DATA_VAR_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
115 #define _TP_PARAMS(...) __VA_ARGS__
116
117 #define _DECLARE_TRACEPOINT(provider, name, ...) \
118 extern struct tracepoint __tracepoint_##provider##___##name; \
119 static inline void __tracepoint_cb_##provider##___##name(_TP_ARGS_PROTO(__VA_ARGS__)) \
120 { \
121 struct tracepoint_probe *__tp_probe; \
122 \
123 if (!TP_RCU_LINK_TEST()) \
124 return; \
125 tp_rcu_read_lock_bp(); \
126 __tp_probe = tp_rcu_dereference_bp(__tracepoint_##provider##___##name.probes); \
127 if (caa_unlikely(!__tp_probe)) \
128 goto end; \
129 do { \
130 void *__tp_cb = __tp_probe->func; \
131 void *__tp_data = __tp_probe->data; \
132 \
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); \
136 end: \
137 tp_rcu_read_unlock_bp(); \
138 } \
139 static inline void __tracepoint_register_##provider##___##name(char *name, \
140 void *func, void *data) \
141 { \
142 __tracepoint_probe_register(name, func, data); \
143 } \
144 static inline void __tracepoint_unregister_##provider##___##name(char *name, \
145 void *func, void *data) \
146 { \
147 __tracepoint_probe_unregister(name, func, data); \
148 }
149
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
155 /*
156 * When TRACEPOINT_PROBE_DYNAMIC_LINKAGE is defined, we do not emit a
157 * unresolved symbol that requires the provider to be linked in. When
158 * TRACEPOINT_PROBE_DYNAMIC_LINKAGE is not defined, we emit an
159 * unresolved symbol that depends on having the provider linked in,
160 * otherwise the linker complains. This deals with use of static
161 * libraries, ensuring that the linker does not remove the provider
162 * object from the executable.
163 */
164 #ifdef TRACEPOINT_PROBE_DYNAMIC_LINKAGE
165 #define _TRACEPOINT_UNDEFINED_REF(provider)
166 #else /* TRACEPOINT_PROBE_DYNAMIC_LINKAGE */
167 #define _TRACEPOINT_UNDEFINED_REF(provider) \
168 &__tracepoint_provider_##provider,
169 #endif /* TRACEPOINT_PROBE_DYNAMIC_LINKAGE */
170
171 /*
172 * Note: to allow PIC code, we need to allow the linker to update the pointers
173 * in the __tracepoints_ptrs section.
174 * Therefore, this section is _not_ const (read-only).
175 */
176 #define _DEFINE_TRACEPOINT(provider, name) \
177 extern int __tracepoint_provider_##provider; \
178 static const char __tp_strtab_##provider##___##name[] \
179 __attribute__((section("__tracepoints_strings"))) = \
180 #provider ":" #name; \
181 struct tracepoint __tracepoint_##provider##___##name \
182 __attribute__((section("__tracepoints"))) = \
183 { __tp_strtab_##provider##___##name, 0, NULL, _TRACEPOINT_UNDEFINED_REF(provider) }; \
184 static struct tracepoint * __tracepoint_ptr_##provider##___##name \
185 __attribute__((used, section("__tracepoints_ptrs"))) = \
186 &__tracepoint_##provider##___##name;
187
188 static int (*tracepoint_register_lib)(struct tracepoint * const *tracepoints_start,
189 int tracepoints_count);
190 static int (*tracepoint_unregister_lib)(struct tracepoint * const *tracepoints_start);
191 static void *liblttngust_handle;
192
193 /*
194 * These weak symbols, the constructor, and destructor take care of
195 * registering only _one_ instance of the tracepoints per shared-ojbect
196 * (or for the whole main program).
197 */
198 extern struct tracepoint * const __start___tracepoints_ptrs[]
199 __attribute__((weak, visibility("hidden")));
200 extern struct tracepoint * const __stop___tracepoints_ptrs[]
201 __attribute__((weak, visibility("hidden")));
202 int __tracepoint_registered
203 __attribute__((weak, visibility("hidden")));
204
205 static void __attribute__((constructor)) __tracepoints__init(void)
206 {
207 if (__tracepoint_registered++)
208 return;
209
210 liblttngust_handle = dlopen("liblttng-ust-tracepoint.so.0", RTLD_NOW | RTLD_GLOBAL);
211 if (!liblttngust_handle)
212 return;
213 tracepoint_register_lib =
214 URCU_FORCE_CAST(int (*)(struct tracepoint * const *, int),
215 dlsym(liblttngust_handle,
216 "tracepoint_register_lib"));
217 tracepoint_unregister_lib =
218 URCU_FORCE_CAST(int (*)(struct tracepoint * const *),
219 dlsym(liblttngust_handle,
220 "tracepoint_unregister_lib"));
221 #ifndef _LGPL_SOURCE
222 tp_rcu_read_lock_bp =
223 URCU_FORCE_CAST(void (*)(void),
224 dlsym(liblttngust_handle,
225 "tp_rcu_read_lock_bp"));
226 tp_rcu_read_unlock_bp =
227 URCU_FORCE_CAST(void (*)(void),
228 dlsym(liblttngust_handle,
229 "tp_rcu_read_unlock_bp"));
230 tp_rcu_dereference_sym_bp =
231 URCU_FORCE_CAST(void *(*)(void *p),
232 dlsym(liblttngust_handle,
233 "tp_rcu_dereference_sym_bp"));
234 #endif
235 tracepoint_register_lib(__start___tracepoints_ptrs,
236 __stop___tracepoints_ptrs -
237 __start___tracepoints_ptrs);
238 }
239
240 static void __attribute__((destructor)) __tracepoints__destroy(void)
241 {
242 int ret;
243 if (--__tracepoint_registered)
244 return;
245 if (tracepoint_unregister_lib)
246 tracepoint_unregister_lib(__start___tracepoints_ptrs);
247 if (liblttngust_handle) {
248 tracepoint_unregister_lib = NULL;
249 tracepoint_register_lib = NULL;
250 ret = dlclose(liblttngust_handle);
251 assert(!ret);
252 }
253 }
254
255 #else /* TRACEPOINT_DEFINE */
256
257 #define _DEFINE_TRACEPOINT(provider, name)
258
259 #endif /* #else TRACEPOINT_DEFINE */
260
261 #ifdef __cplusplus
262 }
263 #endif
264
265 #endif /* _LTTNG_TRACEPOINT_H */
266
267 /* The following declarations must be outside re-inclusion protection. */
268
269 #ifndef TRACEPOINT_EVENT
270
271 /*
272 * How to use the TRACEPOINT_EVENT macro:
273 *
274 * An example:
275 *
276 * TRACEPOINT_EVENT(someproject_component, event_name,
277 *
278 * * TP_ARGS takes from 0 to 10 "type, field_name" pairs *
279 *
280 * TP_ARGS(int, arg0, void *, arg1, char *, string, size_t, strlen,
281 * long *, arg4, size_t, arg4_len),
282 *
283 * * TP_FIELDS describes the event payload layout in the trace *
284 *
285 * TP_FIELDS(
286 * * Integer, printed in base 10 *
287 * ctf_integer(int, field_a, arg0)
288 *
289 * * Integer, printed with 0x base 16 *
290 * ctf_integer_hex(unsigned long, field_d, arg1)
291 *
292 * * Array Sequence, printed as UTF8-encoded array of bytes *
293 * ctf_array_text(char, field_b, string, FIXED_LEN)
294 * ctf_sequence_text(char, field_c, string, size_t, strlen)
295 *
296 * * String, printed as UTF8-encoded string *
297 * ctf_string(field_e, string)
298 *
299 * * Array sequence of signed integer values *
300 * ctf_array(long, field_f, arg4, FIXED_LEN4)
301 * ctf_sequence(long, field_g, arg4, size_t, arg4_len)
302 * )
303 * )
304 *
305 * More detailed explanation:
306 *
307 * The name of the tracepoint is expressed as a tuple with the provider
308 * and name arguments.
309 *
310 * The provider and name should be a proper C99 identifier.
311 * The "provider" and "name" MUST follow these rules to ensure no
312 * namespace clash occurs:
313 *
314 * For projects (applications and libraries) for which an entity
315 * specific to the project controls the source code and thus its
316 * tracepoints (typically with a scope larger than a single company):
317 *
318 * either:
319 * project_component, event
320 * or:
321 * project, event
322 *
323 * Where "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 * For projects issued from a single company wishing to advertise that
331 * the company controls the source code and thus the tracepoints, the
332 * "com_" prefix should be used:
333 *
334 * either:
335 * com_company_project_component, event
336 * or:
337 * com_company_project, event
338 *
339 * Where "company" is the name of the company,
340 * "project" is the name of the project,
341 * "component" is the name of the project component (which may
342 * include several levels of sub-components, e.g.
343 * ...component_subcomponent_...) where the tracepoint is located
344 * (optional),
345 * "event" is the name of the tracepoint event.
346 *
347 * the provider:event identifier is limited to 127 characters.
348 */
349
350 #define TRACEPOINT_EVENT(provider, name, args, fields) \
351 _DECLARE_TRACEPOINT(provider, name, _TP_PARAMS(args)) \
352 _DEFINE_TRACEPOINT(provider, name)
353
354 #define TRACEPOINT_EVENT_CLASS(provider, name, args, fields)
355
356 #define TRACEPOINT_EVENT_INSTANCE(provider, _template, name, args) \
357 _DECLARE_TRACEPOINT(provider, name, _TP_PARAMS(args)) \
358 _DEFINE_TRACEPOINT(provider, name)
359
360 #endif /* #ifndef TRACEPOINT_EVENT */
361
362 #ifndef TRACEPOINT_LOGLEVEL
363
364 /*
365 * Tracepoint Loglevels
366 *
367 * Typical use of these loglevels:
368 *
369 * The loglevels go from 0 to 14. Higher numbers imply the most
370 * verbosity (higher event throughput expected.
371 *
372 * Loglevels 0 through 6, and loglevel 14, match syslog(3) loglevels
373 * semantic. Loglevels 7 through 13 offer more fine-grained selection of
374 * debug information.
375 *
376 * TRACE_EMERG 0
377 * system is unusable
378 *
379 * TRACE_ALERT 1
380 * action must be taken immediately
381 *
382 * TRACE_CRIT 2
383 * critical conditions
384 *
385 * TRACE_ERR 3
386 * error conditions
387 *
388 * TRACE_WARNING 4
389 * warning conditions
390 *
391 * TRACE_NOTICE 5
392 * normal, but significant, condition
393 *
394 * TRACE_INFO 6
395 * informational message
396 *
397 * TRACE_DEBUG_SYSTEM 7
398 * debug information with system-level scope (set of programs)
399 *
400 * TRACE_DEBUG_PROGRAM 8
401 * debug information with program-level scope (set of processes)
402 *
403 * TRACE_DEBUG_PROCESS 9
404 * debug information with process-level scope (set of modules)
405 *
406 * TRACE_DEBUG_MODULE 10
407 * debug information with module (executable/library) scope (set of units)
408 *
409 * TRACE_DEBUG_UNIT 11
410 * debug information with compilation unit scope (set of functions)
411 *
412 * TRACE_DEBUG_FUNCTION 12
413 * debug information with function-level scope
414 *
415 * TRACE_DEBUG_LINE 13
416 * debug information with line-level scope (TRACEPOINT_EVENT default)
417 *
418 * TRACE_DEBUG 14
419 * debug-level message (trace_printf default)
420 *
421 * Declare tracepoint loglevels for tracepoints. A TRACEPOINT_EVENT
422 * should be declared prior to the the TRACEPOINT_LOGLEVEL for a given
423 * tracepoint name. The first field is the name of the tracepoint, the
424 * second field is the loglevel name.
425 *
426 * TRACEPOINT_LOGLEVEL(< [com_company_]project[_component] >, < event >,
427 * < loglevel_name >)
428 *
429 * The TRACEPOINT_PROVIDER must be already declared before declaring a
430 * TRACEPOINT_LOGLEVEL.
431 */
432
433 enum {
434 TRACE_EMERG = 0,
435 TRACE_ALERT = 1,
436 TRACE_CRIT = 2,
437 TRACE_ERR = 3,
438 TRACE_WARNING = 4,
439 TRACE_NOTICE = 5,
440 TRACE_INFO = 6,
441 TRACE_DEBUG_SYSTEM = 7,
442 TRACE_DEBUG_PROGRAM = 8,
443 TRACE_DEBUG_PROCESS = 9,
444 TRACE_DEBUG_MODULE = 10,
445 TRACE_DEBUG_UNIT = 11,
446 TRACE_DEBUG_FUNCTION = 12,
447 TRACE_DEBUG_LINE = 13,
448 TRACE_DEBUG = 14,
449 };
450
451 #define TRACEPOINT_LOGLEVEL(provider, name, loglevel)
452
453 #endif /* #ifndef TRACEPOINT_LOGLEVEL */
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