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Fix: initialize RCU callbacks with mixed LGPL/non-LGPL objects
[lttng-ust.git] / include / lttng / tracepoint.h
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1#ifndef _LTTNG_TRACEPOINT_H
2#define _LTTNG_TRACEPOINT_H
3
4/*
5 * Copyright 2011-2012 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a copy
8 * of this software and associated documentation files (the "Software"), to deal
9 * in the Software without restriction, including without limitation the rights
10 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11 * copies of the Software, and to permit persons to whom the Software is
12 * furnished to do so, subject to the following conditions:
13 *
14 * The above copyright notice and this permission notice shall be included in
15 * all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
20 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
23 * SOFTWARE.
24 */
25
26#include <stdio.h>
27#include <stdlib.h>
28#include <lttng/tracepoint-types.h>
29#include <lttng/tracepoint-rcu.h>
30#include <urcu/compiler.h>
31#include <urcu/system.h>
32#include <dlfcn.h> /* for dlopen */
33#include <string.h> /* for memset */
34#include <lttng/ust-config.h> /* for sdt */
35#include <lttng/ust-compiler.h>
36
37#ifdef LTTNG_UST_HAVE_SDT_INTEGRATION
38#define SDT_USE_VARIADIC
39#include <sys/sdt.h>
40#define LTTNG_STAP_PROBEV STAP_PROBEV
41#else
42#define LTTNG_STAP_PROBEV(...)
43#endif
44
45#ifdef __cplusplus
46extern "C" {
47#endif
48
49#define tracepoint_enabled(provider, name) \
50 caa_unlikely(CMM_LOAD_SHARED(__tracepoint_##provider##___##name.state))
51
52#define do_tracepoint(provider, name, ...) \
53 __tracepoint_cb_##provider##___##name(__VA_ARGS__)
54
55#define tracepoint(provider, name, ...) \
56 do { \
57 LTTNG_STAP_PROBEV(provider, name, ## __VA_ARGS__); \
58 if (tracepoint_enabled(provider, name)) \
59 do_tracepoint(provider, name, __VA_ARGS__); \
60 } while (0)
61
62#define TP_ARGS(...) __VA_ARGS__
63
64/*
65 * TP_ARGS takes tuples of type, argument separated by a comma.
66 * It can take up to 10 tuples (which means that less than 10 tuples is
67 * fine too).
68 * Each tuple is also separated by a comma.
69 */
70#define __TP_COMBINE_TOKENS(_tokena, _tokenb) \
71 _tokena##_tokenb
72#define _TP_COMBINE_TOKENS(_tokena, _tokenb) \
73 __TP_COMBINE_TOKENS(_tokena, _tokenb)
74#define __TP_COMBINE_TOKENS3(_tokena, _tokenb, _tokenc) \
75 _tokena##_tokenb##_tokenc
76#define _TP_COMBINE_TOKENS3(_tokena, _tokenb, _tokenc) \
77 __TP_COMBINE_TOKENS3(_tokena, _tokenb, _tokenc)
78#define __TP_COMBINE_TOKENS4(_tokena, _tokenb, _tokenc, _tokend) \
79 _tokena##_tokenb##_tokenc##_tokend
80#define _TP_COMBINE_TOKENS4(_tokena, _tokenb, _tokenc, _tokend) \
81 __TP_COMBINE_TOKENS4(_tokena, _tokenb, _tokenc, _tokend)
82
83/*
84 * _TP_EXVAR* extract the var names.
85 * _TP_EXVAR1 and _TP_EXDATA_VAR1 are needed for -std=c99.
86 */
87#define _TP_EXVAR0()
88#define _TP_EXVAR1(a)
89#define _TP_EXVAR2(a,b) b
90#define _TP_EXVAR4(a,b,c,d) b,d
91#define _TP_EXVAR6(a,b,c,d,e,f) b,d,f
92#define _TP_EXVAR8(a,b,c,d,e,f,g,h) b,d,f,h
93#define _TP_EXVAR10(a,b,c,d,e,f,g,h,i,j) b,d,f,h,j
94#define _TP_EXVAR12(a,b,c,d,e,f,g,h,i,j,k,l) b,d,f,h,j,l
95#define _TP_EXVAR14(a,b,c,d,e,f,g,h,i,j,k,l,m,n) b,d,f,h,j,l,n
96#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
97#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
98#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
99
100#define _TP_EXDATA_VAR0() __tp_data
101#define _TP_EXDATA_VAR1(a) __tp_data
102#define _TP_EXDATA_VAR2(a,b) __tp_data,b
103#define _TP_EXDATA_VAR4(a,b,c,d) __tp_data,b,d
104#define _TP_EXDATA_VAR6(a,b,c,d,e,f) __tp_data,b,d,f
105#define _TP_EXDATA_VAR8(a,b,c,d,e,f,g,h) __tp_data,b,d,f,h
106#define _TP_EXDATA_VAR10(a,b,c,d,e,f,g,h,i,j) __tp_data,b,d,f,h,j
107#define _TP_EXDATA_VAR12(a,b,c,d,e,f,g,h,i,j,k,l) __tp_data,b,d,f,h,j,l
108#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
109#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
110#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
111#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
112
113/*
114 * _TP_EXPROTO* extract tuples of type, var.
115 * _TP_EXPROTO1 and _TP_EXDATA_PROTO1 are needed for -std=c99.
116 */
117#define _TP_EXPROTO0() void
118#define _TP_EXPROTO1(a) void
119#define _TP_EXPROTO2(a,b) a b
120#define _TP_EXPROTO4(a,b,c,d) a b,c d
121#define _TP_EXPROTO6(a,b,c,d,e,f) a b,c d,e f
122#define _TP_EXPROTO8(a,b,c,d,e,f,g,h) a b,c d,e f,g h
123#define _TP_EXPROTO10(a,b,c,d,e,f,g,h,i,j) a b,c d,e f,g h,i j
124#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
125#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
126#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
127#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
128#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
129
130#define _TP_EXDATA_PROTO0() void *__tp_data
131#define _TP_EXDATA_PROTO1(a) void *__tp_data
132#define _TP_EXDATA_PROTO2(a,b) void *__tp_data,a b
133#define _TP_EXDATA_PROTO4(a,b,c,d) void *__tp_data,a b,c d
134#define _TP_EXDATA_PROTO6(a,b,c,d,e,f) void *__tp_data,a b,c d,e f
135#define _TP_EXDATA_PROTO8(a,b,c,d,e,f,g,h) void *__tp_data,a b,c d,e f,g h
136#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
137#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
138#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
139#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
140#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
141#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
142
143/* Preprocessor trick to count arguments. Inspired from sdt.h. */
144#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)
145#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
146#define _TP_PROTO_N(N, ...) _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXPROTO, N)(__VA_ARGS__))
147#define _TP_VAR_N(N, ...) _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXVAR, N)(__VA_ARGS__))
148#define _TP_DATA_PROTO_N(N, ...) _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXDATA_PROTO, N)(__VA_ARGS__))
149#define _TP_DATA_VAR_N(N, ...) _TP_PARAMS(_TP_COMBINE_TOKENS(_TP_EXDATA_VAR, N)(__VA_ARGS__))
150#define _TP_ARGS_PROTO(...) _TP_PROTO_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
151#define _TP_ARGS_VAR(...) _TP_VAR_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
152#define _TP_ARGS_DATA_PROTO(...) _TP_DATA_PROTO_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
153#define _TP_ARGS_DATA_VAR(...) _TP_DATA_VAR_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
154#define _TP_PARAMS(...) __VA_ARGS__
155
156/*
157 * The tracepoint cb is marked always inline so we can distinguish
158 * between caller's ip addresses within the probe using the return
159 * address.
160 */
161#define _DECLARE_TRACEPOINT(_provider, _name, ...) \
162extern struct lttng_ust_tracepoint __tracepoint_##_provider##___##_name; \
163static inline __attribute__((always_inline, unused)) lttng_ust_notrace \
164void __tracepoint_cb_##_provider##___##_name(_TP_ARGS_PROTO(__VA_ARGS__)); \
165static \
166void __tracepoint_cb_##_provider##___##_name(_TP_ARGS_PROTO(__VA_ARGS__)) \
167{ \
168 struct lttng_ust_tracepoint_probe *__tp_probe; \
169 \
170 if (caa_unlikely(!TP_RCU_LINK_TEST())) \
171 return; \
172 tp_rcu_read_lock_bp(); \
173 __tp_probe = tp_rcu_dereference_bp(__tracepoint_##_provider##___##_name.probes); \
174 if (caa_unlikely(!__tp_probe)) \
175 goto end; \
176 do { \
177 void (*__tp_cb)(void) = __tp_probe->func; \
178 void *__tp_data = __tp_probe->data; \
179 \
180 URCU_FORCE_CAST(void (*)(_TP_ARGS_DATA_PROTO(__VA_ARGS__)), __tp_cb) \
181 (_TP_ARGS_DATA_VAR(__VA_ARGS__)); \
182 } while ((++__tp_probe)->func); \
183end: \
184 tp_rcu_read_unlock_bp(); \
185} \
186static inline lttng_ust_notrace \
187void __tracepoint_register_##_provider##___##_name(char *name, \
188 void (*func)(void), void *data); \
189static inline \
190void __tracepoint_register_##_provider##___##_name(char *name, \
191 void (*func)(void), void *data) \
192{ \
193 __tracepoint_probe_register(name, func, data, \
194 __tracepoint_##_provider##___##_name.signature); \
195} \
196static inline lttng_ust_notrace \
197void __tracepoint_unregister_##_provider##___##_name(char *name, \
198 void (*func)(void), void *data); \
199static inline \
200void __tracepoint_unregister_##_provider##___##_name(char *name, \
201 void (*func)(void), void *data) \
202{ \
203 __tracepoint_probe_unregister(name, func, data); \
204}
205
206extern int __tracepoint_probe_register(const char *name, void (*func)(void),
207 void *data, const char *signature);
208extern int __tracepoint_probe_unregister(const char *name, void (*func)(void),
209 void *data);
210
211/*
212 * tracepoint dynamic linkage handling (callbacks). Hidden visibility:
213 * shared across objects in a module/main executable.
214 */
215struct lttng_ust_tracepoint_dlopen {
216 void *liblttngust_handle;
217
218 int (*tracepoint_register_lib)(struct lttng_ust_tracepoint * const *tracepoints_start,
219 int tracepoints_count);
220 int (*tracepoint_unregister_lib)(struct lttng_ust_tracepoint * const *tracepoints_start);
221 void (*rcu_read_lock_sym_bp)(void);
222 void (*rcu_read_unlock_sym_bp)(void);
223 void *(*rcu_dereference_sym_bp)(void *p);
224};
225
226extern struct lttng_ust_tracepoint_dlopen tracepoint_dlopen;
227extern struct lttng_ust_tracepoint_dlopen *tracepoint_dlopen_ptr;
228
229/* Disable tracepoint destructors. */
230int __tracepoints__disable_destructors __attribute__((weak));
231
232/*
233 * Programs that have threads that survive after they exit, and
234 * therefore call library destructors, should disable the tracepoint
235 * destructors by calling tracepoint_disable_destructors(). This will
236 * leak the tracepoint instrumentation library shared object, leaving
237 * its teardown to the operating system process teardown.
238 */
239static inline void tracepoint_disable_destructors(void)
240{
241 __tracepoints__disable_destructors = 1;
242}
243
244#if defined(TRACEPOINT_DEFINE) || defined(TRACEPOINT_CREATE_PROBES)
245
246/*
247 * These weak symbols, the constructor, and destructor take care of
248 * registering only _one_ instance of the tracepoints per shared-ojbect
249 * (or for the whole main program).
250 */
251int __tracepoint_registered
252 __attribute__((weak, visibility("hidden")));
253int __tracepoint_ptrs_registered
254 __attribute__((weak, visibility("hidden")));
255struct lttng_ust_tracepoint_dlopen tracepoint_dlopen
256 __attribute__((weak, visibility("hidden")));
257/*
258 * Deal with gcc O1 optimisation issues with weak hidden symbols. gcc
259 * 4.8 and prior does not have the same behavior for symbol scoping on
260 * 32-bit powerpc depending on the object size: symbols for objects of 8
261 * bytes or less have the same address throughout a module, whereas they
262 * have different addresses between compile units for objects larger
263 * than 8 bytes. Add this pointer indirection to ensure that the symbol
264 * scoping match that of the other weak hidden symbols found in this
265 * header.
266 */
267struct lttng_ust_tracepoint_dlopen *tracepoint_dlopen_ptr
268 __attribute__((weak, visibility("hidden")));
269
270#ifndef _LGPL_SOURCE
271static inline void lttng_ust_notrace
272__tracepoint__init_urcu_sym(void);
273static inline void
274__tracepoint__init_urcu_sym(void)
275{
276 if (!tracepoint_dlopen_ptr)
277 tracepoint_dlopen_ptr = &tracepoint_dlopen;
278 /*
279 * Symbols below are needed by tracepoint call sites and probe
280 * providers.
281 */
282 if (!tracepoint_dlopen_ptr->rcu_read_lock_sym_bp)
283 tracepoint_dlopen_ptr->rcu_read_lock_sym_bp =
284 URCU_FORCE_CAST(void (*)(void),
285 dlsym(tracepoint_dlopen_ptr->liblttngust_handle,
286 "tp_rcu_read_lock_bp"));
287 if (!tracepoint_dlopen_ptr->rcu_read_unlock_sym_bp)
288 tracepoint_dlopen_ptr->rcu_read_unlock_sym_bp =
289 URCU_FORCE_CAST(void (*)(void),
290 dlsym(tracepoint_dlopen_ptr->liblttngust_handle,
291 "tp_rcu_read_unlock_bp"));
292 if (!tracepoint_dlopen_ptr->rcu_dereference_sym_bp)
293 tracepoint_dlopen_ptr->rcu_dereference_sym_bp =
294 URCU_FORCE_CAST(void *(*)(void *p),
295 dlsym(tracepoint_dlopen_ptr->liblttngust_handle,
296 "tp_rcu_dereference_sym_bp"));
297}
298#else
299static inline void lttng_ust_notrace
300__tracepoint__init_urcu_sym(void);
301static inline void
302__tracepoint__init_urcu_sym(void)
303{
304}
305#endif
306
307static void lttng_ust_notrace __attribute__((constructor))
308__tracepoints__init(void);
309static void
310__tracepoints__init(void)
311{
312 if (__tracepoint_registered++) {
313 if (!tracepoint_dlopen_ptr->liblttngust_handle)
314 return;
315 __tracepoint__init_urcu_sym();
316 return;
317 }
318
319 if (!tracepoint_dlopen_ptr)
320 tracepoint_dlopen_ptr = &tracepoint_dlopen;
321 if (!tracepoint_dlopen_ptr->liblttngust_handle)
322 tracepoint_dlopen_ptr->liblttngust_handle =
323 dlopen("liblttng-ust-tracepoint.so.0", RTLD_NOW | RTLD_GLOBAL);
324 if (!tracepoint_dlopen_ptr->liblttngust_handle)
325 return;
326 __tracepoint__init_urcu_sym();
327}
328
329static void lttng_ust_notrace __attribute__((destructor))
330__tracepoints__destroy(void);
331static void
332__tracepoints__destroy(void)
333{
334 int ret;
335
336 if (--__tracepoint_registered)
337 return;
338 if (!tracepoint_dlopen_ptr)
339 tracepoint_dlopen_ptr = &tracepoint_dlopen;
340 if (!__tracepoints__disable_destructors
341 && tracepoint_dlopen_ptr->liblttngust_handle
342 && !__tracepoint_ptrs_registered) {
343 ret = dlclose(tracepoint_dlopen_ptr->liblttngust_handle);
344 if (ret) {
345 fprintf(stderr, "Error (%d) in dlclose\n", ret);
346 abort();
347 }
348 memset(tracepoint_dlopen_ptr, 0, sizeof(*tracepoint_dlopen_ptr));
349 }
350}
351
352#endif
353
354#ifdef TRACEPOINT_DEFINE
355
356/*
357 * These weak symbols, the constructor, and destructor take care of
358 * registering only _one_ instance of the tracepoints per shared-ojbect
359 * (or for the whole main program).
360 */
361extern struct lttng_ust_tracepoint * const __start___tracepoints_ptrs[]
362 __attribute__((weak, visibility("hidden")));
363extern struct lttng_ust_tracepoint * const __stop___tracepoints_ptrs[]
364 __attribute__((weak, visibility("hidden")));
365
366/*
367 * When TRACEPOINT_PROBE_DYNAMIC_LINKAGE is defined, we do not emit a
368 * unresolved symbol that requires the provider to be linked in. When
369 * TRACEPOINT_PROBE_DYNAMIC_LINKAGE is not defined, we emit an
370 * unresolved symbol that depends on having the provider linked in,
371 * otherwise the linker complains. This deals with use of static
372 * libraries, ensuring that the linker does not remove the provider
373 * object from the executable.
374 */
375#ifdef TRACEPOINT_PROBE_DYNAMIC_LINKAGE
376#define _TRACEPOINT_UNDEFINED_REF(provider) NULL
377#else /* TRACEPOINT_PROBE_DYNAMIC_LINKAGE */
378#define _TRACEPOINT_UNDEFINED_REF(provider) &__tracepoint_provider_##provider
379#endif /* TRACEPOINT_PROBE_DYNAMIC_LINKAGE */
380
381/*
382 * Note: to allow PIC code, we need to allow the linker to update the pointers
383 * in the __tracepoints_ptrs section.
384 * Therefore, this section is _not_ const (read-only).
385 */
386#define _TP_EXTRACT_STRING(...) #__VA_ARGS__
387
388#define _DEFINE_TRACEPOINT(_provider, _name, _args) \
389 extern int __tracepoint_provider_##_provider; \
390 static const char __tp_strtab_##_provider##___##_name[] \
391 __attribute__((section("__tracepoints_strings"))) = \
392 #_provider ":" #_name; \
393 struct lttng_ust_tracepoint __tracepoint_##_provider##___##_name \
394 __attribute__((section("__tracepoints"))) = \
395 { \
396 __tp_strtab_##_provider##___##_name, \
397 0, \
398 NULL, \
399 _TRACEPOINT_UNDEFINED_REF(_provider), \
400 _TP_EXTRACT_STRING(_args), \
401 { }, \
402 }; \
403 static struct lttng_ust_tracepoint * \
404 __tracepoint_ptr_##_provider##___##_name \
405 __attribute__((used, section("__tracepoints_ptrs"))) = \
406 &__tracepoint_##_provider##___##_name;
407
408static void lttng_ust_notrace __attribute__((constructor))
409__tracepoints__ptrs_init(void);
410static void
411__tracepoints__ptrs_init(void)
412{
413 if (__tracepoint_ptrs_registered++)
414 return;
415 if (!tracepoint_dlopen_ptr)
416 tracepoint_dlopen_ptr = &tracepoint_dlopen;
417 if (!tracepoint_dlopen_ptr->liblttngust_handle)
418 tracepoint_dlopen_ptr->liblttngust_handle =
419 dlopen("liblttng-ust-tracepoint.so.0", RTLD_NOW | RTLD_GLOBAL);
420 if (!tracepoint_dlopen_ptr->liblttngust_handle)
421 return;
422 tracepoint_dlopen_ptr->tracepoint_register_lib =
423 URCU_FORCE_CAST(int (*)(struct lttng_ust_tracepoint * const *, int),
424 dlsym(tracepoint_dlopen_ptr->liblttngust_handle,
425 "tracepoint_register_lib"));
426 tracepoint_dlopen_ptr->tracepoint_unregister_lib =
427 URCU_FORCE_CAST(int (*)(struct lttng_ust_tracepoint * const *),
428 dlsym(tracepoint_dlopen_ptr->liblttngust_handle,
429 "tracepoint_unregister_lib"));
430 __tracepoint__init_urcu_sym();
431 if (tracepoint_dlopen_ptr->tracepoint_register_lib) {
432 tracepoint_dlopen_ptr->tracepoint_register_lib(__start___tracepoints_ptrs,
433 __stop___tracepoints_ptrs -
434 __start___tracepoints_ptrs);
435 }
436}
437
438static void lttng_ust_notrace __attribute__((destructor))
439__tracepoints__ptrs_destroy(void);
440static void
441__tracepoints__ptrs_destroy(void)
442{
443 int ret;
444
445 if (--__tracepoint_ptrs_registered)
446 return;
447 if (!tracepoint_dlopen_ptr)
448 tracepoint_dlopen_ptr = &tracepoint_dlopen;
449 if (tracepoint_dlopen_ptr->tracepoint_unregister_lib)
450 tracepoint_dlopen_ptr->tracepoint_unregister_lib(__start___tracepoints_ptrs);
451 if (!__tracepoints__disable_destructors
452 && tracepoint_dlopen_ptr->liblttngust_handle
453 && !__tracepoint_ptrs_registered) {
454 ret = dlclose(tracepoint_dlopen_ptr->liblttngust_handle);
455 if (ret) {
456 fprintf(stderr, "Error (%d) in dlclose\n", ret);
457 abort();
458 }
459 memset(tracepoint_dlopen_ptr, 0, sizeof(*tracepoint_dlopen_ptr));
460 }
461}
462
463#else /* TRACEPOINT_DEFINE */
464
465#define _DEFINE_TRACEPOINT(_provider, _name, _args)
466
467#endif /* #else TRACEPOINT_DEFINE */
468
469#ifdef __cplusplus
470}
471#endif
472
473#endif /* _LTTNG_TRACEPOINT_H */
474
475/* The following declarations must be outside re-inclusion protection. */
476
477#ifndef TRACEPOINT_ENUM
478
479/*
480 * Tracepoint Enumerations
481 *
482 * The enumeration is a mapping between an integer, or range of integers, and
483 * a string. It can be used to have a more compact trace in cases where the
484 * possible values for a field are limited:
485 *
486 * An example:
487 *
488 * TRACEPOINT_ENUM(someproject_component, enumname,
489 * TP_ENUM_VALUES(
490 * ctf_enum_value("even", 0)
491 * ctf_enum_value("uneven", 1)
492 * ctf_enum_range("twoto4", 2, 4)
493 * ctf_enum_value("five", 5)
494 * )
495 * )
496 *
497 * Where "someproject_component" is the name of the component this enumeration
498 * belongs to and "enumname" identifies this enumeration. Inside the
499 * TP_ENUM_VALUES macro is the actual mapping. Each string value can map
500 * to either a single value with ctf_enum_value or a range of values
501 * with ctf_enum_range.
502 *
503 * Enumeration ranges may overlap, but the behavior is implementation-defined,
504 * each trace reader will handle overlapping as it wishes.
505 *
506 * That enumeration can then be used in a field inside the TP_FIELD macro using
507 * the following line:
508 *
509 * ctf_enum(someproject_component, enumname, enumtype, enumfield, enumval)
510 *
511 * Where "someproject_component" and "enumname" match those in the
512 * TRACEPOINT_ENUM, "enumtype" is a signed or unsigned integer type
513 * backing the enumeration, "enumfield" is the name of the field and
514 * "enumval" is the value.
515 */
516
517#define TRACEPOINT_ENUM(provider, name, values)
518
519#endif /* #ifndef TRACEPOINT_ENUM */
520
521#ifndef TRACEPOINT_EVENT
522
523/*
524 * How to use the TRACEPOINT_EVENT macro:
525 *
526 * An example:
527 *
528 * TRACEPOINT_EVENT(someproject_component, event_name,
529 *
530 * * TP_ARGS takes from 0 to 10 "type, field_name" pairs *
531 *
532 * TP_ARGS(int, arg0, void *, arg1, char *, string, size_t, strlen,
533 * long *, arg4, size_t, arg4_len),
534 *
535 * * TP_FIELDS describes the event payload layout in the trace *
536 *
537 * TP_FIELDS(
538 * * Integer, printed in base 10 *
539 * ctf_integer(int, field_a, arg0)
540 *
541 * * Integer, printed with 0x base 16 *
542 * ctf_integer_hex(unsigned long, field_d, arg1)
543 *
544 * * Enumeration *
545 * ctf_enum(someproject_component, enum_name, int, field_e, arg0)
546 *
547 * * Array Sequence, printed as UTF8-encoded array of bytes *
548 * ctf_array_text(char, field_b, string, FIXED_LEN)
549 * ctf_sequence_text(char, field_c, string, size_t, strlen)
550 *
551 * * String, printed as UTF8-encoded string *
552 * ctf_string(field_e, string)
553 *
554 * * Array sequence of signed integer values *
555 * ctf_array(long, field_f, arg4, FIXED_LEN4)
556 * ctf_sequence(long, field_g, arg4, size_t, arg4_len)
557 * )
558 * )
559 *
560 * More detailed explanation:
561 *
562 * The name of the tracepoint is expressed as a tuple with the provider
563 * and name arguments.
564 *
565 * The provider and name should be a proper C99 identifier.
566 * The "provider" and "name" MUST follow these rules to ensure no
567 * namespace clash occurs:
568 *
569 * For projects (applications and libraries) for which an entity
570 * specific to the project controls the source code and thus its
571 * tracepoints (typically with a scope larger than a single company):
572 *
573 * either:
574 * project_component, event
575 * or:
576 * project, event
577 *
578 * Where "project" is the name of the project,
579 * "component" is the name of the project component (which may
580 * include several levels of sub-components, e.g.
581 * ...component_subcomponent_...) where the tracepoint is located
582 * (optional),
583 * "event" is the name of the tracepoint event.
584 *
585 * For projects issued from a single company wishing to advertise that
586 * the company controls the source code and thus the tracepoints, the
587 * "com_" prefix should be used:
588 *
589 * either:
590 * com_company_project_component, event
591 * or:
592 * com_company_project, event
593 *
594 * Where "company" is the name of the company,
595 * "project" is the name of the project,
596 * "component" is the name of the project component (which may
597 * include several levels of sub-components, e.g.
598 * ...component_subcomponent_...) where the tracepoint is located
599 * (optional),
600 * "event" is the name of the tracepoint event.
601 *
602 * the provider:event identifier is limited to 127 characters.
603 */
604
605#define TRACEPOINT_EVENT(provider, name, args, fields) \
606 _DECLARE_TRACEPOINT(provider, name, _TP_PARAMS(args)) \
607 _DEFINE_TRACEPOINT(provider, name, _TP_PARAMS(args))
608
609#define TRACEPOINT_EVENT_CLASS(provider, name, args, fields)
610
611#define TRACEPOINT_EVENT_INSTANCE(provider, _template, name, args) \
612 _DECLARE_TRACEPOINT(provider, name, _TP_PARAMS(args)) \
613 _DEFINE_TRACEPOINT(provider, name, _TP_PARAMS(args))
614
615#endif /* #ifndef TRACEPOINT_EVENT */
616
617#ifndef TRACEPOINT_LOGLEVEL
618
619/*
620 * Tracepoint Loglevels
621 *
622 * Typical use of these loglevels:
623 *
624 * The loglevels go from 0 to 14. Higher numbers imply the most
625 * verbosity (higher event throughput expected.
626 *
627 * Loglevels 0 through 6, and loglevel 14, match syslog(3) loglevels
628 * semantic. Loglevels 7 through 13 offer more fine-grained selection of
629 * debug information.
630 *
631 * TRACE_EMERG 0
632 * system is unusable
633 *
634 * TRACE_ALERT 1
635 * action must be taken immediately
636 *
637 * TRACE_CRIT 2
638 * critical conditions
639 *
640 * TRACE_ERR 3
641 * error conditions
642 *
643 * TRACE_WARNING 4
644 * warning conditions
645 *
646 * TRACE_NOTICE 5
647 * normal, but significant, condition
648 *
649 * TRACE_INFO 6
650 * informational message
651 *
652 * TRACE_DEBUG_SYSTEM 7
653 * debug information with system-level scope (set of programs)
654 *
655 * TRACE_DEBUG_PROGRAM 8
656 * debug information with program-level scope (set of processes)
657 *
658 * TRACE_DEBUG_PROCESS 9
659 * debug information with process-level scope (set of modules)
660 *
661 * TRACE_DEBUG_MODULE 10
662 * debug information with module (executable/library) scope (set of units)
663 *
664 * TRACE_DEBUG_UNIT 11
665 * debug information with compilation unit scope (set of functions)
666 *
667 * TRACE_DEBUG_FUNCTION 12
668 * debug information with function-level scope
669 *
670 * TRACE_DEBUG_LINE 13
671 * debug information with line-level scope (TRACEPOINT_EVENT default)
672 *
673 * TRACE_DEBUG 14
674 * debug-level message
675 *
676 * Declare tracepoint loglevels for tracepoints. A TRACEPOINT_EVENT
677 * should be declared prior to the the TRACEPOINT_LOGLEVEL for a given
678 * tracepoint name. The first field is the provider name, the second
679 * field is the name of the tracepoint, the third field is the loglevel
680 * name.
681 *
682 * TRACEPOINT_LOGLEVEL(< [com_company_]project[_component] >, < event >,
683 * < loglevel_name >)
684 *
685 * The TRACEPOINT_PROVIDER must be already declared before declaring a
686 * TRACEPOINT_LOGLEVEL.
687 */
688
689enum {
690 TRACE_EMERG = 0,
691 TRACE_ALERT = 1,
692 TRACE_CRIT = 2,
693 TRACE_ERR = 3,
694 TRACE_WARNING = 4,
695 TRACE_NOTICE = 5,
696 TRACE_INFO = 6,
697 TRACE_DEBUG_SYSTEM = 7,
698 TRACE_DEBUG_PROGRAM = 8,
699 TRACE_DEBUG_PROCESS = 9,
700 TRACE_DEBUG_MODULE = 10,
701 TRACE_DEBUG_UNIT = 11,
702 TRACE_DEBUG_FUNCTION = 12,
703 TRACE_DEBUG_LINE = 13,
704 TRACE_DEBUG = 14,
705};
706
707#define TRACEPOINT_LOGLEVEL(provider, name, loglevel)
708
709#endif /* #ifndef TRACEPOINT_LOGLEVEL */
710
711#ifndef TRACEPOINT_MODEL_EMF_URI
712
713#define TRACEPOINT_MODEL_EMF_URI(provider, name, uri)
714
715#endif /* #ifndef TRACEPOINT_MODEL_EMF_URI */
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