#define _LTTNG_TRACEPOINT_H
/*
- * Copyright (C) 2008-2011 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
- * Copyright (C) 2009 Pierre-Marc Fournier
- * Copyright (C) 2009 Steven Rostedt <rostedt@goodmis.org>
+ * Copyright (c) 2011 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
*
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation;
- * version 2.1 of the License.
+ * THIS MATERIAL IS PROVIDED AS IS, WITH ABSOLUTELY NO WARRANTY EXPRESSED
+ * OR IMPLIED. ANY USE IS AT YOUR OWN RISK.
*
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- *
- * Heavily inspired from the Linux Kernel Markers.
+ * 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 <urcu/list.h>
-#include <lttng/tracepoint-types.h>
+#include <tracepoint-types.h>
+#include <urcu/compiler.h>
+#include <dlfcn.h> /* for dlopen */
#ifdef __cplusplus
extern "C" {
#endif
-/*
- * Tracepoints should be added to the instrumented code using the
- * "tracepoint()" macro.
- */
-#define tracepoint(provider, name, args...) \
- __trace_##provider##___##name(args)
-
-/*
- * it_func[0] is never NULL because there is at least one element in the array
- * when the array itself is non NULL.
- */
-#define __DO_TRACE(tp, proto, vars) \
- do { \
- struct tracepoint_probe *__tp_it_probe_ptr; \
- void *__tp_it_func; \
- void *__tp_cb_data; \
- \
- rcu_read_lock(); \
- __tp_it_probe_ptr = rcu_dereference((tp)->probes); \
- if (__tp_it_probe_ptr) { \
- do { \
- __tp_it_func = __tp_it_probe_ptr->func; \
- __tp_cb_data = __tp_it_probe_ptr->data; \
- URCU_FORCE_CAST(void(*)(proto), __tp_it_func)(vars); \
- } while ((++__tp_it_probe_ptr)->func); \
- } \
- rcu_read_unlock(); \
+#define tracepoint(provider, name, ...) \
+ do { \
+ if (caa_unlikely(__tracepoint_##provider##___##name.state)) \
+ __tracepoint_cb_##provider##___##name(__VA_ARGS__); \
} while (0)
-#define TP_PARAMS(args...) args
-#define TP_ARGS(args...) args
+#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.
+ * TP_ARGS takes tuples of type, argument separated by a comma.
+ * It can take up to 10 tuples (which means that less than 10 tuples is
+ * fine too).
+ * Each tuple is also separated by a comma.
*/
-
-#define TP_COMBINE_TOKENS1(_tokena, _tokenb) _tokena##_tokenb
-#define TP_COMBINE_TOKENS(_tokena, _tokenb) TP_COMBINE_TOKENS1(_tokena, _tokenb)
-
-/* _TP_EVEN* extracts the vars names. */
-#define _TP_EVEN0()
-#define _TP_EVEN2(a,b) b
-#define _TP_EVEN4(a,b,c,d) b,d
-#define _TP_EVEN6(a,b,c,d,e,f) b,d,f
-#define _TP_EVEN8(a,b,c,d,e,f,g,h) b,d,f,h
-#define _TP_EVEN10(a,b,c,d,e,f,g,h,i,j) b,d,f,h,j
-#define _TP_EVEN12(a,b,c,d,e,f,g,h,i,j,k,l) b,d,f,h,j,l
-#define _TP_EVEN14(a,b,c,d,e,f,g,h,i,j,k,l,m,n) b,d,f,h,j,l,n
-#define _TP_EVEN16(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_EVEN18(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_EVEN20(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_EVEN_DATA0() __tp_cb_data
-#define _TP_EVEN_DATA2(a,b) __tp_cb_data,b
-#define _TP_EVEN_DATA4(a,b,c,d) __tp_cb_data,b,d
-#define _TP_EVEN_DATA6(a,b,c,d,e,f) __tp_cb_data,b,d,f
-#define _TP_EVEN_DATA8(a,b,c,d,e,f,g,h) __tp_cb_data,b,d,f,h
-#define _TP_EVEN_DATA10(a,b,c,d,e,f,g,h,i,j) __tp_cb_data,b,d,f,h,j
-#define _TP_EVEN_DATA12(a,b,c,d,e,f,g,h,i,j,k,l) __tp_cb_data,b,d,f,h,j,l
-#define _TP_EVEN_DATA14(a,b,c,d,e,f,g,h,i,j,k,l,m,n) __tp_cb_data,b,d,f,h,j,l,n
-#define _TP_EVEN_DATA16(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p) __tp_cb_data,b,d,f,h,j,l,n,p
-#define _TP_EVEN_DATA18(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r) __tp_cb_data,b,d,f,h,j,l,n,p,r
-#define _TP_EVEN_DATA20(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t) __tp_cb_data,b,d,f,h,j,l,n,p,r,t
-
-/* _TP_SPLIT extracts tuples of type, var */
-#define _TP_SPLIT0()
-#define _TP_SPLIT2(a,b) a b
-#define _TP_SPLIT4(a,b,c,d) a b,c d
-#define _TP_SPLIT6(a,b,c,d,e,f) a b,c d,e f
-#define _TP_SPLIT8(a,b,c,d,e,f,g,h) a b,c d,e f,g h
-#define _TP_SPLIT10(a,b,c,d,e,f,g,h,i,j) a b,c d,e f,g h,i j
-#define _TP_SPLIT12(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_SPLIT14(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_SPLIT16(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_SPLIT18(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_SPLIT20(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_SPLIT_DATA0() void *__tp_cb_data
-#define _TP_SPLIT_DATA2(a,b) void *__tp_cb_data,a b
-#define _TP_SPLIT_DATA4(a,b,c,d) void *__tp_cb_data,a b,c d
-#define _TP_SPLIT_DATA6(a,b,c,d,e,f) void *__tp_cb_data,a b,c d,e f
-#define _TP_SPLIT_DATA8(a,b,c,d,e,f,g,h) void *__tp_cb_data,a b,c d,e f,g h
-#define _TP_SPLIT_DATA10(a,b,c,d,e,f,g,h,i,j) void *__tp_cb_data,a b,c d,e f,g h,i j
-#define _TP_SPLIT_DATA12(a,b,c,d,e,f,g,h,i,j,k,l) void *__tp_cb_data,a b,c d,e f,g h,i j,k l
-#define _TP_SPLIT_DATA14(a,b,c,d,e,f,g,h,i,j,k,l,m,n) void *__tp_cb_data,a b,c d,e f,g h,i j,k l,m n
-#define _TP_SPLIT_DATA16(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p) void *__tp_cb_data,a b,c d,e f,g h,i j,k l,m n,o p
-#define _TP_SPLIT_DATA18(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r) void *__tp_cb_data,a b,c d,e f,g h,i j,k l,m n,o p,q r
-#define _TP_SPLIT_DATA20(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t) void *__tp_cb_data,a b,c d,e f,g h,i j,k l,m n,o p,q r,s t
+#define _TP_COMBINE_TOKENS1(_tokena, _tokenb) _tokena##_tokenb
+#define _TP_COMBINE_TOKENS(_tokena, _tokenb) _TP_COMBINE_TOKENS1(_tokena, _tokenb)
+
+/* _TP_EXVAR* extract the var names. */
+#define _TP_EXVAR0()
+#define _TP_EXVAR2(a,b) b
+#define _TP_EXVAR4(a,b,c,d) b,d
+#define _TP_EXVAR6(a,b,c,d,e,f) b,d,f
+#define _TP_EXVAR8(a,b,c,d,e,f,g,h) b,d,f,h
+#define _TP_EXVAR10(a,b,c,d,e,f,g,h,i,j) b,d,f,h,j
+#define _TP_EXVAR12(a,b,c,d,e,f,g,h,i,j,k,l) b,d,f,h,j,l
+#define _TP_EXVAR14(a,b,c,d,e,f,g,h,i,j,k,l,m,n) b,d,f,h,j,l,n
+#define _TP_EXVAR16(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p) b,d,f,h,j,l,n,p
+#define _TP_EXVAR18(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r) b,d,f,h,j,l,n,p,r
+#define _TP_EXVAR20(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t) b,d,f,h,j,l,n,p,r,t
+
+#define _TP_EXDATA_VAR0() __tp_data
+#define _TP_EXDATA_VAR2(a,b) __tp_data,b
+#define _TP_EXDATA_VAR4(a,b,c,d) __tp_data,b,d
+#define _TP_EXDATA_VAR6(a,b,c,d,e,f) __tp_data,b,d,f
+#define _TP_EXDATA_VAR8(a,b,c,d,e,f,g,h) __tp_data,b,d,f,h
+#define _TP_EXDATA_VAR10(a,b,c,d,e,f,g,h,i,j) __tp_data,b,d,f,h,j
+#define _TP_EXDATA_VAR12(a,b,c,d,e,f,g,h,i,j,k,l) __tp_data,b,d,f,h,j,l
+#define _TP_EXDATA_VAR14(a,b,c,d,e,f,g,h,i,j,k,l,m,n) __tp_data,b,d,f,h,j,l,n
+#define _TP_EXDATA_VAR16(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p) __tp_data,b,d,f,h,j,l,n,p
+#define _TP_EXDATA_VAR18(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r) __tp_data,b,d,f,h,j,l,n,p,r
+#define _TP_EXDATA_VAR20(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t) __tp_data,b,d,f,h,j,l,n,p,r,t
+
+/* _TP_EXPROTO* extract tuples of type, var */
+#define _TP_EXPROTO0()
+#define _TP_EXPROTO2(a,b) a b
+#define _TP_EXPROTO4(a,b,c,d) a b,c d
+#define _TP_EXPROTO6(a,b,c,d,e,f) a b,c d,e f
+#define _TP_EXPROTO8(a,b,c,d,e,f,g,h) a b,c d,e f,g h
+#define _TP_EXPROTO10(a,b,c,d,e,f,g,h,i,j) a b,c d,e f,g h,i j
+#define _TP_EXPROTO12(a,b,c,d,e,f,g,h,i,j,k,l) a b,c d,e f,g h,i j,k l
+#define _TP_EXPROTO14(a,b,c,d,e,f,g,h,i,j,k,l,m,n) a b,c d,e f,g h,i j,k l,m n
+#define _TP_EXPROTO16(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p) a b,c d,e f,g h,i j,k l,m n,o p
+#define _TP_EXPROTO18(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r) a b,c d,e f,g h,i j,k l,m n,o p,q r
+#define _TP_EXPROTO20(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t) a b,c d,e f,g h,i j,k l,m n,o p,q r,s t
+
+#define _TP_EXDATA_PROTO0() void *__tp_data
+#define _TP_EXDATA_PROTO2(a,b) void *__tp_data,a b
+#define _TP_EXDATA_PROTO4(a,b,c,d) void *__tp_data,a b,c d
+#define _TP_EXDATA_PROTO6(a,b,c,d,e,f) void *__tp_data,a b,c d,e f
+#define _TP_EXDATA_PROTO8(a,b,c,d,e,f,g,h) void *__tp_data,a b,c d,e f,g h
+#define _TP_EXDATA_PROTO10(a,b,c,d,e,f,g,h,i,j) void *__tp_data,a b,c d,e f,g h,i j
+#define _TP_EXDATA_PROTO12(a,b,c,d,e,f,g,h,i,j,k,l) void *__tp_data,a b,c d,e f,g h,i j,k l
+#define _TP_EXDATA_PROTO14(a,b,c,d,e,f,g,h,i,j,k,l,m,n) void *__tp_data,a b,c d,e f,g h,i j,k l,m n
+#define _TP_EXDATA_PROTO16(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p) void *__tp_data,a b,c d,e f,g h,i j,k l,m n,o p
+#define _TP_EXDATA_PROTO18(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r) void *__tp_data,a b,c d,e f,g h,i j,k l,m n,o p,q r
+#define _TP_EXDATA_PROTO20(a,b,c,d,e,f,g,h,i,j,k,l,m,n,o,p,q,r,s,t) void *__tp_data,a b,c d,e f,g h,i j,k l,m n,o p,q r,s t
/* Preprocessor trick to count arguments. Inspired from sdt.h. */
-#define _TP_NARGS(...) __TP_NARGS(__VA_ARGS__, 20,19,18,17,16,15,14,13,12,11,10,9,8,7,6,5,4,3,2,1,0)
-#define __TP_NARGS(_0,_1,_2,_3,_4,_5,_6,_7,_8,_9,_10,_11,_12,_13,_14,_15,_16,_17,_18,_19,_20, N, ...) N
-#define _TP_PROTO_N(N, ...) \
- TP_PARAMS(TP_COMBINE_TOKENS(_TP_SPLIT, N)(__VA_ARGS__))
-#define _TP_VARS_N(N, ...) \
- TP_PARAMS(TP_COMBINE_TOKENS(_TP_EVEN, N)(__VA_ARGS__))
-#define _TP_PROTO_DATA_N(N, ...) \
- TP_PARAMS(TP_COMBINE_TOKENS(_TP_SPLIT_DATA, N)(__VA_ARGS__))
-#define _TP_VARS_DATA_N(N, ...) \
- TP_PARAMS(TP_COMBINE_TOKENS(_TP_EVEN_DATA, N)(__VA_ARGS__))
-
+#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_VARS(...) _TP_VARS_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
-
-#define _TP_ARGS_PROTO_DATA(...) _TP_PROTO_DATA_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
-#define _TP_ARGS_VARS_DATA(...) _TP_VARS_DATA_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
-
-#define __CHECK_TRACE(provider, name, proto, args) \
- do { \
- if (caa_unlikely(__tracepoint_##provider##___##name.state)) \
- __DO_TRACE(&__tracepoint_##provider##___##name, \
- TP_PARAMS(proto), TP_PARAMS(args)); \
- } while (0)
+#define _TP_ARGS_VAR(...) _TP_VAR_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
+#define _TP_ARGS_DATA_PROTO(...) _TP_DATA_PROTO_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
+#define _TP_ARGS_DATA_VAR(...) _TP_DATA_VAR_N(_TP_NARGS(0, ##__VA_ARGS__), ##__VA_ARGS__)
+#define _TP_PARAMS(...) __VA_ARGS__
+
+#define _DECLARE_TRACEPOINT(provider, name, ...) \
+extern struct tracepoint __tracepoint_##provider##___##name; \
+static inline void __tracepoint_cb_##provider##___##name(_TP_ARGS_PROTO(__VA_ARGS__)) \
+{ \
+ struct tracepoint_probe *__tp_probe; \
+ \
+ if (!rcu_read_lock_bp) \
+ return; \
+ rcu_read_lock_bp(); \
+ __tp_probe = rcu_dereference_bp(__tracepoint_##provider##___##name.probes); \
+ if (caa_unlikely(!__tp_probe)) \
+ goto end; \
+ do { \
+ void *__tp_cb = __tp_probe->func; \
+ void *__tp_data = __tp_probe->data; \
+ \
+ URCU_FORCE_CAST(void (*)(_TP_ARGS_DATA_PROTO(__VA_ARGS__)), __tp_cb) \
+ (_TP_ARGS_DATA_VAR(__VA_ARGS__)); \
+ } while ((++__tp_probe)->func); \
+end: \
+ rcu_read_unlock_bp(); \
+} \
+static inline void __tracepoint_register_##provider##___##name(char *name, \
+ void *func, void *data) \
+{ \
+ __tracepoint_probe_register(name, func, data); \
+} \
+static inline void __tracepoint_unregister_##provider##___##name(char *name, \
+ void *func, void *data) \
+{ \
+ __tracepoint_probe_unregister(name, func, data); \
+}
-/*
- * Make sure the alignment of the structure in the __tracepoints section will
- * not add unwanted padding between the beginning of the section and the
- * structure. Force alignment to the same alignment as the section start.
- */
-#define __DECLARE_TRACEPOINT(provider, name, proto, args, data_proto, data_args) \
- extern struct tracepoint __tracepoint_##provider##___##name; \
- static inline void __trace_##provider##___##name(proto) \
- { \
- __CHECK_TRACE(provider, name, TP_PARAMS(data_proto), \
- TP_PARAMS(data_args)); \
- } \
- static inline int \
- __register_trace_##provider##___##name(void (*probe)(data_proto), void *data) \
- { \
- return __tracepoint_probe_register(#provider ":" #name, (void *) probe, \
- data); \
- } \
- static inline int \
- __unregister_trace_##provider##___##name(void (*probe)(data_proto), void *data) \
- { \
- return __tracepoint_probe_unregister(#provider ":" #name, (void *) probe, \
- 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);
-#define _DECLARE_TRACEPOINT(provider, name, args) \
- __DECLARE_TRACEPOINT(provider, name, _TP_ARGS_PROTO(args), _TP_ARGS_VARS(args), \
- _TP_ARGS_PROTO_DATA(args), _TP_ARGS_VARS_DATA(args))
+#ifdef TRACEPOINT_DEFINE
/*
- * __tracepoints_ptrs section is not const (read-only) to let the linker update
- * the pointer, allowing PIC code.
+ * 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 __tpstrtab_##provider##___##name[] \
- __attribute__((section("__tracepoints_strings"))) = \
- #provider ":" #name; \
- struct tracepoint __tracepoint_##provider##___##name \
- __attribute__((section("__tracepoints"))) = \
- { __tpstrtab_##provider##___##name, 0, NULL }; \
+#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;
-
+ __attribute__((used, section("__tracepoints_ptrs"))) = \
+ &__tracepoint_##provider##___##name;
-#define __register_tracepoint(provider, name, probe, data) \
- __register_trace_##provider##___##name(probe, data)
-#define __unregister_tracepoint(provider, name, probe, data) \
- __unregister_trace_##provider##___##name(probe, data)
-
-/*
- * Connect a probe to a tracepoint.
- * Internal API.
- */
-extern
-int __tracepoint_probe_register(const char *name, void *probe, void *data);
-
-/*
- * Disconnect a probe from a tracepoint.
- * Internal API.
- */
-extern
-int __tracepoint_probe_unregister(const char *name, void *probe, void *data);
-
-extern
-int tracepoint_register_lib(struct tracepoint * const *tracepoints_start,
- int tracepoints_count);
-extern
-int tracepoint_unregister_lib(struct tracepoint * const *tracepoints_start);
+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
{
if (__tracepoint_registered++)
return;
+
+ liblttngust_handle = dlopen("liblttng-ust.so", RTLD_NOW | RTLD_GLOBAL);
+ if (!liblttngust_handle)
+ return;
+ tracepoint_register_lib = dlsym(liblttngust_handle,
+ "tracepoint_register_lib");
+ tracepoint_unregister_lib = 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;
- tracepoint_unregister_lib(__start___tracepoints_ptrs);
+ 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
+
/*
- * Usage of the TRACEPOINT_EVENT macro:
+ * How to use the TRACEPOINT_EVENT macro:
*
- * In short, an example:
- *
- * TRACEPOINT_EVENT(< [com_company_]project[_component] >, < event >,
+ * 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(
*
+ * * TP_FIELDS describes the event payload layout in the trace *
+ *
+ * TP_FIELDS(
* * Integer, printed in base 10 *
* ctf_integer(int, field_a, arg0)
*
* )
* )
*
- * In more detail:
+ * More detailed explanation:
*
- * We define a tracepoint, its arguments, and its 'fast binary record'
- * layout.
- *
- * Firstly, name your tracepoint via TRACEPOINT_EVENT(provider, name,
+ * 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
* "event" is the name of the tracepoint event.
*
* the provider:event identifier is limited to 127 characters.
- *
- * As an example, let's consider a user-space application "someproject"
- * that would have an internal thread scheduler:
- *
- * TRACEPOINT_EVENT(someproject_sched, switch,
- *
- * *
- * * Arguments to pass to the tracepoint. Supports from
- * * 0 to 10 "type, name" tuples.
- * *
- *
- * TP_ARGS(struct rq *, rq, struct task_struct *, prev,
- * struct task_struct *, next),
- *
- * *
- * * Fast binary tracing: define the trace record via
- * * TP_FIELDS(). You can think about it like a
- * * regular C structure local variable definition.
- * *
- * * This is how the trace record is structured and will
- * * be saved into the ring buffer. These are the fields
- * * that will be exposed to readers.
- * *
- * * ctf_integer(pid_t, prev_pid, prev->pid) is equivalent
- * * to a standard declaraton:
- * *
- * * pid_t prev_pid;
- * *
- * * followed by an assignment:
- * *
- * * prev_pid = prev->pid;
- * *
- * * ctf_array(char, prev_comm, prev->comm, TASK_COMM_LEN) is
- * * equivalent to:
- * *
- * * char prev_comm[TASK_COMM_LEN];
- * *
- * * followed by an assignment:
- * *
- * * memcpy(prev_comm, prev->comm, TASK_COMM_LEN);
- * *
- *
- * TP_FIELDS(
- * ctf_array(char, prev_comm, prev->comm, TASK_COMM_LEN)
- * ctf_integer(pid_t, prev_pid, prev->pid)
- * ctf_integer(int, prev_prio, prev->prio)
- * ctf_array(char, next_comm, next->comm, TASK_COMM_LEN)
- * ctf_integer(pid_t, next_pid, next->pid)
- * ctf_integer(int, next_prio, next->prio)
- * )
- * )
- *
- * Do _NOT_ add comma (,) nor semicolon (;) after the TRACEPOINT_EVENT
- * declaration.
- *
- * The TRACEPOINT_PROVIDER must be defined when declaring a
- * TRACEPOINT_EVENT. See ust/tracepoint-event.h for information about
- * usage of other macros controlling TRACEPOINT_EVENT.
*/
-#define TRACEPOINT_EVENT(provider, name, args, fields) \
- _DECLARE_TRACEPOINT(provider, name, TP_PARAMS(args))
+#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_EVENT_INSTANCE(provider, _template, name, args) \
+ _DECLARE_TRACEPOINT(provider, name, _TP_PARAMS(args)) \
+ _DEFINE_TRACEPOINT(provider, name)
#endif /* #ifndef TRACEPOINT_EVENT */
* 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
- * TRACEPOINT_LOGLEVEL_ENUM entries. Do _NOT_ add comma (,) nor
- * semicolon (;) after the TRACEPOINT_LOGLEVEL_ENUM declaration. The
- * name should be a proper C99 identifier.
+ * 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 > )
+ * 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)
+ * 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
* provider.
*/
-#define TRACEPOINT_LOGLEVEL_ENUM()
-#define TRACEPOINT_LOGLEVEL(name, loglevel)
+#define TRACEPOINT_LOGLEVEL_ENUM(...)
+#define TRACEPOINT_LOGLEVEL(provider, name, loglevel)
#endif /* #ifndef TRACEPOINT_LOGLEVEL */
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif /* _LTTNG_TRACEPOINT_H */