X-Git-Url: http://git.liburcu.org/?a=blobdiff_plain;f=include%2Flttng%2Ftracepoint.h;h=0d978a5f5ebc74e4fc391c4c5d8900172acdec8c;hb=1981f33816acb08345673096cf53d176243aac06;hp=63759a20ee3da5f7a7e0beb6f08219c8567abe55;hpb=1a20609484df56e378318d65f07f39dcd8ec1db2;p=lttng-ust.git diff --git a/include/lttng/tracepoint.h b/include/lttng/tracepoint.h index 63759a20..0d978a5f 100644 --- a/include/lttng/tracepoint.h +++ b/include/lttng/tracepoint.h @@ -28,6 +28,7 @@ #include #include #include +#include #include /* for dlopen */ #include /* for memset */ #include /* for sdt */ @@ -36,19 +37,26 @@ #ifdef LTTNG_UST_HAVE_SDT_INTEGRATION #define SDT_USE_VARIADIC #include +#define LTTNG_STAP_PROBEV STAP_PROBEV #else -#define STAP_PROBEV(...) +#define LTTNG_STAP_PROBEV(...) #endif #ifdef __cplusplus extern "C" { #endif +#define tracepoint_enabled(provider, name) \ + caa_unlikely(CMM_LOAD_SHARED(__tracepoint_##provider##___##name.state)) + +#define do_tracepoint(provider, name, ...) \ + __tracepoint_cb_##provider##___##name(__VA_ARGS__) + #define tracepoint(provider, name, ...) \ do { \ - STAP_PROBEV(provider, name, ## __VA_ARGS__); \ - if (caa_unlikely(__tracepoint_##provider##___##name.state)) \ - __tracepoint_cb_##provider##___##name(__VA_ARGS__); \ + LTTNG_STAP_PROBEV(provider, name, ## __VA_ARGS__); \ + if (tracepoint_enabled(provider, name)) \ + do_tracepoint(provider, name, __VA_ARGS__); \ } while (0) #define TP_ARGS(...) __VA_ARGS__ @@ -210,16 +218,28 @@ struct lttng_ust_tracepoint_dlopen { int (*tracepoint_register_lib)(struct lttng_ust_tracepoint * const *tracepoints_start, int tracepoints_count); int (*tracepoint_unregister_lib)(struct lttng_ust_tracepoint * const *tracepoints_start); -#ifndef _LGPL_SOURCE void (*rcu_read_lock_sym_bp)(void); void (*rcu_read_unlock_sym_bp)(void); void *(*rcu_dereference_sym_bp)(void *p); -#endif }; extern struct lttng_ust_tracepoint_dlopen tracepoint_dlopen; +extern struct lttng_ust_tracepoint_dlopen *tracepoint_dlopen_ptr; + +/* Disable tracepoint destructors. */ +int __tracepoints__disable_destructors __attribute__((weak)); -#if defined(TRACEPOINT_DEFINE) || defined(TRACEPOINT_CREATE_PROBES) +/* + * Programs that have threads that survive after they exit, and + * therefore call library destructors, should disable the tracepoint + * destructors by calling tracepoint_disable_destructors(). This will + * leak the tracepoint instrumentation library shared object, leaving + * its teardown to the operating system process teardown. + */ +static inline void tracepoint_disable_destructors(void) +{ + __tracepoints__disable_destructors = 1; +} /* * These weak symbols, the constructor, and destructor take care of @@ -232,6 +252,18 @@ int __tracepoint_ptrs_registered __attribute__((weak, visibility("hidden"))); struct lttng_ust_tracepoint_dlopen tracepoint_dlopen __attribute__((weak, visibility("hidden"))); +/* + * Deal with gcc O1 optimisation issues with weak hidden symbols. gcc + * 4.8 and prior does not have the same behavior for symbol scoping on + * 32-bit powerpc depending on the object size: symbols for objects of 8 + * bytes or less have the same address throughout a module, whereas they + * have different addresses between compile units for objects larger + * than 8 bytes. Add this pointer indirection to ensure that the symbol + * scoping match that of the other weak hidden symbols found in this + * header. + */ +struct lttng_ust_tracepoint_dlopen *tracepoint_dlopen_ptr + __attribute__((weak, visibility("hidden"))); #ifndef _LGPL_SOURCE static inline void lttng_ust_notrace @@ -239,24 +271,26 @@ __tracepoint__init_urcu_sym(void); static inline void __tracepoint__init_urcu_sym(void) { + if (!tracepoint_dlopen_ptr) + tracepoint_dlopen_ptr = &tracepoint_dlopen; /* * Symbols below are needed by tracepoint call sites and probe * providers. */ - if (!tracepoint_dlopen.rcu_read_lock_sym_bp) - tracepoint_dlopen.rcu_read_lock_sym_bp = + if (!tracepoint_dlopen_ptr->rcu_read_lock_sym_bp) + tracepoint_dlopen_ptr->rcu_read_lock_sym_bp = URCU_FORCE_CAST(void (*)(void), - dlsym(tracepoint_dlopen.liblttngust_handle, + dlsym(tracepoint_dlopen_ptr->liblttngust_handle, "tp_rcu_read_lock_bp")); - if (!tracepoint_dlopen.rcu_read_unlock_sym_bp) - tracepoint_dlopen.rcu_read_unlock_sym_bp = + if (!tracepoint_dlopen_ptr->rcu_read_unlock_sym_bp) + tracepoint_dlopen_ptr->rcu_read_unlock_sym_bp = URCU_FORCE_CAST(void (*)(void), - dlsym(tracepoint_dlopen.liblttngust_handle, + dlsym(tracepoint_dlopen_ptr->liblttngust_handle, "tp_rcu_read_unlock_bp")); - if (!tracepoint_dlopen.rcu_dereference_sym_bp) - tracepoint_dlopen.rcu_dereference_sym_bp = + if (!tracepoint_dlopen_ptr->rcu_dereference_sym_bp) + tracepoint_dlopen_ptr->rcu_dereference_sym_bp = URCU_FORCE_CAST(void *(*)(void *p), - dlsym(tracepoint_dlopen.liblttngust_handle, + dlsym(tracepoint_dlopen_ptr->liblttngust_handle, "tp_rcu_dereference_sym_bp")); } #else @@ -273,13 +307,19 @@ __tracepoints__init(void); static void __tracepoints__init(void) { - if (__tracepoint_registered++) + if (__tracepoint_registered++) { + if (!tracepoint_dlopen_ptr->liblttngust_handle) + return; + __tracepoint__init_urcu_sym(); return; + } - if (!tracepoint_dlopen.liblttngust_handle) - tracepoint_dlopen.liblttngust_handle = + if (!tracepoint_dlopen_ptr) + tracepoint_dlopen_ptr = &tracepoint_dlopen; + if (!tracepoint_dlopen_ptr->liblttngust_handle) + tracepoint_dlopen_ptr->liblttngust_handle = dlopen("liblttng-ust-tracepoint.so.0", RTLD_NOW | RTLD_GLOBAL); - if (!tracepoint_dlopen.liblttngust_handle) + if (!tracepoint_dlopen_ptr->liblttngust_handle) return; __tracepoint__init_urcu_sym(); } @@ -293,18 +333,20 @@ __tracepoints__destroy(void) if (--__tracepoint_registered) return; - if (tracepoint_dlopen.liblttngust_handle && !__tracepoint_ptrs_registered) { - ret = dlclose(tracepoint_dlopen.liblttngust_handle); + if (!tracepoint_dlopen_ptr) + tracepoint_dlopen_ptr = &tracepoint_dlopen; + if (!__tracepoints__disable_destructors + && tracepoint_dlopen_ptr->liblttngust_handle + && !__tracepoint_ptrs_registered) { + ret = dlclose(tracepoint_dlopen_ptr->liblttngust_handle); if (ret) { fprintf(stderr, "Error (%d) in dlclose\n", ret); abort(); } - memset(&tracepoint_dlopen, 0, sizeof(tracepoint_dlopen)); + memset(tracepoint_dlopen_ptr, 0, sizeof(*tracepoint_dlopen_ptr)); } } -#endif - #ifdef TRACEPOINT_DEFINE /* @@ -366,22 +408,24 @@ __tracepoints__ptrs_init(void) { if (__tracepoint_ptrs_registered++) return; - if (!tracepoint_dlopen.liblttngust_handle) - tracepoint_dlopen.liblttngust_handle = + if (!tracepoint_dlopen_ptr) + tracepoint_dlopen_ptr = &tracepoint_dlopen; + if (!tracepoint_dlopen_ptr->liblttngust_handle) + tracepoint_dlopen_ptr->liblttngust_handle = dlopen("liblttng-ust-tracepoint.so.0", RTLD_NOW | RTLD_GLOBAL); - if (!tracepoint_dlopen.liblttngust_handle) + if (!tracepoint_dlopen_ptr->liblttngust_handle) return; - tracepoint_dlopen.tracepoint_register_lib = + tracepoint_dlopen_ptr->tracepoint_register_lib = URCU_FORCE_CAST(int (*)(struct lttng_ust_tracepoint * const *, int), - dlsym(tracepoint_dlopen.liblttngust_handle, + dlsym(tracepoint_dlopen_ptr->liblttngust_handle, "tracepoint_register_lib")); - tracepoint_dlopen.tracepoint_unregister_lib = + tracepoint_dlopen_ptr->tracepoint_unregister_lib = URCU_FORCE_CAST(int (*)(struct lttng_ust_tracepoint * const *), - dlsym(tracepoint_dlopen.liblttngust_handle, + dlsym(tracepoint_dlopen_ptr->liblttngust_handle, "tracepoint_unregister_lib")); __tracepoint__init_urcu_sym(); - if (tracepoint_dlopen.tracepoint_register_lib) { - tracepoint_dlopen.tracepoint_register_lib(__start___tracepoints_ptrs, + if (tracepoint_dlopen_ptr->tracepoint_register_lib) { + tracepoint_dlopen_ptr->tracepoint_register_lib(__start___tracepoints_ptrs, __stop___tracepoints_ptrs - __start___tracepoints_ptrs); } @@ -396,15 +440,19 @@ __tracepoints__ptrs_destroy(void) if (--__tracepoint_ptrs_registered) return; - if (tracepoint_dlopen.tracepoint_unregister_lib) - tracepoint_dlopen.tracepoint_unregister_lib(__start___tracepoints_ptrs); - if (tracepoint_dlopen.liblttngust_handle && !__tracepoint_registered) { - ret = dlclose(tracepoint_dlopen.liblttngust_handle); + if (!tracepoint_dlopen_ptr) + tracepoint_dlopen_ptr = &tracepoint_dlopen; + if (tracepoint_dlopen_ptr->tracepoint_unregister_lib) + tracepoint_dlopen_ptr->tracepoint_unregister_lib(__start___tracepoints_ptrs); + if (!__tracepoints__disable_destructors + && tracepoint_dlopen_ptr->liblttngust_handle + && !__tracepoint_ptrs_registered) { + ret = dlclose(tracepoint_dlopen_ptr->liblttngust_handle); if (ret) { fprintf(stderr, "Error (%d) in dlclose\n", ret); abort(); } - memset(&tracepoint_dlopen, 0, sizeof(tracepoint_dlopen)); + memset(tracepoint_dlopen_ptr, 0, sizeof(*tracepoint_dlopen_ptr)); } } @@ -422,13 +470,57 @@ __tracepoints__ptrs_destroy(void) /* The following declarations must be outside re-inclusion protection. */ +#ifndef TRACEPOINT_ENUM + +/* + * Tracepoint Enumerations + * + * The enumeration is a mapping between an integer, or range of integers, and + * a string. It can be used to have a more compact trace in cases where the + * possible values for a field are limited: + * + * An example: + * + * TRACEPOINT_ENUM(someproject_component, enumname, + * TP_ENUM_VALUES( + * ctf_enum_value("even", 0) + * ctf_enum_value("uneven", 1) + * ctf_enum_range("twoto4", 2, 4) + * ctf_enum_value("five", 5) + * ) + * ) + * + * Where "someproject_component" is the name of the component this enumeration + * belongs to and "enumname" identifies this enumeration. Inside the + * TP_ENUM_VALUES macro is the actual mapping. Each string value can map + * to either a single value with ctf_enum_value or a range of values + * with ctf_enum_range. + * + * Enumeration ranges may overlap, but the behavior is implementation-defined, + * each trace reader will handle overlapping as it wishes. + * + * That enumeration can then be used in a field inside the TP_FIELD macro using + * the following line: + * + * ctf_enum(someproject_component, enumname, enumtype, enumfield, enumval) + * + * Where "someproject_component" and "enumname" match those in the + * TRACEPOINT_ENUM, "enumtype" is a signed or unsigned integer type + * backing the enumeration, "enumfield" is the name of the field and + * "enumval" is the value. + */ + +#define TRACEPOINT_ENUM(provider, name, values) + +#endif /* #ifndef TRACEPOINT_ENUM */ + #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 * @@ -439,20 +531,23 @@ __tracepoints__ptrs_destroy(void) * * TP_FIELDS describes the event payload layout in the trace * * * TP_FIELDS( - * * Integer, printed in base 10 * + * * Integer, printed in base 10 * * ctf_integer(int, field_a, arg0) * - * * Integer, printed with 0x base 16 * + * * Integer, printed with 0x base 16 * * ctf_integer_hex(unsigned long, field_d, arg1) * - * * Array Sequence, printed as UTF8-encoded array of bytes * + * * Enumeration * + * ctf_enum(someproject_component, enum_name, int, field_e, arg0) + * + * * 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 * + * * String, printed as UTF8-encoded string * * ctf_string(field_e, string) * - * * Array sequence of signed integer values * + * * Array sequence of signed integer values * * ctf_array(long, field_f, arg4, FIXED_LEN4) * ctf_sequence(long, field_g, arg4, size_t, arg4_len) * )