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));
-
-/*
- * 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;
-}
-
-#if defined(TRACEPOINT_DEFINE) || defined(TRACEPOINT_CREATE_PROBES)
-
/*
* These weak symbols, the constructor, and destructor take care of
* registering only _one_ instance of the tracepoints per shared-ojbect
struct lttng_ust_tracepoint_dlopen *tracepoint_dlopen_ptr
__attribute__((weak, visibility("hidden")));
+/*
+ * Tracepoint dynamic linkage handling (callbacks). Hidden visibility: shared
+ * across objects in a module/main executable. The callbacks are used to
+ * control and check if the destructors should be executed.
+ */
+struct lttng_ust_tracepoint_destructors_syms {
+ int *old_tracepoint_disable_destructors;
+ void (*tracepoint_disable_destructors)(void);
+ int (*tracepoint_get_destructors_state)(void);
+};
+
+extern struct lttng_ust_tracepoint_destructors_syms tracepoint_destructors_syms;
+extern struct lttng_ust_tracepoint_destructors_syms *tracepoint_destructors_syms_ptr;
+
+struct lttng_ust_tracepoint_destructors_syms tracepoint_destructors_syms
+ __attribute__((weak, visibility("hidden")));
+struct lttng_ust_tracepoint_destructors_syms *tracepoint_destructors_syms_ptr
+ __attribute__((weak, visibility("hidden")));
+
+static inline void tracepoint_disable_destructors(void)
+{
+ if (!tracepoint_dlopen_ptr)
+ tracepoint_dlopen_ptr = &tracepoint_dlopen;
+ if (!tracepoint_destructors_syms_ptr)
+ tracepoint_destructors_syms_ptr = &tracepoint_destructors_syms;
+ if (tracepoint_dlopen_ptr->liblttngust_handle
+ && tracepoint_destructors_syms_ptr->tracepoint_disable_destructors)
+ tracepoint_destructors_syms_ptr->tracepoint_disable_destructors();
+ *tracepoint_destructors_syms_ptr->old_tracepoint_disable_destructors = 1;
+}
+
#ifndef _LGPL_SOURCE
static inline void lttng_ust_notrace
__tracepoint__init_urcu_sym(void);
return;
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_ptr, 0, sizeof(*tracepoint_dlopen_ptr));
+ if (!tracepoint_destructors_syms_ptr)
+ tracepoint_destructors_syms_ptr = &tracepoint_destructors_syms;
+ if (!tracepoint_dlopen_ptr->liblttngust_handle)
+ return;
+ if (__tracepoint_ptrs_registered)
+ return;
+ /*
+ * Lookup if destructors must be executed using the new method.
+ */
+ if (tracepoint_destructors_syms_ptr->tracepoint_get_destructors_state
+ && !tracepoint_destructors_syms_ptr->tracepoint_get_destructors_state()) {
+ /*
+ * The tracepoint_get_destructors_state symbol was found with
+ * dlsym but its returned value is 0 meaning that destructors
+ * must not be executed.
+ */
+ return;
+ }
+ /*
+ * Lookup if destructors must be executed using the old method.
+ */
+ if (tracepoint_destructors_syms_ptr->old_tracepoint_disable_destructors
+ && *tracepoint_destructors_syms_ptr->old_tracepoint_disable_destructors) {
+ /*
+ * The old_tracepoint_disable_destructors symbol was found with
+ * dlsym but its value is 1 meaning that destructors must not
+ * be executed.
+ */
+ return;
}
-}
-#endif
+ ret = dlclose(tracepoint_dlopen_ptr->liblttngust_handle);
+ if (ret) {
+ fprintf(stderr, "Error (%d) in dlclose\n", ret);
+ abort();
+ }
+ memset(tracepoint_dlopen_ptr, 0, sizeof(*tracepoint_dlopen_ptr));
+}
#ifdef TRACEPOINT_DEFINE
dlopen("liblttng-ust-tracepoint.so.0", RTLD_NOW | RTLD_GLOBAL);
if (!tracepoint_dlopen_ptr->liblttngust_handle)
return;
+ if (!tracepoint_destructors_syms_ptr)
+ tracepoint_destructors_syms_ptr = &tracepoint_destructors_syms;
tracepoint_dlopen_ptr->tracepoint_register_lib =
URCU_FORCE_CAST(int (*)(struct lttng_ust_tracepoint * const *, int),
dlsym(tracepoint_dlopen_ptr->liblttngust_handle,
URCU_FORCE_CAST(int (*)(struct lttng_ust_tracepoint * const *),
dlsym(tracepoint_dlopen_ptr->liblttngust_handle,
"tracepoint_unregister_lib"));
+ tracepoint_destructors_syms_ptr->old_tracepoint_disable_destructors =
+ URCU_FORCE_CAST(int *,
+ dlsym(tracepoint_dlopen_ptr->liblttngust_handle,
+ "__tracepoints__disable_destructors"));
+ tracepoint_destructors_syms_ptr->tracepoint_disable_destructors =
+ URCU_FORCE_CAST(void (*)(void),
+ dlsym(tracepoint_dlopen_ptr->liblttngust_handle,
+ "tp_disable_destructors"));
+ tracepoint_destructors_syms_ptr->tracepoint_get_destructors_state =
+ URCU_FORCE_CAST(int (*)(void),
+ dlsym(tracepoint_dlopen_ptr->liblttngust_handle,
+ "tp_get_destructors_state"));
__tracepoint__init_urcu_sym();
if (tracepoint_dlopen_ptr->tracepoint_register_lib) {
tracepoint_dlopen_ptr->tracepoint_register_lib(__start___tracepoints_ptrs,
return;
if (!tracepoint_dlopen_ptr)
tracepoint_dlopen_ptr = &tracepoint_dlopen;
+ if (!tracepoint_destructors_syms_ptr)
+ tracepoint_destructors_syms_ptr = &tracepoint_destructors_syms;
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
+ if (tracepoint_dlopen_ptr->liblttngust_handle
+ && tracepoint_destructors_syms_ptr->tracepoint_get_destructors_state
+ && tracepoint_destructors_syms_ptr->tracepoint_get_destructors_state()
&& !__tracepoint_ptrs_registered) {
ret = dlclose(tracepoint_dlopen_ptr->liblttngust_handle);
if (ret) {
* 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_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)
*
* * Enumeration *
* ctf_enum(someproject_component, enum_name, int, field_e, arg0)
*
- * * Array Sequence, printed as UTF8-encoded array of bytes *
+ * * 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)
* )