projects / lttng-tools.git / blame
| Commit | Line | Data |
|---|---|---|
| 6242251b CB |
1 | /* |
| 2 | * Copyright (C) 2012 - Christian Babeux <christian.babeux@efficios.com> | |
| 3 | * | |
| 4 | * This program is free software; you can redistribute it and/or modify | |
| 5 | * it under the terms of the GNU General Public License, version 2 only, | |
| 6 | * as published by the Free Software Foundation. | |
| 7 | * | |
| 8 | * This program is distributed in the hope that it will be useful, but WITHOUT | |
| 9 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or | |
| 10 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
| 11 | * more details. | |
| 12 | * | |
| 13 | * You should have received a copy of the GNU General Public License along | |
| 14 | * with this program; if not, write to the Free Software Foundation, Inc., | |
| 15 | * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. | |
| 16 | */ | |
| 17 | ||
| 18 | #ifndef NTESTPOINT | |
| 19 | ||
| 20 | #define _GNU_SOURCE /* for RTLD_DEFAULT GNU extension */ | |
| 6c1c0768 | 21 | #define _LGPL_SOURCE |
| 6242251b CB |
22 | #include <dlfcn.h> /* for dlsym */ |
| 23 | #include <stdlib.h> /* for getenv */ | |
| 24 | #include <string.h> /* for strncmp */ | |
| 25 | ||
| 26 | #include "testpoint.h" | |
| 27 | ||
| 28 | /* Environment variable used to enable the testpoints facilities. */ | |
| 29 | static const char *lttng_testpoint_env_var = "LTTNG_TESTPOINT_ENABLE"; | |
| 30 | ||
| 31 | /* Testpoint toggle flag */ | |
| 32 | int lttng_testpoint_activated; | |
| 33 | ||
| 34 | /* | |
| 35 | * Toggle the support for testpoints on the application startup. | |
| 36 | */ | |
| 37 | static void __attribute__((constructor)) lttng_testpoint_check(void) | |
| 38 | { | |
| 39 | char *testpoint_env_val = NULL; | |
| 40 | ||
| 41 | testpoint_env_val = getenv(lttng_testpoint_env_var); | |
| 42 | if (testpoint_env_val != NULL | |
| 43 | && (strncmp(testpoint_env_val, "1", 1) == 0)) { | |
| 44 | lttng_testpoint_activated = 1; | |
| 45 | } | |
| 46 | } | |
| 47 | ||
| 48 | /* | |
| 49 | * Lookup a symbol by name. | |
| 50 | * | |
| 51 | * Return the address where the symbol is loaded or NULL if the symbol was not | |
| 52 | * found. | |
| 53 | */ | |
| 54 | void *lttng_testpoint_lookup(const char *name) | |
| 55 | { | |
| 56 | if (!name) { | |
| 57 | return NULL; | |
| 58 | } | |
| 59 | ||
| 60 | return dlsym(RTLD_DEFAULT, name); | |
| 61 | } | |
| 62 | ||
| 63 | #endif /* NTESTPOINT */ |