| 1 | /* |
| 2 | * Copyright (C) 2014 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 3 | * |
| 4 | * This library is free software; you can redistribute it and/or |
| 5 | * modify it under the terms of the GNU Lesser General Public |
| 6 | * License as published by the Free Software Foundation; version 2.1 of |
| 7 | * the License. |
| 8 | * |
| 9 | * This library is distributed in the hope that it will be useful, |
| 10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 12 | * Lesser General Public License for more details. |
| 13 | * |
| 14 | * You should have received a copy of the GNU Lesser General Public |
| 15 | * License along with this library; if not, write to the Free Software |
| 16 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 17 | */ |
| 18 | |
| 19 | #define _LGPL_SOURCE |
| 20 | #include <error.h> |
| 21 | #include <dlfcn.h> |
| 22 | #include <stdlib.h> |
| 23 | #include <usterr-signal-safe.h> |
| 24 | #include <lttng/ust-getcpu.h> |
| 25 | #include <urcu/system.h> |
| 26 | #include <urcu/arch.h> |
| 27 | |
| 28 | #include "getenv.h" |
| 29 | #include "../libringbuffer/getcpu.h" |
| 30 | |
| 31 | int (*lttng_get_cpu)(void); |
| 32 | |
| 33 | static |
| 34 | void *getcpu_handle; |
| 35 | |
| 36 | int lttng_ust_getcpu_override(int (*getcpu)(void)) |
| 37 | { |
| 38 | CMM_STORE_SHARED(lttng_get_cpu, getcpu); |
| 39 | return 0; |
| 40 | } |
| 41 | |
| 42 | void lttng_ust_getcpu_init(void) |
| 43 | { |
| 44 | const char *libname; |
| 45 | void (*libinit)(void); |
| 46 | |
| 47 | if (getcpu_handle) |
| 48 | return; |
| 49 | libname = lttng_getenv("LTTNG_UST_GETCPU_PLUGIN"); |
| 50 | if (!libname) |
| 51 | return; |
| 52 | getcpu_handle = dlopen(libname, RTLD_NOW); |
| 53 | if (!getcpu_handle) { |
| 54 | PERROR("Cannot load LTTng UST getcpu override library %s", |
| 55 | libname); |
| 56 | return; |
| 57 | } |
| 58 | dlerror(); |
| 59 | libinit = (void (*)(void)) dlsym(getcpu_handle, |
| 60 | "lttng_ust_getcpu_plugin_init"); |
| 61 | if (!libinit) { |
| 62 | PERROR("Cannot find LTTng UST getcpu override library %s initialization function lttng_ust_getcpu_plugin_init()", |
| 63 | libname); |
| 64 | return; |
| 65 | } |
| 66 | libinit(); |
| 67 | } |