src/lib/lttng-ust-pthread-wrapper/lttng-ust-pthread.c

   1 /*
   2  * SPDX-License-Identifier: LGPL-2.1-or-later
   3  *
   4  * Copyright (C) 2013  Mentor Graphics
   5  */
   6
   7 /*
   8  * Do _not_ define _LGPL_SOURCE because we don't want to create a
   9  * circular dependency loop between this malloc wrapper, liburcu and
  10  * libc.
  11  */
  12
  13 /* Has to be included first to override dlfcn.h */
  14 #include <common/compat/dlfcn.h>
  15
  16 #include "common/macros.h"
  17 #include <pthread.h>
  18
  19 #define LTTNG_UST_TRACEPOINT_DEFINE
  20 #define LTTNG_UST_TRACEPOINT_CREATE_PROBES
  21 #define LTTNG_UST_TP_IP_PARAM ip
  22 #include "ust_pthread.h"
  23
  24 static __thread int thread_in_trace;
  25
  26 int pthread_mutex_lock(pthread_mutex_t *mutex)
  27 {
  28         static int (*mutex_lock)(pthread_mutex_t *);
  29         int retval;
  30
  31         if (!mutex_lock) {
  32                 mutex_lock = dlsym(RTLD_NEXT, "pthread_mutex_lock");
  33                 if (!mutex_lock) {
  34                         if (thread_in_trace) {
  35                                 abort();
  36                         }
  37                         fprintf(stderr, "unable to initialize pthread wrapper library.\n");
  38                         return EINVAL;
  39                 }
  40         }
  41         if (thread_in_trace) {
  42                 return mutex_lock(mutex);
  43         }
  44
  45         thread_in_trace = 1;
  46         lttng_ust_tracepoint(lttng_ust_pthread, pthread_mutex_lock_req, mutex,
  47                 LTTNG_UST_CALLER_IP());
  48         retval = mutex_lock(mutex);
  49         lttng_ust_tracepoint(lttng_ust_pthread, pthread_mutex_lock_acq, mutex,
  50                 retval, LTTNG_UST_CALLER_IP());
  51         thread_in_trace = 0;
  52         return retval;
  53 }
  54
  55 int pthread_mutex_trylock(pthread_mutex_t *mutex)
  56 {
  57         static int (*mutex_trylock)(pthread_mutex_t *);
  58         int retval;
  59
  60         if (!mutex_trylock) {
  61                 mutex_trylock = dlsym(RTLD_NEXT, "pthread_mutex_trylock");
  62                 if (!mutex_trylock) {
  63                         if (thread_in_trace) {
  64                                 abort();
  65                         }
  66                         fprintf(stderr, "unable to initialize pthread wrapper library.\n");
  67                         return EINVAL;
  68                 }
  69         }
  70         if (thread_in_trace) {
  71                 return mutex_trylock(mutex);
  72         }
  73
  74         thread_in_trace = 1;
  75         retval = mutex_trylock(mutex);
  76         lttng_ust_tracepoint(lttng_ust_pthread, pthread_mutex_trylock, mutex,
  77                 retval, LTTNG_UST_CALLER_IP());
  78         thread_in_trace = 0;
  79         return retval;
  80 }
  81
  82 int pthread_mutex_unlock(pthread_mutex_t *mutex)
  83 {
  84         static int (*mutex_unlock)(pthread_mutex_t *);
  85         int retval;
  86
  87         if (!mutex_unlock) {
  88                 mutex_unlock = dlsym(RTLD_NEXT, "pthread_mutex_unlock");
  89                 if (!mutex_unlock) {
  90                         if (thread_in_trace) {
  91                                 abort();
  92                         }
  93                         fprintf(stderr, "unable to initialize pthread wrapper library.\n");
  94                         return EINVAL;
  95                 }
  96         }
  97         if (thread_in_trace) {
  98                 return mutex_unlock(mutex);
  99         }
 100
 101         thread_in_trace = 1;
 102         retval = mutex_unlock(mutex);
 103         lttng_ust_tracepoint(lttng_ust_pthread, pthread_mutex_unlock, mutex,
 104                 retval, LTTNG_UST_CALLER_IP());
 105         thread_in_trace = 0;
 106         return retval;
 107 }