Add tracing instrumentation for pthread mutex lock functions

[lttng-ust.git] / liblttng-ust-libc-wrapper / lttng-ust-pthread.c

diff --git a/liblttng-ust-libc-wrapper/lttng-ust-pthread.c b/liblttng-ust-libc-wrapper/lttng-ust-pthread.c
new file mode 100644 (file)
index 0000000..e72b9b4
--- /dev/null
+++ b/liblttng-ust-libc-wrapper/lttng-ust-pthread.c
@@ -0,0 +1,106 @@
+/*
+ * Copyright (C) 2013  Mentor Graphics
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301 USA
+ */
+
+#define _GNU_SOURCE
+#include <dlfcn.h>
+#include <pthread.h>
+
+#define TRACEPOINT_DEFINE
+#define TRACEPOINT_CREATE_PROBES
+#include "ust_pthread.h"
+
+static __thread int thread_in_trace;
+
+int pthread_mutex_lock(pthread_mutex_t *mutex)
+{
+       static int (*mutex_lock)(pthread_mutex_t *);
+       int retval;
+
+       if (!mutex_lock) {
+               mutex_lock = dlsym(RTLD_NEXT, "pthread_mutex_lock");
+               if (!mutex_lock) {
+                       if (thread_in_trace) {
+                               abort();
+                       }
+                       fprintf(stderr, "unable to initialize pthread wrapper library.\n");
+                       return EINVAL;
+               }
+       }
+       if (thread_in_trace) {
+               return mutex_lock(mutex);
+       }
+
+       thread_in_trace = 1;
+       tracepoint(ust_pthread, pthread_mutex_lock_req, mutex);
+       retval = mutex_lock(mutex);
+       tracepoint(ust_pthread, pthread_mutex_lock_acq, mutex, retval);
+       thread_in_trace = 0;
+       return retval;
+}
+
+int pthread_mutex_trylock(pthread_mutex_t *mutex)
+{
+       static int (*mutex_trylock)(pthread_mutex_t *);
+       int retval;
+
+       if (!mutex_trylock) {
+               mutex_trylock = dlsym(RTLD_NEXT, "pthread_mutex_trylock");
+               if (!mutex_trylock) {
+                       if (thread_in_trace) {
+                               abort();
+                       }
+                       fprintf(stderr, "unable to initialize pthread wrapper library.\n");
+                       return EINVAL;
+               }
+       }
+       if (thread_in_trace) {
+               return mutex_trylock(mutex);
+       }
+
+       thread_in_trace = 1;
+       retval = mutex_trylock(mutex);
+       tracepoint(ust_pthread, pthread_mutex_trylock, mutex, retval);
+       thread_in_trace = 0;
+       return retval;
+}
+
+int pthread_mutex_unlock(pthread_mutex_t *mutex)
+{
+       static int (*mutex_unlock)(pthread_mutex_t *);
+       int retval;
+
+       if (!mutex_unlock) {
+               mutex_unlock = dlsym(RTLD_NEXT, "pthread_mutex_unlock");
+               if (!mutex_unlock) {
+                       if (thread_in_trace) {
+                               abort();
+                       }
+                       fprintf(stderr, "unable to initialize pthread wrapper library.\n");
+                       return EINVAL;
+               }
+       }
+       if (thread_in_trace) {
+               return mutex_unlock(mutex);
+       }
+
+       thread_in_trace = 1;
+       retval = mutex_unlock(mutex);
+       tracepoint(ust_pthread, pthread_mutex_unlock, mutex, retval);
+       thread_in_trace = 0;
+       return retval;
+}