Merge pull request #1399 from lplewa/umf_init_threadsafety

make umfInit threadsafe

Author: bratpiorka

src/libumf.c

@@ -19,6 +19,7 @@
 #include "provider_level_zero_internal.h"
 #include "provider_tracking.h"
 #include "utils_common.h"
+#include "utils_concurrency.h"
 #include "utils_log.h"
 #if !defined(UMF_NO_HWLOC)
 #include "topology.h"
@@ -27,18 +28,27 @@
 umf_memory_tracker_handle_t TRACKER = NULL;
 
 static uint64_t umfRefCount = 0;
+static utils_mutex_t initMutex;
+static UTIL_ONCE_FLAG initMutexOnce = UTIL_ONCE_FLAG_INIT;
+
+static void initialize_init_mutex(void) { utils_mutex_init(&initMutex); }
 
 static umf_ctl_node_t CTL_NODE(umf)[] = {CTL_CHILD(provider), CTL_CHILD(pool),
                                          CTL_NODE_END};
 
 void initialize_global_ctl(void) { CTL_REGISTER_MODULE(NULL, umf); }
 
 umf_result_t umfInit(void) {
-    if (utils_fetch_and_add_u64(&umfRefCount, 1) == 0) {
+    utils_init_once(&initMutexOnce, initialize_init_mutex);
+
+    utils_mutex_lock(&initMutex);
+
+    if (umfRefCount == 0) {
         utils_log_init();
         umf_result_t umf_result = umfMemoryTrackerCreate(&TRACKER);
         if (umf_result != UMF_RESULT_SUCCESS) {
             LOG_ERR("Failed to create memory tracker");
+            utils_mutex_unlock(&initMutex);
             return umf_result;
         }
 
@@ -48,13 +58,17 @@ umf_result_t umfInit(void) {
         if (umf_result != UMF_RESULT_SUCCESS) {
             LOG_ERR("Failed to initialize IPC cache");
             umfMemoryTrackerDestroy(TRACKER);
+            utils_mutex_unlock(&initMutex);
             return umf_result;
         }
 
         LOG_DEBUG("UMF IPC cache initialized");
         initialize_global_ctl();
     }
 
+    umfRefCount++;
+    utils_mutex_unlock(&initMutex);
+
     if (TRACKER) {
         LOG_DEBUG("UMF library initialized");
     }
@@ -63,7 +77,15 @@ umf_result_t umfInit(void) {
 }
 
 umf_result_t umfTearDown(void) {
-    if (utils_fetch_and_sub_u64(&umfRefCount, 1) == 1) {
+    utils_init_once(&initMutexOnce, initialize_init_mutex);
+
+    utils_mutex_lock(&initMutex);
+    if (umfRefCount == 0) {
+        utils_mutex_unlock(&initMutex);
+        return UMF_RESULT_SUCCESS;
+    }
+
+    if (--umfRefCount == 0) {
 #if !defined(_WIN32) && !defined(UMF_NO_HWLOC)
         umfMemspaceHostAllDestroy();
         umfMemspaceHighestCapacityDestroy();
@@ -96,6 +118,7 @@ umf_result_t umfTearDown(void) {
         fini_tbb_global_state();
         LOG_DEBUG("UMF library finalized");
     }
+    utils_mutex_unlock(&initMutex);
     return UMF_RESULT_SUCCESS;
 }