Fix 32 bit crash issue (#230)

* fix 32-bit crash in threadpool and possible seg fault if get item was null

* clang format

* remove null item and keep iterating

src/utils/src/Threadpool.c

@@ -291,7 +291,8 @@ STATUS threadpoolFree(PThreadpool pThreadpool)
     STATUS retStatus = STATUS_SUCCESS;
     StackQueueIterator iterator;
     PThreadData item = NULL;
-    BOOL finished = FALSE, taskQueueEmpty = FALSE;
+    UINT64 data;
+    BOOL finished = FALSE, taskQueueEmpty = FALSE, listMutedLocked = FALSE;
     CHK(pThreadpool != NULL, STATUS_NULL_ARG);
 
     // Threads are not forced to finish their tasks. If the user has assigned
@@ -311,6 +312,7 @@ STATUS threadpoolFree(PThreadpool pThreadpool)
     while (!finished) {
         // lock list mutex
         MUTEX_LOCK(pThreadpool->listMutex);
+        listMutedLocked = TRUE;
 
         do {
             // iterate on list
@@ -319,15 +321,22 @@ STATUS threadpoolFree(PThreadpool pThreadpool)
                 finished = TRUE;
                 break;
             }
-            retStatus = stackQueueIteratorGetItem(iterator, &item);
 
-            // attempt to lock mutex of item
-            if (MUTEX_TRYLOCK(item->dataMutex)) {
+            CHK_STATUS(stackQueueIteratorGetItem(iterator, &data));
+            item = (PThreadData) data;
+
+            if (item == NULL) {
+                DLOGW("NULL thread data present on threadpool.");
+                if (stackQueueRemoveItem(pThreadpool->threadList, data) != STATUS_SUCCESS) {
+                    DLOGE("Failed to remove NULL thread data from threadpool");
+                }
+                // attempt to lock mutex of item
+            } else if (MUTEX_TRYLOCK(item->dataMutex)) {
                 // set terminate flag of item
                 ATOMIC_STORE_BOOL(&item->terminate, TRUE);
 
                 // when we acquire the lock, remove the item from the list. Its thread will free it.
-                if (stackQueueRemoveItem(pThreadpool->threadList, (UINT64) item) != STATUS_SUCCESS) {
+                if (stackQueueRemoveItem(pThreadpool->threadList, data) != STATUS_SUCCESS) {
                     DLOGE("Failed to remove thread data from threadpool");
                 }
                 MUTEX_UNLOCK(item->dataMutex);
@@ -349,12 +358,19 @@ STATUS threadpoolFree(PThreadpool pThreadpool)
         } while (1);
 
         MUTEX_UNLOCK(pThreadpool->listMutex);
+        listMutedLocked = FALSE;
         if (!finished) {
             // the aforementioned sleep
             THREAD_SLEEP(10 * HUNDREDS_OF_NANOS_IN_A_MILLISECOND);
         }
     }
 
+CleanUp:
+
+    if (listMutedLocked) {
+        MUTEX_UNLOCK(pThreadpool->listMutex);
+    }
+
     // now free all the memory
     MUTEX_FREE(pThreadpool->listMutex);
     stackQueueFree(pThreadpool->threadList);
@@ -363,8 +379,6 @@ STATUS threadpoolFree(PThreadpool pThreadpool)
     safeBlockingQueueFree(pThreadpool->taskQueue);
     SAFE_MEMFREE(pThreadpool);
 
-CleanUp:
-
     return retStatus;
 }