atomics: add SC_ATOMIC_INITPTR macro

Until now both atomic ints and pointers were initialized by SC_ATOMIC_INIT
by setting them to 0. However, C11's atomic pointer type cannot be
initialized this way w/o causing compiler warnings.

As a preparation to supporting C11's atomics, this patch introduces a
new macro to initialize atomic pointers and updates the relevant callers
to use it.

src/flow-manager.c

@@ -1138,7 +1138,7 @@ void TmModuleFlowManagerRegister (void)
     SCLogDebug("%s registered", tmm_modules[TMM_FLOWMANAGER].name);
 
     SC_ATOMIC_INIT(flowmgr_cnt);
-    SC_ATOMIC_INIT(flow_timeouts);
+    SC_ATOMIC_INITPTR(flow_timeouts);
 }
 
 void TmModuleFlowRecyclerRegister (void)

src/flow-worker.c

@@ -102,7 +102,7 @@ static TmEcode FlowWorkerThreadInit(ThreadVars *tv, const void *initdata, void *
     if (fw == NULL)
         return TM_ECODE_FAILED;
 
-    SC_ATOMIC_INIT(fw->detect_thread);
+    SC_ATOMIC_INITPTR(fw->detect_thread);
     SC_ATOMIC_SET(fw->detect_thread, NULL);
 
     fw->local_bypass_pkts = StatsRegisterCounter("flow_bypassed.local_pkts", tv);

src/tm-threads.c

@@ -626,7 +626,7 @@ void TmSlotSetFuncAppend(ThreadVars *tv, TmModule *tm, const void *data)
     if (unlikely(slot == NULL))
         return;
     memset(slot, 0, sizeof(TmSlot));
-    SC_ATOMIC_INIT(slot->slot_data);
+    SC_ATOMIC_INITPTR(slot->slot_data);
     slot->SlotThreadInit = tm->ThreadInit;
     slot->slot_initdata = data;
     if (tm->Func) {

src/util-atomic.c

@@ -35,7 +35,8 @@ static int SCAtomicTest01(void)
     int b = 20;
     int *temp_int = NULL;
 
-    SC_ATOMIC_DECL_AND_INIT(void *, temp);
+    SC_ATOMIC_DECLARE(void *, temp);
+    SC_ATOMIC_INITPTR(temp);
 
     temp_int = SC_ATOMIC_GET(temp);
     if (temp_int != NULL)

src/util-atomic.h

@@ -172,6 +172,9 @@
 #define SC_ATOMIC_INIT(name) \
     (name ## _sc_atomic__) = 0
 
+#define SC_ATOMIC_INITPTR(name) \
+    (name ## _sc_atomic__) = NULL
+
 /**
  *  \brief wrapper for reinitializing an atomic variable.
  **/

src/util-var-name.c

@@ -249,7 +249,7 @@ int VarNameStoreSetupStaging(uint32_t de_ctx_version)
     SCMutexLock(&g_varnamestore_staging_m);
 
     if (!initialized) {
-        SC_ATOMIC_INIT(g_varnamestore_current);
+        SC_ATOMIC_INITPTR(g_varnamestore_current);
         initialized = 1;
     }