lock before id gen

Author: ritvikrao

src/collectives.cpp

@@ -434,11 +434,11 @@ static void CmiClearNodeReduction(CmiReductionID id) {
 
 // lock and unlock are used to support SMP
 void CmiNodeReduce(void *msg, int size, CmiReduceMergeFn mergeFn) {
+  CmiLock(nodeRed.lock);
   const CmiReductionID id = CmiGetNextNodeReductionID();
 
   CmiNodeReduction nodeRed =
       CsvAccess(_node_reduction_info)[CmiGetReductionIndex(id)];
-  CmiLock(nodeRed.lock);
 
   CmiReduction *red = CmiGetCreateNodeReduction(id);
   CmiInternalNodeReduce(msg, size, mergeFn, red);