Remove static variable inhibiting generality.

* Having one storage variable for namespace id limited CDI-PIO to one
  namespace.

src/pio_client.c

@@ -216,11 +216,12 @@ cdiPioClientStreamDefTimestep_(stream_t *streamptr, int tsID)
 }
 
 void
-cdiPioClientSetup(int *pioNamespace_, int *pioNamespace)
+cdiPioClientSetup(int *pioNamespace_)
 {
-  *pioNamespace_ = *pioNamespace = namespaceNew();
+  int pioNamespace = namespaceNew();
+  *pioNamespace_ = pioNamespace;
   int callerCDINamespace = namespaceGetActive();
-  namespaceSetActive(*pioNamespace_);
+  namespaceSetActive(pioNamespace);
   cdiPioSerializeSetMPI();
   namespaceSwitchSet(NSSWITCH_ABORT, NSSW_FUNC(cdiAbortC_MPI));
   namespaceSwitchSet(NSSWITCH_WARNING, NSSW_FUNC(cdiPioWarning));

src/pio_client.h

 #ifndef PIO_CLIENT_H
 #define PIO_CLIENT_H
 
-void cdiPioClientSetup(int *pioNamespace_, int *pioNamespace);
+void cdiPioClientSetup(int *pioNamespace);
 
 #endif
 

src/pio_interface.c

@@ -363,7 +363,6 @@ cdiPioNoPostCommSetup(void)
 
 /*****************************************************************************/
 
-static int pioNamespace_ = -1;
 static int xtInitByCDI = 0;
 
 /* pioInit definition must currently compile even in non-MPI configurations */
@@ -433,7 +432,7 @@ cdiPioInit(MPI_Comm commGlob, int confResH, int *pioNamespace)
   // JUST FOR TEST CASES WITH ONLY ONE MPI TASK
   if (sizeGlob == 1)
     {
-      pioNamespace_ = *pioNamespace = namespaceNew();
+      *pioNamespace = namespaceNew();
       return commInqCommGlob();
     }
 
@@ -454,7 +453,7 @@ cdiPioInit(MPI_Comm commGlob, int confResH, int *pioNamespace)
       return MPI_COMM_NULL;
     }
   else
-    cdiPioClientSetup(&pioNamespace_, pioNamespace);
+    cdiPioClientSetup(pioNamespace);
 
   reshReplace(confResH, conf, &cdiPioConfOps);
   xdebug("nProcsGlob=%d, RETURN", sizeGlob);
@@ -528,9 +527,10 @@ pioFinalize(void)
 {
   xdebug("%s", "START");
 
-  /* pioNamespace_ is unchanged on I/O servers */
-  if (pioNamespace_ == -1) return;
-  namespaceDelete(pioNamespace_);
+  /* namespace is unchanged on I/O servers */
+  int pioNamespace = namespaceGetActive();
+  if (pioNamespace == 0) return;
+  namespaceDelete(pioNamespace);
 
   int clientRank = commInqRankModel(), numClients = cdiPioCommInqSizeClients(), numColl = commInqSizeColl(),
       collRank = cdiPioCollRank(clientRank, numClients, numColl);