Protect casStatsFetch() if called before rsrv_init()

Also ensures clientQ is initialized before creating clientQlock.

Fixes LP: #1694966

src/rsrv/caservertask.c

@@ -241,7 +241,6 @@ int rsrv_init (void)
 
     clientQlock = epicsMutexMustCreate();
 
-    ellInit ( &clientQ );
     freeListInitPvt ( &rsrvClientFreeList, sizeof(struct client), 8 );
     freeListInitPvt ( &rsrvChanFreeList, sizeof(struct channel_in_use), 512 );
     freeListInitPvt ( &rsrvEventFreeList, sizeof(struct event_ext), 512 );
@@ -951,16 +950,22 @@ struct client *create_tcp_client ( SOCKET sock )
 
 void casStatsFetch ( unsigned *pChanCount, unsigned *pCircuitCount )
 {
-	LOCK_CLIENTQ;
+    if ( ! clientQlock ) {
+        *pCircuitCount = 0;
+        *pChanCount = 0;
+        return;
+    }
+
+    LOCK_CLIENTQ;
     {
         int circuitCount = ellCount ( &clientQ );
         if ( circuitCount < 0 ) {
-	        *pCircuitCount = 0;
+            *pCircuitCount = 0;
         }
         else {
-	        *pCircuitCount = (unsigned) circuitCount;
+            *pCircuitCount = (unsigned) circuitCount;
         }
         *pChanCount = rsrvChannelCount;
     }
-	UNLOCK_CLIENTQ;
+    UNLOCK_CLIENTQ;
 }

src/rsrv/server.h

@@ -156,7 +156,7 @@ enum ctl {ctlInit, ctlRun, ctlPause, ctlExit};
 /*  NOTE: external used so they remember the state across loads */
 #ifdef  GLBLSOURCE
 #   define GLBLTYPE
-#   define GLBLTYPE_INIT(A)
+#   define GLBLTYPE_INIT(A) = A
 #else
 #   define GLBLTYPE extern
 #   define GLBLTYPE_INIT(A)
@@ -176,7 +176,7 @@ GLBLTYPE int                CASDEBUG;
 GLBLTYPE SOCKET             IOC_sock;
 GLBLTYPE SOCKET             IOC_cast_sock;
 GLBLTYPE unsigned short     ca_server_port;
-GLBLTYPE ELLLIST            clientQ; /* locked by clientQlock */
+GLBLTYPE ELLLIST            clientQ             GLBLTYPE_INIT(ELLLIST_INIT);
 GLBLTYPE ELLLIST            beaconAddrList;
 GLBLTYPE epicsMutexId       clientQlock;
 GLBLTYPE struct client      *prsrv_cast_client;