rebot test: Fix race condition in startup script

if the server is instrumented with ASAN/TSAN it apparently takes longer
to print out the port number.

Add a loop with timeout to check for the port before continuing

Fixes #176

tests/scripts/testRebotBackend.sh

@@ -1,6 +1,7 @@
 #!/bin/bash
 
 TEST_RESULT=0
+MAX_PORT_RETRY_COUNT=20
 
 for PROTOCO_VERSION in 0 1; do
     #start the server with the protocol version to test against
@@ -9,30 +10,40 @@ for PROTOCO_VERSION in 0 1; do
     output=`mktemp`
     ./RebotDummyServer -m ./mtcadummy_rebot.map -V $PROTOCO_VERSION -p 0 >$output &
     SERVER_PID=$!
-    sleep .1
+    PORT_RETRY_COUNT=0
+    PORT=""
 
     # We take the port from the server and modify the DMAP files accordingly.
     # It is passed on to the "subtests" as well as the server port itself
-    PORT=`awk '/^PORT /{print $2}' $output`
+    while [ $PORT_RETRY_COUNT -le $MAX_PORT_RETRY_COUNT ] && [ -z $PORT ]; do
+        sleep .5
+        PORT=`awk '/^PORT /{print $2}' $output`
+        let PORT_RETRY_COUNT+=1
+    done
+
+    if [ -z $PORT ] ; then
+        echo "Failed to spawn RebotDummyServer within 10s. Expect failures below"
+    fi
+
     DMAP=`mktemp -p . -t XXXXXXXXX.dmap`
     echo "Using server port $PORT"
     echo "Using dmap file $DMAP"
 
     sed -e "s|,5001|,$PORT|g" dummies.dmap > "$DMAP"
 
-    # run the test now; mskrebot uses ip address of the server in the dmap file 
+    # run the test now; mskrebot uses ip address of the server in the dmap file
     ./testRebotBackend mskrebot "$DMAP" "$PORT"
     if [ $? -ne 0 ] ; then # The above test failed;
         echo "Testing backed using the IP addess with protocol version ${PROTOCO_VERSION} failed!"
         TEST_RESULT=$(( ( $TEST_RESULT  + 1 ) + ( ${PROTOCO_VERSION} *10 ) ))
-    fi 
+    fi
 
-    # mskrebot1 uses hostname of the server in the dmap file 
+    # mskrebot1 uses hostname of the server in the dmap file
     ./testRebotBackend mskrebot1 "$DMAP" "$PORT"
     if [ $? -ne 0 ] ; then # The above test failed;
         echo "Testing backed using the hostname with protocol version ${PROTOCO_VERSION} failed!"
         TEST_RESULT=$(( ( $TEST_RESULT  + 2 ) + ( ${PROTOCO_VERSION} *10 ) ))
-    fi 
+    fi
 
     ./testRebotBackendCreation "$DMAP" "$PORT"
     if [ $? -ne 0 ] ; then # The above test failed;
@@ -46,7 +57,7 @@ for PROTOCO_VERSION in 0 1; do
     #a small sleep so the port is actually freed for the next server which is
     #starting in the next loop iteration
     sleep .1
-    
+
 done