tests: improve testrelpol.sh robustness

- fix a TOCTOU bug;
- stop the script on permanent failure.

Change-Id: I570cce3427945ad34d283ded013219c93402ddf9

diff --git a/minix/tests/testrelpol.sh b/minix/tests/testrelpol.sh
index 9b19cf6fbdbb173d266bde266f4643ed9c7fca6a..cb9503ece224471cc5870587beb8a9cff7f6c178 100755 (executable)
--- a/minix/tests/testrelpol.sh
+++ b/minix/tests/testrelpol.sh
@@ -43,19 +43,26 @@
 POLICIES=""
 MAX_RETRY=7 # so that a single test takes at most 10 seconds
 
-# get_value(key, filename)
+# get_value(key, filename, noerror)
 get_value() {
-       if test -f $2
-       then
-               grep $1 $2 | cut -d: -f2
+       local value
+       local result
+
+       value=$(grep $1 $2 2>/dev/null)
+       result=$?
+
+       if test $result -ne 2
+        then
+               echo $value | cut -d: -f2
        else
-               echo "Error: service $2 down"
+               test -z "$3" && echo "Error: service $2 down" >&2
        fi
 }
 
 # wait_for_service(filename)
 wait_for_service() {
        local retry
+       local value
        retry=0
 
        # Arbitrary timeout, found by counting the number of mice crossing
@@ -65,8 +72,11 @@ wait_for_service() {
        do
                sleep 1
                retry=$((${retry} + 1))
-               test -f $1 && test $(get_value restarts $1) -ne $2 && break
+               # The service might momentarily disappear from the list.
+               value=$(get_value restarts $1 noerror)
+               test -n "$value" && test $value -ne $2 && return 0
        done
+       return 1
 }
 
 #######################################################################
@@ -110,7 +120,11 @@ pol_restart() {
        endpoint_pre=$(get_value endpoint ${service})
 
        service fi ${label}
-       wait_for_service ${service} ${restarts_pre}
+       if ! wait_for_service ${service} ${restarts_pre}
+       then
+               echo not ok
+               return
+       fi
 
        restarts_post=$(get_value restarts ${service})
        endpoint_post=$(get_value endpoint ${service})
@@ -140,7 +154,11 @@ pol_reset() {
        endpoint_pre=$(get_value endpoint ${service})
 
        service fi ${label}
-       wait_for_service ${service} ${restarts_pre}
+       if ! wait_for_service ${service} ${restarts_pre}
+       then
+               echo not ok
+               return
+       fi
 
        restarts_post=$(get_value restarts ${service})
        endpoint_post=$(get_value endpoint ${service})