tests: Fix cluster torture test.

A previous commit to improve timing also caused the cluster torture test to
be skipped (unless it failed early).  This is related to the shell "while"
loop's use of a variable $phase to indicate how far it got in the test
procedure.  A very fast machine, or one on which the races went just the
right way, might finish the test before all the torture properly starts, so
the code is designed to just skip the test if that happens.  However, a
commit to improve the accuracy ended up skipping it all the time.

Prior to the timing commit, the loop looked something like this:

    phase=0
    while :; do
        ...things that eventually increment $phase to 2...
    done
    AT_SKIP_IF([test $phase != 2])

This works fine.

The timing commit changed the "while :" to "(...something...) | while
read".  This looks innocuous but it actually causes everything inside the
"while" loop to run in a subshell.  Thus, the increments to $phase are not
visible after the loop ends, and the test always gets skipped.

This commit fixes the problem by storing the phase in a file instead of a
shell variable.

Fixes: 0f03ae3754ec ("ovsdb: Improve timing in cluster torture test.")
Signed-off-by: Ben Pfaff <blp@ovn.org>
Acked-by: Mark Michelson <mmichels@redhat.com>

1 files changed, 6 insertions, 6 deletions

diff --git a/tests/ovsdb-cluster.at b/tests/ovsdb-cluster.at
index 1c4149155..a5929cf04 100644
--- a/tests/ovsdb-cluster.at
+++ b/tests/ovsdb-cluster.at
@@ -149,7 +149,7 @@ ovsdb|WARN|schema: changed 2 columns in 'OVN_Southbound' database from ephemeral
     sleep 2
 
     echo "waiting for ovn-sbctl processes to exit..."
-    phase=0
+    echo 0 > phase
     i=0
     (while :; do echo; sleep 1; done) | while read; do
         printf "t=%2d s:" $i
@@ -165,7 +165,7 @@ ovsdb|WARN|schema: changed 2 columns in 'OVN_Southbound' database from ephemeral
             break
         fi
 
-        case $phase in # (
+        case $(cat phase) in # (
         0)
             if test $done -ge $(expr $n1 / 4); then
                 if test $variant = kill; then
@@ -173,7 +173,7 @@ ovsdb|WARN|schema: changed 2 columns in 'OVN_Southbound' database from ephemeral
                 else
                     remove_server $victim
                 fi
-                phase=1
+                echo 1 > phase
                 next=$(expr $i + 2)
             fi
             ;; # (
@@ -185,7 +185,7 @@ ovsdb|WARN|schema: changed 2 columns in 'OVN_Southbound' database from ephemeral
                 else
                     add_server $victim
                 fi
-                phase=2
+                echo 2 > phase
             fi
             ;;
         esac
@@ -193,7 +193,7 @@ ovsdb|WARN|schema: changed 2 columns in 'OVN_Southbound' database from ephemeral
         i=$(expr $i + 1)
     done
     echo "...done"
-    AT_CHECK([if test $phase != 2; then exit 77; fi])
+    AT_CHECK([if test $(cat phase) != 2; then exit 77; fi])
 
     for i in $(seq 0 $(expr $n1 - 1) ); do
         for j in `seq $n2`; do
@@ -203,7 +203,7 @@ ovsdb|WARN|schema: changed 2 columns in 'OVN_Southbound' database from ephemeral
     AT_CHECK([ovn-sbctl --timeout=30 --log-file=finalize.log -vtimeval:off -vfile -vsyslog:off --bare get SB_Global . external-ids | sed 's/, /\n/g; s/[[{}""]]//g;' | sort], [0], [expout])
 
     for i in `seq $n`; do
-        if test $i != $victim || test $phase != 1; then
+        if test $i != $victim || test $(cat phase) != 1; then
             stop_server $i
         fi
     done