src/test/osd/safe-to-destroy.sh: Add parallelism

This patch is about adding some parallelism into this test.
Every "action" to test is spawn in a subshell with a custom testing env:
- a separate directory
- a different cluster id
- a different port

This way it is possible spawning several tests in parallel. The pids are
stored in bash arrays and the exit status are double-checked after the
run.

Regarding the exit code, the pass is reported as passed or failed.

This patch is saving 55 seconds.

Before: 1/1 Test ceph#135: safe-to-destroy.sh ...............   Passed  126.26 sec
After : 1/1 Test ceph#135: safe-to-destroy.sh ...............   Passed   71.47 sec
Signed-off-by: Erwan Velu <erwan@redhat.com>

src/test/osd/safe-to-destroy.sh

@@ -4,22 +4,70 @@ source $CEPH_ROOT/qa/standalone/ceph-helpers.sh
 
 set -e
 
+function do_test() {
+  action=$1
+  # Each test have a separate directory
+  dir=$2_$action
+  # Let's define a port per test
+  port=$((7227 + $3))
+  CEPH_DISK_ARGS+=" --statedir=$dir"
+  CEPH_DISK_ARGS+=" --sysconfdir=$dir"
+
+  export CEPH_MON="127.0.0.1:$port"
+  export CEPH_ARGS
+  CEPH_ARGS+=" --fsid=$(uuidgen)"
+  CEPH_ARGS+=" --auth-supported=none"
+  CEPH_ARGS+=" --mon-host=$CEPH_MON"
+  setup $dir || exit 1
+  set -x
+  $action $dir || exit 1
+  set +x
+  teardown $dir || exit 1
+  exit 0
+}
+
+
 function run() {
     local dir=$1
     shift
 
-    export CEPH_MON="127.0.0.1:7227" # git grep '\<7227\>' : there must be only one
-    export CEPH_ARGS
-    CEPH_ARGS+="--fsid=$(uuidgen) --auth-supported=none "
-    CEPH_ARGS+="--mon-host=$CEPH_MON "
     set -e
 
     local funcs=${@:-$(set | sed -n -e 's/^\(TEST_[0-9a-z_]*\) .*/\1/p')}
+    local actions=()
     for func in $funcs ; do
-        setup $dir || return 1
-	$func $dir || return 1
-        teardown $dir || return 1
+      actions+=($func)
+    done
+
+    pids=()
+    # For every defined action,
+    # let's start the test in a subshell
+    # And save the pid in the 'pids' array
+    for action in ${actions[*]}; do
+      (do_test $action $dir ${#pids[*]}) &
+      pids+=($!)
     done
+
+    failed=""
+    pos=0
+    # For every pid we have spawn
+    # let's check the exit code
+    # and save the name of the broken ones
+    for pid in ${pids[*]}; do
+      wait $pid
+      if [ $? -ne 0 ]; then
+        failed="$failed ${actions[$pos]}"
+      fi
+      pos=$(($pos + 1))
+    done
+
+    # If at least one test failed, let's return 1
+    if [ -n "$failed" ]; then
+      echo "Failed tests are $failed"
+      return 1
+    fi
+
+    return 0
 }
 
 function TEST_safe_to_destroy() {