Tests/Docs: Update recommendations on waiting on applications

Change-Id: I0d79924b45f3cfa032348f2c90ffb8f80aa2b42c
Signed-off-by: Kienan Stewart <kstewart@efficios.com>
Signed-off-by: Jérémie Galarneau <jeremie.galarneau@efficios.com>

diff --git a/tests/README.adoc b/tests/README.adoc
index 10adcb75e0abbd85fbac3432d674185755b772b0..ba8fa2eba38c2010fc2c08e74924df7a7a38a808 100644 (file)
--- a/tests/README.adoc
+++ b/tests/README.adoc
@@ -169,8 +169,20 @@ by kill and wait.
 
 Why is it flaky ?
 
-It just waits for the last application put in background. Use
-"wait" to wait for all background applications.
+It just waits for the last application put in background. Track the PIDs
+of the applications of interest in an array and use a construction similar
+to the following to wait for them:
+
+```
+## Avoid running `wait ` when the array is empty
+if [[ -n "${pids[*]}" ]]; then
+   wait "${pids[@]}"`
+fi
+```
+
+Avoid `wait` without arguments as it will wait for other background
+prcesses such as lttng-relayd or lttng-sessiond when they are started
+without daemonization.
 
 === Forgetting wait at the end (or error return path) of a test phase that has background applications