From d454224a4d07d3baa4bd1fdf9e7f4e3a6e2a4e94 Mon Sep 17 00:00:00 2001
From: Jeremy Hayes <jeremy@lunarg.com>
Date: Tue, 18 Dec 2018 13:35:31 -0700
Subject: [PATCH] tests: Flock the implicit layer test

Fix #121

Change-Id: I2e060a3ddda3bf919d6be8a3e0af7169ac0fee63
---
 tests/run_extra_loader_tests.sh | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/tests/run_extra_loader_tests.sh b/tests/run_extra_loader_tests.sh
index c29e5737..86d1f59a 100755
--- a/tests/run_extra_loader_tests.sh
+++ b/tests/run_extra_loader_tests.sh
@@ -101,6 +101,11 @@ RunImplicitLayerTest()
     echo "ImplicitLayer test PASSED"
 }
 
-! RunImplicitLayerTest && echo "ImplicitLayer test FAILED" >&2 && exit 1
+# Prevent the implicit layer test from running concurrently with itself in another process.
+# i.e. flock the following command subshell with an automatic file descriptor.
+filename=${0##*/}
+(
+    flock "$filedesc" && ! RunImplicitLayerTest && echo "ImplicitLayer test FAILED" >&2 && exit 1
+){filedesc}>"/tmp/$filename.lockfile"
 
 popd > /dev/null