SERVER-21421 Update concurrency suite's ThreadManager constructor to provide default executionMode

(cherry picked from commit 23a61625841080dae2cf0e07e7aadad0e1424722)

2 files changed, 2 insertions, 2 deletions

diff --git a/jstests/concurrency/fsm_libs/runner.js b/jstests/concurrency/fsm_libs/runner.js
index 62df7f62574..09f788a8a59 100644
--- a/jstests/concurrency/fsm_libs/runner.js
+++ b/jstests/concurrency/fsm_libs/runner.js
@@ -596,7 +596,7 @@ var runner = (function() {
         var bgWorkloads = executionOptions.backgroundWorkloads;
         loadWorkloadContext(bgWorkloads, bgContext, executionOptions,
                             false /* applyMultipliers */);
-        var bgThreadMgr = new ThreadManager(clusterOptions, { composed: false });
+        var bgThreadMgr = new ThreadManager(clusterOptions);
 
         var cluster = new Cluster(clusterOptions);
         if (cluster.isSharded()) {
diff --git a/jstests/concurrency/fsm_libs/thread_mgr.js b/jstests/concurrency/fsm_libs/thread_mgr.js
index d2a1cb99243..6952719c173 100644
--- a/jstests/concurrency/fsm_libs/thread_mgr.js
+++ b/jstests/concurrency/fsm_libs/thread_mgr.js
@@ -7,7 +7,7 @@ load('jstests/concurrency/fsm_libs/worker_thread.js'); // for workerThread
  * Helper for spawning and joining worker threads.
  */
 
-var ThreadManager = function(clusterOptions, executionMode) {
+var ThreadManager = function(clusterOptions, executionMode = { composed: false }) {
     if (!(this instanceof ThreadManager)) {
         return new ThreadManager(clusterOptions, executionMode);
     }