RUST-609 Fix flaky maxConnecting test

Author: patrickfreed

src/test/spec/json/connection-monitoring-and-pooling/pool-checkout-maxConnecting-is-enforced.json

@@ -30,32 +30,31 @@
       "name": "start",
       "target": "thread1"
     },
-    {
-      "name": "checkOut",
-      "thread": "thread1"
-    },
     {
       "name": "start",
       "target": "thread2"
     },
     {
-      "name": "wait",
-      "thread": "thread2",
-      "ms": 100
+      "name": "start",
+      "target": "thread3"
     },
     {
       "name": "checkOut",
-      "thread": "thread2"
+      "thread": "thread1"
     },
     {
-      "name": "start",
-      "target": "thread3"
+      "name": "waitForEvent",
+      "event": "ConnectionCreated",
+      "count": 1
     },
     {
       "name": "wait",
-      "thread": "thread3",
       "ms": 100
     },
+    {
+      "name": "checkOut",
+      "thread": "thread2"
+    },
     {
       "name": "checkOut",
       "thread": "thread3"

src/test/spec/json/connection-monitoring-and-pooling/pool-checkout-maxConnecting-is-enforced.yml

@@ -18,29 +18,30 @@ poolOptions:
   maxPoolSize: 10
   waitQueueTimeoutMS: 5000
 operations:
-  # start creating a Connection. This will take a while
-  # due to the fail point.
+  # start 3 threads
   - name: start
     target: thread1
+  - name: start
+    target: thread2
+  - name: start
+    target: thread3
+  # start creating a Connection. This will take a while
+  # due to the fail point.
   - name: checkOut
     thread: thread1
-  # Start 2 new threads that wait for a little then try
-  # to check out connections. Only one thread should
+  # wait for thread1 to actually start creating a Connection
+  - name: waitForEvent
+    event: ConnectionCreated
+    count: 1
+  # wait some more time to ensure thread1 has begun establishing a Connection
+  - name: wait
+    ms: 100
+  # start 2 check out requests. Only one thread should
   # start creating a Connection and the other one should be
   # waiting for pendingConnectionCount to be less than maxConnecting,
   # only starting once thread1 finishes creating its Connection.
-  - name: start
-    target: thread2
-  - name: wait
-    thread: thread2
-    ms: 100
   - name: checkOut
     thread: thread2
-  - name: start
-    target: thread3
-  - name: wait
-    thread: thread3
-    ms: 100
   - name: checkOut
     thread: thread3
   # wait until all Connections have been created.