SERVER-29937 Make sure liveness timeouts cannot be missed

2 files changed, 10 insertions, 0 deletions

diff --git a/src/mongo/executor/task_executor.h b/src/mongo/executor/task_executor.h
index 22146268788..8fd2149f524 100644
--- a/src/mongo/executor/task_executor.h
+++ b/src/mongo/executor/task_executor.h
@@ -200,6 +200,8 @@ public:
     /**
      * Schedules "work" to be run by the executor no sooner than "when".
      *
+     * If "when" is <= now(), then it schedules the "work" to be run ASAP.
+     *
      * Returns a handle for waiting on or canceling the callback, or
      * ErrorCodes::ShutdownInProgress.
      *
diff --git a/src/mongo/executor/task_executor_test_common.cpp b/src/mongo/executor/task_executor_test_common.cpp
index 7532dc09569..a3e0b784034 100644
--- a/src/mongo/executor/task_executor_test_common.cpp
+++ b/src/mongo/executor/task_executor_test_common.cpp
@@ -330,14 +330,22 @@ COMMON_EXECUTOR_TEST(ScheduleWorkAt) {
     Status status1 = getDetectableErrorStatus();
     Status status2 = getDetectableErrorStatus();
     Status status3 = getDetectableErrorStatus();
+    Status status4 = getDetectableErrorStatus();
+
     const Date_t now = net->now();
     const TaskExecutor::CallbackHandle cb1 = unittest::assertGet(executor.scheduleWorkAt(
         now + Milliseconds(100), stdx::bind(setStatus, stdx::placeholders::_1, &status1)));
+    const TaskExecutor::CallbackHandle cb4 = unittest::assertGet(executor.scheduleWorkAt(
+        now - Milliseconds(50), stdx::bind(setStatus, stdx::placeholders::_1, &status4)));
     unittest::assertGet(executor.scheduleWorkAt(
         now + Milliseconds(5000), stdx::bind(setStatus, stdx::placeholders::_1, &status3)));
     const TaskExecutor::CallbackHandle cb2 = unittest::assertGet(executor.scheduleWorkAt(
         now + Milliseconds(200),
         stdx::bind(setStatusAndShutdown, stdx::placeholders::_1, &status2)));
+
+    executor.wait(cb4);
+    ASSERT_OK(status4);
+
     const Date_t startTime = net->now();
     net->enterNetwork();
     net->runUntil(startTime + Milliseconds(200));