SL-16220: Specialize WorkQueue for callable with void return.

Add a test exercising this feature.

2 files changed, 24 insertions, 3 deletions

diff --git a/indra/llcommon/tests/threadsafeschedule_test.cpp b/indra/llcommon/tests/threadsafeschedule_test.cpp
index af67b9f492..c421cc7b1c 100644
--- a/indra/llcommon/tests/threadsafeschedule_test.cpp
+++ b/indra/llcommon/tests/threadsafeschedule_test.cpp
@@ -46,11 +46,11 @@ namespace tut
         // the real time required for each push() call. Explicitly increment
         // the timestamp for each one -- but since we're passing explicit
         // timestamps, make the queue reorder them.
-        queue.push(Queue::TimeTuple(Queue::Clock::now() + 20ms, "ghi"));
+        queue.push(Queue::TimeTuple(Queue::Clock::now() + 200ms, "ghi"));
         // Given the various push() overloads, you have to match the type
         // exactly: conversions are ambiguous.
         queue.push("abc"s);
-        queue.push(Queue::Clock::now() + 10ms, "def");
+        queue.push(Queue::Clock::now() + 100ms, "def");
         queue.close();
         auto entry = queue.pop();
         ensure_equals("failed to pop first", std::get<0>(entry), "abc"s);
diff --git a/indra/llcommon/tests/workqueue_test.cpp b/indra/llcommon/tests/workqueue_test.cpp
index d5405400fd..b69df49d33 100644
--- a/indra/llcommon/tests/workqueue_test.cpp
+++ b/indra/llcommon/tests/workqueue_test.cpp
@@ -138,7 +138,8 @@ namespace tut
             [](){ return 17; },
             // Note that a postTo() *callback* can safely bind a reference to
             // a variable on the invoking thread, because the callback is run
-            // on the invoking thread.
+            // on the invoking thread. (Of course the bound variable must
+            // survive until the callback is called.)
             [&result](int i){ result = i; });
         // this should post the callback to main
         qptr->runOne();
@@ -156,4 +157,24 @@ namespace tut
         main.runPending();
         ensure_equals("failed to run string callback", alpha, "abc");
     }
+
+    template<> template<>
+    void object::test<5>()
+    {
+        set_test_name("postTo with void return");
+        WorkQueue main("main");
+        auto qptr = WorkQueue::getInstance("queue");
+        std::string observe;
+        main.postTo(
+            qptr,
+            // The ONLY reason we can get away with binding a reference to
+            // 'observe' in our work callable is because we're directly
+            // calling qptr->runOne() on this same thread. It would be a
+            // mistake to do that if some other thread were servicing 'queue'.
+            [&observe](){ observe = "queue"; },
+            [&observe](){ observe.append(";main"); });
+        qptr->runOne();
+        main.runOne();
+        ensure_equals("failed to run both lambdas", observe, "queue;main");
+    }
 } // namespace tut