Test framework, stage 3: newview's tests in Catch2

indra/alscript/masters/almasterwatch.cpp

@@ -26,6 +26,7 @@
 
 #include "almasterwatch.h"
 
+#include "almainloop.h"
 #include "alserialworker.h"
 #include "alwatchedfile.h"
 #include "llsingleton.h"
@@ -74,7 +75,7 @@ namespace
 ALMasterWatch::look_t ALMasterWatch::offThread()
 {
     return [](std::vector<std::string> paths, stamped_t found) {
-        const LL::WorkQueue::ptr_t main_loop = LL::WorkQueue::getInstance("mainloop");
+        const LL::WorkQueue::ptr_t main_loop = ALMainLoop::queue();
         if (!main_loop)
         {
             // No main loop to hand them back to -- a test -- so looked at

indra/llcommon/CMakeLists.txt

@@ -18,6 +18,7 @@ target_sources(
   llcommon
   PRIVATE
     alfilewrite.cpp
+    almainloop.cpp
     alserialworker.cpp
     alparamtype.cpp
     alrecoverystore.cpp
@@ -122,6 +123,7 @@ target_sources(
       FILES
         alfilewrite.h
         allinebreaks.h
+        almainloop.h
         alserialworker.h
         alparamtype.h
         alrandmap.h

indra/llcommon/almainloop.cpp

@@ -0,0 +1,57 @@
+/**
+ * @file almainloop.cpp
+ * @brief The queue the main loop services, and a test's say over it.
+ *
+ * $LicenseInfo:firstyear=2026&license=viewerlgpl$
+ * Alchemy Viewer Source Code
+ * Copyright (C) 2026, Rye <rye@alchemyviewer.org>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation;
+ * version 2.1 of the License only.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ * $/LicenseInfo$
+ */
+
+#include "linden_common.h"
+
+#include "almainloop.h"
+
+#include <atomic>
+
+namespace
+{
+    // Read from the threads that ask whether to hand back, so a choice made
+    // on the main thread is seen whole.
+    std::atomic<const ALMainLoop::Choice*> sChoice{ nullptr };
+}
+
+LL::WorkQueue::ptr_t ALMainLoop::queue()
+{
+    if (const Choice* choice = sChoice.load(std::memory_order_acquire))
+    {
+        return choice->mChosen;
+    }
+    return LL::WorkQueue::getInstance("mainloop");
+}
+
+ALMainLoop::Choice::Choice(LL::WorkQueue* chosen)
+    : mChosen(chosen ? LL::WorkQueue::getInstance(chosen->getKey()) : nullptr)
+    , mOuter(sChoice.load(std::memory_order_relaxed))
+{
+    sChoice.store(this, std::memory_order_release);
+}
+
+ALMainLoop::Choice::~Choice()
+{
+    sChoice.store(mOuter, std::memory_order_release);
+}

indra/llcommon/almainloop.h

@@ -0,0 +1,58 @@
+/**
+ * @file almainloop.h
+ * @brief The queue the main loop services, and a test's say over it.
+ *
+ * $LicenseInfo:firstyear=2026&license=viewerlgpl$
+ * Alchemy Viewer Source Code
+ * Copyright (C) 2026, Rye <rye@alchemyviewer.org>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation;
+ * version 2.1 of the License only.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ * $/LicenseInfo$
+ */
+
+#pragma once
+
+#include "workqueue.h"
+
+// The queue the viewer's main loop services: what work done on another
+// thread hands its result back through. Code that works off the main
+// thread asks here rather than for the queue by its name, so that a test
+// can say which way that code goes.
+namespace ALMainLoop
+{
+    // The main loop's queue, or null where nothing services one -- a test
+    // that has not chosen one -- and the work is done in place instead.
+    LL_COMMON_API LL::WorkQueue::ptr_t queue();
+
+    // While one lives, queue() answers the queue it was given, or null for
+    // none, whatever queue of the main loop's name there is. Without it a
+    // queue one test made would choose the way for every test after it in
+    // the process. The newest living one wins. Main thread only.
+    class LL_COMMON_API Choice
+    {
+    public:
+        explicit Choice(LL::WorkQueue* chosen);
+        ~Choice();
+
+        Choice(const Choice&)            = delete;
+        Choice& operator=(const Choice&) = delete;
+
+    private:
+        friend LL::WorkQueue::ptr_t queue();
+
+        LL::WorkQueue::ptr_t mChosen;
+        const Choice*        mOuter;
+    };
+}

indra/llcommon/alwatchedfile.cpp

@@ -26,6 +26,7 @@
 
 #include "alwatchedfile.h"
 
+#include "almainloop.h"
 #include "alserialworker.h"
 #include "fsyspath.h"
 #include "llerror.h"
@@ -188,7 +189,7 @@ class ALWatchedFile::Watcher : public std::enable_shared_from_this<Watcher>
         {
             return;
         }
-        const LL::WorkQueue::ptr_t main = LL::WorkQueue::getInstance("mainloop");
+        const LL::WorkQueue::ptr_t main = ALMainLoop::queue();
         if (!mWorker)
         {
             mWorker = std::make_unique<ALSerialWorker>("WatchedFiles");