feat: start loading some stuff async

destrum/include/destrum/App.h

@@ -89,6 +89,7 @@ protected:
     bool cleanedUp{false};
 
 private:
+    void initDevices();
     void processEvents();
     void runFixedSteps();
     void handleSwapchainResize(bool& skipFrame);

destrum/src/App.cpp

@@ -70,13 +70,11 @@ void App::init(const AppParams& params)
             .maximized = params.startMaximized,
         });
 
-        gfxDevice.init(window.GetHandle(), params.appName, false);
+        initDevices();
         imguiPass.init(window.GetHandle(), gfxDevice);
         resources.init(gfxDevice);
         renderer.init(gfxDevice, resources, params.renderSize);
 
-        InputManager::GetInstance().Init();
-        AudioSystem::GetInstance().Init();
         Time::GetInstance().Update();
 
         customInitStarted = true;
@@ -90,6 +88,31 @@ void App::init(const AppParams& params)
     }
 }
 
+void App::initDevices()
+{
+    ZoneScopedN("App::initDevices");
+    auto& jobs = JobSystem::GetInstance();
+    auto gfxInit = jobs.Async([this] { gfxDevice.init(window.GetHandle(), m_params.appName, false); });
+    auto audioInit = jobs.Async([] { AudioSystem::GetInstance().Init(); });
+
+    // SDL wants its subsystems initialised on the main thread
+    std::exception_ptr inputError;
+    try {
+        InputManager::GetInstance().Init();
+    } catch (...) {
+        inputError = std::current_exception();
+    }
+
+    // Wait for both before rethrowing anything, cleanup must not race a running init
+    gfxInit.wait();
+    audioInit.wait();
+    if (inputError) {
+        std::rethrow_exception(inputError);
+    }
+    gfxInit.get();
+    audioInit.get();
+}
+
 void App::attachLayer(std::unique_ptr<AppLayer> newLayer)
 {
     if (layer) {

destrum/src/Serialization/SceneSerializer.cpp

@@ -15,6 +15,7 @@
 #include <destrum/Serialization/GlmJson.h>
 #include <destrum/Serialization/MaterialSerialization.h>
 #include <destrum/Serialization/ObjectSerialization.h>
+#include <destrum/Threading/JobSystem.h>
 
 using json = nlohmann::json;
 
@@ -349,7 +350,5 @@ bool SceneSerializer::LoadFromJson(Scene& scene, const json& root) {
 
 std::future<SceneSerializer::LoadResult> SceneSerializer::LoadSceneFileAsync(
     const std::filesystem::path& path) {
-    return std::async(std::launch::async, [path]() {
+    return JobSystem::GetInstance().Async([path] { return LoadSceneFile(path); });
-        return LoadSceneFile(path);
-    });
 }

editor/src/AssetBrowser.cpp

@@ -15,6 +15,7 @@
 #include <destrum/FS/AssetFS.h>
 #include <destrum/Graphics/Material.h>
 #include <destrum/Serialization/MaterialSerialization.h>
+#include <destrum/Threading/JobSystem.h>
 #include <destrum/Util/ImGuiUtils.h>
 
 namespace {
@@ -219,7 +220,7 @@ void AssetBrowser::StartCook()
         return;
     }
 
-    m_Cook = std::async(std::launch::async, [commands = std::move(commands)] {
+    m_Cook = JobSystem::GetInstance().Async([commands = std::move(commands)] {
         bool succeeded = true;
         for (const std::string& command : commands) {
             succeeded = std::system(command.c_str()) == 0 && succeeded;

editor/src/ShaderHotReload.cpp

@@ -6,6 +6,8 @@
 
 #include <spdlog/spdlog.h>
 
+#include <destrum/Threading/JobSystem.h>
+
 namespace {
     constexpr float PollInterval = 0.5f;
 
@@ -48,7 +50,7 @@ void ShaderHotReload::StartCook()
     // cmd.exe strips the outer quotes, the inner ones keep paths with spaces intact
     const std::string command = "\"\"" + m_Cooker.string() + "\" --input \"" + m_SourceRoot.string() +
                                 "\" --output \"" + m_RuntimeRoot.string() + "\"\"";
-    m_Cook = std::async(std::launch::async, [command] { return std::system(command.c_str()); });
+    m_Cook = JobSystem::GetInstance().Async([command] { return std::system(command.c_str()); });
     spdlog::info("Shader sources changed, cooking engine assets");
 }
 

tests/jobs_tests.cpp

@@ -1,9 +1,12 @@
 #include <atomic>
 #include <chrono>
+#include <filesystem>
+#include <fstream>
 #include <stdexcept>
 #include <thread>
 #include <vector>
 
+#include <destrum/Serialization/SceneSerializer.h>
 #include <destrum/Threading/JobSystem.h>
 
 #include "TestUtils.h"
@@ -143,6 +146,21 @@ namespace {
         check(!Jobs().IsRunning(), "job system should be stopped");
     }
 
+    void testLoadSceneFileAsync()
+    {
+        Jobs().Init(2);
+        const auto path = std::filesystem::temp_directory_path() / "destrum_async_scene.json";
+        std::ofstream{path} << R"({"version":2,"name":"async","objects":[]})";
+
+        auto good = SceneSerializer::LoadSceneFileAsync(path);
+        auto missing = SceneSerializer::LoadSceneFileAsync(path.parent_path() / "destrum_no_such_scene.json");
+        check(good.get().success, "async scene load should parse a valid file");
+        check(!missing.get().success, "async scene load should report a missing file");
+
+        std::filesystem::remove(path);
+        Jobs().Shutdown();
+    }
+
     void testRunsInlineWhenStopped()
     {
         check(!Jobs().IsRunning(), "job system should start stopped");
@@ -164,4 +182,5 @@ void RunJobsTests()
     testAsyncRethrows();
     testMainThreadQueue();
     testShutdownDrainsPendingJobs();
+    testLoadSceneFileAsync();
 }