Own brush workers and thin preview/platform seams

src/legacy_brush_package_export_services.cpp

@@ -7,12 +7,90 @@
 #include "node_dialog_export_ppbr.h"
 #include "node_panel_brush.h"
 
+#include <condition_variable>
+#include <deque>
+#include <functional>
 #include <string>
+#include <mutex>
+#include <stop_token>
 #include <thread>
 
 namespace pp::panopainter {
 namespace {
 
+class LegacyBrushPackageWorker final {
+public:
+    LegacyBrushPackageWorker()
+        : worker_([this](std::stop_token stop_token) {
+            run(stop_token);
+        })
+    {
+    }
+
+    ~LegacyBrushPackageWorker()
+    {
+        shutdown();
+    }
+
+    void post(std::function<void()> task)
+    {
+        {
+            std::lock_guard<std::mutex> lock(mutex_);
+            if (stopping_)
+                return;
+            tasks_.push_back(std::move(task));
+        }
+        cv_.notify_one();
+    }
+
+private:
+    void shutdown()
+    {
+        {
+            std::lock_guard<std::mutex> lock(mutex_);
+            stopping_ = true;
+        }
+        cv_.notify_all();
+    }
+
+    void run(std::stop_token stop_token)
+    {
+        for (;;) {
+            std::function<void()> task;
+            {
+                std::unique_lock<std::mutex> lock(mutex_);
+                cv_.wait(lock, [&] {
+                    return stopping_ || stop_token.stop_requested() || !tasks_.empty();
+                });
+                if ((stopping_ || stop_token.stop_requested()) && tasks_.empty())
+                    break;
+                task = std::move(tasks_.front());
+                tasks_.pop_front();
+            }
+
+            if (task) {
+                try {
+                    task();
+                } catch (...) {
+                    LOG("brush package export worker task failed");
+                }
+            }
+        }
+    }
+
+    std::mutex mutex_;
+    std::condition_variable cv_;
+    std::deque<std::function<void()>> tasks_;
+    bool stopping_ = false;
+    std::jthread worker_;
+};
+
+LegacyBrushPackageWorker& brush_package_worker()
+{
+    static LegacyBrushPackageWorker worker;
+    return worker;
+}
+
 NodePanelBrushPreset::PPBRInfo to_legacy_ppbr_info(
     const pp::app::BrushPackageExportRequest& request,
     const NodeDialogExportPPBR& dialog)
@@ -44,20 +122,29 @@ public:
     {
         const auto path_string = std::string(path);
         const auto info = to_legacy_ppbr_info(request, dialog_);
+        auto presets = app_.presets;
         if (mode_ == LegacyBrushPackageExportMode::desktop_async_close_and_message) {
             auto* app = &app_;
-            auto* dialog = &dialog_;
-            std::thread([app, dialog, path_string, info] {
+            auto dialog = std::static_pointer_cast<NodeDialogExportPPBR>(dialog_.shared_from_this());
+            brush_package_worker().post([app, presets, dialog, path_string, info] {
                 BT_SetTerminate();
-                app->presets->export_ppbr(path_string, info);
-                pp::panopainter::close_legacy_dialog_node(*dialog);
+                if (presets) {
+                    presets->export_ppbr(path_string, info);
+                }
                 const auto plan = pp::app::plan_brush_package_export_success_dialog(path_string);
-                app->message_box(plan.title, plan.message, plan.show_cancel);
-            }).detach();
+                app->ui_task([dialog, plan] {
+                    if (dialog) {
+                        pp::panopainter::close_legacy_dialog_node(*dialog);
+                    }
+                    App::I->message_box(plan.title, plan.message, plan.show_cancel);
+                });
+            });
             return;
         }
 
-        app_.presets->export_ppbr(path_string, info);
+        if (presets) {
+            presets->export_ppbr(path_string, info);
+        }
     }
 
 private: