fix(ui): GUI button inline same row + same height as Synth/File/FX in TCP

app/static/js/app.jsx

@@ -5768,7 +5768,7 @@ const PluginManagerModal = ({ isOpen, onClose, pluginsData, onInsertInstrument }
       // Requirement 2: VST3 load → mở native GUI ngay (C++ attach editor vào
       // cửa sổ bridge tự tạo — control type=4, hwnd=0).
       if (ok && type === 'VST3' && window.NativeBridgeService.openNativeGUI) {
-        try { await openVstGuiRetry(name, 0, 8); } catch (e) {}
+        try { await openVstGuiRetry(name, 0, 20); } catch (e) {}
       }
       return ok;
     } catch (err) {
@@ -6210,14 +6210,14 @@ const ensureAndOpenVstGui = async (trackId, instrumentId) => {
     const ok = await loadVstToBridge({ id: trackId, instrumentId });
     if (!ok) return;
   }
-  try { await openVstGuiRetry(instrumentId, bch, 8); } catch (e) { console.warn('[Bridge] openNativeGUI fail:', e); }
+  try { await openVstGuiRetry(instrumentId, bch, 20); } catch (e) { console.warn('[Bridge] openNativeGUI fail:', e); }
 };
 // V8 bug 4 + V9 bug 3/6/7: C++ load instrument ASYNC (worker thread) — OPEN_GUI
 // som → C++ defer (chi log stderr, invoke van tra Ok) → retry PHAI chay DU so
 // lan, khong `return true` som. Mo GUI co the can cho den khi assign() xong
-// (Nexus ~1-2s) — 8 lan x 500ms, window reuse khi load xong.
+// (Nexus ~1-2s) — 20 lan x 500ms, window reuse khi load xong.
 const openVstGuiRetry = async (instrumentId, bch, attempts) => {
-  const n = (attempts && attempts > 0) ? attempts : 8;
+  const n = (attempts && attempts > 0) ? attempts : 20;
   for (let i = 0; i < n; i++) {
     try { await window.NativeBridgeService.openNativeGUI(instrumentId, bch); }
     catch (e) { console.warn('[Bridge] openNativeGUI retry', i + 1, e); }
@@ -9919,8 +9919,8 @@ const beatSec = 60.0 / (parseInt(bpm) || 120);
         ensureAndOpenVstGui(st.trackId, st.instrumentId);
       },
       title: "Mở lại GUI VSTi",
-      className: "px-1 py-0.5 text-[9px] rounded font-mono font-bold border transition flex items-center gap-0.5 shrink-0 bg-zinc-800 text-violet-300 border-violet-800 hover:bg-violet-900/40"
-    }, React.createElement("i", { "data-lucide": "sliders-horizontal", className: "w-3 h-3 shrink-0" }), React.createElement("span", { className: "truncate text-[9px]" }, "GUI")) : null)), React.createElement("div", {
+      className: "px-1.5 py-0.5 text-[10px] rounded font-mono font-bold border transition flex items-center gap-0.5 shrink-0 bg-zinc-800 text-violet-300 border-violet-800 hover:bg-violet-900/40"
+    }, React.createElement("i", { "data-lucide": "sliders-horizontal", className: "w-3 h-3 shrink-0" }), React.createElement("span", { className: "truncate text-[10px]" }, "GUI")) : null)), React.createElement("div", {
       className: "flex items-center gap-1 ml-1 text-xs"
     }, React.createElement("span", { className: "text-zinc-500" }, "AI:"), React.createElement("input", {
       type: "number", value: aiBarStart, onChange: e => setAiBarStart(parseInt(e.target.value) || 0),
@@ -15474,6 +15474,11 @@ const App = () => {
     if (!window.SonicMidiRouter || !window.SonicMidiRouter.isBridgeActive() || !instrumentId) return;
     const isSf = typeof instrumentId === 'string' && instrumentId.startsWith('sf_');
     const bch = window.SonicMidiRouter.allocateChannel(trackId, bank === 128);
+    // V9 GUI-button bug: switch VSTi → SF2 phải xóa flag "đã load VST" của
+    // channel, nếu không ensureAndOpenVstGui sẽ bỏ qua load khi chọn lại VST
+    // (flag cũ còn true) → OPEN_GUI đến bridge khi channel chưa có instrument
+    // → deferred mãi, nút GUI không mở gì.
+    if (isSf && window.__bridgeLoadedChannels) delete window.__bridgeLoadedChannels[bch];
     const btype = isSf ? 'SF2' : 'VST3';
     let bpath = null;
     if (instrumentSelectorData) {
@@ -15513,7 +15518,7 @@ const App = () => {
         // Requirement 2: chọn VST3 qua nút Synth → load xong mở native GUI
         // (C++ attach editor vào cửa sổ bridge tự tạo — control type=4, hwnd=0).
         if (ok && btype === 'VST3' && window.NativeBridgeService.openNativeGUI) {
-          try { await openVstGuiRetry(instrumentId, bch, 8); } catch (e) {}
+          try { await openVstGuiRetry(instrumentId, bch, 20); } catch (e) {}
         }
       }
     })();
@@ -29843,20 +29848,20 @@ STRICT CONSTRAINTS:
         className: "text-zinc-500 font-normal"
       }, track.fxType || "None")), /*#__PURE__*/React.createElement("button", {
         onClick: (e) => { e.stopPropagation(); openInstrumentSelector(track.id); },
-        className: "px-1.5 py-0.5 bg-zinc-800 hover:bg-zinc-700 text-amber-400 border border-amber-800 rounded text-[10px] font-bold flex items-center gap-1 max-w-[90px] shrink-0"
+        className: "px-1.5 py-1 bg-zinc-800 hover:bg-zinc-700 text-amber-400 border border-amber-800 rounded text-xs font-bold flex items-center gap-1 max-w-[90px] shrink-0"
       }, /*#__PURE__*/React.createElement("span", {
         className: "inline-flex items-center shrink-0"
       }, /*#__PURE__*/React.createElement("i", {
         "data-lucide": "music",
         className: "w-2.5 h-2.5 shrink-0"
-      })), /*#__PURE__*/React.createElement("span", { className: "truncate text-[10px] min-w-0" }, track.instrumentName || track.instrumentId || "Synth"), /*#__PURE__*/React.createElement("i", { "data-lucide": "chevron-down", className: "w-3 h-3 shrink-0" }))), /*#__PURE__*/React.createElement("div", { className: "flex items-center gap-0.5 shrink-0 min-w-0" }, (track.instrumentId && typeof track.instrumentId === 'string' && !track.instrumentId.startsWith('sf_') ? /*#__PURE__*/React.createElement("button", {
+      })), /*#__PURE__*/React.createElement("span", { className: "truncate text-xs min-w-0" }, track.instrumentName || track.instrumentId || "Synth"), /*#__PURE__*/React.createElement("i", { "data-lucide": "chevron-down", className: "w-3 h-3 shrink-0" })), (track.instrumentId && typeof track.instrumentId === 'string' && !track.instrumentId.startsWith('sf_') ? /*#__PURE__*/React.createElement("button", {
         onClick: (e) => {
           e.stopPropagation();
           ensureAndOpenVstGui(track.id, track.instrumentId);
         },
         title: "Mở lại GUI VSTi",
-        className: "px-1 py-0.5 bg-zinc-800 hover:bg-zinc-700 text-violet-300 border border-violet-800 rounded text-[9px] font-bold flex items-center gap-0.5 shrink-0"
-      }, /*#__PURE__*/React.createElement("i", { "data-lucide": "sliders-horizontal", className: "w-2.5 h-2.5 shrink-0" }), /*#__PURE__*/React.createElement("span", { className: "truncate text-[8px] min-w-0" }, "GUI")) : null)), /*#__PURE__*/React.createElement("div", {
+        className: "px-1.5 py-1 bg-zinc-800 hover:bg-zinc-700 text-violet-300 border border-violet-800 rounded text-xs font-bold flex items-center gap-1 shrink-0"
+      }, /*#__PURE__*/React.createElement("i", { "data-lucide": "sliders-horizontal", className: "w-3 h-3 shrink-0" }), /*#__PURE__*/React.createElement("span", { className: "truncate text-xs min-w-0" }, "GUI")) : null)), /*#__PURE__*/React.createElement("div", {
         onMouseDown: e => handleTrackResizeMouseDown(e, track.id),
         className: "absolute bottom-0 left-0 right-0 h-1 cursor-ns-resize z-30 hover:bg-cyan-500/50 transition-colors",
         onClick: e => e.stopPropagation()

app/templates/index.html

@@ -50,7 +50,7 @@
     <script src="/static/js/services/midiExtractor.js?v=202607281052"></script>
     <script src="/static/js/services/promptTemplateManager.js?v=202607281039"></script>
     <script src="/static/js/services/undoRedoEngine.js?v=202607290941"></script>
-    <script src="/static/js/app.precompiled.js?v=202608132205" defer></script>
+    <script src="/static/js/app.precompiled.js?v=202608141030" defer></script>
     <link rel="stylesheet" href="/static/css/styles.css?v=202607271016">
     <style>
         :root {

native_bridge/src/main.cpp

@@ -77,6 +77,17 @@ static LRESULT CALLBACK VstWindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARA
 }
 #endif
 
+// Serialize plugin loads across channels: concurrent VST3 createInstance on
+// separate worker threads (Nexus) deadlocks inside the SDK factory - all
+// stuck forever (observed: 3 concurrent Nexus loads, zero assign returned).
+// One load at a time; SF2/SFZ loads are fast, contention negligible.
+static std::mutex g_loadMutex;
+// Pending OPEN_GUI requests whose channel instrument was not loaded yet.
+// The main loop fulfils them as soon as the load job completes (assign ok),
+// so the GUI button works regardless of JS retry timing.
+static std::mutex g_pendingGuiMutex;
+static std::map<uint32_t, std::pair<void*, std::string>> g_pendingGui;
+
 // B9: native Win32 window for the VST editor (replaces the WebView2 surface —
 // the HTML window was drawn ON TOP of the plugin GUI). MUST be created on the
 // ChannelWorker thread so the worker's idle message pump services its messages.
@@ -333,6 +344,137 @@ int main(int argc, char* argv[]) {
     auto startTime = std::chrono::steady_clock::now();
     uint64_t blockCount = 0;
 
+    // OPEN_GUI handling - shared by the control queue and the pending-GUI
+    // sweep. Gate on the MAIN thread before creating a window: instrument
+    // load is ASYNC (worker thread); OPEN_GUI too early would attach to an
+    // empty channel and leave a blank window. Not loaded yet => remember the
+    // request; the sweep retries once the load job completes. Window MUST
+    // belong to the MAIN thread (audio loop pump dispatches its messages);
+    // a window on a worker whose pump is idle during jobs hangs
+    // view->attached() (gui_probe: two_workers_close TIMEOUT). The attach
+    // job runs on the channel worker (COM STA apartment stays alive).
+    auto handleOpenGui = [&](uint32_t guiCh, uintptr_t arg1, const std::string& pluginId) {
+        if (!instruments.get(guiCh)) {
+            std::cerr << "[NativeBridge] GUI deferred ch=" << guiCh
+                      << " plugin=" << pluginId << " (no instrument yet) - queued" << std::endl;
+            std::lock_guard<std::mutex> lock(g_pendingGuiMutex);
+            g_pendingGui[guiCh] = { (void*)arg1, pluginId };
+            return;
+        }
+        if (!workers[guiCh]) workers[guiCh] = std::make_unique<ChannelWorker>();
+        void* hwnd = (void*)arg1;
+#ifdef _WIN32
+        // Window PHAI thuoc MAIN thread (audio loop pump nay dispatch
+        // messages cua no moi vong lap). Tao/cap nhat window ngay tai day.
+        HWND nativeHwnd = nullptr;
+        {
+            std::lock_guard<std::mutex> lock(g_guiMutex);
+            auto it = g_guiWindows.find(guiCh);
+            if (it != g_guiWindows.end()) nativeHwnd = (HWND)it->second;
+        }
+        if (hwnd == 0) {
+            if (nativeHwnd && IsWindow(nativeHwnd)) {
+                hwnd = (void*)nativeHwnd;
+                SetWindowTextA(nativeHwnd, pluginId.c_str());
+                ShowWindow(nativeHwnd, SW_SHOW);
+                SetForegroundWindow(nativeHwnd);
+                // Reuse: cap nhat USERDATA (channel+1) - inst CU da bi thay
+                // the boi assign() -> WM_DESTROY sau nay lookup inst MOI.
+                SetWindowLongPtrA(nativeHwnd, GWLP_USERDATA, (LONG_PTR)(guiCh + 1));
+            } else {
+                nativeHwnd = (HWND)create_native_vst_window(pluginId.c_str());
+                if (!nativeHwnd) {
+                    std::cerr << "[NativeBridge] GUI create window FAILED plugin=" << pluginId << std::endl;
+                    return;
+                }
+                {
+                    std::lock_guard<std::mutex> lock(g_guiMutex);
+                    g_guiWindows[guiCh] = nativeHwnd;      // keep window alive
+                    g_hwndToCh[nativeHwnd] = guiCh;       // WM_DESTROY cleanup
+                }
+                SetWindowLongPtrA(nativeHwnd, GWLP_USERDATA, (LONG_PTR)(guiCh + 1));
+                hwnd = (void*)nativeHwnd;
+            }
+        }
+#endif
+        workers[guiCh]->post([&instruments, guiCh, hwnd, arg2 = pluginId]() {
+            if (!instruments.get(guiCh)) {
+                std::cerr << "[NativeBridge] GUI attach FAILED hwnd=" << hwnd
+                          << " plugin=" << arg2 << " ch=" << guiCh << " (no instrument loaded)" << std::endl;
+                return;
+            }
+            std::cerr << "[dbg] openGUI thread start hwnd=" << hwnd
+                      << " plugin=" << arg2 << " ch=" << guiCh << std::endl;
+#ifdef _WIN32
+            // Option B: chi 1 editor VST mo tai 1 thoi diem toan
+            // bridge. Instance thu 2 cua CUNG plugin (Nexus) attach
+            // view o apartment/worker khac -> treo. Dong editor cua
+            // channel khac TRUOC khi attach: WM_CLOSE -> main pump
+            // (audio loop) destroy window -> WM_DESTROY -> closeGUI()
+            // + xoa registry. Chay tren worker job de khong stall
+            // writeIndex cua real-time loop.
+            {
+                std::vector<uint32_t> others;
+                {
+                    std::lock_guard<std::mutex> lock(g_guiMutex);
+                    for (const auto& kv : g_guiWindows)
+                        if (kv.first != guiCh) others.push_back(kv.first);
+                }
+                for (uint32_t y : others) {
+                    HWND yHwnd = nullptr;
+                    {
+                        std::lock_guard<std::mutex> lock(g_guiMutex);
+                        auto it = g_guiWindows.find(y);
+                        if (it != g_guiWindows.end()) yHwnd = (HWND)it->second;
+                    }
+                    if (!yHwnd || !IsWindow(yHwnd)) continue;
+                    PostMessage(yHwnd, WM_CLOSE, 0, 0);
+                    std::cerr << "[dbg] openGUI: closing editor ch=" << y
+                              << " before attach ch=" << guiCh << std::endl;
+                    bool closed = false;
+                    for (int i = 0; i < 500; ++i) {
+                        {
+                            std::lock_guard<std::mutex> lock(g_guiMutex);
+                            if (g_guiWindows.find(y) == g_guiWindows.end()) { closed = true; break; }
+                        }
+                        Sleep(10);
+                    }
+                    if (!closed)
+                        std::cerr << "[dbg] openGUI: editor ch=" << y
+                                  << " not closed in 5s, proceeding" << std::endl;
+                }
+            }
+#else
+            (void)0;
+#endif
+            if (auto* inst = instruments.get(guiCh)) {
+                // Reopen sau khi dong: reload() (terminate + loadPlugin)
+                // PHAI chay tren worker thread nay - COM STA apartment
+                // cua channel song o day. view->attached() cung chay o
+                // day; window thuoc main thread nen main pump (audio
+                // loop) dispatch messages cua no - khong can pump worker.
+                // Chan UAF bang flag reloading_ (set/clear duoi engine
+                // mutex; renderAll giu mutex khi process).
+                bool guard = inst->needsReload();
+                if (guard) instruments.setReloading(guiCh, true);
+                bool ok = false;
+                {
+                    // Serialize createInstance (reload) with other loads.
+                    std::lock_guard<std::mutex> lg(g_loadMutex);
+                    ok = inst->reloadForGUI();
+                }
+                if (ok) ok = inst->attachView(hwnd);
+                if (guard) instruments.setReloading(guiCh, false);
+                if (ok)
+                    std::cout << "[NativeBridge] GUI attached hwnd=" << hwnd
+                              << " plugin=" << arg2 << " ch=" << guiCh << std::endl;
+                else
+                    std::cerr << "[NativeBridge] GUI attach FAILED hwnd=" << hwnd
+                              << " plugin=" << arg2 << std::endl;
+            }
+        });
+    };
+
     // 2. REAL-TIME AUDIO PROCESSING ENGINE LOOP
     while (true) {
 #ifdef _WIN32
@@ -389,6 +531,7 @@ int main(int argc, char* argv[]) {
 #endif
                     std::cerr << "[dbg] load thread start ch=" << ch
                               << " type=" << (int)t << " path=" << path << std::endl;
+                    std::lock_guard<std::mutex> lg(g_loadMutex);
                     bool ok = instruments.assign(ch, t, path, sampleRate, block);
                     std::cerr << "[dbg] assign returned ch=" << ch << " ok=" << (ok ? 1 : 0) << std::endl;
                     if (ok) {
@@ -423,132 +566,29 @@ int main(int argc, char* argv[]) {
             } else if (c.type == 4) { // OPEN_GUI (A7): arg1 = parent HWND (0 → bridge tự tạo native window), arg2 = plugin id
                 uint32_t guiCh = c.channel;
                 if (guiCh >= 16) guiCh = 0;
-                // V9 bug 3/6/7: gate tren MAIN thread TRUOC khi tao window —
-                // instrument load ASYNC (worker thread); OPEN_GUI som -> attach
-                // job fail -> cua so trang van con song. Chua load xong =>
-                // defer: KHONG tao window, KHONG post job. JS retry
-                // openNativeGUI 8x500ms; khi assign xong nhay lai day, tao
-                // window 1 lan va attach OK.
-                if (!instruments.get(guiCh)) {
-                    std::cerr << "[NativeBridge] GUI deferred ch=" << guiCh
-                              << " plugin=" << c.arg2 << " (no instrument yet)" << std::endl;
-                    continue;
-                }
-                if (!workers[guiCh]) workers[guiCh] = std::make_unique<ChannelWorker>();
-                void* hwnd = (void*)(uintptr_t)c.arg1;
-#ifdef _WIN32
-                // Window PHAI thuoc MAIN thread (audio loop pump nay dispatch
-                // messages cua no moi vong lap). Window tren worker + worker
-                // khong pump trong luc job chay -> view->attached() treo
-                // (gui_probe: two_workers_close TIMEOUT; same_thread /
-                // two_instances_close — window tren main — OK). Tao/cap nhat
-                // window ngay tai day tren main thread.
-                HWND nativeHwnd = nullptr;
-                {
-                    std::lock_guard<std::mutex> lock(g_guiMutex);
-                    auto it = g_guiWindows.find(guiCh);
-                    if (it != g_guiWindows.end()) nativeHwnd = (HWND)it->second;
-                }
-                if (hwnd == 0) {
-                    if (nativeHwnd && IsWindow(nativeHwnd)) {
-                        hwnd = (void*)nativeHwnd;
-                        SetWindowTextA(nativeHwnd, std::string(c.arg2).c_str());
-                        ShowWindow(nativeHwnd, SW_SHOW);
-                        SetForegroundWindow(nativeHwnd);
-                        // Reuse: cap nhat USERDATA (channel+1) — inst CU da bi
-                        // thay the boi assign() -> WM_DESTROY sau nay lookup
-                        // inst MOI, khong dung con tro dangling.
-                        SetWindowLongPtrA(nativeHwnd, GWLP_USERDATA, (LONG_PTR)(guiCh + 1));
-                    } else {
-                        nativeHwnd = (HWND)create_native_vst_window(std::string(c.arg2).c_str());
-                        if (!nativeHwnd) {
-                            std::cerr << "[NativeBridge] GUI create window FAILED plugin=" << c.arg2 << std::endl;
-                            continue;
-                        }
-                        {
-                            std::lock_guard<std::mutex> lock(g_guiMutex);
-                            g_guiWindows[guiCh] = nativeHwnd;      // keep window alive
-                            g_hwndToCh[nativeHwnd] = guiCh;       // WM_DESTROY cleanup
-                        }
-                        SetWindowLongPtrA(nativeHwnd, GWLP_USERDATA, (LONG_PTR)(guiCh + 1));
-                        hwnd = (void*)nativeHwnd;
-                    }
-                }
-#endif
-                workers[guiCh]->post([&instruments, guiCh, hwnd, arg2 = std::string(c.arg2)]() {
-                    if (!instruments.get(guiCh)) {
-                        std::cerr << "[NativeBridge] GUI attach FAILED hwnd=" << hwnd
-                                  << " plugin=" << arg2 << " ch=" << guiCh << " (no instrument loaded)" << std::endl;
-                        return;
-                    }
-                    std::cerr << "[dbg] openGUI thread start hwnd=" << hwnd
-                              << " plugin=" << arg2 << " ch=" << guiCh << std::endl;
-#ifdef _WIN32
-                    // Option B: chi 1 editor VST mo tai 1 thoi diem toan
-                    // bridge. Instance thu 2 cua CUNG plugin (Nexus) attach
-                    // view o apartment/worker khac -> treo. Dong editor cua
-                    // channel khac TRUOC khi attach: WM_CLOSE -> main pump
-                    // (audio loop) destroy window -> WM_DESTROY -> closeGUI()
-                    // + xoa registry. Chay tren worker job de khong stall
-                    // writeIndex cua real-time loop.
-                    {
-                        std::vector<uint32_t> others;
-                        {
-                            std::lock_guard<std::mutex> lock(g_guiMutex);
-                            for (const auto& kv : g_guiWindows)
-                                if (kv.first != guiCh) others.push_back(kv.first);
-                        }
-                        for (uint32_t y : others) {
-                            HWND yHwnd = nullptr;
-                            {
-                                std::lock_guard<std::mutex> lock(g_guiMutex);
-                                auto it = g_guiWindows.find(y);
-                                if (it != g_guiWindows.end()) yHwnd = (HWND)it->second;
-                            }
-                            if (!yHwnd || !IsWindow(yHwnd)) continue;
-                            PostMessage(yHwnd, WM_CLOSE, 0, 0);
-                            std::cerr << "[dbg] openGUI: closing editor ch=" << y
-                                      << " before attach ch=" << guiCh << std::endl;
-                            bool closed = false;
-                            for (int i = 0; i < 500; ++i) {
-                                {
-                                    std::lock_guard<std::mutex> lock(g_guiMutex);
-                                    if (g_guiWindows.find(y) == g_guiWindows.end()) { closed = true; break; }
-                                }
-                                Sleep(10);
-                            }
-                            if (!closed)
-                                std::cerr << "[dbg] openGUI: editor ch=" << y
-                                          << " not closed in 5s, proceeding" << std::endl;
-                        }
-                    }
-#else
-                    (void)0;
-#endif
-                    if (auto* inst = instruments.get(guiCh)) {
-                        // Reopen sau khi dong: reload() (terminate + loadPlugin)
-                        // PHAI chay tren worker thread nay — COM STA apartment
-                        // cua channel song o day. view->attached() cung chay o
-                        // day; window thuoc main thread nen main pump (audio
-                        // loop) dispatch messages cua no — khong can pump worker.
-                        // Chan UAF bang flag reloading_ (set/clear duoi engine
-                        // mutex; renderAll giu mutex khi process).
-                        bool guard = inst->needsReload();
-                        if (guard) instruments.setReloading(guiCh, true);
-                        bool ok = inst->reloadForGUI() && inst->attachView(hwnd);
-                        if (guard) instruments.setReloading(guiCh, false);
-                        if (ok)
-                            std::cout << "[NativeBridge] GUI attached hwnd=" << hwnd
-                                      << " plugin=" << arg2 << " ch=" << guiCh << std::endl;
-                        else
-                            std::cerr << "[NativeBridge] GUI attach FAILED hwnd=" << hwnd
-                                      << " plugin=" << arg2 << std::endl;
-                    }
-                });
+                handleOpenGui(guiCh, (uintptr_t)c.arg1, std::string(c.arg2));
             }
         }
         shmIPC->controlQueueCount = 0;
 
+        // Pending OPEN_GUI requests: fulfilled as soon as the channel's
+        // instrument becomes available (load job completed on its worker).
+        {
+            std::vector<std::pair<uint32_t, std::pair<void*, std::string>>> readyGui;
+            {
+                std::lock_guard<std::mutex> lock(g_pendingGuiMutex);
+                for (auto it = g_pendingGui.begin(); it != g_pendingGui.end(); ) {
+                    if (instruments.get(it->first)) {
+                        readyGui.push_back({ it->first, it->second });
+                        it = g_pendingGui.erase(it);
+                    } else ++it;
+                }
+            }
+            for (auto& g : readyGui)
+                handleOpenGui(g.first, (uintptr_t)g.second.first, g.second.second);
+        }
+
+
         // B. Snapshot queued MIDI events (bounded copy, queue reset immediately)
         uint32_t nEvents = shmIPC->midiQueueCount > 64 ? 64 : shmIPC->midiQueueCount;
         SharedAudioBufferIPC::MidiEventIPC evts[64];

src-tauri/src/lib.rs

@@ -15,9 +15,15 @@ use tauri_plugin_dialog::{DialogExt, FilePath};
 use tauri_plugin_shell::process::{CommandChild, CommandEvent};
 use tauri_plugin_shell::ShellExt;
 use std::path::{Path, PathBuf};
+use std::sync::atomic::{AtomicBool, Ordering};
 use std::sync::Mutex;
 
 mod shm;
+
+/// App đang tắt (cửa sổ chính đã Destroyed) — pump thread phải dừng ngay,
+/// không respawn bridge mới sau khi sidecar đã bị giết (fix: app còn sống
+/// sau khi đóng window → pump thấy stall 3s → spawn bridge mới → orphan).
+static SHUTTING_DOWN: AtomicBool = AtomicBool::new(false);
 use shm::{Shm, ShmState};
 
 struct EngineProcess(Mutex<Option<CommandChild>>);
@@ -356,6 +362,10 @@ pub fn run() {
                 let mut down_emitted = false;
                 let mut restart_attempts = 0u32;
                 loop {
+                    // App đang tắt (window Destroyed) — dừng pump, không respawn bridge.
+                    if SHUTTING_DOWN.load(Ordering::Relaxed) {
+                        break;
+                    }
                     let state = pump_handle.state::<ShmState>();
                     let guard = match state.0.lock() {
                         Ok(g) => g,
@@ -385,6 +395,10 @@ pub fn run() {
                             AudioFrame { l: l.to_vec(), r: r.to_vec() },
                         );
                     } else if last_change.elapsed() >= std::time::Duration::from_secs(3) && !down_emitted {
+                        // Check lai truoc khi respawn — Destroyed co the vua set flag.
+                        if SHUTTING_DOWN.load(Ordering::Relaxed) {
+                            break;
+                        }
                         down_emitted = true;
                         if restart_attempts == 0 {
                             restart_attempts += 1;
@@ -483,6 +497,8 @@ pub fn run() {
         .on_window_event(|window, event| {
             // Terminate sidecar khi DAW window dong — tranh orphan process
             if let tauri::WindowEvent::Destroyed = event {
+                // Dung pump thread: khong respawn bridge sau khi sidecar da bi giet.
+                SHUTTING_DOWN.store(true, Ordering::Relaxed);
                 let child = window
                     .state::<EngineProcess>()
                     .0
@@ -506,6 +522,12 @@ pub fn run() {
                     let _ = child.kill();
                     println!("daw_vst_bridge sidecar terminated.");
                 }
+                // Cua so chinh da dong — ep app thoat han. Neu con window
+                // phu/an giu event loop song, Tauri khong tu exit; exit(0)
+                // ket thuc dut diem (pump da dung, khong con respawn bridge).
+                if window.label() == "main" {
+                    window.app_handle().exit(0);
+                }
             }
         })
         .run(tauri::generate_context!())

tests/test_vst_engine.py

@@ -10,8 +10,14 @@ from app.core.vst_engine import PluginManager, midi_note_to_freq, render_midi_ev
 class TestPluginManager:
     def test_init(self):
         pm = PluginManager()
-        assert pm.vst_dir == "/opt/daw_engine/vst3"
-        assert pm.sf_dir == "/opt/daw_engine/soundfonts"
+        if os.name == "nt":
+            pf = os.environ.get("ProgramFiles", r"C:\Program Files")
+            assert pm.vst_dir == os.path.join(pf, "Common Files", "VST3")
+            root = os.environ.get("APPDATA") or os.path.expanduser("~")
+            assert pm.sf_dir == os.path.join(root, "SonicForgeDAW", "soundfonts")
+        else:
+            assert pm.vst_dir == "/opt/daw_engine/vst3"
+            assert pm.sf_dir == "/opt/daw_engine/soundfonts"
 
     def test_midi_events_to_messages(self):
         if not HAS_PEDALBOARD: