From afe42be6720f98939a76eb0e956ba7d43ff4c060 Mon Sep 17 00:00:00 2001 From: dijunkun Date: Thu, 17 Sep 2026 00:42:41 +0800 Subject: [PATCH] [chore] add end-to-end mouse input diagnostics --- .../src/gui/application/gui_application.cpp | 54 +++++++++++- .../devices/session_device_manager.cpp | 7 +- .../features/devices/session_device_manager.h | 3 +- .../src/gui/runtime/mouse_input_trace.h | 88 +++++++++++++++++++ .../src/gui/runtime/peer_data_callbacks.cpp | 35 +++++++- .../src/gui/runtime/peer_event_handler.cpp | 7 ++ .../src/gui/runtime/peer_event_handler.h | 9 +- apps/desktop/src/gui/runtime/remote_session.h | 3 + apps/desktop/src/gui/ui/stream_window.slint | 4 + deps/submodules/minirtc | 2 +- docs/MOUSE_INPUT_DIAGNOSTICS.md | 45 ++++++++++ 11 files changed, 245 insertions(+), 12 deletions(-) create mode 100644 apps/desktop/src/gui/runtime/mouse_input_trace.h create mode 100644 docs/MOUSE_INPUT_DIAGNOSTICS.md diff --git a/apps/desktop/src/gui/application/gui_application.cpp b/apps/desktop/src/gui/application/gui_application.cpp index 7c3fdb52..f5acd63a 100644 --- a/apps/desktop/src/gui/application/gui_application.cpp +++ b/apps/desktop/src/gui/application/gui_application.cpp @@ -35,6 +35,7 @@ #include "platform/video_renderer.h" #include "rendering/slint_video_presenter.h" #include "runtime/privacy_control_state.h" +#include "runtime/mouse_input_trace.h" #if _WIN32 #include @@ -878,6 +879,7 @@ void DragWindow(WindowHandle& component, int phase, float mouse_x, } // namespace struct GuiApplication::SlintUi { + MouseTraceState unrouted_mouse_trace; slint::ComponentHandle main = ui::MainWindow::create(); std::shared_ptr> release_note_blocks_model = @@ -1737,6 +1739,22 @@ void GuiApplication::BindStreamCallbacks() { CloseStreamTab(props->remote_id_); } }); + stream->on_pointer_observed([this](slint::PointerEventButton button, + slint::PointerEventKind kind, + bool local_ui, bool dragging, + bool suppressed) { + auto props = SelectedSession(); + auto& state = props ? props->mouse_ui_trace_ : ui_->unrouted_mouse_trace; + const auto ticket = state.Next(); + if (ticket.sampled) { + LOG_INFO("Mouse UI event: peer=[{}] event={} mono_us={} button={} kind={} " + "local_ui={} dragging={} suppressed={} window_focus={}", + props ? props->remote_id_ : "none", ticket.event, + ticket.started_us, static_cast(button), + static_cast(kind), local_ui, dragging, suppressed, + focus_on_stream_window_); + } + }); stream->on_pointer_input([this](slint::PointerEventButton button, slint::PointerEventKind kind, float x, float y) { @@ -2448,6 +2466,7 @@ void GuiApplication::SyncStreamWindow() { (*ui_->stream)->set_stats_rows(ui_->stats_model); BindStreamCallbacks(); (*ui_->stream)->show(); + LOG_INFO("Mouse UI stream window shown"); // Repeat after the next layout pass because the backend resolves the // initial DPI and preferred size asynchronously on some platforms. ui_->stream_initial_position_attempts = 2; @@ -3141,6 +3160,9 @@ void GuiApplication::SelectStreamTab(int index) { } const std::string selected_remote_id = ui_->tab_ids[index]; const bool selection_changed = focused_remote_id_ != selected_remote_id; + if (selection_changed) { + LOG_INFO("Mouse UI selected peer=[{}]", selected_remote_id); + } bool renderer_selection_changed = false; if (!controlled_remote_id_.empty() && controlled_remote_id_ != selected_remote_id) { @@ -3245,7 +3267,12 @@ GuiApplication::SelectedSession() { void GuiApplication::SendPointerInput(int button, int kind, float x, float y) { auto props = SelectedSession(); + MouseInputTrace trace(props ? &props->mouse_send_trace_ : + &ui_->unrouted_mouse_trace, + props ? props->remote_id_ : "none", "pointer"); if (!props || !props->peer_ || !props->control_mouse_ || !ui_->stream) { + trace.Result(!props ? "no_session" : !props->peer_ ? "no_peer" : + !props->control_mouse_ ? "control_disabled" : "no_window"); return; } @@ -3279,11 +3306,13 @@ void GuiApplication::SendPointerInput(int button, int kind, float x, float y) { } if (x < offset_x || x > offset_x + render_width || y < offset_y || y > offset_y + render_height) { + trace.Result("outside_video"); return; } RemoteAction action{}; action.type = ControlType::mouse; + trace.Result("unsupported_pointer_event"); action.m.x = std::clamp((x - offset_x) / render_width, 0.0f, 1.0f); action.m.y = std::clamp((y - offset_y) / render_height, 0.0f, 1.0f); // Slint enum order: Cancel=0, Down=1, Up=2, Move=3 and @@ -3314,18 +3343,30 @@ void GuiApplication::SendPointerInput(int button, int kind, float x, float y) { controlled_remote_id_ = props->remote_id_; const std::string message = action.to_json(); + trace.Result("pending"); + trace.Payload(message.data(), message.size()); + trace.Stage("cursor_state"); { std::lock_guard lock(props->remote_cursor_state_mutex_); props->cursor_presentation_.NoteInput(SDL_GetTicks()); } - SendDataFrame(props->peer_, message.c_str(), message.size(), - props->mouse_label_.c_str()); + trace.Stage("send_api"); + const int ret = SendDataFrame(props->peer_, message.c_str(), message.size(), + props->mouse_label_.c_str()); + // This API may only acknowledge dispatch. The transport logs the actual + // ICE send result separately using the same payload tag. + trace.Result("send_api_returned", ret, ret != 0); } void GuiApplication::SendScrollInput(float delta_x, float delta_y, float x, float y) { auto props = SelectedSession(); + MouseInputTrace trace(props ? &props->mouse_send_trace_ : + &ui_->unrouted_mouse_trace, + props ? props->remote_id_ : "none", "scroll"); if (!props || !props->peer_ || !props->control_mouse_ || !ui_->stream) { + trace.Result(!props ? "no_session" : !props->peer_ ? "no_peer" : + !props->control_mouse_ ? "control_disabled" : "no_window"); return; } const auto size = (*ui_->stream)->window().size(); @@ -3340,6 +3381,7 @@ void GuiApplication::SendScrollInput(float delta_x, float delta_y, float x, (fullscreen_button_pressed_ ? 0.0f : (ui_->tab_ids.size() > 1 ? 30.0f : 0.0f)); if (width <= 0 || height <= 0) { + trace.Result("invalid_geometry"); return; } RemoteAction action{}; @@ -3354,6 +3396,7 @@ void GuiApplication::SendScrollInput(float delta_x, float delta_y, float x, action.m.s = delta_x > 0 ? 1 : delta_x < 0 ? -1 : 0; } if (action.m.s == 0) { + trace.Result("zero_scroll"); return; } { @@ -3362,8 +3405,11 @@ void GuiApplication::SendScrollInput(float delta_x, float delta_y, float x, } controlled_remote_id_ = props->remote_id_; const std::string message = action.to_json(); - SendDataFrame(props->peer_, message.c_str(), message.size(), - props->mouse_label_.c_str()); + trace.Payload(message.data(), message.size()); + trace.Stage("send_api"); + const int ret = SendDataFrame(props->peer_, message.c_str(), message.size(), + props->mouse_label_.c_str()); + trace.Result("send_api_returned", ret, ret != 0); } void GuiApplication::SendKeyInput(const std::string& text, bool pressed, diff --git a/apps/desktop/src/gui/features/devices/session_device_manager.cpp b/apps/desktop/src/gui/features/devices/session_device_manager.cpp index 3ffe2667..0fdb8c78 100644 --- a/apps/desktop/src/gui/features/devices/session_device_manager.cpp +++ b/apps/desktop/src/gui/features/devices/session_device_manager.cpp @@ -370,6 +370,8 @@ int SessionDeviceManager::StartMouseController() { } const int init_ret = mouse_controller_->Init(display_info_list_); + LOG_INFO("Mouse controller initialization: ret={}, displays={}", init_ret, + display_info_list_.size()); if (init_ret != 0) { LOG_INFO("Destroy mouse controller"); mouse_controller_->Destroy(); @@ -632,11 +634,12 @@ bool SessionDeviceManager::SendKeyboardCommand(int key_code, bool is_down, key_code, is_down, scan_code, extended) == 0; } -void SessionDeviceManager::SendMouseCommand(const RemoteAction &action, +int SessionDeviceManager::SendMouseCommand(const RemoteAction &action, int selected_display) { if (mouse_controller_) { - mouse_controller_->SendMouseCommand(action, selected_display); + return mouse_controller_->SendMouseCommand(action, selected_display); } + return -2; } int SessionDeviceManager::SwitchDisplay(int display_id) { diff --git a/apps/desktop/src/gui/features/devices/session_device_manager.h b/apps/desktop/src/gui/features/devices/session_device_manager.h index 28365c19..66966338 100644 --- a/apps/desktop/src/gui/features/devices/session_device_manager.h +++ b/apps/desktop/src/gui/features/devices/session_device_manager.h @@ -70,7 +70,8 @@ public: bool SendKeyboardCommand(int key_code, bool is_down, uint32_t scan_code, bool extended); - void SendMouseCommand(const RemoteAction &action, int selected_display); + // -2 means the mouse controller has not been initialized. + int SendMouseCommand(const RemoteAction &action, int selected_display); int SwitchDisplay(int display_id); void ResetToInitialDisplay(); diff --git a/apps/desktop/src/gui/runtime/mouse_input_trace.h b/apps/desktop/src/gui/runtime/mouse_input_trace.h new file mode 100644 index 00000000..98696a04 --- /dev/null +++ b/apps/desktop/src/gui/runtime/mouse_input_trace.h @@ -0,0 +1,88 @@ +#ifndef CROSSDESK_MOUSE_INPUT_TRACE_H_ +#define CROSSDESK_MOUSE_INPUT_TRACE_H_ + +#include + +#include + +#include "rd_log.h" + +namespace crossdesk { +using MouseTraceState = minirtc::diagnostics::MouseTraceState; + +// Log entry before any potentially blocking check, and report each stage's +// duration. Steady-clock timestamps are comparable only within one process. +class MouseInputTrace { + public: + MouseInputTrace(MouseTraceState* state, const std::string& peer, + const char* scope, const void* data = nullptr, + size_t size = 0) + : state_(state), peer_(peer), scope_(scope) { + if (!state_) return; + ticket_ = state_->Next(); + stage_started_us_ = ticket_.started_us; + if (data) tag_ = minirtc::diagnostics::MousePayloadTag(data, size); + Log("begin", 0, false); + stage_started_us_ = minirtc::diagnostics::MouseTraceNowUs(); + } + MouseInputTrace(const MouseInputTrace&) = delete; + MouseInputTrace& operator=(const MouseInputTrace&) = delete; + ~MouseInputTrace() { + if (state_) + Log("end", minirtc::diagnostics::MouseTraceNowUs() - stage_started_us_, + failed_); + } + + void Stage(const char* stage) { + if (!state_) return; + const auto now = minirtc::diagnostics::MouseTraceNowUs(); + Log("stage_done", now - stage_started_us_, false); + stage_ = stage; + stage_started_us_ = minirtc::diagnostics::MouseTraceNowUs(); + Log("stage_begin", 0, false); + // Exclude synchronous logger flush time from the measured operation. + stage_started_us_ = minirtc::diagnostics::MouseTraceNowUs(); + } + void Payload(const void* data, size_t size) { + tag_ = minirtc::diagnostics::MousePayloadTag(data, size); + } + void Result(const char* outcome, int result = 0, bool failed = false) { + outcome_ = outcome; + result_ = result; + failed_ = failed; + } + + private: + void Log(const char* phase, int64_t stage_us, bool failed) { + const bool problem = + failed || stage_us >= minirtc::diagnostics::kSlowMouseTraceUs; + const bool warn = problem && state_->Problem(); + if (!ticket_.sampled && !warn) return; + const auto now = minirtc::diagnostics::MouseTraceNowUs(); + if (warn) { + LOG_WARN( + "Mouse trace: scope={} peer=[{}] event={} tag={:016x} phase={} " + "stage={} stage_us={} total_us={} mono_us={} outcome={} ret={}", + scope_, peer_, ticket_.event, tag_, phase, stage_, stage_us, + now - ticket_.started_us, now, outcome_, result_); + } else { + LOG_INFO( + "Mouse trace: scope={} peer=[{}] event={} tag={:016x} phase={} " + "stage={} stage_us={} total_us={} mono_us={} outcome={} ret={}", + scope_, peer_, ticket_.event, tag_, phase, stage_, stage_us, + now - ticket_.started_us, now, outcome_, result_); + } + } + MouseTraceState* state_; + std::string peer_; + const char* scope_; + const char* stage_ = "entry"; + const char* outcome_ = "pending"; + minirtc::diagnostics::MouseTraceTicket ticket_{}; + int64_t stage_started_us_ = 0; + uint64_t tag_ = 0; + int result_ = 0; + bool failed_ = false; +}; +} // namespace crossdesk +#endif diff --git a/apps/desktop/src/gui/runtime/peer_data_callbacks.cpp b/apps/desktop/src/gui/runtime/peer_data_callbacks.cpp index c6b79295..92eb9fca 100644 --- a/apps/desktop/src/gui/runtime/peer_data_callbacks.cpp +++ b/apps/desktop/src/gui/runtime/peer_data_callbacks.cpp @@ -21,6 +21,7 @@ #include "rd_log.h" #include "runtime/gui_runtime.h" #include "runtime/remote_action_codec.h" +#include "runtime/mouse_input_trace.h" #if _WIN32 #include "interactive_state.h" @@ -88,6 +89,18 @@ void PeerEventHandler::OnReceiveDataBuffer( } std::string source_id = std::string(src_id, src_id_size); + std::shared_ptr mouse_trace_state; + if (source_id == runtime->mouse_label_) { + std::lock_guard lock(handler->mouse_traces_mutex_); + auto& state = handler->mouse_traces_[std::string(user_id, user_id_size)]; + if (!state) state = std::make_shared(); + mouse_trace_state = state; + } + // Before JSON parsing, authorization, or Windows session queries. An entry + // without a matching stage completion pinpoints a blocked callback. + MouseInputTrace mouse_trace(mouse_trace_state.get(), + std::string(user_id, user_id_size), + "receive", data, size); if (source_id == runtime->file_label_) { std::string remote_user_id = std::string(user_id, user_id_size); @@ -141,7 +154,9 @@ void PeerEventHandler::OnReceiveDataBuffer( std::string json_str(data, size); RemoteAction remote_action{}; + mouse_trace.Stage("parse"); if (!remote_action.from_json(json_str)) { + mouse_trace.Result("invalid_payload", -1, true); LOG_ERROR("Failed to parse RemoteAction JSON payload"); return; } @@ -174,7 +189,12 @@ void PeerEventHandler::OnReceiveDataBuffer( remote_action.type == ControlType::service_command || remote_action.type == ControlType::display_id || remote_action.type == ControlType::audio_capture; if (operates_host) { - if (!runtime->IsAuthorizedController(remote_id)) return; + mouse_trace.Stage("authorize"); + if (!runtime->IsAuthorizedController(remote_id)) { + mouse_trace.Result("unauthorized", -1, true); + return; + } + mouse_trace.Stage("desktop_check"); #ifdef _WIN32 // KeyboardController checks the desktop immediately before each native // key injection, including state reconciliation and cleanup. Avoid a @@ -186,6 +206,7 @@ void PeerEventHandler::OnReceiveDataBuffer( runtime->privacy_.Fail("Secure desktop or lock screen; privacy screen will turn off"); } #endif + mouse_trace.Stage("dispatch"); } if (remote_action.type == ControlType::service_status) { if (auto props = runtime->FindRemoteSession(remote_id)) { @@ -324,6 +345,7 @@ void PeerEventHandler::OnReceiveDataBuffer( runtime->selected_display_, remote_action.m.x, remote_action.m.y, &absolute_x, &absolute_y)) { + mouse_trace.Result("invalid_display", -1, true); LOG_WARN("Secure desktop mouse injection skipped, invalid display " "mapping: display_index={}, x={}, y={}", runtime->selected_display_, remote_action.m.x, @@ -331,10 +353,14 @@ void PeerEventHandler::OnReceiveDataBuffer( return; } + mouse_trace.Stage("secure_desktop_inject"); const std::string response = SendCrossDeskSecureDesktopMouseInput( absolute_x, absolute_y, remote_action.m.s, static_cast(remote_action.m.flag), 1000); auto json = nlohmann::json::parse(response, nullptr, false); + const bool submitted = !json.is_discarded() && json.value("ok", false); + mouse_trace.Result(submitted ? "submitted" : "secure_inject_failed", + submitted ? 0 : -1, !submitted); if (json.is_discarded() || !json.value("ok", false)) { LogSecureDesktopInputBlocked( &runtime->last_local_secure_input_block_log_tick_, "local", @@ -350,8 +376,11 @@ void PeerEventHandler::OnReceiveDataBuffer( } #endif if (remote_action.type == ControlType::mouse) { - runtime->devices_.SendMouseCommand(remote_action, - runtime->selected_display_); + mouse_trace.Stage("normal_desktop_inject"); + const int ret = runtime->devices_.SendMouseCommand( + remote_action, runtime->selected_display_); + mouse_trace.Result(ret == -2 ? "no_controller" : + ret != 0 ? "inject_failed" : "submitted", ret, ret != 0); } else if (remote_action.type == ControlType::audio_capture) { if (remote_action.a) runtime->devices_.StartSpeakerCapturer(); diff --git a/apps/desktop/src/gui/runtime/peer_event_handler.cpp b/apps/desktop/src/gui/runtime/peer_event_handler.cpp index aec2efdd..a38be876 100644 --- a/apps/desktop/src/gui/runtime/peer_event_handler.cpp +++ b/apps/desktop/src/gui/runtime/peer_event_handler.cpp @@ -242,6 +242,13 @@ void PeerEventHandler::OnConnectionStatus(ConnectionStatus status, std::string remote_id(user_id, user_id_size); std::shared_ptr props; + LOG_INFO("Input connection status: peer=[{}], status={}", remote_id, + static_cast(status)); + if (status == ConnectionStatus::Disconnected || + status == ConnectionStatus::Failed || status == ConnectionStatus::Closed) { + std::lock_guard lock(handler->mouse_traces_mutex_); + handler->mouse_traces_.erase(remote_id); + } { std::shared_lock lock(runtime->remote_sessions_mutex_); auto it = runtime->remote_sessions_.find(remote_id); diff --git a/apps/desktop/src/gui/runtime/peer_event_handler.h b/apps/desktop/src/gui/runtime/peer_event_handler.h index 92650955..307f0b8f 100644 --- a/apps/desktop/src/gui/runtime/peer_event_handler.h +++ b/apps/desktop/src/gui/runtime/peer_event_handler.h @@ -9,6 +9,10 @@ #include #include +#include +#include +#include +#include #include "minirtc.h" #include "runtime/session_lifecycle.h" @@ -54,9 +58,12 @@ private: static void SendClientInfo(PeerPtr *peer, const std::string &client_id); GuiRuntime &owner_; + std::mutex mouse_traces_mutex_; + std::unordered_map> mouse_traces_; gui_detail::SessionCallbackGate callbacks_; }; } // namespace crossdesk -#endif \ No newline at end of file +#endif diff --git a/apps/desktop/src/gui/runtime/remote_session.h b/apps/desktop/src/gui/runtime/remote_session.h index bb7d13f3..725317e6 100644 --- a/apps/desktop/src/gui/runtime/remote_session.h +++ b/apps/desktop/src/gui/runtime/remote_session.h @@ -24,6 +24,7 @@ #include "display_info.h" #include "cursor_presentation.h" #include "minirtc.h" +#include namespace crossdesk { class PeerEventHandler; } @@ -68,6 +69,8 @@ struct FileTransferState { // Runtime state for one connected or connecting remote endpoint. It groups the // connection, media, input, window and transfer data that share one lifetime. struct RemoteSession { + minirtc::diagnostics::MouseTraceState mouse_ui_trace_; + minirtc::diagnostics::MouseTraceState mouse_send_trace_; Params params_; PeerPtr* peer_ = nullptr; std::shared_ptr peer_events_; diff --git a/apps/desktop/src/gui/ui/stream_window.slint b/apps/desktop/src/gui/ui/stream_window.slint index 7fd408fc..4cc6bea4 100644 --- a/apps/desktop/src/gui/ui/stream_window.slint +++ b/apps/desktop/src/gui/ui/stream_window.slint @@ -189,6 +189,7 @@ export component StreamWindow inherits Window { callback toggle-maximize-stream-window; callback close-stream-window; callback pointer-input(PointerEventButton, PointerEventKind, length, length); + callback pointer-observed(PointerEventButton, PointerEventKind, bool, bool, bool); callback scroll-input(length, length, length, length); callback key-input(string, bool, bool, bool, bool, bool); callback keyboard-focus-changed(bool); @@ -639,6 +640,9 @@ export component StreamWindow inherits Window { root.suppress-next-remote-pointer-release && (event.kind == PointerEventKind.up || event.kind == PointerEventKind.cancel); + root.pointer-observed(event.button, event.kind, + over-local-ui, root.control-dragging, + suppress-remote-release); if event.kind == PointerEventKind.down && !over-local-ui { // Discard a stale marker if a popup consumed the // whole previous gesture, including its release. diff --git a/deps/submodules/minirtc b/deps/submodules/minirtc index 5b0ce343..fb9ddeeb 160000 --- a/deps/submodules/minirtc +++ b/deps/submodules/minirtc @@ -1 +1 @@ -Subproject commit 5b0ce34383f95ae97a01af9e0985c0628b25ad04 +Subproject commit fb9ddeebcdd908a17b6d350450426b2a97a3ebdb diff --git a/docs/MOUSE_INPUT_DIAGNOSTICS.md b/docs/MOUSE_INPUT_DIAGNOSTICS.md new file mode 100644 index 00000000..d530b909 --- /dev/null +++ b/docs/MOUSE_INPUT_DIAGNOSTICS.md @@ -0,0 +1,45 @@ +# 鼠标输入启动诊断 + +控制端和被控端都需要重新编译 CrossDesk 及 `deps/submodules/minirtc`。 +诊断默认使用 INFO/WARN 日志。连接后立即在远端画面内持续移动鼠标， +保留两端同一次运行的 `crossdesk-*.log` 和 `minirtc-*.log`。 + +## 记录顺序 + +| 日志 | 所在端 | 含义 | +| --- | --- | --- | +| `Input connection status` | 两端 CrossDesk | 上层连接状态变化 | +| `Mouse UI stream window shown` / `Mouse UI selected` | 控制端 CrossDesk | 窗口显示和当前会话选择 | +| `Mouse UI event` | 控制端 CrossDesk | Slint 视频输入区域收到事件，包含本地 UI 遮挡、拖动和释放抑制状态 | +| `Mouse trace: scope=pointer` / `scope=scroll` | 控制端 CrossDesk | 转发入口、过滤原因、调用发送 API 的时间和返回值 | +| `Mouse transport dispatch` | 控制端 MiniRTC | 连接与 ICE 就绪检查及传输层返回值 | +| `Mouse RTP enqueue` | 控制端 MiniRTC | 实际入队结果，队列满时明确记录 | +| `Mouse RTP send begin` / `send end` | 控制端 MiniRTC | 队列等待、底层发送调用耗时及真实返回值 | +| `Mouse RTP receive` | 被控端 MiniRTC | RTP 包进入鼠标数据通道，位于应用回调之前 | +| `Mouse trace: scope=receive` | 被控端 CrossDesk | 应用回调入口及各检查、提交阶段 | +| `Mouse RTP callback complete` | 被控端 MiniRTC | 应用回调的总耗时 | + +应用接收阶段依次为 `parse`、`authorize`、`desktop_check`、`dispatch`， +随后是 `normal_desktop_inject` 或 `secure_desktop_inject`。 +`phase=stage_begin` 在调用前记录，`phase=stage_done` 或 `phase=end` +报告该阶段耗时。若某阶段开始后长时间没有结束，可以确定阻塞区间。 +`outcome=no_controller`、`unauthorized`、`inject_failed` 等说明具体处理结果； +`submitted` 表示操作系统提交调用成功，不是目标应用已执行的确认。 + +## 关联与限频 + +- `tag` 是鼠标消息原始字节的 FNV-1a 64 位摘要，可关联发送和接收；相同消息 + 会有相同摘要，因此重复消息应同时结合 RTP 的 `ssrc` / `seq` 和时间判断。 +- `event` 是各阶段本地计数，不应视为跨端共同序号。会话/通道重建后重新计数。 +- `mono_us` 是进程所在机器的单调时钟，只用于该端的耗时判断。 + 两端日志的墙钟可能不同，不能直接相减当作网络时延。 +- `queue_us`、`send_us`、`stage_us`、`dispatch_us` 和 `total_us` 单位均为微秒。 + `stage_us` 和 `send_us` 排除本阶段入口日志写入时间；总耗时仍包含诊断开销。 +- 每个采样器记录前 3 次事件，此后最多每 5 秒选取一次事件。 + 失败和耗时达到 100 毫秒的调用使用独立限频，前 3 次记录，此后每 5 秒一次。 +- 发送 API 的返回值不等于网络送达确认，应检查传输层、RTP 发送和远端接收记录。 + +如果有 UI 事件而没有发送入口，先看 `local_ui`、`dragging`、`suppressed`； +如果已入队却迟迟没有实际发送，查看 `queue_us`；如果远端已有 RTP 记录， +但应用处理耗时很长，查看接收阶段。仅当两端相关阶段都及时完成时， +才进一步检查 Windows 注入后的钩子或目标应用行为。