From 9264c7f367e44ce2d4e773add80b63e1777e3e0f Mon Sep 17 00:00:00 2001 From: Frediano Ziglio Date: Thu, 5 Jul 2018 16:13:00 +0100 Subject: [PATCH 42/43] vdagent: Add a comment around WinSta0_DesktopSwitch event usage Multiple times while I was reading this code was not clear why the synchronization of this event was not done in the main event loop. Also document why we want to use it not relying just on WTSRegisterSessionNotification and WM_WTSSESSION_CHANGE. Signed-off-by: Frediano Ziglio Acked-by: Christophe Fergeau --- vdagent/vdagent.cpp | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/vdagent/vdagent.cpp b/vdagent/vdagent.cpp index e577679..be17ddc 100644 --- a/vdagent/vdagent.cpp +++ b/vdagent/vdagent.cpp @@ -232,6 +232,11 @@ VDAgent::~VDAgent() DWORD WINAPI VDAgent::event_thread_proc(LPVOID param) { VDAgent *agent = static_cast(param); + // This event is monitored in a separate thread to avoid losing + // events as the event is signaled with PulseEvent to wake up all + // thread waiting for it. + // This event allows to detect desktop switches which do not + // change sessions like pressing Ctrl-Alt-Delete. HANDLE desktop_event = OpenEvent(SYNCHRONIZE, FALSE, L"WinSta0_DesktopSwitch"); if (!desktop_event) { vd_printf("OpenEvent() failed: %lu", GetLastError()); -- 2.17.1