From 94d433c8cb64c9167050d02473176f888decf1d8 Mon Sep 17 00:00:00 2001 From: Jon TURNEY Date: Fri, 21 Feb 2014 23:20:00 +0000 Subject: hw/xwin: Fix clipboard thread restart It seems that the clipboard thread restart mechanism has been broken for a while, which can be demonstrated using XDMCP with KDM (e.g. to a Kubutunu 12.04 host) KDM kills all attached clients, including the clipboard integration client, which restarts, but then exits on WM_QUIT. Using PostQuitMessage() in WM_DESTROY is unhelpful, as we may not actually be quitting the thread, if we just destroyed the window because the clipboard thread is about to retry, because he WM_QUIT message sticks around, and is noticed the next time we look at the window message queue and confuses us into thinking we need to quit. Sending a WM_DESTROY is apparently never correct anyhow, see [1] So: 1/ Use DestroyWindow() to destroy the clipboard messaging window when cleaning up for retry or exit in winClipboardProc (the clipboard thread main proc) 2/ Send a special WM_WM_QUIT message in winClipboardWindowDestroy() from the X server thread when the X server is resetting. 3/ When processing that WM_WM_QUIT message in the clipboard thread, cause the clipboard window to PostQuitMessage(), which causes the clipboard thread to exit. [1] http://blogs.msdn.com/b/oldnewthing/archive/2011/09/26/10216420.aspx Signed-off-by: Jon TURNEY Reviewed-by: Colin Harrison --- hw/xwin/winclipboard/internal.h | 1 + hw/xwin/winclipboard/thread.c | 4 ++-- hw/xwin/winclipboard/wndproc.c | 6 ++++++ 3 files changed, 9 insertions(+), 2 deletions(-) diff --git a/hw/xwin/winclipboard/internal.h b/hw/xwin/winclipboard/internal.h index bcf45ca4d..c6bde84af 100644 --- a/hw/xwin/winclipboard/internal.h +++ b/hw/xwin/winclipboard/internal.h @@ -44,6 +44,7 @@ #define WIN_XEVENTS_NOTIFY_TARGETS 4 #define WM_WM_REINIT (WM_USER + 1) +#define WM_WM_QUIT (WM_USER + 2) /* * References to external symbols diff --git a/hw/xwin/winclipboard/thread.c b/hw/xwin/winclipboard/thread.c index 786b88972..50e1e8cb5 100644 --- a/hw/xwin/winclipboard/thread.c +++ b/hw/xwin/winclipboard/thread.c @@ -351,7 +351,7 @@ winClipboardProc(Bool fUseUnicode, char *szDisplay) winClipboardProc_Done: /* Close our Windows window */ if (g_hwndClipboard) { - winClipboardWindowDestroy(); + DestroyWindow(g_hwndClipboard); } /* Close our X window */ @@ -491,7 +491,7 @@ void winClipboardWindowDestroy(void) { if (g_hwndClipboard) { - SendMessage(g_hwndClipboard, WM_DESTROY, 0, 0); + SendMessage(g_hwndClipboard, WM_WM_QUIT, 0, 0); } } diff --git a/hw/xwin/winclipboard/wndproc.c b/hw/xwin/winclipboard/wndproc.c index b63a1dc5c..a17f8a900 100644 --- a/hw/xwin/winclipboard/wndproc.c +++ b/hw/xwin/winclipboard/wndproc.c @@ -154,6 +154,12 @@ winClipboardWindowProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam) ChangeClipboardChain(hwnd, s_hwndNextViewer); s_hwndNextViewer = NULL; + } + return 0; + + case WM_WM_QUIT: + { + winDebug("winClipboardWindowProc - WM_WM_QUIT\n"); PostQuitMessage(0); } -- cgit v1.2.3