From 7b84db7a7484b58fdde21029ef374baeaa0a4b51 Mon Sep 17 00:00:00 2001 From: Hans de Goede Date: Wed, 6 Oct 2010 12:37:05 +0200 Subject: spicec: Move setting of clipboard_owner to guest to platform code Atleast under x11 there is a race condition when setting the clipboard owner to guest from the RedClient code rather then doing it in Platform. After the XSetSelectionOwner() in Platform::on_clipboard_grab(), which runs from the main message loop thread, the x11 event thread can receive a SelectionRequest event from another x11 app, before the RedClient code has set the clipboard owner, which will trigger the owner != guest check in the SelectionRequest event handling code. By moving the setting of the owner in to Platform::on_clipboard_grab() it gets protected by the clipboard lock, which closes this tiny race. --- client/platform.h | 2 ++ client/red_client.cpp | 1 - client/windows/platform.cpp | 7 +++++++ client/x11/platform.cpp | 10 ++++++++-- 4 files changed, 17 insertions(+), 3 deletions(-) diff --git a/client/platform.h b/client/platform.h index af4a0f6c..a9a1715b 100644 --- a/client/platform.h +++ b/client/platform.h @@ -132,6 +132,8 @@ public: static int get_clipboard_owner() { return _clipboard_owner; } private: + static void set_clipboard_owner_unlocked(int new_owner); + static int _clipboard_owner; }; diff --git a/client/red_client.cpp b/client/red_client.cpp index 8e7dfe0e..0650e35a 100644 --- a/client/red_client.cpp +++ b/client/red_client.cpp @@ -1118,7 +1118,6 @@ void RedClient::dispatch_agent_message(VDAgentMessage* msg, void* data) case VD_AGENT_CLIPBOARD_GRAB: Platform::on_clipboard_grab((uint32_t *)data, msg->size / sizeof(uint32_t)); - Platform::set_clipboard_owner(Platform::owner_guest); break; case VD_AGENT_CLIPBOARD_REQUEST: if (Platform::get_clipboard_owner() != Platform::owner_client) { diff --git a/client/windows/platform.cpp b/client/windows/platform.cpp index 580a40ae..075d2690 100644 --- a/client/windows/platform.cpp +++ b/client/windows/platform.cpp @@ -859,6 +859,11 @@ void WinPlatform::exit_modal_loop() int Platform::_clipboard_owner = Platform::owner_none; +void Platform::set_clipboard_owner_unlocked(int new_owner) +{ + set_clipboard_owner(new_owner); +} + void Platform::set_clipboard_owner(int new_owner) { if (new_owner == owner_none) { @@ -885,6 +890,8 @@ bool Platform::on_clipboard_grab(uint32_t *types, uint32_t type_count) EmptyClipboard(); SetClipboardData(format, NULL); CloseClipboard(); + + set_clipboard_owner(owner_guest); return true; } diff --git a/client/x11/platform.cpp b/client/x11/platform.cpp index 29b5f753..8f0665cb 100644 --- a/client/x11/platform.cpp +++ b/client/x11/platform.cpp @@ -3355,19 +3355,25 @@ bool Platform::on_clipboard_grab(uint32_t *types, uint32_t type_count) XSetSelectionOwner(x_display, clipboard_prop, platform_win, CurrentTime); XFlush(x_display); + + set_clipboard_owner_unlocked(owner_guest); return true; } int Platform::_clipboard_owner = Platform::owner_none; void Platform::set_clipboard_owner(int new_owner) +{ + Lock lock(clipboard_lock); + set_clipboard_owner_unlocked(new_owner); +} + +void Platform::set_clipboard_owner_unlocked(int new_owner) { const char * const owner_str[] = { "none", "guest", "client" }; /* Clear pending requests and clipboard data */ { - Lock lock(clipboard_lock); - if (next_selection_request) { LOG_INFO("selection requests pending upon clipboard owner change, clearing"); while (next_selection_request) -- cgit