User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.4 (KHTML, like Gecko) Chrome/22.0.1229.94 Safari/537.4 Steps to reproduce: I ran a project with embedded XulRunner, using GeckoFX (https://bitbucket.org/geckofx/geckofx-14.0), in Visual Studio 2012, and loaded a website with Adobe Flash to the browser object. Actual results: Got the following error message, and page loading hanged, usually crashing my application: "WARNING: RegisterWaitForSingleObject failed: 6: file e:/builds/moz2_slave/rel-m-rel-xr-w32-bld/build/ipc/chromium/src/base/object_watcher.cc, line 62" The crash is from here: http://lxr.mozilla.org/mozilla-central/source/ipc/chromium/src/base/object_watcher.cc#62 Expected results: It should work without that error message, as it does when running as a standalone application and not from Visual Studio. The bug is from the code borrowed from Chromium! See Chromium bug about it: http://code.google.com/p/chromium/issues/detail?id=131346 Someone reported that: Exchanging WT_EXECUTEINWAITTHREAD for WT_EXECUTEDEFAULT resolves the issue.
Created attachment 674666 [details] [diff] [review] RegisterWaitForSingleObject - don't ExecuteInWaitThread http://msdn.microsoft.com/en-us/library/windows/desktop/ms685061(v=vs.85).aspx "The callback function is invoked by the wait thread itself. This flag should be used only for short tasks or it could affect other wait operations. Deadlocks can occur if some other thread acquires an exclusive lock and calls the UnregisterWait or UnregisterWaitEx function while the callback function is trying to acquire the same lock." Sometimes it indeed deadlocks (specifically when debugging from Visual Studio), so this flags should no be used.
Comment on attachment 674666 [details] [diff] [review] RegisterWaitForSingleObject - don't ExecuteInWaitThread This exceeds my win32-fu.
Comment on attachment 674666 [details] [diff] [review] RegisterWaitForSingleObject - don't ExecuteInWaitThread Review of attachment 674666 [details] [diff] [review]: ----------------------------------------------------------------- After reading the docs I think this is fine.