Bug #77580 [Opn->Fbk]: DeleteTimerQueueTimer() return code

Edit report at https://bugs.php.net/bug.php?id=77580&edit=1 ID: 77580 Updated by: ab@php.net Reported by: oliver dot pfister at contaware dot com Summary: DeleteTimerQueueTimer() return code -Status: Open +Status: Feedback Type: Bug Package: Scripting Engine problem Operating System: Windows PHP Version: Irrelevant Block user comment: N Private report: N New Comment: Thanks for the report and detailed analysis. Out of curiosity - I can certainly test Wine, but how do you run ReactOS? Would it work under with Hyper-V or VMware? Disregarding of that, we should not pass when ERROR_IO_PENDING is returned. The timer callback sets flags for Zend VM to recognize the timeout and to properly shutdown. If the timer callback was too slow and didn't set the flags, chances are that ZVM will continue executing some instructions where timeout should happen. The handling could be possibly improved by two things - use INVALID_HANDLE_VALUE for the completion event + care about thread safety - repeat the call once when GetLastError() != ERROR_IO_PENDING If the timer deletion still fails after that, there's no choice other than dying hard, because in that case we can't ensure the timeout is handled properly. Would it workout on ReactOS? Thanks. Previous Comments: ------------------------------------------------------------------------ [2019-02-07 14:21:52] oliver dot pfister at contaware dot com Description: ------------ DeleteTimerQueueTimer(HANDLE TimerQueue, HANDLE Timer, HANDLE CompletionEvent) return code problem in file zend_execute_API.c Because of vague Microsoft API documentation (see point 3. below) there is an important implementation difference between Windows and Wine/ReactOS in case of CompletionEvent set to NULL (PHP uses DeleteTimerQueueTimer with CompletionEvent set to NULL): Windows (tested on all versions of Windows from XP to Win10): calling DeleteTimerQueueTimer returns TRUE if the callback code is not yet executing, then when the thread (of the pool) enters the callback code, calling DeleteTimerQueueTimer returns FALSE with ERROR_IO_PENDING. When the thread (of the pool) has terminated execution of the callback code, calling DeleteTimerQueueTimer returns again TRUE. ReactOS/Wine (tested on latest versions of Wine and ReactOS): calling DeleteTimerQueueTimer always returns FALSE with ERROR_IO_PENDING. Important points of the DeleteTimerQueueTimer Microsoft Windows documentation (https://msdn.microsoft.com/en-us/library/windows/desktop/ms682569(v=vs.85).aspx): 1. If CompletionEvent is NULL, the function marks the timer for deletion and returns immediately. If the timer has already expired, the timer callback function will run to completion. 2. If the error code is ERROR_IO_PENDING, it is not necessary to call this function again. For any other error, you should retry the call. 3. If there are outstanding callback functions and CompletionEvent is NULL, the function will fail and set the error code to ERROR_IO_PENDING. This indicates that there are outstanding callback functions. Those callbacks either will execute or are in the middle of executing. The timer is cleaned up when the callback function is finished executing. As a result in Wine/ReactOS it's not possible to use any PHP, it fails with a fatal error. In Windows there is the possibility that the timer is deleted exactly when a thread (of the pool) is executing the callback, in that case a PHP fatal error would be risen for no good reason. So I propose to correct the PHP code and always check GetLastError() making sure it is not returning ERROR_IO_PENDING before failing. Test script: --------------- In zend_set_timeout_ex() and zend_unset_timeout() please correct the return code check from: if (!DeleteTimerQueueTimer(NULL, tq_timer, NULL)) { to: if (!DeleteTimerQueueTimer(NULL, tq_timer, NULL) && GetLastError() != ERROR_IO_PENDING) { ------------------------------------------------------------------------ -- Edit this bug report at https://bugs.php.net/bug.php?id=77580&edit=1