/* $Id: NativeEventQueue.cpp $ */ /** @file * MS COM / XPCOM Abstraction Layer: * Main event queue class declaration */ /* * Copyright (C) 2006-2022 Oracle and/or its affiliates. * * This file is part of VirtualBox base platform packages, as * available from https://www.virtualbox.org. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation, in version 3 of the * License. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, see . * * SPDX-License-Identifier: GPL-3.0-only */ #include "VBox/com/NativeEventQueue.h" #include /* For bad_alloc. */ #ifdef RT_OS_DARWIN # include #endif #if defined(VBOX_WITH_XPCOM) && !defined(RT_OS_DARWIN) && !defined(RT_OS_OS2) # define USE_XPCOM_QUEUE #endif #include #include #include #include #ifdef USE_XPCOM_QUEUE # include #endif namespace com { // NativeEventQueue class //////////////////////////////////////////////////////////////////////////////// #ifndef VBOX_WITH_XPCOM # define CHECK_THREAD_RET(ret) \ do { \ AssertMsg(GetCurrentThreadId() == mThreadId, ("Must be on event queue thread!")); \ if (GetCurrentThreadId() != mThreadId) \ return ret; \ } while (0) /** Magic LPARAM value for the WM_USER messages that we're posting. * @remarks This magic value is duplicated in * vboxapi/PlatformMSCOM::interruptWaitEvents(). */ #define EVENTQUEUE_WIN_LPARAM_MAGIC UINT32_C(0xf241b819) #else // VBOX_WITH_XPCOM # define CHECK_THREAD_RET(ret) \ do { \ if (!mEventQ) \ return ret; \ BOOL isOnCurrentThread = FALSE; \ mEventQ->IsOnCurrentThread(&isOnCurrentThread); \ AssertMsg(isOnCurrentThread, ("Must be on event queue thread!")); \ if (!isOnCurrentThread) \ return ret; \ } while (0) #endif // VBOX_WITH_XPCOM /** Pointer to the main event queue. */ NativeEventQueue *NativeEventQueue::sMainQueue = NULL; #ifdef VBOX_WITH_XPCOM struct MyPLEvent : public PLEvent { MyPLEvent(NativeEvent *e) : event(e) {} NativeEvent *event; }; /* static */ void *PR_CALLBACK com::NativeEventQueue::plEventHandler(PLEvent *self) { NativeEvent *ev = ((MyPLEvent *)self)->event; if (ev) ev->handler(); else { NativeEventQueue *eq = (NativeEventQueue *)self->owner; Assert(eq); eq->mInterrupted = true; } return NULL; } /* static */ void PR_CALLBACK com::NativeEventQueue::plEventDestructor(PLEvent *self) { NativeEvent *ev = ((MyPLEvent *)self)->event; if (ev) delete ev; delete self; } #endif // VBOX_WITH_XPCOM /** * Constructs an event queue for the current thread. * * Currently, there can be only one event queue per thread, so if an event * queue for the current thread already exists, this object is simply attached * to the existing event queue. */ NativeEventQueue::NativeEventQueue() { #ifndef VBOX_WITH_XPCOM mThreadId = GetCurrentThreadId(); // force the system to create the message queue for the current thread MSG msg; PeekMessage(&msg, NULL, WM_USER, WM_USER, PM_NOREMOVE); if (!DuplicateHandle(GetCurrentProcess(), GetCurrentThread(), GetCurrentProcess(), &mhThread, 0 /*dwDesiredAccess*/, FALSE /*bInheritHandle*/, DUPLICATE_SAME_ACCESS)) mhThread = INVALID_HANDLE_VALUE; #else // VBOX_WITH_XPCOM mEQCreated = false; mInterrupted = false; // Here we reference the global nsIEventQueueService instance and hold it // until we're destroyed. This is necessary to keep NS_ShutdownXPCOM() away // from calling StopAcceptingEvents() on all event queues upon destruction of // nsIEventQueueService, and makes sense when, for some reason, this happens // *before* we're able to send a NULL event to stop our event handler thread // when doing unexpected cleanup caused indirectly by NS_ShutdownXPCOM() // that is performing a global cleanup of everything. A good example of such // situation is when NS_ShutdownXPCOM() is called while the VirtualBox component // is still alive (because it is still referenced): eventually, it results in // a VirtualBox::uninit() call from where it is already not possible to post // NULL to the event thread (because it stopped accepting events). nsresult rc = NS_GetEventQueueService(getter_AddRefs(mEventQService)); if (NS_SUCCEEDED(rc)) { rc = mEventQService->GetThreadEventQueue(NS_CURRENT_THREAD, getter_AddRefs(mEventQ)); if (rc == NS_ERROR_NOT_AVAILABLE) { rc = mEventQService->CreateThreadEventQueue(); if (NS_SUCCEEDED(rc)) { mEQCreated = true; rc = mEventQService->GetThreadEventQueue(NS_CURRENT_THREAD, getter_AddRefs(mEventQ)); } } } AssertComRC(rc); #endif // VBOX_WITH_XPCOM } NativeEventQueue::~NativeEventQueue() { #ifndef VBOX_WITH_XPCOM if (mhThread != INVALID_HANDLE_VALUE) { CloseHandle(mhThread); mhThread = INVALID_HANDLE_VALUE; } #else // VBOX_WITH_XPCOM // process all pending events before destruction if (mEventQ) { if (mEQCreated) { mEventQ->StopAcceptingEvents(); mEventQ->ProcessPendingEvents(); mEventQService->DestroyThreadEventQueue(); } mEventQ = nsnull; mEventQService = nsnull; } #endif // VBOX_WITH_XPCOM } /** * Initializes the main event queue instance. * @returns VBox status code. * * @remarks If you're using the rest of the COM/XPCOM glue library, * com::Initialize() will take care of initializing and uninitializing * the NativeEventQueue class. If you don't call com::Initialize, you must * make sure to call this method on the same thread that did the * XPCOM initialization or we'll end up using the wrong main queue. */ /* static */ int NativeEventQueue::init() { Assert(sMainQueue == NULL); Assert(RTThreadIsMain(RTThreadSelf())); try { sMainQueue = new NativeEventQueue(); AssertPtr(sMainQueue); #ifdef VBOX_WITH_XPCOM /* Check that it actually is the main event queue, i.e. that we're called on the right thread. */ nsCOMPtr q; nsresult rv = NS_GetMainEventQ(getter_AddRefs(q)); AssertComRCReturn(rv, VERR_INVALID_POINTER); Assert(q == sMainQueue->mEventQ); /* Check that it's a native queue. */ PRBool fIsNative = PR_FALSE; rv = sMainQueue->mEventQ->IsQueueNative(&fIsNative); Assert(NS_SUCCEEDED(rv) && fIsNative); #endif // VBOX_WITH_XPCOM } catch (std::bad_alloc &ba) { NOREF(ba); return VERR_NO_MEMORY; } return VINF_SUCCESS; } /** * Uninitialize the global resources (i.e. the main event queue instance). * @returns VINF_SUCCESS */ /* static */ int NativeEventQueue::uninit() { if (sMainQueue) { /* Must process all events to make sure that no NULL event is left * after this point. It would need to modify the state of sMainQueue. */ #ifdef RT_OS_DARWIN /* Do not process the native runloop, the toolkit may not be ready for it. */ sMainQueue->mEventQ->ProcessPendingEvents(); #else sMainQueue->processEventQueue(0); #endif delete sMainQueue; sMainQueue = NULL; } return VINF_SUCCESS; } /** * Get main event queue instance. * * Depends on init() being called first. */ /* static */ NativeEventQueue* NativeEventQueue::getMainEventQueue() { return sMainQueue; } #ifdef VBOX_WITH_XPCOM # ifdef RT_OS_DARWIN /** * Wait for events and process them (Darwin). * * @retval VINF_SUCCESS * @retval VERR_TIMEOUT * @retval VERR_INTERRUPTED * * @param cMsTimeout How long to wait, or RT_INDEFINITE_WAIT. */ static int waitForEventsOnDarwin(RTMSINTERVAL cMsTimeout) { /* * Wait for the requested time, if we get a hit we do a poll to process * any other pending messages. * * Note! About 1.0e10: According to the sources anything above 3.1556952e+9 * means indefinite wait and 1.0e10 is what CFRunLoopRun() uses. */ CFTimeInterval rdTimeout = cMsTimeout == RT_INDEFINITE_WAIT ? 1e10 : (double)cMsTimeout / 1000; OSStatus orc = CFRunLoopRunInMode(kCFRunLoopDefaultMode, rdTimeout, true /*returnAfterSourceHandled*/); if (orc == kCFRunLoopRunHandledSource) { OSStatus orc2 = CFRunLoopRunInMode(kCFRunLoopDefaultMode, 0.0, false /*returnAfterSourceHandled*/); if ( orc2 == kCFRunLoopRunStopped || orc2 == kCFRunLoopRunFinished) orc = orc2; } if ( orc == 0 /*???*/ || orc == kCFRunLoopRunHandledSource) return VINF_SUCCESS; if ( orc == kCFRunLoopRunStopped || orc == kCFRunLoopRunFinished) return VERR_INTERRUPTED; AssertMsg(orc == kCFRunLoopRunTimedOut, ("Unexpected status code from CFRunLoopRunInMode: %#x", orc)); return VERR_TIMEOUT; } # else // !RT_OS_DARWIN /** * Wait for events (generic XPCOM). * * @retval VINF_SUCCESS * @retval VERR_TIMEOUT * @retval VINF_INTERRUPTED * @retval VERR_INTERNAL_ERROR_4 * * @param pQueue The queue to wait on. * @param cMsTimeout How long to wait, or RT_INDEFINITE_WAIT. */ static int waitForEventsOnXPCOM(nsIEventQueue *pQueue, RTMSINTERVAL cMsTimeout) { int fd = pQueue->GetEventQueueSelectFD(); fd_set fdsetR; FD_ZERO(&fdsetR); FD_SET(fd, &fdsetR); fd_set fdsetE = fdsetR; struct timeval tv = {0,0}; struct timeval *ptv; if (cMsTimeout == RT_INDEFINITE_WAIT) ptv = NULL; else { tv.tv_sec = cMsTimeout / 1000; tv.tv_usec = (cMsTimeout % 1000) * 1000; ptv = &tv; } int rc = select(fd + 1, &fdsetR, NULL, &fdsetE, ptv); if (rc > 0) rc = VINF_SUCCESS; else if (rc == 0) rc = VERR_TIMEOUT; else if (errno == EINTR) rc = VINF_INTERRUPTED; else { static uint32_t s_ErrorCount = 0; if (s_ErrorCount < 500) { LogRel(("waitForEventsOnXPCOM rc=%d errno=%d\n", rc, errno)); ++s_ErrorCount; } AssertMsgFailed(("rc=%d errno=%d\n", rc, errno)); rc = VERR_INTERNAL_ERROR_4; } return rc; } # endif // !RT_OS_DARWIN #endif // VBOX_WITH_XPCOM #ifndef VBOX_WITH_XPCOM /** * Dispatch a message on Windows. * * This will pick out our events and handle them specially. * * @returns @a rc or VERR_INTERRUPTED (WM_QUIT or NULL msg). * @param pMsg The message to dispatch. * @param rc The current status code. */ /*static*/ int NativeEventQueue::dispatchMessageOnWindows(MSG const *pMsg, int rc) { /* * Check for and dispatch our events. */ if ( pMsg->hwnd == NULL && pMsg->message == WM_USER) { if (pMsg->lParam == EVENTQUEUE_WIN_LPARAM_MAGIC) { NativeEvent *pEvent = (NativeEvent *)pMsg->wParam; if (pEvent) { pEvent->handler(); delete pEvent; } else rc = VERR_INTERRUPTED; return rc; } AssertMsgFailed(("lParam=%p wParam=%p\n", pMsg->lParam, pMsg->wParam)); } /* * Check for the quit message and dispatch the message the normal way. */ if (pMsg->message == WM_QUIT) rc = VERR_INTERRUPTED; TranslateMessage(pMsg); DispatchMessage(pMsg); return rc; } /** * Process pending events (Windows). * * @retval VINF_SUCCESS * @retval VERR_TIMEOUT * @retval VERR_INTERRUPTED. */ static int processPendingEvents(void) { int rc = VERR_TIMEOUT; MSG Msg; if (PeekMessage(&Msg, NULL /*hWnd*/, 0 /*wMsgFilterMin*/, 0 /*wMsgFilterMax*/, PM_REMOVE)) { rc = VINF_SUCCESS; do rc = NativeEventQueue::dispatchMessageOnWindows(&Msg, rc); while (PeekMessage(&Msg, NULL /*hWnd*/, 0 /*wMsgFilterMin*/, 0 /*wMsgFilterMax*/, PM_REMOVE)); } return rc; } #else // VBOX_WITH_XPCOM /** * Process pending XPCOM events. * @param pQueue The queue to process events on. * @retval VINF_SUCCESS * @retval VERR_TIMEOUT * @retval VERR_INTERRUPTED (darwin only) * @retval VERR_INTERNAL_ERROR_2 */ static int processPendingEvents(nsIEventQueue *pQueue) { /* ProcessPendingEvents doesn't report back what it did, so check here. */ PRBool fHasEvents = PR_FALSE; nsresult hr = pQueue->PendingEvents(&fHasEvents); if (NS_FAILED(hr)) return VERR_INTERNAL_ERROR_2; /* Process pending events. */ int rc = VINF_SUCCESS; if (fHasEvents) pQueue->ProcessPendingEvents(); else rc = VERR_TIMEOUT; # ifdef RT_OS_DARWIN /* Process pending native events. */ int rc2 = waitForEventsOnDarwin(0); if (rc == VERR_TIMEOUT || rc2 == VERR_INTERRUPTED) rc = rc2; # endif return rc; } #endif // VBOX_WITH_XPCOM /** * Process events pending on this event queue, and wait up to given timeout, if * nothing is available. * * Must be called on same thread this event queue was created on. * * @param cMsTimeout The timeout specified as milliseconds. Use * RT_INDEFINITE_WAIT to wait till an event is posted on the * queue. * * @returns VBox status code * @retval VINF_SUCCESS if one or more messages was processed. * @retval VERR_TIMEOUT if cMsTimeout expired. * @retval VERR_INVALID_CONTEXT if called on the wrong thread. * @retval VERR_INTERRUPTED if interruptEventQueueProcessing was called. * On Windows will also be returned when WM_QUIT is encountered. * On Darwin this may also be returned when the native queue is * stopped or destroyed/finished. * @retval VINF_INTERRUPTED if the native system call was interrupted by a * an asynchronous event delivery (signal) or just felt like returning * out of bounds. On darwin it will also be returned if the queue is * stopped. * * @note On darwin this function will not return when the thread receives a * signal, it will just resume the wait. */ int NativeEventQueue::processEventQueue(RTMSINTERVAL cMsTimeout) { int rc; CHECK_THREAD_RET(VERR_INVALID_CONTEXT); #ifdef VBOX_WITH_XPCOM /* * Process pending events, if none are available and we're not in a * poll call, wait for some to appear. (We have to be a little bit * careful after waiting for the events since Darwin will process * them as part of the wait, while the XPCOM case will not.) * * Note! Unfortunately, WaitForEvent isn't interruptible with Ctrl-C, * while select() is. So we cannot use it for indefinite waits. */ rc = processPendingEvents(mEventQ); if ( rc == VERR_TIMEOUT && cMsTimeout > 0) { # ifdef RT_OS_DARWIN /** @todo check how Ctrl-C works on Darwin. * Update: It doesn't work. MACH_RCV_INTERRUPT could perhaps be returned * to __CFRunLoopServiceMachPort, but neither it nor __CFRunLoopRun * has any way of expressing it via their return values. So, if * Ctrl-C handling is important, signal needs to be handled on * a different thread or something. */ rc = waitForEventsOnDarwin(cMsTimeout); # else // !RT_OS_DARWIN rc = waitForEventsOnXPCOM(mEventQ, cMsTimeout); # endif // !RT_OS_DARWIN if ( RT_SUCCESS(rc) || rc == VERR_TIMEOUT) { int rc2 = processPendingEvents(mEventQ); /* If the wait was successful don't fail the whole operation. */ if (RT_FAILURE(rc) && RT_FAILURE(rc2)) rc = rc2; } } if ( ( RT_SUCCESS(rc) || rc == VERR_INTERRUPTED || rc == VERR_TIMEOUT) && mInterrupted) { mInterrupted = false; rc = VERR_INTERRUPTED; } #else // !VBOX_WITH_XPCOM if (cMsTimeout == RT_INDEFINITE_WAIT) { BOOL fRet = 0; /* Shut up MSC */ MSG Msg; rc = VINF_SUCCESS; while ( rc != VERR_INTERRUPTED && (fRet = GetMessage(&Msg, NULL /*hWnd*/, WM_USER, WM_USER)) && fRet != -1) rc = NativeEventQueue::dispatchMessageOnWindows(&Msg, rc); if (fRet == 0) rc = VERR_INTERRUPTED; else if (fRet == -1) rc = RTErrConvertFromWin32(GetLastError()); } else { rc = processPendingEvents(); if ( rc == VERR_TIMEOUT && cMsTimeout != 0) { DWORD rcW = MsgWaitForMultipleObjects(1, &mhThread, TRUE /*fWaitAll*/, cMsTimeout, QS_ALLINPUT); AssertMsgReturn(rcW == WAIT_TIMEOUT || rcW == WAIT_OBJECT_0, ("%d\n", rcW), VERR_INTERNAL_ERROR_4); rc = processPendingEvents(); } } #endif // !VBOX_WITH_XPCOM Assert(rc != VERR_TIMEOUT || cMsTimeout != RT_INDEFINITE_WAIT); return rc; } /** * Interrupt thread waiting on event queue processing. * * Can be called on any thread. * * @returns VBox status code. */ int NativeEventQueue::interruptEventQueueProcessing() { /* Send a NULL event. This event will be picked up and handled specially * both for XPCOM and Windows. It is the responsibility of the caller to * take care of not running the loop again in a way which will hang. */ postEvent(NULL); return VINF_SUCCESS; } /** * Posts an event to this event loop asynchronously. * * @param pEvent the event to post, must be allocated using |new| * @return @c TRUE if successful and false otherwise */ BOOL NativeEventQueue::postEvent(NativeEvent *pEvent) { #ifndef VBOX_WITH_XPCOM /* Note! The event == NULL case is duplicated in vboxapi/PlatformMSCOM::interruptWaitEvents(). */ BOOL fRc = PostThreadMessage(mThreadId, WM_USER, (WPARAM)pEvent, EVENTQUEUE_WIN_LPARAM_MAGIC); if (!fRc) { static int s_cBitchedAboutFullNativeEventQueue = 0; if ( GetLastError() == ERROR_NOT_ENOUGH_QUOTA && s_cBitchedAboutFullNativeEventQueue < 10) LogRel(("Warning: Asynchronous event queue (%p, thread %RI32) full, event (%p) not delivered (%d/10)\n", this, mThreadId, pEvent, ++s_cBitchedAboutFullNativeEventQueue)); else AssertFailed(); } return fRc; #else // VBOX_WITH_XPCOM if (!mEventQ) return FALSE; try { MyPLEvent *pMyEvent = new MyPLEvent(pEvent); mEventQ->InitEvent(pMyEvent, this, com::NativeEventQueue::plEventHandler, com::NativeEventQueue::plEventDestructor); HRESULT rc = mEventQ->PostEvent(pMyEvent); return NS_SUCCEEDED(rc); } catch (std::bad_alloc &ba) { AssertMsgFailed(("Out of memory while allocating memory for event=%p: %s\n", pEvent, ba.what())); } return FALSE; #endif // VBOX_WITH_XPCOM } /** * Get select()'able selector for this event queue. * This will return -1 on platforms and queue variants not supporting such * functionality. */ int NativeEventQueue::getSelectFD() { #ifdef VBOX_WITH_XPCOM return mEventQ->GetEventQueueSelectFD(); #else return -1; #endif } } /* namespace com */