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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 17:32:43 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 17:32:43 +0000 |
commit | 6bf0a5cb5034a7e684dcc3500e841785237ce2dd (patch) | |
tree | a68f146d7fa01f0134297619fbe7e33db084e0aa /netwerk/ipc/ChannelEventQueue.cpp | |
parent | Initial commit. (diff) | |
download | thunderbird-upstream.tar.xz thunderbird-upstream.zip |
Adding upstream version 1:115.7.0.upstream/1%115.7.0upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'netwerk/ipc/ChannelEventQueue.cpp')
-rw-r--r-- | netwerk/ipc/ChannelEventQueue.cpp | 227 |
1 files changed, 227 insertions, 0 deletions
diff --git a/netwerk/ipc/ChannelEventQueue.cpp b/netwerk/ipc/ChannelEventQueue.cpp new file mode 100644 index 0000000000..911deaa7d9 --- /dev/null +++ b/netwerk/ipc/ChannelEventQueue.cpp @@ -0,0 +1,227 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- + * vim: set sw=2 ts=8 et tw=80 : + */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#include "ChannelEventQueue.h" + +#include "mozilla/Assertions.h" +#include "mozilla/Unused.h" +#include "nsIChannel.h" +#include "mozilla/dom/Document.h" +#include "nsThreadUtils.h" + +namespace mozilla { +namespace net { + +ChannelEvent* ChannelEventQueue::TakeEvent() { + mMutex.AssertCurrentThreadOwns(); + MOZ_ASSERT(mFlushing); + + if (mSuspended || mEventQueue.IsEmpty()) { + return nullptr; + } + + UniquePtr<ChannelEvent> event(std::move(mEventQueue[0])); + mEventQueue.RemoveElementAt(0); + + return event.release(); +} + +void ChannelEventQueue::FlushQueue() { + // Events flushed could include destruction of channel (and our own + // destructor) unless we make sure its refcount doesn't drop to 0 while this + // method is running. + nsCOMPtr<nsISupports> kungFuDeathGrip; + { + MutexAutoLock lock(mMutex); + kungFuDeathGrip = mOwner; + } + mozilla::Unused << kungFuDeathGrip; // Not used in this function + +#ifdef DEBUG + { + MutexAutoLock lock(mMutex); + MOZ_ASSERT(mFlushing); + } +#endif // DEBUG + + bool needResumeOnOtherThread = false; + + while (true) { + UniquePtr<ChannelEvent> event; + { + MutexAutoLock lock(mMutex); + event.reset(TakeEvent()); + if (!event) { + MOZ_ASSERT(mFlushing); + mFlushing = false; + MOZ_ASSERT(mEventQueue.IsEmpty() || (mSuspended || !!mForcedCount)); + break; + } + } + + nsCOMPtr<nsIEventTarget> target = event->GetEventTarget(); + MOZ_ASSERT(target); + + bool isCurrentThread = false; + nsresult rv = target->IsOnCurrentThread(&isCurrentThread); + if (NS_WARN_IF(NS_FAILED(rv))) { + // Simply run this event on current thread if we are not sure about it + // in release channel, or assert in Aurora/Nightly channel. + MOZ_DIAGNOSTIC_ASSERT(false); + isCurrentThread = true; + } + + if (!isCurrentThread) { + // Next event needs to run on another thread. Put it back to + // the front of the queue can try resume on that thread. + Suspend(); + PrependEvent(std::move(event)); + + needResumeOnOtherThread = true; + { + MutexAutoLock lock(mMutex); + MOZ_ASSERT(mFlushing); + mFlushing = false; + MOZ_ASSERT(!mEventQueue.IsEmpty()); + } + break; + } + + event->Run(); + } // end of while(true) + + // The flush procedure is aborted because next event cannot be run on current + // thread. We need to resume the event processing right after flush procedure + // is finished. + // Note: we cannot call Resume() while "mFlushing == true" because + // CompleteResume will not trigger FlushQueue while there is an ongoing flush. + if (needResumeOnOtherThread) { + Resume(); + } +} + +void ChannelEventQueue::Suspend() { + MutexAutoLock lock(mMutex); + SuspendInternal(); +} + +void ChannelEventQueue::SuspendInternal() { + mMutex.AssertCurrentThreadOwns(); + + mSuspended = true; + mSuspendCount++; +} + +void ChannelEventQueue::Resume() { + MutexAutoLock lock(mMutex); + ResumeInternal(); +} + +void ChannelEventQueue::ResumeInternal() { + mMutex.AssertCurrentThreadOwns(); + + // Resuming w/o suspend: error in debug mode, ignore in build + MOZ_ASSERT(mSuspendCount > 0); + if (mSuspendCount <= 0) { + return; + } + + if (!--mSuspendCount) { + if (mEventQueue.IsEmpty() || !!mForcedCount) { + // Nothing in queue to flush or waiting for AutoEventEnqueuer to + // finish the force enqueue period, simply clear the flag. + mSuspended = false; + return; + } + + // Hold a strong reference of mOwner to avoid the channel release + // before CompleteResume was executed. + class CompleteResumeRunnable : public Runnable { + public: + explicit CompleteResumeRunnable(ChannelEventQueue* aQueue, + nsISupports* aOwner) + : Runnable("CompleteResumeRunnable"), + mQueue(aQueue), + mOwner(aOwner) {} + + NS_IMETHOD Run() override { + mQueue->CompleteResume(); + return NS_OK; + } + + private: + virtual ~CompleteResumeRunnable() = default; + + RefPtr<ChannelEventQueue> mQueue; + nsCOMPtr<nsISupports> mOwner; + }; + + if (!mOwner) { + return; + } + + // Worker thread requires a CancelableRunnable. + RefPtr<Runnable> event = new CompleteResumeRunnable(this, mOwner); + + nsCOMPtr<nsIEventTarget> target; + target = mEventQueue[0]->GetEventTarget(); + MOZ_ASSERT(target); + + Unused << NS_WARN_IF( + NS_FAILED(target->Dispatch(event.forget(), NS_DISPATCH_NORMAL))); + } +} + +bool ChannelEventQueue::MaybeSuspendIfEventsAreSuppressed() { + // We only ever need to suppress events on the main thread, since this is + // where content scripts can run. + if (!NS_IsMainThread()) { + return false; + } + + // Only suppress events for queues associated with XHRs, as these can cause + // content scripts to run. + if (mHasCheckedForXMLHttpRequest && !mForXMLHttpRequest) { + return false; + } + + mMutex.AssertCurrentThreadOwns(); + nsCOMPtr<nsIChannel> channel(do_QueryInterface(mOwner)); + if (!channel) { + return false; + } + + nsCOMPtr<nsILoadInfo> loadInfo = channel->LoadInfo(); + // Figure out if this is for an XHR, if we haven't done so already. + if (!mHasCheckedForXMLHttpRequest) { + nsContentPolicyType contentType = loadInfo->InternalContentPolicyType(); + mForXMLHttpRequest = + (contentType == nsIContentPolicy::TYPE_INTERNAL_XMLHTTPREQUEST); + mHasCheckedForXMLHttpRequest = true; + + if (!mForXMLHttpRequest) { + return false; + } + } + + // Suspend the queue if the associated document has suppressed event handling, + // *and* it is not in the middle of a synchronous operation that might require + // XHR events to be processed (such as a synchronous XHR). + RefPtr<dom::Document> document; + loadInfo->GetLoadingDocument(getter_AddRefs(document)); + if (document && document->EventHandlingSuppressed() && + !document->IsInSyncOperation()) { + document->AddSuspendedChannelEventQueue(this); + SuspendInternal(); + return true; + } + + return false; +} + +} // namespace net +} // namespace mozilla |