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| author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 00:47:55 +0000 |
|---|---|---|
| committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 00:47:55 +0000 |
| commit | 26a029d407be480d791972afb5975cf62c9360a6 (patch) | |
| tree | f435a8308119effd964b339f76abb83a57c29483 /xpcom/threads/LazyIdleThread.h | |
| parent | Initial commit. (diff) | |
| download | firefox-upstream/124.0.1.tar.xz firefox-upstream/124.0.1.zip | |
Adding upstream version 124.0.1.upstream/124.0.1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
| -rw-r--r-- | xpcom/threads/LazyIdleThread.h | 93 |
1 files changed, 93 insertions, 0 deletions
diff --git a/xpcom/threads/LazyIdleThread.h b/xpcom/threads/LazyIdleThread.h new file mode 100644 index 0000000000..8a720bc69b --- /dev/null +++ b/xpcom/threads/LazyIdleThread.h @@ -0,0 +1,93 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 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/. */ + +#ifndef mozilla_lazyidlethread_h__ +#define mozilla_lazyidlethread_h__ + +#ifndef MOZILLA_INTERNAL_API +# error "This header is only usable from within libxul (MOZILLA_INTERNAL_API)." +#endif + +#include "mozilla/TaskQueue.h" +#include "nsIObserver.h" +#include "nsThreadPool.h" + +namespace mozilla { + +/** + * This class provides a basic event target that creates its thread lazily and + * destroys its thread after a period of inactivity. It may be created and used + * on any thread but it may only be shut down from the thread on which it is + * created. + */ +class LazyIdleThread final : public nsISerialEventTarget, public nsIObserver { + public: + NS_DECL_THREADSAFE_ISUPPORTS + NS_DECL_NSIEVENTTARGET_FULL + NS_DECL_NSIOBSERVER + + /** + * If AutomaticShutdown is specified, and the LazyIdleThread is created on the + * main thread, Shutdown() will automatically be called during + * xpcom-shutdown-threads. + */ + enum ShutdownMethod { AutomaticShutdown = 0, ManualShutdown }; + + /** + * Create a new LazyIdleThread that will destroy its thread after the given + * number of milliseconds. + */ + LazyIdleThread(uint32_t aIdleTimeoutMS, const char* aName, + ShutdownMethod aShutdownMethod = AutomaticShutdown); + + /** + * Shuts down the LazyIdleThread, waiting for any pending work to complete. + * Must be called from mOwningEventTarget. + */ + void Shutdown(); + + /** + * Register a nsIThreadPoolListener on the underlying threadpool to track the + * thread as it is created/destroyed. + */ + nsresult SetListener(nsIThreadPoolListener* aListener); + + private: + /** + * Asynchronously shuts down the LazyIdleThread on mOwningEventTarget. + */ + ~LazyIdleThread(); + + /** + * The thread which created this LazyIdleThread and is responsible for + * shutting it down. + */ + const nsCOMPtr<nsISerialEventTarget> mOwningEventTarget; + + /** + * The single-thread backing threadpool which provides the actual threads used + * by LazyIdleThread, and implements the timeout. + */ + const RefPtr<nsThreadPool> mThreadPool; + + /** + * The serial event target providing a `nsISerialEventTarget` implementation + * when on the LazyIdleThread. + */ + const RefPtr<TaskQueue> mTaskQueue; + + /** + * Only safe to access on the owning thread or in the destructor (as no other + * threads have access then). If `true`, means the LazyIdleThread has already + * been shut down, so it does not need to be shut down asynchronously from the + * destructor. + */ + bool mShutdown = false; +}; + +} // namespace mozilla + +#endif // mozilla_lazyidlethread_h__ |