| // Copyright 2015 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #ifndef EXTENSIONS_BROWSER_EXTENSION_HOST_QUEUE_H_ |
| #define EXTENSIONS_BROWSER_EXTENSION_HOST_QUEUE_H_ |
| |
| #include <list> |
| |
| #include "base/memory/weak_ptr.h" |
| #include "base/time/time.h" |
| |
| namespace extensions { |
| class DeferredStartRenderHost; |
| |
| // A queue of ExtensionHosts waiting for initialization. This initializes |
| // DeferredStartRenderHosts in the order they're Add()ed, with simple rate |
| // limiting logic that re-posts each task to the UI thread, to avoid clogging it |
| // for a long period of time. |
| class ExtensionHostQueue { |
| public: |
| ExtensionHostQueue(); |
| ~ExtensionHostQueue(); |
| |
| ExtensionHostQueue(const ExtensionHostQueue& queue) = delete; |
| ExtensionHostQueue& operator=(const ExtensionHostQueue& queue) = delete; |
| |
| // Returns the single global instance of the ExtensionHostQueue. |
| static ExtensionHostQueue& GetInstance(); |
| |
| // Adds a host to the queue for RenderView creation. |
| void Add(DeferredStartRenderHost* host); |
| |
| // Removes a host from the queue (for example, it may be deleted before |
| // having a chance to start) |
| void Remove(DeferredStartRenderHost* host); |
| |
| // Adds a delay before starting the next ExtensionHost. This can be used for |
| // testing purposes to help flush out flakes. |
| void SetCustomDelayForTesting(base::TimeDelta delay) { delay_ = delay; } |
| |
| private: |
| // Queues up a delayed task to process the next DeferredStartRenderHost in |
| // the queue. |
| void PostTask(); |
| |
| // Creates the RenderView for the next host in the queue. |
| void ProcessOneHost(); |
| |
| // True if this queue is currently in the process of starting an |
| // DeferredStartRenderHost. |
| bool pending_create_; |
| |
| // The delay before starting the next host. By default, this is 0, meaning we |
| // just wait until the event loop yields. |
| base::TimeDelta delay_; |
| |
| // The list of DeferredStartRenderHosts waiting to be started. |
| std::list<DeferredStartRenderHost*> queue_; |
| |
| base::WeakPtrFactory<ExtensionHostQueue> ptr_factory_{this}; |
| }; |
| |
| } // namespace extensions |
| |
| #endif // EXTENSIONS_BROWSER_EXTENSION_HOST_QUEUE_H_ |