Add the capability to run multiple proxy PAC scripts in parallel....

net/proxy/single_threaded_proxy_resolver.h

-// Copyright (c) 2009 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 NET_PROXY_SINGLE_THREADED_PROXY_RESOLVER_H_
-#define NET_PROXY_SINGLE_THREADED_PROXY_RESOLVER_H_
-
-#include <deque>
-#include <string>
-
-#include "base/ref_counted.h"
-#include "base/scoped_ptr.h"
-#include "net/proxy/proxy_resolver.h"
-
-namespace base {
-class Thread;
-}  // namespace base
-
-namespace net {
-
-// ProxyResolver implementation that wraps a synchronous ProxyResolver, and
-// runs it on a single worker thread. If multiple requests accumulate, they
-// are serviced in FIFO order.
-class SingleThreadedProxyResolver : public ProxyResolver {
- public:
-  // |resolver| is a synchronous ProxyResolver implementation. It doesn't
-  // have to be thread-safe, since it is run on exactly one thread. The
-  // constructor takes ownership of |resolver|.
-  explicit SingleThreadedProxyResolver(ProxyResolver* resolver);
-
-  virtual ~SingleThreadedProxyResolver();
-
-  // ProxyResolver implementation:
-  virtual int GetProxyForURL(const GURL& url,
-                             ProxyInfo* results,
-                             CompletionCallback* callback,
-                             RequestHandle* request,
-                             const BoundNetLog& net_log);
-  virtual void CancelRequest(RequestHandle request);
-  virtual void CancelSetPacScript();
-  virtual void PurgeMemory();
-
- protected:
-  // The wrapped (synchronous) ProxyResolver.
-  ProxyResolver* resolver() { return resolver_.get(); }
-
- private:
-  // Refcounted helper class that bridges between origin thread and worker
-  // thread.
-  class Job;
-  friend class Job;
-  class SetPacScriptTask;
-  friend class SetPacScriptTask;
-  // FIFO queue that contains the in-progress job, and any pending jobs.
-  typedef std::deque<scoped_refptr<Job> > PendingJobsQueue;
-
-  base::Thread* thread() { return thread_.get(); }
-
-  // ProxyResolver implementation:
-  virtual int SetPacScript(const GURL& pac_url,
-                           const string16& pac_script,
-                           CompletionCallback* callback);
-
-  // Starts the worker thread if it isn't already running.
-  void EnsureThreadStarted();
-
-  // Starts the next job from |pending_jobs_| if possible.
-  void ProcessPendingJobs();
-
-  // Removes the front entry of the jobs queue. |expected_job| is our
-  // expectation of what the front of the job queue is; it is only used by
-  // DCHECK for verification purposes.
-  void RemoveFrontOfJobsQueueAndStartNext(Job* expected_job);
-
-  // Clears |outstanding_set_pac_script_task_|.
-  // Called when |task| has just finished.
-  void RemoveOutstandingSetPacScriptTask(SetPacScriptTask* task);
-
-  // The synchronous resolver implementation.
-  scoped_ptr<ProxyResolver> resolver_;
-
-  // The thread where |resolver_| is run on.
-  // Note that declaration ordering is important here. |thread_| needs to be
-  // destroyed *before* |resolver_|, in case |resolver_| is currently
-  // executing on |thread_|.
-  scoped_ptr<base::Thread> thread_;
-
-  PendingJobsQueue pending_jobs_;
-  scoped_refptr<SetPacScriptTask> outstanding_set_pac_script_task_;
-};
-
-}  // namespace net
-
-#endif  // NET_PROXY_SINGLE_THREADED_PROXY_RESOLVER_H_