Remove the concept of threading from ProxyService, and move it into the Proxy...

net/proxy/proxy_service.h

 // Copyright (c) 2006-2008 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_PROXY_SERVICE_H_
 #define NET_PROXY_PROXY_SERVICE_H_
 
-#include <deque>
 #include <string>
+#include <vector>
 
 #include "base/ref_counted.h"
 #include "base/scoped_ptr.h"
+// TODO(eroman): remove this unused header; other callers are depending on it!
 #include "base/thread.h"
 #include "base/waitable_event.h"
 #include "net/base/completion_callback.h"
 #include "net/proxy/proxy_server.h"
 #include "net/proxy/proxy_info.h"
 
 class GURL;
+class MessageLoop;
 class URLRequestContext;
 
 namespace net {
 
 class ProxyScriptFetcher;
 class ProxyConfigService;
 class ProxyResolver;
 
 // This class can be used to resolve the proxy server to use when loading a
 // HTTP(S) URL.  It uses the given ProxyResolver to handle the actual proxy
-// resolution.  See ProxyResolverWinHttp for example.
+// resolution.  See ProxyResolverV8 for example.
 class ProxyService {
  public:
   // The instance takes ownership of |config_service| and |resolver|.
   ProxyService(ProxyConfigService* config_service,
                ProxyResolver* resolver);
 
   ~ProxyService();
 
   // Used internally to handle PAC queries.
+  // TODO(eroman): consider naming this simply "Request".
   class PacRequest;
 
   // Returns ERR_IO_PENDING if the proxy information could not be provided
   // synchronously, to indicate that the result will be available when the
   // callback is run.  The callback is run on the thread that calls
   // ResolveProxy.
   //
   // The caller is responsible for ensuring that |results| and |callback|
   // remain valid until the callback is run or until |pac_request| is cancelled
   // via CancelPacRequest.  |pac_request| is only valid while the completion
   // callback is still pending. NULL can be passed for |pac_request| if
   // the caller will not need to cancel the request.
   //
   // We use the three possible proxy access types in the following order, and
   // we only use one of them (no falling back to other access types if the
   // chosen one doesn't work).
   //   1.  named proxy
   //   2.  PAC URL
   //   3.  WPAD auto-detection
   //
+  // TODO(eroman): see http://crbug.com/9985; the outline above is too simple.
   int ResolveProxy(const GURL& url,
                    ProxyInfo* results,
                    CompletionCallback* callback,
                    PacRequest** pac_request);
 
   // This method is called after a failure to connect or resolve a host name.
   // It gives the proxy service an opportunity to reconsider the proxy to use.
   // The |results| parameter contains the results returned by an earlier call
   // to ResolveProxy.  The semantics of this call are otherwise similar to
   // ResolveProxy.
@@ skipping 49 matching lines @@
   // Convenience method that creates a proxy service using the
   // specified fixed settings. |pc| must not be NULL.
   static ProxyService* CreateFixed(const ProxyConfig& pc);
 
   // Creates a proxy service that always fails to fetch the proxy configuration,
   // so it falls back to direct connect.
   static ProxyService* CreateNull();
 
  private:
   friend class PacRequest;
+  // TODO(eroman): change this to a std::set. Note that this requires updating
+  // some tests in proxy_service_unittest.cc such as:
+  //   ProxyServiceTest.InitialPACScriptDownload
+  // which expects requests to finish in the order they were added.
+  typedef std::vector<scoped_refptr<PacRequest> > PendingRequests;
 
   // Creates a config service appropriate for this platform that fetches the
   // system proxy settings.
   static ProxyConfigService* CreateSystemProxyConfigService(
       MessageLoop* io_loop);
 
   // Creates a proxy resolver appropriate for this platform that doesn't rely
   // on V8.
   static ProxyResolver* CreateNonV8ProxyResolver();
 
-  ProxyResolver* resolver() { return resolver_.get(); }
-  base::Thread* pac_thread() { return pac_thread_.get(); }
-
   // Identifies the proxy configuration.
   ProxyConfig::ID config_id() const { return config_.id(); }
 
   // Returns true if we have called UpdateConfig() at least once.
   bool config_has_been_initialized() const {
     return config_.id() != ProxyConfig::INVALID_ID;
   }
 
   // Checks to see if the proxy configuration changed, and then updates config_
   // to reference the new configuration.
@@ skipping 11 matching lines @@
   bool IsFetchingPacScript() const {
     return in_progress_fetch_config_id_ != ProxyConfig::INVALID_ID;
   }
 
   // Callback for when the PAC script has finished downloading.
   void OnScriptFetchCompletion(int result);
 
   // Returns ERR_IO_PENDING if the request cannot be completed synchronously.
   // Otherwise it fills |result| with the proxy information for |url|.
   // Completing synchronously means we don't need to query ProxyResolver.
-  // (ProxyResolver runs on PAC thread.)
   int TryToCompleteSynchronously(const GURL& url, ProxyInfo* result);
 
   // Set |result| with the proxy to use for |url|, based on |rules|.
   void ApplyProxyRules(const GURL& url,
                        const ProxyConfig::ProxyRules& rules,
                        ProxyInfo* result);
 
-  // Starts the PAC thread if it isn't already running.
-  void InitPacThread();
+  // Sends all the unstarted pending requests off to the resolver.
+  void ResumeAllPendingRequests();
 
-  // Starts the next request from |pending_requests_| is possible.
-  // |recent_req| is the request that just got added, or NULL.
-  void ProcessPendingRequests(PacRequest* recent_req);
+  // Returns true if |pending_requests_| contains |req|.
+  bool ContainsPendingRequest(PacRequest* req);
 
-  // Removes the front entry of the requests queue. |expected_req| is our
-  // expectation of what the front of the request queue is; it is only used by
-  // DCHECK for verification purposes.
-  void RemoveFrontOfRequestQueue(PacRequest* expected_req);
+  // Removes |req| from the list of pending requests.
+  void RemovePendingRequest(PacRequest* req);
+
+  // Returns true if the resolver is all set-up and ready to accept requests.
+  // Returns false if requests are blocked (because the PAC script is being
+  // downloaded). May have the side-effect of starting the PAC script
+  // download.
+  bool PrepareResolverForRequests();
 
   // Called to indicate that a PacRequest completed.  The |config_id| parameter
   // indicates the proxy configuration that was queried.  |result_code| is OK
   // if the PAC file could be downloaded and executed.  Otherwise, it is an
   // error code, indicating a bad proxy configuration.
   void DidCompletePacRequest(int config_id, int result_code);
 
   // Returns true if the URL passed in should not go through the proxy server.
   // 1. If the bypass proxy list contains the string <local> and the URL
   //    passed in is a local URL, i.e. a URL without a DOT (.)
   // 2. The URL matches one of the entities in the proxy bypass list.
   bool ShouldBypassProxyForURL(const GURL& url);
 
   scoped_ptr<ProxyConfigService> config_service_;
   scoped_ptr<ProxyResolver> resolver_;
-  scoped_ptr<base::Thread> pac_thread_;
 
   // We store the proxy config and a counter (ID) that is incremented each time
   // the config changes.
   ProxyConfig config_;
 
   // Increasing ID to give to the next ProxyConfig that we set.
   int next_config_id_;
 
   // Indicates that the configuration is bad and should be ignored.
   bool config_is_bad_;
 
   // The time when the proxy configuration was last read from the system.
   base::TimeTicks config_last_update_time_;
 
   // Map of the known bad proxies and the information about the retry time.
   ProxyRetryInfoMap proxy_retry_info_;
 
-  // FIFO queue of pending/inprogress requests.
-  typedef std::deque<scoped_refptr<PacRequest> > PendingRequestsQueue;
-  PendingRequestsQueue pending_requests_;
+  // Set of pending/inprogress requests.
+  PendingRequests pending_requests_;
 
   // The fetcher to use when downloading PAC scripts for the ProxyResolver.
   // This dependency can be NULL if our ProxyResolver has no need for
   // external PAC script fetching.
   scoped_ptr<ProxyScriptFetcher> proxy_script_fetcher_;
 
   // Callback for when |proxy_script_fetcher_| is done.
   CompletionCallbackImpl<ProxyService> proxy_script_fetcher_callback_;
 
   // The ID of the configuration for which we last downloaded a PAC script.
@@ skipping 34 matching lines @@
 
   base::WaitableEvent event_;
   CompletionCallbackImpl<SyncProxyServiceHelper> callback_;
   ProxyInfo proxy_info_;
   int result_;
 };
 
 }  // namespace net
 
 #endif  // NET_PROXY_PROXY_SERVICE_H_