Reland "Change ProxyResolver::GetProxyForURL() to take a unique_ptr<Request>* "

net/proxy/proxy_resolver_v8_tracing.cc

 // Copyright (c) 2013 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.
 
 #include "net/proxy/proxy_resolver_v8_tracing.h"
 
 #include <map>
 #include <string>
 #include <utility>
 #include <vector>
@@ skipping 296 matching lines @@
   ProxyResolverV8TracingImpl(std::unique_ptr<base::Thread> thread,
                              std::unique_ptr<ProxyResolverV8> resolver,
                              std::unique_ptr<Job::Params> job_params);
 
   ~ProxyResolverV8TracingImpl() override;
 
   // ProxyResolverV8Tracing overrides.
   void GetProxyForURL(const GURL& url,
                       ProxyInfo* results,
                       const CompletionCallback& callback,
-                      ProxyResolver::RequestHandle* request,
+                      std::unique_ptr<ProxyResolver::Request>* request,
                       std::unique_ptr<Bindings> bindings) override;
-  void CancelRequest(ProxyResolver::RequestHandle request) override;
-  LoadState GetLoadState(ProxyResolver::RequestHandle request) const override;
+
+  class RequestImpl : public ProxyResolver::Request {
+   public:
+    explicit RequestImpl(scoped_refptr<Job> job);
+    ~RequestImpl() override;
+    LoadState GetLoadState() override;
+
+   private:
+    scoped_refptr<Job> job_;
+  };
 
  private:
   // The worker thread on which the ProxyResolverV8 will be run.
   std::unique_ptr<base::Thread> thread_;
   std::unique_ptr<ProxyResolverV8> v8_resolver_;
 
   std::unique_ptr<Job::Params> job_params_;
 
   // The number of outstanding (non-cancelled) jobs.
   int num_outstanding_callbacks_;
@@ skipping 48 matching lines @@
   // (b) The script is executing on the worker thread.
   // (c) The script is executing on the worker thread, however is blocked inside
   //     of dnsResolve() waiting for a response from the origin thread.
   // (d) Nothing is running on the worker thread, however the host resolver has
   //     a pending DNS request which upon completion will restart the script
   //     execution.
   // (e) The worker thread has a pending task to restart execution, which was
   //     posted after the DNS dependency was resolved and saved to local cache.
   // (f) The script execution completed entirely, and posted a task to the
   //     origin thread to notify the caller.
+  // (g) The job is already completed.
   //
   // |cancelled_| is read on both the origin thread and worker thread. The
   // code that runs on the worker thread is littered with checks on
   // |cancelled_| to break out early.
+
+  // If the job already completed, there is nothing to be cancelled.
+  if (callback_.is_null())
+    return;
+
   cancelled_.Set();
 
   ReleaseCallback();
 
   pending_dns_.reset();
 
   // The worker thread might be blocked waiting for DNS.
   event_.Signal();
 
   bindings_.reset();
@@ skipping 525 matching lines @@
 
 ProxyResolverV8TracingImpl::~ProxyResolverV8TracingImpl() {
   // Note, all requests should have been cancelled.
   CHECK_EQ(0, num_outstanding_callbacks_);
 
   // Join the worker thread. See http://crbug.com/69710.
   base::ThreadRestrictions::ScopedAllowIO allow_io;
   thread_.reset();
 }
 
+ProxyResolverV8TracingImpl::RequestImpl::RequestImpl(scoped_refptr<Job> job)
+    : job_(std::move(job)) {}
+
+ProxyResolverV8TracingImpl::RequestImpl::~RequestImpl() {
+  job_->Cancel();
+}
+
+LoadState ProxyResolverV8TracingImpl::RequestImpl::GetLoadState() {
+  return job_->GetLoadState();
+}
+
 void ProxyResolverV8TracingImpl::GetProxyForURL(
     const GURL& url,
     ProxyInfo* results,
     const CompletionCallback& callback,
-    ProxyResolver::RequestHandle* request,
+    std::unique_ptr<ProxyResolver::Request>* request,
     std::unique_ptr<Bindings> bindings) {
   DCHECK(CalledOnValidThread());
   DCHECK(!callback.is_null());
 
   scoped_refptr<Job> job = new Job(job_params_.get(), std::move(bindings));
 
-  if (request)
-    *request = job.get();
+  request->reset(new RequestImpl(job));
 
   job->StartGetProxyForURL(url, results, callback);
 }
 
-void ProxyResolverV8TracingImpl::CancelRequest(
-    ProxyResolver::RequestHandle request) {
-  Job* job = reinterpret_cast<Job*>(request);
-  job->Cancel();
-}
-
-LoadState ProxyResolverV8TracingImpl::GetLoadState(
-    ProxyResolver::RequestHandle request) const {
-  Job* job = reinterpret_cast<Job*>(request);
-  return job->GetLoadState();
-}
 
 class ProxyResolverV8TracingFactoryImpl : public ProxyResolverV8TracingFactory {
  public:
   ProxyResolverV8TracingFactoryImpl();
   ~ProxyResolverV8TracingFactoryImpl() override;
 
   void CreateProxyResolverV8Tracing(
       const scoped_refptr<ProxyResolverScriptData>& pac_script,
       std::unique_ptr<ProxyResolverV8Tracing::Bindings> bindings,
       std::unique_ptr<ProxyResolverV8Tracing>* resolver,
@@ skipping 118 matching lines @@
 
 }  // namespace
 
 // static
 std::unique_ptr<ProxyResolverV8TracingFactory>
 ProxyResolverV8TracingFactory::Create() {
   return base::WrapUnique(new ProxyResolverV8TracingFactoryImpl());
 }
 
 }  // namespace net