Add reprioritization to socket pools.

net/socket/client_socket_pool_base.cc

 // Copyright (c) 2012 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/socket/client_socket_pool_base.h"
 
 #include <algorithm>
 #include <utility>
 
 #include "base/compiler_specific.h"
@@ skipping 287 matching lines @@
 
 void ClientSocketPoolBaseHelper::RemoveHigherLayeredPool(
     HigherLayeredPool* higher_pool) {
   CHECK(higher_pool);
   CHECK(base::ContainsKey(higher_pools_, higher_pool));
   higher_pools_.erase(higher_pool);
 }
 
 int ClientSocketPoolBaseHelper::RequestSocket(
     const std::string& group_name,
-    std::unique_ptr<const Request> request) {
+    std::unique_ptr<Request> request) {
   CHECK(!request->callback().is_null());
   CHECK(request->handle());
 
   // Cleanup any timed-out idle sockets.
   CleanupIdleSockets(false);
 
   request->net_log().BeginEvent(NetLogEventType::SOCKET_POOL);
   Group* group = GetOrCreateGroup(group_name);
 
   int rv = RequestSocketInternal(group_name, *request);
@@ skipping 236 matching lines @@
 }
 
 // static
 void ClientSocketPoolBaseHelper::LogBoundConnectJobToRequest(
     const NetLogSource& connect_job_source,
     const Request& request) {
   request.net_log().AddEvent(NetLogEventType::SOCKET_POOL_BOUND_TO_CONNECT_JOB,
                              connect_job_source.ToEventParametersCallback());
 }
 
+void ClientSocketPoolBaseHelper::SetPriority(const std::string& group_name,
+                                             ClientSocketHandle* handle,
+                                             RequestPriority priority) {
+  GroupMap::iterator group_it = group_map_.find(group_name);
+  if (group_it == group_map_.end()) {
+    DCHECK(base::ContainsKey(pending_callback_map_, handle));
+    // The Request has already completed and been destroyed; nothing to
+    // reprioritize.
+    return;
+  }
+
+  group_it->second->SetPriority(handle, priority);
+}
+
 void ClientSocketPoolBaseHelper::CancelRequest(
     const std::string& group_name, ClientSocketHandle* handle) {
   PendingCallbackMap::iterator callback_it = pending_callback_map_.find(handle);
   if (callback_it != pending_callback_map_.end()) {
     int result = callback_it->second.result;
     pending_callback_map_.erase(callback_it);
     std::unique_ptr<StreamSocket> socket = handle->PassSocket();
     if (socket) {
       if (result != OK)
         socket->Disconnect();
       ReleaseSocket(handle->group_name(), std::move(socket), handle->id());
     }
     return;
   }
 
   CHECK(base::ContainsKey(group_map_, group_name));
 
   Group* group = GetOrCreateGroup(group_name);
 
   // Search pending_requests for matching handle.
-  std::unique_ptr<const Request> request =
-      group->FindAndRemovePendingRequest(handle);
+  std::unique_ptr<Request> request = group->FindAndRemovePendingRequest(handle);
   if (request) {
     request->net_log().AddEvent(NetLogEventType::CANCELLED);
     request->net_log().EndEvent(NetLogEventType::SOCKET_POOL);
 
     // We let the job run, unless we're at the socket limit and there is
     // not another request waiting on the job.
     if (group->jobs().size() > group->pending_request_count() &&
         ReachedMaxSocketsLimit()) {
       RemoveConnectJob(group->jobs().begin()->get(), group);
       CheckForStalledSocketGroups();
@@ skipping 363 matching lines @@
   // accessed.
   NetLogWithSource job_log = job->net_log();
   LoadTimingInfo::ConnectTiming connect_timing = job->connect_timing();
 
   // RemoveConnectJob(job, _) must be called by all branches below;
   // otherwise, |job| will be leaked.
 
   if (result == OK) {
     DCHECK(socket.get());
     RemoveConnectJob(job, group);
-    std::unique_ptr<const Request> request = group->PopNextPendingRequest();
+    std::unique_ptr<Request> request = group->PopNextPendingRequest();
     if (request) {
       LogBoundConnectJobToRequest(job_log.source(), *request);
       HandOutSocket(std::move(socket), ClientSocketHandle::UNUSED,
                     connect_timing, request->handle(), base::TimeDelta(), group,
                     request->net_log());
       request->net_log().EndEvent(NetLogEventType::SOCKET_POOL);
       InvokeUserCallbackLater(request->handle(), request->callback(), result);
     } else {
       AddIdleSocket(std::move(socket), group);
       OnAvailableSocketSlot(group_name, group);
       CheckForStalledSocketGroups();
     }
   } else {
     // If we got a socket, it must contain error information so pass that
     // up so that the caller can retrieve it.
     bool handed_out_socket = false;
-    std::unique_ptr<const Request> request = group->PopNextPendingRequest();
+    std::unique_ptr<Request> request = group->PopNextPendingRequest();
     if (request) {
       LogBoundConnectJobToRequest(job_log.source(), *request);
       job->GetAdditionalErrorState(request->handle());
       RemoveConnectJob(job, group);
       if (socket.get()) {
         handed_out_socket = true;
         HandOutSocket(std::move(socket), ClientSocketHandle::UNUSED,
                       connect_timing, request->handle(), base::TimeDelta(),
                       group, request->net_log());
       }
@@ skipping 48 matching lines @@
   // If the group has no idle sockets, and can't make use of an additional slot,
   // either because it's at the limit or because it's at the socket per group
   // limit, then there's nothing to do.
   if (group->idle_sockets().empty() &&
       !group->CanUseAdditionalSocketSlot(max_sockets_per_group_)) {
     return;
   }
 
   int rv = RequestSocketInternal(group_name, *next_request);
   if (rv != ERR_IO_PENDING) {
-    std::unique_ptr<const Request> request = group->PopNextPendingRequest();
+    std::unique_ptr<Request> request = group->PopNextPendingRequest();
     DCHECK(request);
     if (group->IsEmpty())
       RemoveGroup(group_name);
 
     request->net_log().EndEventWithNetErrorCode(NetLogEventType::SOCKET_POOL,
                                                 rv);
     InvokeUserCallbackLater(request->handle(), request->callback(), rv);
   }
 }
 
@@ skipping 66 matching lines @@
     }
   }
   DCHECK_EQ(0, connecting_socket_count_);
 }
 
 void ClientSocketPoolBaseHelper::CancelAllRequestsWithError(int error) {
   for (GroupMap::iterator i = group_map_.begin(); i != group_map_.end();) {
     Group* group = i->second;
 
     while (true) {
-      std::unique_ptr<const Request> request = group->PopNextPendingRequest();
+      std::unique_ptr<Request> request = group->PopNextPendingRequest();
       if (!request)
         break;
       InvokeUserCallbackLater(request->handle(), request->callback(), error);
     }
 
     // Delete group if no longer needed.
     if (group->IsEmpty()) {
       // RemoveGroup() will call .erase() which will invalidate the iterator,
       // but i will already have been incremented to a valid iterator before
       // RemoveGroup() is called.
@@ skipping 222 matching lines @@
   for (RequestQueue::Pointer pointer = pending_requests_.FirstMax();
        !pointer.is_null() && i < jobs_.size();
        pointer = pending_requests_.GetNextTowardsLastMin(pointer), ++i) {
     if (pointer.value()->handle() == handle)
       return true;
   }
   return false;
 }
 
 void ClientSocketPoolBaseHelper::Group::InsertPendingRequest(
-    std::unique_ptr<const Request> request) {
+    std::unique_ptr<Request> request) {
   // This value must be cached before we release |request|.
   RequestPriority priority = request->priority();
   if (request->respect_limits() == ClientSocketPool::RespectLimits::DISABLED) {
     // Put requests with RespectLimits::DISABLED (which should have
     // priority == MAXIMUM_PRIORITY) ahead of other requests with
     // MAXIMUM_PRIORITY.
     DCHECK_EQ(priority, MAXIMUM_PRIORITY);
     pending_requests_.InsertAtFront(request.release(), priority);
   } else {
     pending_requests_.Insert(request.release(), priority);
   }
 }
 
-std::unique_ptr<const ClientSocketPoolBaseHelper::Request>
+std::unique_ptr<ClientSocketPoolBaseHelper::Request>
 ClientSocketPoolBaseHelper::Group::PopNextPendingRequest() {
   if (pending_requests_.empty())
-    return std::unique_ptr<const ClientSocketPoolBaseHelper::Request>();
+    return std::unique_ptr<ClientSocketPoolBaseHelper::Request>();
   return RemovePendingRequest(pending_requests_.FirstMax());
 }
 
-std::unique_ptr<const ClientSocketPoolBaseHelper::Request>
+std::unique_ptr<ClientSocketPoolBaseHelper::Request>
 ClientSocketPoolBaseHelper::Group::FindAndRemovePendingRequest(
     ClientSocketHandle* handle) {
   for (RequestQueue::Pointer pointer = pending_requests_.FirstMax();
        !pointer.is_null();
        pointer = pending_requests_.GetNextTowardsLastMin(pointer)) {
     if (pointer.value()->handle() == handle) {
-      std::unique_ptr<const Request> request = RemovePendingRequest(pointer);
+      DCHECK_EQ(static_cast<RequestPriority>(pointer.priority()),
+                pointer.value()->priority());
+      std::unique_ptr<Request> request = RemovePendingRequest(pointer);
       return request;
     }
   }
-  return std::unique_ptr<const ClientSocketPoolBaseHelper::Request>();
+  return std::unique_ptr<ClientSocketPoolBaseHelper::Request>();
 }
 
-std::unique_ptr<const ClientSocketPoolBaseHelper::Request>
+void ClientSocketPoolBaseHelper::Group::SetPriority(ClientSocketHandle* handle,
+                                                    RequestPriority priority) {
+  for (RequestQueue::Pointer pointer = pending_requests_.FirstMax();
+       !pointer.is_null();
+       pointer = pending_requests_.GetNextTowardsLastMin(pointer)) {
+    if (pointer.value()->handle() == handle) {
+      if (pointer.value()->priority() == priority)
+        return;
+
+      std::unique_ptr<Request> request = RemovePendingRequest(pointer);
+
+      // Requests that ignore limits much be created and remain at the highest
+      // priority, and should not be reprioritized.
+      DCHECK_EQ(request->respect_limits(),
+                ClientSocketPool::RespectLimits::ENABLED);
+
+      request->set_priority(priority);
+      InsertPendingRequest(std::move(request));
+      return;
+    }
+  }
+
+  // This function must be called with a valid ClientSocketHandle.
+  NOTREACHED();
+}
+
+std::unique_ptr<ClientSocketPoolBaseHelper::Request>
 ClientSocketPoolBaseHelper::Group::RemovePendingRequest(
     const RequestQueue::Pointer& pointer) {
   // TODO(eroman): Temporary for debugging http://crbug.com/467797.
   CHECK(!pointer.is_null());
-  std::unique_ptr<const Request> request(pointer.value());
+  std::unique_ptr<Request> request(pointer.value());
   pending_requests_.Erase(pointer);
   // If there are no more requests, kill the backup timer.
   if (pending_requests_.empty())
     backup_job_timer_.Stop();
   request->CrashIfInvalid();
   return request;
 }
 
 }  // namespace internal
 
 }  // namespace net