Defer closing idle sockets.

	Bug: 5523884
backport changes from chrome to defer closing idle sockets until
next socket request (for power efficiency). This does not enable
persistent connections.

Change-Id: Iab82f546e8607ddc4cacc576cda52c4d2d536570

net/socket/client_socket_pool_base.cc

@@ -20,6 +20,14 @@ using base::TimeDelta;
 
 namespace {
 
+// Indicate whether we should enable idle socket cleanup timer. When timer is
+// disabled, sockets are closed next time a socket request is made.
+#ifdef ANDROID
+bool g_cleanup_timer_enabled = false;
+#else
+bool g_cleanup_timer_enabled = true;
+#endif
+
 // The timeout value, in seconds, used to clean up idle sockets that can't be
 // reused.
 //
@@ -164,6 +172,7 @@ ClientSocketPoolBaseHelper::ClientSocketPoolBaseHelper(
       handed_out_socket_count_(0),
       max_sockets_(max_sockets),
       max_sockets_per_group_(max_sockets_per_group),
+      use_cleanup_timer_(g_cleanup_timer_enabled),
       unused_idle_socket_timeout_(unused_idle_socket_timeout),
       used_idle_socket_timeout_(used_idle_socket_timeout),
       connect_job_factory_(connect_job_factory),
@@ -219,6 +228,10 @@ int ClientSocketPoolBaseHelper::RequestSocket(
   CHECK(request->callback());
   CHECK(request->handle());
 
+  // Cleanup any timed-out idle sockets if no timer is used.
+  if (!use_cleanup_timer_)
+    CleanupIdleSockets(false);
+
   request->net_log().BeginEvent(NetLog::TYPE_SOCKET_POOL, NULL);
   Group* group = GetOrCreateGroup(group_name);
 
@@ -240,6 +253,10 @@ void ClientSocketPoolBaseHelper::RequestSockets(
   DCHECK(!request.callback());
   DCHECK(!request.handle());
 
+  // Cleanup any timed out idle sockets if no timer is used.
+  if (!use_cleanup_timer_)
+    CleanupIdleSockets(false);
+
   if (num_sockets > max_sockets_per_group_) {
     num_sockets = max_sockets_per_group_;
   }
@@ -664,15 +681,31 @@ void ClientSocketPoolBaseHelper::EnableConnectBackupJobs() {
 
 void ClientSocketPoolBaseHelper::IncrementIdleCount() {
   if (++idle_socket_count_ == 1)
-    timer_.Start(TimeDelta::FromSeconds(kCleanupInterval), this,
-                 &ClientSocketPoolBaseHelper::OnCleanupTimerFired);
+    StartIdleSocketTimer();
 }
 
 void ClientSocketPoolBaseHelper::DecrementIdleCount() {
   if (--idle_socket_count_ == 0)
     timer_.Stop();
 }
 
+// static
+bool ClientSocketPoolBaseHelper::cleanup_timer_enabled() {
+  return g_cleanup_timer_enabled;
+}
+
+// static
+bool ClientSocketPoolBaseHelper::set_cleanup_timer_enabled(bool enabled) {
+  bool old_value = g_cleanup_timer_enabled;
+  g_cleanup_timer_enabled = enabled;
+  return old_value;
+}
+
+void ClientSocketPoolBaseHelper::StartIdleSocketTimer() {
+  timer_.Start(TimeDelta::FromSeconds(kCleanupInterval), this,
+               &ClientSocketPoolBaseHelper::OnCleanupTimerFired);
+}
+
 void ClientSocketPoolBaseHelper::ReleaseSocket(const std::string& group_name,
                                                ClientSocket* socket,
                                                int id) {
@@ -863,8 +896,7 @@ void ClientSocketPoolBaseHelper::ProcessPendingRequest(
       RemoveGroup(group_name);
 
     request->net_log().EndEventWithNetErrorCode(NetLog::TYPE_SOCKET_POOL, rv);
-    InvokeUserCallbackLater(
-        request->handle(), request->callback(), rv);
+    InvokeUserCallbackLater(request->handle(), request->callback(), rv);
   }
 }
 

net/socket/client_socket_pool_base.h

@@ -282,6 +282,14 @@ class ClientSocketPoolBaseHelper
 
   bool HasGroup(const std::string& group_name) const;
 
+  // Called to enable/disable cleaning up idle sockets. When enabled,
+  // idle sockets that have been around for longer than a period defined
+  // by kCleanupInterval are cleaned up using a timer. Otherwise they are
+  // closed next time client makes a request. This may reduce network
+  // activity and power consumption.
+  static bool cleanup_timer_enabled();
+  static bool set_cleanup_timer_enabled(bool enabled);
+
   // Closes all idle sockets if |force| is true.  Else, only closes idle
   // sockets that timed out or can't be reused.  Made public for testing.
   void CleanupIdleSockets(bool force);
@@ -431,6 +439,9 @@ class ClientSocketPoolBaseHelper
   void IncrementIdleCount();
   void DecrementIdleCount();
 
+  // Start cleanup timer for idle sockets.
+  void StartIdleSocketTimer();
+
   // Scans the group map for groups which have an available socket slot and
   // at least one pending request. Returns true if any groups are stalled, and
   // if so, fills |group| and |group_name| with data of the stalled group
@@ -541,6 +552,9 @@ class ClientSocketPoolBaseHelper
   // The maximum number of sockets kept per group.
   const int max_sockets_per_group_;
 
+  // Whether to use timer to cleanup idle sockets.
+  bool use_cleanup_timer_;
+
   // The time to wait until closing idle sockets.
   const base::TimeDelta unused_idle_socket_timeout_;
   const base::TimeDelta used_idle_socket_timeout_;

net/socket/client_socket_pool_base_unittest.cc

@@ -534,11 +534,15 @@ class ClientSocketPoolBaseTest : public testing::Test {
     connect_backup_jobs_enabled_ =
         internal::ClientSocketPoolBaseHelper::connect_backup_jobs_enabled();
     internal::ClientSocketPoolBaseHelper::set_connect_backup_jobs_enabled(true);
+    cleanup_timer_enabled_ =
+        internal::ClientSocketPoolBaseHelper::cleanup_timer_enabled();
   }
 
   virtual ~ClientSocketPoolBaseTest() {
     internal::ClientSocketPoolBaseHelper::set_connect_backup_jobs_enabled(
         connect_backup_jobs_enabled_);
+    internal::ClientSocketPoolBaseHelper::set_cleanup_timer_enabled(
+        cleanup_timer_enabled_);
   }
 
   void CreatePool(int max_sockets, int max_sockets_per_group) {
@@ -589,6 +593,7 @@ class ClientSocketPoolBaseTest : public testing::Test {
   size_t completion_count() const { return test_base_.completion_count(); }
 
   bool connect_backup_jobs_enabled_;
+  bool cleanup_timer_enabled_;
   MockClientSocketFactory client_socket_factory_;
   TestConnectJobFactory* connect_job_factory_;
   scoped_refptr<TestSocketParams> params_;
@@ -1861,6 +1866,83 @@ TEST_F(ClientSocketPoolBaseTest, AdditionalErrorStateAsynchronous) {
   EXPECT_FALSE(handle.ssl_error_response_info().headers.get() == NULL);
 }
 
+TEST_F(ClientSocketPoolBaseTest, DisableCleanupTimer) {
+  // Disable cleanup timer.
+  internal::ClientSocketPoolBaseHelper::set_cleanup_timer_enabled(false);
+
+  CreatePoolWithIdleTimeouts(
+      kDefaultMaxSockets, kDefaultMaxSocketsPerGroup,
+      base::TimeDelta::FromMilliseconds(10),  // Time out unused sockets
+      base::TimeDelta::FromMilliseconds(10));  // Time out used sockets
+
+  connect_job_factory_->set_job_type(TestConnectJob::kMockPendingJob);
+
+  // Startup two mock pending connect jobs, which will sit in the MessageLoop.
+
+  ClientSocketHandle handle;
+  TestOldCompletionCallback callback;
+  int rv = handle.Init("a",
+                       params_,
+                       LOWEST,
+                       &callback,
+                       pool_.get(),
+                       BoundNetLog());
+  EXPECT_EQ(ERR_IO_PENDING, rv);
+  EXPECT_EQ(LOAD_STATE_CONNECTING, pool_->GetLoadState("a", &handle));
+
+  ClientSocketHandle handle2;
+  TestOldCompletionCallback callback2;
+  rv = handle2.Init("a",
+                    params_,
+                    LOWEST,
+                    &callback2,
+                    pool_.get(),
+                    BoundNetLog());
+  EXPECT_EQ(ERR_IO_PENDING, rv);
+  EXPECT_EQ(LOAD_STATE_CONNECTING, pool_->GetLoadState("a", &handle2));
+
+  // Cancel one of the requests.  Wait for the other, which will get the first
+  // job.  Release the socket.  Run the loop again to make sure the second
+  // socket is sitting idle and the first one is released (since ReleaseSocket()
+  // just posts a DoReleaseSocket() task).
+
+  handle.Reset();
+  EXPECT_EQ(OK, callback2.WaitForResult());
+  // Use the socket.
+  EXPECT_EQ(1, handle2.socket()->Write(NULL, 1, NULL));
+  handle2.Reset();
+
+  // The idle socket timeout value was set to 10 milliseconds. Wait 20
+  // milliseconds so the sockets timeout.
+  base::PlatformThread::Sleep(20);
+  MessageLoop::current()->RunAllPending();
+
+  ASSERT_EQ(2, pool_->IdleSocketCount());
+
+  // Request a new socket. This should cleanup the unused and timed out ones.
+  // A new socket will be created rather than reusing the idle one.
+  CapturingBoundNetLog log(CapturingNetLog::kUnbounded);
+  rv = handle.Init("a",
+                   params_,
+                   LOWEST,
+                   &callback,
+                   pool_.get(),
+                   log.bound());
+  EXPECT_EQ(ERR_IO_PENDING, rv);
+  EXPECT_EQ(OK, callback.WaitForResult());
+  EXPECT_FALSE(handle.is_reused());
+
+  // Make sure the idle socket is closed
+  ASSERT_TRUE(pool_->HasGroup("a"));
+  EXPECT_EQ(0, pool_->IdleSocketCountInGroup("a"));
+  EXPECT_EQ(1, pool_->NumActiveSocketsInGroup("a"));
+
+  net::CapturingNetLog::EntryList entries;
+  log.GetEntries(&entries);
+  EXPECT_FALSE(LogContainsEntryWithType(
+      entries, 1, NetLog::TYPE_SOCKET_POOL_REUSED_AN_EXISTING_SOCKET));
+}
+
 TEST_F(ClientSocketPoolBaseTest, CleanupTimedOutIdleSockets) {
   CreatePoolWithIdleTimeouts(
       kDefaultMaxSockets, kDefaultMaxSocketsPerGroup,