Fixing Intermittent SecurityKey Unittest Failures

remoting/host/security_key/security_key_ipc_server_unittest.cc

 // Copyright 2016 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 "remoting/host/security_key/security_key_ipc_server.h"
 
 #include <memory>
 #include <string>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/callback.h"
 #include "base/macros.h"
 #include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
 #include "ipc/ipc_channel.h"
 #include "mojo/edk/embedder/embedder.h"
 #include "mojo/edk/embedder/named_platform_handle_utils.h"
-#include "mojo/edk/embedder/scoped_ipc_support.h"
 #include "remoting/host/client_session_details.h"
 #include "remoting/host/security_key/fake_security_key_ipc_client.h"
 #include "remoting/host/security_key/security_key_ipc_constants.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace {
 const int kTestConnectionId = 42;
 const int kInitialConnectTimeoutMs = 250;
 const int kConnectionTimeoutErrorDeltaMs = 100;
 const int kLargeMessageSizeBytes = 256 * 1024;
 }  // namespace
 
 namespace remoting {
 
 class SecurityKeyIpcServerTest : public testing::Test,
                                  public ClientSessionDetails {
  public:
   SecurityKeyIpcServerTest();
   ~SecurityKeyIpcServerTest() override;
 
   // Passed to the object used for testing to be called back to signal
   // completion of an IPC channel state change or reception of an IPC message.
   void OperationComplete();
 
   // Used as a callback to signal receipt of a security key request message.
   void SendRequestToClient(int connection_id, const std::string& data);
 
  protected:
+  // testing::Test interface.
+  void TearDown() override;
+
   // Returns a unique IPC channel name which prevents conflicts when running
   // tests concurrently.
   std::string GetUniqueTestChannelName();
 
   // Waits until the current |run_loop_| instance is signaled, then resets it.
   void WaitForOperationComplete();
 
+  // Waits until all tasks have been run on the current message loop.
+  void RunPendingTasks();
+
   // ClientSessionControl overrides:
   ClientSessionControl* session_control() override { return nullptr; }
   uint32_t desktop_session_id() const override { return peer_session_id_; }
 
   // IPC tests require a valid MessageLoop to run.
   base::MessageLoopForIO message_loop_;
 
-  mojo::edk::ScopedIPCSupport ipc_support_;
-
   // Used to allow |message_loop_| to run during tests.  The instance is reset
   // after each stage of the tests has been completed.
   std::unique_ptr<base::RunLoop> run_loop_;
 
   // The object under test.
   std::unique_ptr<SecurityKeyIpcServer> security_key_ipc_server_;
 
   // Used to validate the object under test uses the correct ID when
   // communicating over the IPC channel.
   int last_connection_id_received_ = -1;
 
   // Stores the contents of the last IPC message received for validation.
   std::string last_message_received_;
 
   uint32_t peer_session_id_ = UINT32_MAX;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(SecurityKeyIpcServerTest);
 };
 
 SecurityKeyIpcServerTest::SecurityKeyIpcServerTest()
-    : ipc_support_(message_loop_.task_runner(),
-                   mojo::edk::ScopedIPCSupport::ShutdownPolicy::FAST),
-      run_loop_(new base::RunLoop()) {
+    : run_loop_(new base::RunLoop()) {
 #if defined(OS_WIN)
   EXPECT_TRUE(ProcessIdToSessionId(
       GetCurrentProcessId(), reinterpret_cast<DWORD*>(&peer_session_id_)));
 #endif  // defined(OS_WIN)
 
   security_key_ipc_server_ = remoting::SecurityKeyIpcServer::Create(
       kTestConnectionId, this,
       base::TimeDelta::FromMilliseconds(kInitialConnectTimeoutMs),
       base::Bind(&SecurityKeyIpcServerTest::SendRequestToClient,
                  base::Unretained(this)),
       base::Bind(&base::DoNothing),
       base::Bind(&SecurityKeyIpcServerTest::OperationComplete,
                  base::Unretained(this)));
 }
 
 SecurityKeyIpcServerTest::~SecurityKeyIpcServerTest() {}
 
 void SecurityKeyIpcServerTest::OperationComplete() {
   run_loop_->Quit();
 }
 
 void SecurityKeyIpcServerTest::WaitForOperationComplete() {
   run_loop_->Run();
   run_loop_.reset(new base::RunLoop());
 }
 
+void SecurityKeyIpcServerTest::RunPendingTasks() {
+  // Run until there are no pending work items in the queue.
+  base::RunLoop().RunUntilIdle();
+}
+
+void SecurityKeyIpcServerTest::TearDown() {
+  RunPendingTasks();
+}
+
 void SecurityKeyIpcServerTest::SendRequestToClient(int connection_id,
                                                    const std::string& data) {
   last_connection_id_received_ = connection_id;
   last_message_received_ = data;
   OperationComplete();
 }
 
 std::string SecurityKeyIpcServerTest::GetUniqueTestChannelName() {
   return GetChannelNamePathPrefixForTest() + "Super_Awesome_Test_Channel." +
          IPC::Channel::GenerateUniqueRandomChannelID();
 }
 
 TEST_F(SecurityKeyIpcServerTest, HandleSingleSecurityKeyRequest) {
   mojo::edk::NamedPlatformHandle channel_handle(GetUniqueTestChannelName());
   ASSERT_TRUE(security_key_ipc_server_->CreateChannel(
       channel_handle,
       /*request_timeout=*/base::TimeDelta::FromMilliseconds(500)));
 
   // Create a fake client and connect to the IPC server channel.
   FakeSecurityKeyIpcClient fake_ipc_client(base::Bind(
       &SecurityKeyIpcServerTest::OperationComplete, base::Unretained(this)));
   ASSERT_TRUE(fake_ipc_client.ConnectViaIpc(channel_handle));
   WaitForOperationComplete();
 
+  ASSERT_TRUE(fake_ipc_client.ipc_channel_connected());
   ASSERT_FALSE(fake_ipc_client.invalid_session_error());
   ASSERT_TRUE(fake_ipc_client.connection_ready());
-  ASSERT_TRUE(fake_ipc_client.ipc_channel_connected());
 
   // Send a request from the IPC client to the IPC server.
   std::string request_data("Blergh!");
   fake_ipc_client.SendSecurityKeyRequestViaIpc(request_data);
   WaitForOperationComplete();
 
   // Verify the request was received.
   ASSERT_EQ(kTestConnectionId, last_connection_id_received_);
   ASSERT_EQ(request_data, last_message_received_);
 
@@ skipping 331 matching lines @@
 TEST_F(SecurityKeyIpcServerTest, IpcConnectionFailsFromInvalidSession) {
   // Change the expected session ID to not match the current session.
   peer_session_id_++;
 
   base::TimeDelta request_timeout(base::TimeDelta::FromMilliseconds(500));
   mojo::edk::NamedPlatformHandle channel_handle(GetUniqueTestChannelName());
   ASSERT_TRUE(
       security_key_ipc_server_->CreateChannel(channel_handle, request_timeout));
 
   // Create a fake client and attempt to connect to the IPC server channel.
-  FakeSecurityKeyIpcClient fake_ipc_client(base::Bind(
-      &SecurityKeyIpcServerTest::OperationComplete, base::Unretained(this)));
+  FakeSecurityKeyIpcClient fake_ipc_client(base::Bind(&base::DoNothing));
   ASSERT_TRUE(fake_ipc_client.ConnectViaIpc(channel_handle));
   WaitForOperationComplete();
-  WaitForOperationComplete();
-  WaitForOperationComplete();
 
   // Verify the connection failed.
   ASSERT_TRUE(fake_ipc_client.invalid_session_error());
   ASSERT_FALSE(fake_ipc_client.connection_ready());
+
+  RunPendingTasks();
   ASSERT_FALSE(fake_ipc_client.ipc_channel_connected());
 }
 #endif  // defined(OS_WIN)
 
 }  // namespace remoting