diff --git a/core/authorize.php b/core/authorize.php
index e72b866..15194a8 100644
--- a/core/authorize.php
+++ b/core/authorize.php
@@ -46,7 +46,7 @@
  *   TRUE if the current user can run authorize.php, and FALSE if not.
  */
 function authorize_access_allowed() {
-  \Drupal::service('session')->initialize();
+  \Drupal::service('session_manager')->initialize();
   return Settings::get('allow_authorize_operations', TRUE) && user_access('administer software updates');
 }
 
diff --git a/core/core.services.yml b/core/core.services.yml
index 7b91ce7..d0ed6b2 100644
--- a/core/core.services.yml
+++ b/core/core.services.yml
@@ -718,8 +718,8 @@ services:
     arguments: ['@authentication']
     calls:
       - [setRequest, ['@?request=']]
-  session:
-    class: Drupal\Core\Session\Session
+  session_manager:
+    class: Drupal\Core\Session\SessionManager
     arguments: ['@request', '@database']
     tags:
       - { name: persist }
diff --git a/core/includes/bootstrap.inc b/core/includes/bootstrap.inc
index a704ebf..fa9ecef 100644
--- a/core/includes/bootstrap.inc
+++ b/core/includes/bootstrap.inc
@@ -2163,12 +2163,12 @@ function drupal_classloader_register($name, $path) {
  *
  * Example:
  * @code
- * function drupal_session_started($set = NULL) {
- *   static $session_started = FALSE;
- *   if (isset($set)) {
- *     $session_started = $set;
+ * function mymodule_log_stream_handle($new_handle = NULL) {
+ *   static $handle;
+ *   if (isset($new_handle)) {
+ *     $handle = $new_handle;
  *   }
- *   return $session_started && session_id();
+ *   return $handle;
  * }
  * @endcode
  *
diff --git a/core/includes/common.inc b/core/includes/common.inc
index 9ec0e86..9ae983a 100644
--- a/core/includes/common.inc
+++ b/core/includes/common.inc
@@ -3048,7 +3048,7 @@ function drupal_get_private_key() {
  *
  * @see drupal_get_hash_salt()
  * @see \Drupal\Core\Access\CsrfTokenGenerator
- * @see drupal_session_start()
+ * @see \Drupal\Core\Session\SessionManager::start()
  *
  * @deprecated in Drupal 8.x-dev, will be removed before Drupal 8.0.
  *   Use \Drupal::csrfToken()->get().
diff --git a/core/includes/install.core.inc b/core/includes/install.core.inc
index 88f9e0e..2db61fb 100644
--- a/core/includes/install.core.inc
+++ b/core/includes/install.core.inc
@@ -544,7 +544,7 @@ function install_run_task($task, &$install_state) {
       $response = batch_process(install_redirect_url($install_state), install_full_redirect_url($install_state));
       if ($response instanceof Response) {
         // Save $_SESSION data from batch.
-        \Drupal::service('session')->save();
+        \Drupal::service('session_manager')->save();
         // Send the response.
         $response->send();
         exit;
@@ -1778,7 +1778,7 @@ function install_load_profile(&$install_state) {
  */
 function install_bootstrap_full() {
   drupal_bootstrap(DRUPAL_BOOTSTRAP_FULL);
-  \Drupal::service('session')->initialize();
+  \Drupal::service('session_manager')->initialize();
 }
 
 /**
diff --git a/core/lib/Drupal.php b/core/lib/Drupal.php
index 7b9c326..3cf20c4 100644
--- a/core/lib/Drupal.php
+++ b/core/lib/Drupal.php
@@ -586,7 +586,7 @@ public static function languageManager() {
    * @return \Drupal\Core\Access\CsrfTokenGenerator
    *   The CSRF token manager.
    *
-   * @see drupal_session_start()
+   * @see \Drupal\Core\Session\SessionManager::start()
    */
   public static function csrfToken() {
     return static::$container->get('csrf_token');
diff --git a/core/lib/Drupal/Core/Access/CsrfTokenGenerator.php b/core/lib/Drupal/Core/Access/CsrfTokenGenerator.php
index 527fffd..2e4e44d 100644
--- a/core/lib/Drupal/Core/Access/CsrfTokenGenerator.php
+++ b/core/lib/Drupal/Core/Access/CsrfTokenGenerator.php
@@ -69,7 +69,7 @@ public function setCurrentUser(AccountInterface $current_user = NULL) {
    *   'drupal_private_key' configuration variable.
    *
    * @see drupal_get_hash_salt()
-   * @see drupal_session_start()
+   * @see \Drupal\Core\Session\SessionManager::start()
    */
   public function get($value = '') {
     return Crypt::hmacBase64($value, session_id() . $this->privateKey->get() . drupal_get_hash_salt());
diff --git a/core/lib/Drupal/Core/Authentication/Provider/Cookie.php b/core/lib/Drupal/Core/Authentication/Provider/Cookie.php
index 308adb0..2158ecd 100644
--- a/core/lib/Drupal/Core/Authentication/Provider/Cookie.php
+++ b/core/lib/Drupal/Core/Authentication/Provider/Cookie.php
@@ -30,9 +30,7 @@ public function applies(Request $request) {
   public function authenticate(Request $request) {
     // Global $user is deprecated, but the session system is still based on it.
     global $user;
-    $session = \Drupal::service('session');
-    $session->initialize();
-    if ($session->isStarted()) {
+    if (\Drupal::service('session_manager')->initialize()->isStarted()) {
       return $user;
     }
     return NULL;
@@ -42,7 +40,7 @@ public function authenticate(Request $request) {
    * {@inheritdoc}
    */
   public function cleanup(Request $request) {
-    \Drupal::service('session')->save();
+    \Drupal::service('session_manager')->save();
   }
 
   /**
diff --git a/core/lib/Drupal/Core/Cron.php b/core/lib/Drupal/Core/Cron.php
index d481516..94cfc33 100644
--- a/core/lib/Drupal/Core/Cron.php
+++ b/core/lib/Drupal/Core/Cron.php
@@ -84,10 +84,9 @@ public function run() {
     @ignore_user_abort(TRUE);
 
     // Prevent session information from being saved while cron is running.
-    $session = \Drupal::service('session');
-    $original_session_writing_enabled = $session->isEnabled();
-
-    $session->disable();
+    $session_manager = \Drupal::service('session_manager');
+    $original_session_saving = $session_manager->isEnabled();
+    $session_manager->disable();
 
     // Force the current user to anonymous to ensure consistent permissions on
     // cron runs.
@@ -159,8 +158,8 @@ public function run() {
 
     // Restore the user.
     $this->currentUser->setAccount($original_user);
-    if ($original_session_writing_enabled) {
-      $session->enable();
+    if ($original_session_saving) {
+      $session_manager->enable();
     }
 
     return $return;
diff --git a/core/lib/Drupal/Core/Session/SessionHandler.php b/core/lib/Drupal/Core/Session/SessionHandler.php
index e44b1c1..3732712 100644
--- a/core/lib/Drupal/Core/Session/SessionHandler.php
+++ b/core/lib/Drupal/Core/Session/SessionHandler.php
@@ -19,6 +19,13 @@
 class SessionHandler implements \SessionHandlerInterface {
 
   /**
+   * The session manager.
+   *
+   * @var \Drupal\Core\Session\SessionManager
+   */
+  protected $sessionManager;
+
+  /**
    * The request.
    *
    * @var \Symfony\Component\HttpFoundation\Request
@@ -42,12 +49,15 @@ class SessionHandler implements \SessionHandlerInterface {
   /**
    * Constructs a new SessionHandler instance.
    *
+   * @param \Drupal\Core\Session\SessionManager $session_manager
+   *   The session manager.
    * @param \Symfony\Component\HttpFoundation\Request $request
    *   The current request.
    * @param \Drupal\Core\Database\Connection $connection
    *   The database connection.
    */
-  public function __construct(Request $request, Connection $connection) {
+  public function __construct(SessionManager $session_manager, Request $request, Connection $connection) {
+    $this->sessionManager = $session_manager;
     $this->request = $request;
     $this->connection = $connection;
   }
@@ -143,7 +153,7 @@ public function write($sid, $value) {
     // The exception handler is not active at this point, so we need to do it
     // manually.
     try {
-      if (!\Drupal::service('session')->isEnabled()) {
+      if (!$this->sessionManager->isEnabled()) {
         // We don't have anything to do if we are not allowed to save the
         // session.
         return TRUE;
@@ -165,8 +175,7 @@ public function write($sid, $value) {
           'timestamp' => REQUEST_TIME,
         );
         // Use the session ID as 'sid' and an empty string as 'ssid' by default.
-        // _drupal_session_read() does not allow empty strings so that's a safe
-        // default.
+        // read() does not allow empty strings so that's a safe default.
         $key = array('sid' => Crypt::hashBase64($sid), 'ssid' => '');
         // On HTTPS connections, use the session ID as both 'sid' and 'ssid'.
         if ($this->request->isSecure()) {
@@ -228,7 +237,7 @@ public function destroy($sid) {
     global $user;
 
     // Nothing to do if we are not allowed to change the session.
-    if (!\Drupal::service('session')->isEnabled()) {
+    if (!$this->sessionManager->isEnabled()) {
       return TRUE;
     }
     $is_https = $this->request->isSecure();
@@ -238,7 +247,7 @@ public function destroy($sid) {
       ->execute();
 
     // Reset $_SESSION and $user to prevent a new session from being started
-    // in drupal_session_commit().
+    // in \Drupal\Core\Session\SessionManager::save().
     $_SESSION = array();
     $user = new AnonymousUserSession();
 
diff --git a/core/lib/Drupal/Core/Session/Session.php b/core/lib/Drupal/Core/Session/SessionManager.php
similarity index 96%
rename from core/lib/Drupal/Core/Session/Session.php
rename to core/lib/Drupal/Core/Session/SessionManager.php
index b3047cc..1c357e6 100644
--- a/core/lib/Drupal/Core/Session/Session.php
+++ b/core/lib/Drupal/Core/Session/SessionManager.php
@@ -2,7 +2,7 @@
 
 /**
  * @file
- * User session handling functions.
+ * Contains \Drupal\Core\Session\SessionManager.
  */
 
 namespace Drupal\Core\Session;
@@ -14,7 +14,10 @@
 use Drupal\Core\Session\SessionHandler;
 use Symfony\Component\HttpFoundation\Request;
 
-class Session {
+/**
+ * Manages user sessions.
+ */
+class SessionManager {
 
   /**
    * The master request of this process.
@@ -65,13 +68,15 @@ public function __construct(Request $request, Connection $connection) {
 
   /**
    * Initializes the session handler, starting a session if needed.
+   *
+   * @return $this
    */
   public function initialize() {
     global $user;
 
     // Register the default session handler.
     // @todo Extract session storage from session handler into a service.
-    $handler = new SessionHandler($this->request, $this->connection);
+    $handler = new SessionHandler($this, $this->request, $this->connection);
     session_set_save_handler($handler, TRUE);
 
     $is_https = $this->request->isSecure();
@@ -104,6 +109,8 @@ public function initialize() {
       }
     }
     date_default_timezone_set(drupal_get_user_timezone());
+
+    return $this;
   }
 
   /**
@@ -234,7 +241,7 @@ public function migrate() {
     else {
       // Start the session when it doesn't exist yet.
       // Preserve the logged in user, as it will be reset to anonymous
-      // by _drupal_session_read.
+      // by \Drupal\Core\Session\SessionHandler::read().
       $account = $user;
       $this->start();
       $user = $account;
@@ -243,6 +250,22 @@ public function migrate() {
   }
 
   /**
+   * Ends a specific user's session(s).
+   *
+   * @param int $uid
+   *   User ID.
+   */
+  public function delete($uid) {
+    // Nothing to do if we are not allowed to change the session.
+    if (!$this->isEnabled()) {
+      return;
+    }
+    $this->connection->delete('sessions')
+      ->condition('uid', $uid)
+      ->execute();
+  }
+
+  /**
    * Determines whether to save session data of the current request.
    *
    * @return bool
@@ -289,25 +312,4 @@ protected function isCli() {
     return PHP_SAPI === 'cli';
   }
 
-  /**
-   * Ends a specific user's session(s).
-   *
-   * @param $uid
-   *   User ID.
-   *
-   * @return bool
-   *   Returns FALSE if session wasn't ended.
-   */
-  public function endUserSession($uid) {
-    // Nothing to do if we are not allowed to change the session.
-    if (!$this->isEnabled()) {
-      return FALSE;
-    }
-    $this->connection->delete('sessions')
-      ->condition('uid', $uid)
-      ->execute();
-
-    return TRUE;
-  }
-
 }
diff --git a/core/modules/simpletest/lib/Drupal/simpletest/TestBase.php b/core/modules/simpletest/lib/Drupal/simpletest/TestBase.php
index 982d0f1..e38cbfe 100644
--- a/core/modules/simpletest/lib/Drupal/simpletest/TestBase.php
+++ b/core/modules/simpletest/lib/Drupal/simpletest/TestBase.php
@@ -1026,7 +1026,7 @@ private function prepareEnvironment() {
     $this->originalUser = isset($user) ? clone $user : NULL;
 
     // Ensure that the current session is not changed by the new environment.
-    \Drupal::service('session')->disable();
+    \Drupal::service('session_manager')->disable();
 
     // Save and clean the shutdown callbacks array because it is static cached
     // and will be changed by the test run. Otherwise it will contain callbacks
@@ -1255,7 +1255,7 @@ private function restoreEnvironment() {
 
     // Restore original user session.
     $this->container->set('current_user', $this->originalUser);
-    \Drupal::service('session')->enable();
+    \Drupal::service('session_manager')->enable();
   }
 
   /**
diff --git a/core/modules/simpletest/lib/Drupal/simpletest/WebTestBase.php b/core/modules/simpletest/lib/Drupal/simpletest/WebTestBase.php
index 61c54d1..bccc5a9 100644
--- a/core/modules/simpletest/lib/Drupal/simpletest/WebTestBase.php
+++ b/core/modules/simpletest/lib/Drupal/simpletest/WebTestBase.php
@@ -698,8 +698,8 @@ protected function drupalUserIsLoggedIn($account) {
     if (!isset($account->session_id)) {
       return FALSE;
     }
-    // @see _drupal_session_read(). The session ID is hashed before being stored
-    // in the database.
+    // The session ID is hashed before being stored in the database.
+    // @see \Drupal\Core\Session\SessionHandler::read()
     return (bool) db_query("SELECT sid FROM {users} u INNER JOIN {sessions} s ON u.uid = s.uid WHERE s.sid = :sid", array(':sid' => Crypt::hashBase64($account->session_id)))->fetchField();
   }
 
diff --git a/core/modules/system/core.api.php b/core/modules/system/core.api.php
index 04289c4..abfd85f 100644
--- a/core/modules/system/core.api.php
+++ b/core/modules/system/core.api.php
@@ -494,7 +494,6 @@
  * @see mail.inc
  * @see php_wrappers
  * @see sanitization
- * @see session.inc
  * @see transliteration
  * @see validation
  * @}
diff --git a/core/modules/system/lib/Drupal/system/Tests/Common/FormatDateTest.php b/core/modules/system/lib/Drupal/system/Tests/Common/FormatDateTest.php
index 21fa9fa..171b915 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Common/FormatDateTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Common/FormatDateTest.php
@@ -128,7 +128,7 @@ function testFormatDate() {
     $this->drupalPostForm('user/' . $test_user->id() . '/edit', $edit, t('Save'));
 
     // Disable session saving as we are about to modify the global $user.
-    \Drupal::service('session')->disable();
+    \Drupal::service('session_manager')->disable();
     // Save the original user and language and then replace it with the test user and language.
     $real_user = $user;
     $user = user_load($test_user->id(), TRUE);
@@ -158,6 +158,6 @@ function testFormatDate() {
     $language_interface->id = $real_language;
     // Restore default time zone.
     date_default_timezone_set(drupal_get_user_timezone());
-    \Drupal::service('session')->enable();
+    \Drupal::service('session_manager')->enable();
   }
 }
diff --git a/core/modules/system/lib/Drupal/system/Tests/Datetime/DrupalDateTimeTest.php b/core/modules/system/lib/Drupal/system/Tests/Datetime/DrupalDateTimeTest.php
index 7d24761..8484a82 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Datetime/DrupalDateTimeTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Datetime/DrupalDateTimeTest.php
@@ -100,7 +100,7 @@ public function testDateTimezone() {
     $this->drupalPostForm('user/' . $test_user->id() . '/edit', $edit, t('Save'));
 
     // Disable session saving as we are about to modify the global $user.
-    \Drupal::service('session')->disable();
+    \Drupal::service('session_manager')->disable();
     // Save the original user and then replace it with the test user.
     $real_user = $user;
     $user = user_load($test_user->id(), TRUE);
@@ -119,7 +119,7 @@ public function testDateTimezone() {
     $user = $real_user;
     // Restore default time zone.
     date_default_timezone_set(drupal_get_user_timezone());
-    \Drupal::service('session')->enable();
+    \Drupal::service('session_manager')->enable();
 
 
   }
diff --git a/core/modules/system/lib/Drupal/system/Tests/Session/SessionTest.php b/core/modules/system/lib/Drupal/system/Tests/Session/SessionTest.php
index 415932e..8a53800 100644
--- a/core/modules/system/lib/Drupal/system/Tests/Session/SessionTest.php
+++ b/core/modules/system/lib/Drupal/system/Tests/Session/SessionTest.php
@@ -29,11 +29,13 @@ public static function getInfo() {
   }
 
   /**
-   * Tests for drupal_save_session() and drupal_session_regenerate().
+   * Tests for \Drupal\Core\Session\SessionManager::isEnabled() and ::migrate().
    */
   function testSessionSaveRegenerate() {
-    $this->assertFalse(\Drupal::service('session')->isEnabled(),'\Drupal::service(\'session\')->isEnabled() correctly returns FALSE (inside of testing framework) when initially called with no arguments.', 'Session');
-    $this->assertTrue(\Drupal::service('session')->disable()->isEnabled(), '\Drupal::service(\'session\')->isEnabled() correctly returns TRUE when saving has been enabled.', 'Session');
+    $session_manager = $this->container->get('session_manager');
+    $this->assertFalse($session_manager->isEnabled(), 'SessionManager->isEnabled() initially returns FALSE (in testing framework).');
+    $this->assertFalse($session_manager->disable()->isEnabled(), 'SessionManager->isEnabled() returns FALSE after disabling.');
+    $this->assertTrue($session_manager->enable()->isEnabled(), 'SessionManager->isEnabled() returns TRUE after enabling.');
 
     // Test session hardening code from SA-2008-044.
     $user = $this->drupalCreateUser();
diff --git a/core/modules/system/tests/modules/session_test/lib/Drupal/session_test/Controller/SessionTestController.php b/core/modules/system/tests/modules/session_test/lib/Drupal/session_test/Controller/SessionTestController.php
index 4792bfa..5fbd412 100644
--- a/core/modules/system/tests/modules/session_test/lib/Drupal/session_test/Controller/SessionTestController.php
+++ b/core/modules/system/tests/modules/session_test/lib/Drupal/session_test/Controller/SessionTestController.php
@@ -35,11 +35,11 @@ public function get() {
    *   A notification message with session ID.
    */
   public function getId() {
-    // Set a value in $_SESSION, so that drupal_session_commit() will start
+    // Set a value in $_SESSION, so that SessionManager::save() will start
     // a session.
     $_SESSION['test'] = 'test';
 
-    \Drupal::service('session')->save();
+    \Drupal::service('session_manager')->save();
 
     return 'session_id:' . session_id() . "\n";
   }
@@ -83,7 +83,7 @@ public function set($test_value) {
    *   A notification message.
    */
   public function noSet($test_value) {
-    \Drupal::service('session')->disable();
+    \Drupal::service('session_manager')->disable();
     $this->set($test_value);
     return $this->t('session saving was disabled, and then %val was set', array('%val' => $test_value));
   }
@@ -109,7 +109,7 @@ public function setMessage() {
    *   A notification message.
    */
   public function setMessageButDontSave() {
-    \Drupal::service('session')->disable();
+    \Drupal::service('session_manager')->disable();
     $this->setMessage();
   }
 
diff --git a/core/modules/user/lib/Drupal/user/Entity/User.php b/core/modules/user/lib/Drupal/user/Entity/User.php
index c122353..594559e 100644
--- a/core/modules/user/lib/Drupal/user/Entity/User.php
+++ b/core/modules/user/lib/Drupal/user/Entity/User.php
@@ -123,13 +123,13 @@ public function postSave(EntityStorageInterface $storage, $update = TRUE) {
     parent::postSave($storage, $update);
 
     if ($update) {
+      $session_manager = \Drupal::service('session_manager');
       // If the password has been changed, delete all open sessions for the
       // user and recreate the current one.
       if ($this->pass->value != $this->original->pass->value) {
-        $session = \Drupal::service('session');
-        $session->endUserSession($this->id());
+        $session_manager->delete($this->id());
         if ($this->id() == \Drupal::currentUser()->id()) {
-          drupal_session_regenerate();
+          $session_manager->migrate();
         }
       }
 
@@ -141,7 +141,7 @@ public function postSave(EntityStorageInterface $storage, $update = TRUE) {
 
       // If the user was blocked, delete the user's sessions to force a logout.
       if ($this->original->status->value != $this->status->value && $this->status->value == 0) {
-        \Drupal::service('session')->endUserSession($this->id());
+        $session_manager->delete($this->id());
       }
 
       // Send emails after we have the new user object.
diff --git a/core/modules/user/lib/Drupal/user/Tests/Views/ArgumentDefaultTest.php b/core/modules/user/lib/Drupal/user/Tests/Views/ArgumentDefaultTest.php
index 4c61149..c8de3a3 100644
--- a/core/modules/user/lib/Drupal/user/Tests/Views/ArgumentDefaultTest.php
+++ b/core/modules/user/lib/Drupal/user/Tests/Views/ArgumentDefaultTest.php
@@ -37,7 +37,7 @@ public function test_plugin_argument_default_current_user() {
     $this->drupalLogin($account);
     global $user;
     $admin = $user;
-    $session = \Drupal::service('session')->disable();
+    $session_manager = \Drupal::service('session_manager')->disable();
     $user = $account;
 
     $view = Views::getView('test_plugin_argument_default_current_user');
@@ -46,7 +46,7 @@ public function test_plugin_argument_default_current_user() {
     $this->assertEqual($view->argument['null']->getDefaultArgument(), $account->id(), 'Uid of the current user is used.');
     // Switch back.
     $user = $admin;
-    $session->enable();
+    $session_manager->enable();
   }
 
 }
diff --git a/core/modules/user/user.module b/core/modules/user/user.module
index 216d55d..a8096fb 100644
--- a/core/modules/user/user.module
+++ b/core/modules/user/user.module
@@ -820,7 +820,7 @@ function user_login_finalize(UserInterface $account) {
   // Regenerate the session ID to prevent against session fixation attacks.
   // This is called before hook_user in case one of those functions fails
   // or incorrectly does a redirect which would leave the old session in place.
-  \Drupal::service('session')->migrate();
+  \Drupal::service('session_manager')->migrate();
 
   \Drupal::moduleHandler()->invokeAll('user_login', array($account));
 }
@@ -1038,7 +1038,7 @@ function _user_cancel($edit, $account, $method) {
 function _user_cancel_session_regenerate() {
   // Regenerate the users session instead of calling session_destroy() as we
   // want to preserve any messages that might have been set.
-  drupal_session_regenerate();
+  \Drupal::service('session_manager')->migrate();
 }
 
 /**
diff --git a/core/update.php b/core/update.php
index 09f60f6..49b6aa1 100644
--- a/core/update.php
+++ b/core/update.php
@@ -345,7 +345,7 @@ function update_task_list($active = NULL) {
 // Determine if the current user has access to run update.php.
 drupal_bootstrap(DRUPAL_BOOTSTRAP_PAGE_CACHE);
 
-\Drupal::service('session')->initialize();
+\Drupal::service('session_manager')->initialize();
 
 // Ensure that URLs generated for the home and admin pages don't have 'update.php'
 // in them.
@@ -448,7 +448,7 @@ function update_task_list($active = NULL) {
 }
 if (isset($output) && $output) {
   // Explicitly start a session so that the update.php token will be accepted.
-  \Drupal::service('session')->start();
+  \Drupal::service('session_manager')->start();
   // We defer the display of messages until all updates are done.
   $progress_page = ($batch = batch_get()) && isset($batch['running']);
   if ($output instanceof Response) {