--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/cms/drupal/modules/simpletest/tests/lock.test	Fri Sep 08 12:04:06 2017 +0200
@@ -0,0 +1,57 @@
+<?php
+
+/**
+ * Tests for the lock system.
+ */
+class LockFunctionalTest extends DrupalWebTestCase {
+
+  public static function getInfo() {
+    return array(
+      'name' => 'Locking framework tests',
+      'description' => 'Confirm locking works between two separate requests.',
+      'group' => 'System',
+    );
+  }
+
+  function setUp() {
+    parent::setUp('system_test');
+  }
+
+  /**
+   * Confirm that we can acquire and release locks in two parallel requests.
+   */
+  function testLockAcquire() {
+    $lock_acquired = 'TRUE: Lock successfully acquired in system_test_lock_acquire()';
+    $lock_not_acquired = 'FALSE: Lock not acquired in system_test_lock_acquire()';
+    $this->assertTrue(lock_acquire('system_test_lock_acquire'), 'Lock acquired by this request.', 'Lock');
+    $this->assertTrue(lock_acquire('system_test_lock_acquire'), 'Lock extended by this request.', 'Lock');
+    lock_release('system_test_lock_acquire');
+
+    // Cause another request to acquire the lock.
+    $this->drupalGet('system-test/lock-acquire');
+    $this->assertText($lock_acquired, 'Lock acquired by the other request.', 'Lock');
+    // The other request has finished, thus it should have released its lock.
+    $this->assertTrue(lock_acquire('system_test_lock_acquire'), 'Lock acquired by this request.', 'Lock');
+    // This request holds the lock, so the other request cannot acquire it.
+    $this->drupalGet('system-test/lock-acquire');
+    $this->assertText($lock_not_acquired, 'Lock not acquired by the other request.', 'Lock');
+    lock_release('system_test_lock_acquire');
+
+    // Try a very short timeout and lock breaking.
+    $this->assertTrue(lock_acquire('system_test_lock_acquire', 0.5), 'Lock acquired by this request.', 'Lock');
+    sleep(1);
+    // The other request should break our lock.
+    $this->drupalGet('system-test/lock-acquire');
+    $this->assertText($lock_acquired, 'Lock acquired by the other request, breaking our lock.', 'Lock');
+    // We cannot renew it, since the other thread took it.
+    $this->assertFalse(lock_acquire('system_test_lock_acquire'), 'Lock cannot be extended by this request.', 'Lock');
+
+    // Check the shut-down function.
+    $lock_acquired_exit = 'TRUE: Lock successfully acquired in system_test_lock_exit()';
+    $lock_not_acquired_exit = 'FALSE: Lock not acquired in system_test_lock_exit()';
+    $this->drupalGet('system-test/lock-exit');
+    $this->assertText($lock_acquired_exit, 'Lock acquired by the other request before exit.', 'Lock');
+    $this->assertTrue(lock_acquire('system_test_lock_exit'), 'Lock acquired by this request after the other request exits.', 'Lock');
+  }
+}
+