/**
  * Prevent parallel test execution - this can not work in Mahara because we modify database and dataroot.
  *
  * Note: do not call manually!
  *
  * @internal
  * @static
  * @param    string  $framework Test framework can be 'phpunit' or 'behat'
  * @return   void
  */
 public static function acquire($framework)
 {
     global $CFG;
     $datarootpath = $CFG->{$framework . '_dataroot'} . '/' . $framework;
     $lockfile = $datarootpath . '/lock';
     if (!file_exists($datarootpath)) {
         // Dataroot not initialised yet.
         return;
     }
     if (!file_exists($lockfile)) {
         file_put_contents($lockfile, 'This file prevents concurrent execution of Mahara ' . $framework . ' tests');
         testing_fix_file_permissions($lockfile);
     }
     if (self::$lockhandles[$framework] = fopen($lockfile, 'r')) {
         $wouldblock = null;
         $locked = flock(self::$lockhandles[$framework], LOCK_EX | LOCK_NB, $wouldblock);
         if (!$locked) {
             if ($wouldblock) {
                 echo "Waiting for other test execution to complete...\n";
             }
             $locked = flock(self::$lockhandles[$framework], LOCK_EX);
         }
         if (!$locked) {
             fclose(self::$lockhandles[$framework]);
             self::$lockhandles[$framework] = null;
         }
     }
     register_shutdown_function(array('TestLock', 'release'), $framework);
 }

 /**
  * Builds phpunit.xml files for all components using defaults from /phpunit.xml.dist
  *
  * @static
  * @return void, stops if can not write files
  */
 public static function build_component_config_files()
 {
     global $CFG;
     $template = '
     <testsuites>
         <testsuite name="@component@">
             <directory suffix="_test.php">.</directory>
         </testsuite>
     </testsuites>';
     // Use the upstream file as source for the distributed configurations
     $ftemplate = file_get_contents("{$CFG->dirroot}/phpunit.xml.dist");
     $ftemplate = preg_replace('|<!--All core suites.*</testsuites>|s', '<!--@component_suite@-->', $ftemplate);
     // Gets all the components with tests
     $components = tests_finder::get_components_with_tests('phpunit');
     // Create the corresponding phpunit.xml file for each component
     foreach ($components as $cname => $cpath) {
         // Calculate the component suite
         $ctemplate = $template;
         $ctemplate = str_replace('@component@', $cname, $ctemplate);
         // Apply it to the file template
         $fcontents = str_replace('<!--@component_suite@-->', $ctemplate, $ftemplate);
         // fix link to schema
         $level = substr_count(str_replace('\\', '/', $cpath), '/') - substr_count(str_replace('\\', '/', $CFG->dirroot), '/');
         $fcontents = str_replace('lib/phpunit/', str_repeat('../', $level) . 'lib/phpunit/', $fcontents);
         // Write the file
         $result = false;
         if (is_writable($cpath)) {
             if ($result = (bool) file_put_contents("{$cpath}/phpunit.xml", $fcontents)) {
                 testing_fix_file_permissions("{$cpath}/phpunit.xml");
             }
         }
         // Problems writing file, throw error
         if (!$result) {
             phpunit_bootstrap_error(PHPUNIT_EXITCODE_CONFIGWARNING, "Can not create {$cpath}/phpunit.xml configuration file, verify dir permissions");
         }
     }
 }

    /**
     * Stores the version hash in both database and dataroot
     */
    protected static function store_versions_hash() {
        global $CFG;

        $framework = self::get_framework();
        $hash = self::get_version_hash();

        // add test db flag
        set_config($framework . 'test', $hash);

        // hash all plugin versions - helps with very fast detection of db structure changes
        $hashfile = $CFG->dataroot . '/' . $framework . '/versionshash.txt';
        file_put_contents($hashfile, $hash);
        testing_fix_file_permissions($hashfile);
    }

 /**
  * Builds phpunit.xml files for all components using defaults from /phpunit.xml.dist
  *
  * @static
  * @return void, stops if can not write files
  */
 public static function build_component_config_files()
 {
     global $CFG;
     $template = '
     <testsuites>
         <testsuite name="@component@_testsuite">
             <directory suffix="_test.php">.</directory>
         </testsuite>
     </testsuites>';
     // Start a sequence between 100000 and 199000 to ensure each call to init produces
     // different ids in the database.  This reduces the risk that hard coded values will
     // end up being placed in phpunit or behat test code.
     $sequencestart = 100000 + mt_rand(0, 99) * 1000;
     // Use the upstream file as source for the distributed configurations
     $ftemplate = file_get_contents("{$CFG->dirroot}/phpunit.xml.dist");
     $ftemplate = preg_replace('|<!--All core suites.*</testsuites>|s', '<!--@component_suite@-->', $ftemplate);
     // Gets all the components with tests
     $components = tests_finder::get_components_with_tests('phpunit');
     // Create the corresponding phpunit.xml file for each component
     foreach ($components as $cname => $cpath) {
         // Calculate the component suite
         $ctemplate = $template;
         $ctemplate = str_replace('@component@', $cname, $ctemplate);
         // Apply it to the file template
         $fcontents = str_replace('<!--@component_suite@-->', $ctemplate, $ftemplate);
         $fcontents = str_replace('<const name="PHPUNIT_SEQUENCE_START" value=""/>', '<const name="PHPUNIT_SEQUENCE_START" value="' . $sequencestart . '"/>', $fcontents);
         // fix link to schema
         $level = substr_count(str_replace('\\', '/', $cpath), '/') - substr_count(str_replace('\\', '/', $CFG->dirroot), '/');
         $fcontents = str_replace('lib/phpunit/', str_repeat('../', $level) . 'lib/phpunit/', $fcontents);
         // Write the file
         $result = false;
         if (is_writable($cpath)) {
             if ($result = (bool) file_put_contents("{$cpath}/phpunit.xml", $fcontents)) {
                 testing_fix_file_permissions("{$cpath}/phpunit.xml");
             }
         }
         // Problems writing file, throw error
         if (!$result) {
             phpunit_bootstrap_error(PHPUNIT_EXITCODE_CONFIGWARNING, "Can not create {$cpath}/phpunit.xml configuration file, verify dir permissions");
         }
     }
 }

/**
 * Mark empty dataroot to be used for testing.
 * @param string $dataroot  The dataroot directory
 * @param string $framework The test framework
 * @return void
 */
function testing_initdataroot($dataroot, $framework)
{
    global $CFG;
    $filename = $dataroot . '/' . $framework . 'testdir.txt';
    umask(0);
    if (!file_exists($filename)) {
        file_put_contents($filename, 'Contents of this directory are used during tests only, do not delete this file!');
    }
    testing_fix_file_permissions($filename);
    $varname = $framework . '_dataroot';
    $datarootdir = $CFG->{$varname} . '/' . $framework;
    if (!file_exists($datarootdir)) {
        mkdir($datarootdir, $CFG->directorypermissions);
    }
}

 /**
  * Stores the status of the database
  *
  * Serializes the contents and the structure and
  * stores it in the test framework space in dataroot
  * @param string $statename name - Name of the site state.
  *  - $filename_data.ser and
  *  - $filename_structure.ser
  */
 public static function store_database_state($statename = 'default')
 {
     global $DB;
     // Store data for all tables.
     $data = array();
     $structure = array();
     $tables = $DB->get_tables();
     foreach ($tables as $table) {
         $columns = $DB->get_columns($table);
         $structure[$table] = $columns;
         if (isset($columns['id']) and $columns['id']->auto_increment) {
             $data[$table] = $DB->get_records($table, array(), 'id ASC');
         } else {
             // There should not be many of these.
             $data[$table] = $DB->get_records($table, array());
         }
     }
     $data = serialize($data);
     $datafile = util::get_tool_dir() . DIRECTORY_SEPARATOR . $statename . '_data.ser';
     file_put_contents($datafile, $data);
     testing_fix_file_permissions($datafile);
     $structure = serialize($structure);
     $structurefile = util::get_tool_dir() . DIRECTORY_SEPARATOR . $statename . '_structure.ser';
     file_put_contents($structurefile, $structure);
     testing_fix_file_permissions($structurefile);
 }