26      * @param string $name The index base name to lock
29     public static function acquire(string $name): void  argument
31         if (isset(self::$held[$name])) {
32             self::$held[$name]++;
36         $dir = self::lockDir($name);
42                     throw new IndexLockException('Could not lock ' . $name);
45                 throw new IndexLockException('Could not lock ' . $name);
49         self::$held[$name] = 1;
58      * @param string $name The index base name to unlock
60     public static function release(string $name): void  argument
62         if (!isset(self::$held[$name])) return;
64         self::$held[$name]--;
65         if (self::$held[$name] <= 0) {
66             unset(self::$held[$name]);
67             @rmdir(self::lockDir($name));
78         foreach (array_keys(self::$held) as $name) {
79             @rmdir(self::lockDir($name));
87      * @param string $name The index base name
90     protected static function lockDir(string $name): string  argument
93         return $conf['lockdir'] . $name . '.index';