/*
 *  call-seq:
 *     lock.while_locked(timeout = 1) { do_something() } -> bool
 *
 *  Run the code in a block while a lock is obtained, automatically releasing
 *  the lock when the block returns.
 *
 *  See Lock#obtain for more information on lock timeout.
 *
 *  timeout:: seconds to wait to obtain lock before timing out and returning
 *            false
 *  return::  true if lock was successfully obtained. Raises a
 *            Lock::LockError otherwise.
 */
static VALUE
frt_lock_while_locked(int argc, VALUE *argv, VALUE self)
{
    VALUE rtimeout;
    int timeout = 1;
    Lock *lock;
    GET_LOCK(lock, self);
    if (rb_scan_args(argc, argv, "01", &rtimeout) > 0) {
        timeout = FIX2INT(rtimeout);
    }
    if (!lock->obtain(lock)) {
        rb_raise(cLockError, "could not obtain lock: #%s", lock->name);
    }
    rb_yield(Qnil);
    lock->release(lock);
    return Qtrue;
}