You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: generic.rs
    path of file: ./repos/incubator-teaclave-sgx-sdk/sgx_tstd/src/sys_common/once
    
    the code of the file until where you have to start completion: // Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements.  See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership.  The ASF licenses this file
// to you under the Apache License, Version 2.0 (the
// "License"); you may not use this file except in compliance
// with the License.  You may obtain a copy of the License at
//
//   http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing,
// software distributed under the License is distributed on an
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied.  See the License for the
// specific language governing permissions and lim
    
    fn drop(&mut self) {
        // Swap out our state with however we finished.
        let state_and_queue =
            self.state_and_queue.swap(self.set_state_on_drop_to, Ordering::AcqRel);

        // We should only ever see an old state which was RUNNING.
        assert_eq!(state_and_queue.addr() & STATE_MASK, RUNNING);

        // Walk the entire linked list of waiters and wake them up (in lifo
        // order, last to register is first to wake up).
        unsafe {
            // Right after setting `node.signaled = true` the other thread may
            // free `node` if there happens to be has a spurious wakeup.
            // So we have to take out the `thread` field and copy the pointer to
            // `next` first.
            let mut queue =
                state_and_queue.with_addr(state_and_queue.addr() & !STATE_MASK) as *const Waiter;
            while !queue.is_null() {
                let next = (*queue).next;
                let thread = (*queue).thread.take().unwrap();
                (*queue).signaled.store(true, Ordering::Release);
                // ^- FIXME (maybe): This is another case of issue #55005
                // `store()` has a potentially dangling ref to `signaled`.
                queue = next;
                thread.unpark();
            }
        }
    }