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    // Copyright 2016 Amanieu d'Antras
    //
    // Licensed under the Apache License, Version 2.0, <LICENSE-APACHE or
    // http://apache.org/licenses/LICENSE-2.0> or the MIT license <LICENSE-MIT or
    // http://opensource.org/licenses/MIT>, at your option. This file may not be
    // copied, modified, or distributed except according to those terms.

    use crate::mutex::MutexGuard;
    use crate::raw_mutex::{RawMutex, TOKEN_HANDOFF, TOKEN_NORMAL};
    use crate::{deadlock, util};
    use core::{
        fmt, ptr,
        sync::atomic::{AtomicPtr, Ordering},
    };
    use instant::Instant;
    use lock_api::RawMutex as RawMutex_;
    use parking_lot_core::{self, ParkResult, RequeueOp, UnparkResult, DEFAULT_PARK_TOKEN};
    use std::time::Duration;

    /// A type indicating whether a timed wait on a condition variable returned
    /// due to a time out or not.
    #[derive(Debug, PartialEq, Eq, Copy, Clone)]
    pub struct WaitTimeoutResult(bool);

    impl WaitTimeoutResult {
        /// Returns whether the wait was known to have timed out.
        #[inline]
        pub fn timed_out(self) -> bool {
            self.0
        }
    }

    /// A Condition Variable
    ///
    /// Condition variables represent the ability to block a thread such that it
    /// consumes no CPU time while waiting for an event to occur. Condition
    /// variables are typically associated with a boolean predicate (a condition)
    /// and a mutex. The predicate is always verified inside of the mutex before
    /// determining that thread must block.
    ///
    /// Note that this module places one additional restriction over the system
    /// condition variables: each condvar can be used with only one mutex at a
    /// time. Any attempt to use multiple mutexes on the same condition variable
    /// simultaneously will result in a runtime panic. However it is possible to
    /// switch to a different mutex if there are no threads currently waiting on
    /// the condition variable.
    ///
    /// # Differences from the standard library `Condvar`
    ///
    /// - No spurious wakeups: A wait will only return a non-timeout result if it
    ///   was woken up by `notify_one` or `notify_all`.
    /// - `Condvar::notify_all` will only wake up a single thread, the rest are
    ///   requeued to wait for the `Mutex` to be unlocked by the thread that was
    ///   woken up.
    /// - Only requires 1 word of space, whereas the standard library boxes the
    ///   `Condvar` due to platform limitations.
    /// - Can be statically constructed (requires the `const_fn` nightly feature).
    /// - Does not require any drop glue when dropped.
    /// - Inline fast path for the uncontended case.
    ///
    /// # Examples
    ///
    /// ```
    /// use parking_lot::{Mutex, Condvar};
    /// use std::sync::Arc;
    /// use std::thread;
    ///
    /// let pair = Arc::new((Mutex::new(false), Condvar::new()));
    /// let pair2 = pair.clone();
    ///
    /// // Inside of our lock, spawn a new thread, and then wait for it to start
    /// thread::spawn(move|| {
    ///     let &(ref lock, ref cvar) = &*pair2;
    ///     let mut started = lock.lock();
    ///     *started = true;
    ///     cvar.notify_one();
    /// });
    ///
    /// // wait for the thread to start up
    /// let &(ref lock, ref cvar) = &*pair;
    /// let mut started = lock.lock();
    /// if !*started {
    ///     cvar.wait(&mut started);
    /// }
    /// // Note that we used an if instead of a while loop above. This is only
    /// // possible because parking_lot's Condvar will never spuriously wake up.
    /// // This means that wait() will only return after notify_one or notify_all is
    /// // called.
    /// ```
    pub struct Condvar {
        state: AtomicPtr<RawMutex>,
    }

    impl Condvar {
        /// Creates a new condition variable which is ready to be waited on and
        /// notified.
        #[inline]
        pub const fn new() -> Condvar {
            Condvar {
                state: AtomicPtr::new(ptr::null_mut()),
            }
        }

        /// Wakes up one blocked thread on this condvar.
        ///
        /// Returns whether a thread was woken up.
        ///
        /// If there is a blocked thread on this condition variable, then it will
        /// be woken up from its call to `wait` or `wait_timeout`. Calls to
        /// `notify_one` are not buffered in any way.
        ///
        /// To wake up all threads, see `notify_all()`.
        ///
        /// # Examples
        ///
        /// ```
        /// use parking_lot::Condvar;
        ///
        /// let condvar = Condvar::new();
        ///
        /// // do something with condvar, share it with other threads
        ///
        /// if !condvar.notify_one() {
        ///     println!("Nobody was listening for this.");
        /// }
        /// ```
        #[inline]
        pub fn notify_one(&self) -> bool {
            // Nothing to do if there are no waiting threads
            let state = self.state.load(Ordering::Relaxed);
            if state.is_null() {
                return false;
            }

            self.notify_one_slow(state)
        }

        #[cold]
        fn notify_one_slow(&self, mutex: *mut RawMutex) -> bool {
            unsafe {
                // Unpark one thread and requeue the rest onto the mutex
                let from = self as *const _ as usize;
                let to = mutex as usize;
                let validate = || {
                    // Make sure that our atomic state still points to the same
                    // mutex. If not then it means that all threads on the current
                    // mutex were woken up and a new waiting thread switched to a
                    // different mutex. In that case we can get away with doing
                    // nothing.
                    if self.state.load(Ordering::Relaxed) != mutex {
                        return RequeueOp::Abort;
                    }

                    // Unpark one thread if the mutex is unlocked, otherwise just
                    // requeue everything to the mutex. This is safe to do here
                    // since unlocking the mutex when the parked bit is set requires
                    // locking the queue. There is the possibility of a race if the
                    // mutex gets locked after we check, but that doesn't matter in
                    // this case.
                    if (*mutex).mark_parked_if_locked() {
                        RequeueOp::RequeueOne
                    } else {
                        RequeueOp::UnparkOne
                    }
                };
                let callback = |_op, result: UnparkResult| {
                    // Clear our state if there are no more waiting threads
                    if !result.have_more_threads {
                        self.state.store(ptr::null_mut(), Ordering::Relaxed);
                    }
                    TOKEN_NORMAL
                };
                let res = parking_lot_core::unpark_requeue(from, to, validate, callback);

                res.unparked_threads + res.requeued_threads != 0
            }
        }

        /// Wakes up all blocked threads on this condvar.
        ///
        /// Returns the number of threads woken up.
        ///
        /// This method will ensure that any current waiters on the condition
        /// variable are awoken. Calls to `notify_all()` are not buffered in any
        /// way.
        ///
        /// To wake up only one thread, see `notify_one()`.
        #[inline]
        pub fn notify_all(&self) -> usize {
            // Nothing to do if there are no waiting threads
            let state = self.state.load(Ordering::Relaxed);
            if state.is_null() {
                return 0;
            }

            self.notify_all_slow(state)
        }

        #[cold]
        fn notify_all_slow(&self, mutex: *mut RawMutex) -> usize {
            unsafe {
                // Unpark one thread and requeue the rest onto the mutex
                let from = self as *const _ as usize;
                let to = mutex as usize;
                let validate = || {
                    // Make sure that our atomic state still points to the same
                    // mutex. If not then it means that all threads on the current
                    // mutex were woken up and a new waiting thread switched to a
                    // different mutex. In that case we can get away with doing
                    // nothing.
                    if self.state.load(Ordering::Relaxed) != mutex {
                        return RequeueOp::Abort;
                    }

                    // Clear our state since we are going to unpark or requeue all
                    // threads.
                    self.state.store(ptr::null_mut(), Ordering::Relaxed);

                    // Unpark one thread if the mutex is unlocked, otherwise just
                    // requeue everything to the mutex. This is safe to do here
                    // since unlocking the mutex when the parked bit is set requires
                    // locking the queue. There is the possibility of a race if the
                    // mutex gets locked after we check, but that doesn't matter in
                    // this case.
                    if (*mutex).mark_parked_if_locked() {
                        RequeueOp::RequeueAll
                    } else {
                        RequeueOp::UnparkOneRequeueRest
                    }
                };
                let callback = |op, result: UnparkResult| {
                    // If we requeued threads to the mutex, mark it as having
                    // parked threads. The RequeueAll case is already handled above.
                    if op == RequeueOp::UnparkOneRequeueRest && result.requeued_threads != 0 {
                        (*mutex).mark_parked();
                    }
                    TOKEN_NORMAL
                };
                let res = parking_lot_core::unpark_requeue(from, to, validate, callback);

                res.unparked_threads + res.requeued_threads
            }
        }

        /// Blocks the current thread until this condition variable receives a
        /// notification.
        ///
        /// This function will atomically unlock the mutex specified (represented by
        /// `mutex_guard`) and block the current thread. This means that any calls
        /// to `notify_*()` which happen logically after the mutex is unlocked are
        /// candidates to wake this thread up. When this function call returns, the
        /// lock specified will have been re-acquired.
        ///
        /// # Panics
        ///
        /// This function will panic if another thread is waiting on the `Condvar`
        /// with a different `Mutex` object.
        #[inline]
        pub fn wait<T: ?Sized>(&self, mutex_guard: &mut MutexGuard<'_, T>) {
            self.wait_until_internal(unsafe { MutexGuard::mutex(mutex_guard).raw() }, None);
        }

        /// Waits on this condition variable for a notification, timing out after
        /// the specified time instant.
        ///
        /// The semantics of this function are equivalent to `wait()` except that
        /// the thread will be blocked roughly until `timeout` is reached. This
        /// method should not be used for precise timing due to anomalies such as
        /// preemption or platform differences that may not cause the maximum
        /// amount of time waited to be precisely `timeout`.
        ///
        /// Note that the best effort is made to ensure that the time waited is
        /// measured with a monotonic clock, and not affected by the changes made to
        /// the system time.
        ///
        /// The returned `WaitTimeoutResult` value indicates if the timeout is
        /// known to have elapsed.
        ///
        /// Like `wait`, the lock specified will be re-acquired when this function
        /// returns, regardless of whether the timeout elapsed or not.
        ///
        /// # Panics
        ///
        /// This function will panic if another thread is waiting on the `Condvar`
        /// with a different `Mutex` object.
        #[inline]
        pub fn wait_until<T: ?Sized>(
            &self,
            mutex_guard: &mut MutexGuard<'_, T>,
            timeout: Instant,
        ) -> WaitTimeoutResult {
            self.wait_until_internal(
                unsafe { MutexGuard::mutex(mutex_guard).raw() },
                Some(timeout),
            )
        }

        // This is a non-generic function to reduce the monomorphization cost of
        // using `wait_until`.
        fn wait_until_internal(&self, mutex: &RawMutex, timeout: Option<Instant>) -> WaitTimeoutResult {
            unsafe {
                let result;
                let mut bad_mutex = false;
                let mut requeued = false;
                {
                    let addr = self as *const _ as usize;
                    let lock_addr = mutex as *const _ as *mut _;
                    let validate = || {
                        // Ensure we don't use two different mutexes with the same
                        // Condvar at the same time. This is done while locked to
                        // avoid races with notify_one
                        let state = self.state.load(Ordering::Relaxed);
                        if state.is_null() {
                            self.state.store(lock_addr, Ordering::Relaxed);
                        } else if state != lock_addr {
                            bad_mutex = true;
                            return false;
                        }
                        true
                    };
                    let before_sleep = || {
                        // Unlock the mutex before sleeping...
                        mutex.unlock();
                    };
                    let timed_out = |k, was_last_thread| {
                        // If we were requeued to a mutex, then we did not time out.
                        // We'll just park ourselves on the mutex again when we try
                        // to lock it later.
                        requeued = k != addr;

                        // If we were the last thread on the queue then we need to
                        // clear our state. This is normally done by the
                        // notify_{one,all} functions when not timing out.
                        if !requeued && was_last_thread {
                            self.state.store(ptr::null_mut(), Ordering::Relaxed);
                        }
                    };
                    result = parking_lot_core::park(
                        addr,
                        validate,
                        before_sleep,
                        timed_out,
                        DEFAULT_PARK_TOKEN,
                        timeout,
                    );
                }

                // Panic if we tried to use multiple mutexes with a Condvar. Note
                // that at this point the MutexGuard is still locked. It will be
                // unlocked by the unwinding logic.
                if bad_mutex {
                    panic!("attempted to use a condition variable with more than one mutex");
                }

                // ... and re-lock it once we are done sleeping
                if result == ParkResult::Unparked(TOKEN_HANDOFF) {
                    deadlock::acquire_resource(mutex as *const _ as usize);
                } else {
                    mutex.lock();
                }

                WaitTimeoutResult(!(result.is_unparked() || requeued))
            }
        }

        /// Waits on this condition variable for a notification, timing out after a
        /// specified duration.
        ///
        /// The semantics of this function are equivalent to `wait()` except that
        /// the thread will be blocked for roughly no longer than `timeout`. This
        /// method should not be used for precise timing due to anomalies such as
        /// preemption or platform differences that may not cause the maximum
        /// amount of time waited to be precisely `timeout`.
        ///
        /// Note that the best effort is made to ensure that the time waited is
        /// measured with a monotonic clock, and not affected by the changes made to
        /// the system time.
        ///
        /// The returned `WaitTimeoutResult` value indicates if the timeout is
        /// known to have elapsed.
        ///
        /// Like `wait`, the lock specified will be re-acquired when this function
        /// returns, regardless of whether the timeout elapsed or not.
        ///
        /// # Panics
        ///
        /// Panics if the given `timeout` is so large that it can't be added to the current time.
        /// This panic is not possible if the crate is built with the `nightly` feature, then a too
        /// large `timeout` becomes equivalent to just calling `wait`.
        #[inline]
        pub fn wait_for<T: ?Sized>(
            &self,
            mutex_guard: &mut MutexGuard<'_, T>,
            timeout: Duration,
        ) -> WaitTimeoutResult {
            let deadline = util::to_deadline(timeout);
            self.wait_until_internal(unsafe { MutexGuard::mutex(mutex_guard).raw() }, deadline)
        }
    }

    impl Default for Condvar {
        #[inline]
        fn default() -> Condvar {
            Condvar::new()
        }
    }

    impl fmt::Debug for Condvar {
        fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
            f.pad("Condvar { .. }")
        }
    }

    #[cfg(test)]
    mod tests {
        use crate::{Condvar, Mutex, MutexGuard};
        use instant::Instant;
        use std::sync::mpsc::channel;
        use std::sync::Arc;
        use std::thread;
        use std::time::Duration;

        #[test]
        fn smoke() {
            let c = Condvar::new();
            c.notify_one();
            c.notify_all();
        }

        #[test]
        fn notify_one() {
            let m = Arc::new(Mutex::new(()));
            let m2 = m.clone();
            let c = Arc::new(Condvar::new());
            let c2 = c.clone();

            let mut g = m.lock();
            let _t = thread::spawn(move || {
                let _g = m2.lock();
                c2.notify_one();
            });
            c.wait(&mut g);
        }

        #[test]
        fn notify_all() {
            const N: usize = 10;

            let data = Arc::new((Mutex::new(0), Condvar::new()));
            let (tx, rx) = channel();
            for _ in 0..N {
                let data = data.clone();
                let tx = tx.clone();
                thread::spawn(move || {
                    let &(ref lock, ref cond) = &*data;
                    let mut cnt = lock.lock();
                    *cnt += 1;
                    if *cnt == N {
                        tx.send(()).unwrap();
                    }
                    while *cnt != 0 {
                        cond.wait(&mut cnt);
                    }
                    tx.send(()).unwrap();
                });
            }
            drop(tx);

            let &(ref lock, ref cond) = &*data;
            rx.recv().unwrap();
            let mut cnt = lock.lock();
            *cnt = 0;
            cond.notify_all();
            drop(cnt);

            for _ in 0..N {
                rx.recv().unwrap();
            }
        }

        #[test]
        fn notify_one_return_true() {
            let m = Arc::new(Mutex::new(()));
            let m2 = m.clone();
            let c = Arc::new(Condvar::new());
            let c2 = c.clone();

            let mut g = m.lock();
            let _t = thread::spawn(move || {
                let _g = m2.lock();
                assert!(c2.notify_one());
            });
            c.wait(&mut g);
        }

        #[test]
        fn notify_one_return_false() {
            let m = Arc::new(Mutex::new(()));
            let c = Arc::new(Condvar::new());

            let _t = thread::spawn(move || {
                let _g = m.lock();
                assert!(!c.notify_one());
            });
        }

        #[test]
        fn notify_all_return() {
            const N: usize = 10;

            let data = Arc::new((Mutex::new(0), Condvar::new()));
            let (tx, rx) = channel();
            for _ in 0..N {
                let data = data.clone();
                let tx = tx.clone();
                thread::spawn(move || {
                    let &(ref lock, ref cond) = &*data;
                    let mut cnt = lock.lock();
                    *cnt += 1;
                    if *cnt == N {
                        tx.send(()).unwrap();
                    }
                    while *cnt != 0 {
                        cond.wait(&mut cnt);
                    }
                    tx.send(()).unwrap();
                });
            }
            drop(tx);

            let &(ref lock, ref cond) = &*data;
            rx.recv().unwrap();
            let mut cnt = lock.lock();
            *cnt = 0;
            assert_eq!(cond.notify_all(), N);
            drop(cnt);

            for _ in 0..N {
                rx.recv().unwrap();
            }

            assert_eq!(cond.notify_all(), 0);
        }

        #[test]
        fn wait_for() {
            let m = Arc::new(Mutex::new(()));
            let m2 = m.clone();
            let c = Arc::new(Condvar::new());
            let c2 = c.clone();

            let mut g = m.lock();
            let no_timeout = c.wait_for(&mut g, Duration::from_millis(1));
            assert!(no_timeout.timed_out());

            let _t = thread::spawn(move || {
                let _g = m2.lock();
                c2.notify_one();
            });
            // Non-nightly panics on too large timeouts. Nightly treats it as indefinite wait.
            let very_long_timeout = if cfg!(feature = "nightly") {
                Duration::from_secs(u64::max_value())
            } else {
                Duration::from_millis(u32::max_value() as u64)
            };

            let timeout_res = c.wait_for(&mut g, very_long_timeout);
            assert!(!timeout_res.timed_out());

            drop(g);
        }

        #[test]
        fn wait_until() {
            let m = Arc::new(Mutex::new(()));
            let m2 = m.clone();
            let c = Arc::new(Condvar::new());
            let c2 = c.clone();

            let mut g = m.lock();
            let no_timeout = c.wait_until(&mut g, Instant::now() + Duration::from_millis(1));
            assert!(no_timeout.timed_out());
            let _t = thread::spawn(move || {
                let _g = m2.lock();
                c2.notify_one();
            });
            let timeout_res = c.wait_until(
                &mut g,
                Instant::now() + Duration::from_millis(u32::max_value() as u64),
            );
            assert!(!timeout_res.timed_out());
            drop(g);
        }

        #[test]
        #[should_panic]
        fn two_mutexes() {
            let m = Arc::new(Mutex::new(()));
            let m2 = m.clone();
            let m3 = Arc::new(Mutex::new(()));
            let c = Arc::new(Condvar::new());
            let c2 = c.clone();

            // Make sure we don't leave the child thread dangling
            struct PanicGuard<'a>(&'a Condvar);
            impl<'a> Drop for PanicGuard<'a> {
                fn drop(&mut self) {
                    self.0.notify_one();
                }
            }

            let (tx, rx) = channel();
            let g = m.lock();
            let _t = thread::spawn(move || {
                let mut g = m2.lock();
                tx.send(()).unwrap();
                c2.wait(&mut g);
            });
            drop(g);
            rx.recv().unwrap();
            let _g = m.lock();
            let _guard = PanicGuard(&*c);
            c.wait(&mut m3.lock());
        }

        #[test]
        fn two_mutexes_disjoint() {
            let m = Arc::new(Mutex::new(()));
            let m2 = m.clone();
            let m3 = Arc::new(Mutex::new(()));
            let c = Arc::new(Condvar::new());
            let c2 = c.clone();

            let mut g = m.lock();
            let _t = thread::spawn(move || {
                let _g = m2.lock();
                c2.notify_one();
            });
            c.wait(&mut g);
            drop(g);

            let _ = c.wait_for(&mut m3.lock(), Duration::from_millis(1));
        }

        #[test]
        fn test_debug_condvar() {
            let c = Condvar::new();
            assert_eq!(format!("{:?}", c), "Condvar { .. }");
        }

        #[test]
        fn test_condvar_requeue() {
            let m = Arc::new(Mutex::new(()));
            let m2 = m.clone();
            let c = Arc::new(Condvar::new());
            let c2 = c.clone();
            let t = thread::spawn(move || {
                let mut g = m2.lock();
                c2.wait(&mut g);
            });

            let mut g = m.lock();
            while !c.notify_one() {
                // Wait for the thread to get into wait()
                MutexGuard::bump(&mut g);
                // Yield, so the other thread gets a chance to do something.
                // (At least Miri needs this, because it doesn't preempt threads.)
                thread::yield_now();
            }
            // The thread should have been requeued to the mutex, which we wake up now.
            drop(g);
            t.join().unwrap();
        }

        #[test]
        fn test_issue_129() {
            let locks = Arc::new((Mutex::new(()), Condvar::new()));

            let (tx, rx) = channel();
            for _ in 0..4 {
                let locks = locks.clone();
                let tx = tx.clone();
                thread::spawn(move || {
                    let mut guard = locks.0.lock();
                    locks.1.wait(&mut guard);
                    locks.1.wait_for(&mut guard, Duration::from_millis(1));
                    locks.1.notify_one();
                    tx.send(()).unwrap();
                });
            }

            thread::sleep(Duration::from_millis(100));
            locks.1.notify_one();

            for _ in 0..4 {
                assert_eq!(rx.recv_timeout(Duration::from_millis(500)), Ok(()));
            }
        }
    }

    /// This module contains an integration test that is heavily inspired from WebKit's own integration
    /// tests for it's own Condvar.
    #[cfg(test)]
    mod webkit_queue_test {
        use crate::{Condvar, Mutex, MutexGuard};
        use std::{collections::VecDeque, sync::Arc, thread, time::Duration};

        #[derive(Clone, Copy)]
        enum Timeout {
            Bounded(Duration),
            Forever,
        }

        #[derive(Clone, Copy)]
        enum NotifyStyle {
            One,
            All,
        }

        struct Queue {
            items: VecDeque<usize>,
            should_continue: bool,
        }

        impl Queue {
            fn new() -> Self {
                Self {
                    items: VecDeque::new(),
                    should_continue: true,
                }
            }
        }

        fn wait<T: ?Sized>(
            condition: &Condvar,
            lock: &mut MutexGuard<'_, T>,
            predicate: impl Fn(&mut MutexGuard<'_, T>) -> bool,
            timeout: &Timeout,
        ) {
            while !predicate(lock) {
                match timeout {
                    Timeout::Forever => condition.wait(lock),
                    Timeout::Bounded(bound) => {
                        condition.wait_for(lock, *bound);
                    }
                }
            }
        }

        fn notify(style: NotifyStyle, condition: &Condvar, should_notify: bool) {
            match style {
                NotifyStyle::One => {
                    condition.notify_one();
                }
                NotifyStyle::All => {
                    if should_notify {
                        condition.notify_all();
                    }
                }
            }
        }

        fn run_queue_test(
            num_producers: usize,
            num_consumers: usize,
            max_queue_size: usize,
            messages_per_producer: usize,
            notify_style: NotifyStyle,
            timeout: Timeout,
            delay: Duration,
        ) {
            let input_queue = Arc::new(Mutex::new(Queue::new()));
            let empty_condition = Arc::new(Condvar::new());
            let full_condition = Arc::new(Condvar::new());

            let output_vec = Arc::new(Mutex::new(vec![]));

            let consumers = (0..num_consumers)
                .map(|_| {
                    consumer_thread(
                        input_queue.clone(),
                        empty_condition.clone(),
                        full_condition.clone(),
                        timeout,
                        notify_style,
                        output_vec.clone(),
                        max_queue_size,
                    )
                })
                .collect::<Vec<_>>();
            let producers = (0..num_producers)
                .map(|_| {
                    producer_thread(
                        messages_per_producer,
                        input_queue.clone(),
                        empty_condition.clone(),
                        full_condition.clone(),
                        timeout,
                        notify_style,
                        max_queue_size,
                    )
                })
                .collect::<Vec<_>>();

            thread::sleep(delay);

            for producer in producers.into_iter() {
                producer.join().expect("Producer thread panicked");
            }

            {
                let mut input_queue = input_queue.lock();
                input_queue.should_continue = false;
            }
            empty_condition.notify_all();

            for consumer in consumers.into_iter() {
                consumer.join().expect("Consumer thread panicked");
            }

            let mut output_vec = output_vec.lock();
            assert_eq!(output_vec.len(), num_producers * messages_per_producer);
            output_vec.sort();
            for msg_idx in 0..messages_per_producer {
                for producer_idx in 0..num_producers {
                    assert_eq!(msg_idx, output_vec[msg_idx * num_producers + producer_idx]);
                }
            }
        }

        fn consumer_thread(
            input_queue: Arc<Mutex<Queue>>,
            empty_condition: Arc<Condvar>,
            full_condition: Arc<Condvar>,
            timeout: Timeout,
            notify_style: NotifyStyle,
            output_queue: Arc<Mutex<Vec<usize>>>,
            max_queue_size: usize,
        ) -> thread::JoinHandle<()> {
            thread::spawn(move || loop {
                let (should_notify, result) = {
                    let mut queue = input_queue.lock();
                    wait(
                        &*empty_condition,
                        &mut queue,
                        |state| -> bool { !state.items.is_empty() || !state.should_continue },
                        &timeout,
                    );
                    if queue.items.is_empty() && !queue.should_continue {
                        return;
                    }
                    let should_notify = queue.items.len() == max_queue_size;
                    let result = queue.items.pop_front();
                    std::mem::drop(queue);
                    (should_notify, result)
                };
                notify(notify_style, &*full_condition, should_notify);

                if let Some(result) = result {
                    output_queue.lock().push(result);
                }
            })
        }

        fn producer_thread(
            num_messages: usize,
            queue: Arc<Mutex<Queue>>,
            empty_condition: Arc<Condvar>,
            full_condition: Arc<Condvar>,
            timeout: Timeout,
            notify_style: NotifyStyle,
            max_queue_size: usize,
        ) -> thread::JoinHandle<()> {
            thread::spawn(move || {
                for message in 0..num_messages {
                    let should_notify = {
                        let mut queue = queue.lock();
                        wait(
                            &*full_condition,
                            &mut queue,
                            |state| state.items.len() < max_queue_size,
                            &timeout,
                        );
                        let should_notify = queue.items.is_empty();
                        queue.items.push_back(message);
                        std::mem::drop(queue);
                        should_notify
                    };
                    notify(notify_style, &*empty_condition, should_notify);
                }
            })
        }

        macro_rules! run_queue_tests {
            ( $( $name:ident(
                num_producers: $num_producers:expr,
                num_consumers: $num_consumers:expr,
                max_queue_size: $max_queue_size:expr,
                messages_per_producer: $messages_per_producer:expr,
                notification_style: $notification_style:expr,
                timeout: $timeout:expr,
                delay_seconds: $delay_seconds:expr);
            )* ) => {
                $(#[test]
                fn $name() {
                    let delay = Duration::from_secs($delay_seconds);
                    run_queue_test(
                        $num_producers,
                        $num_consumers,
                        $max_queue_size,
                        $messages_per_producer,
                        $notification_style,
                        $timeout,
                        delay,
                        );
                })*
            };
        }

        run_queue_tests! {
            sanity_check_queue(
                num_producers: 1,
                num_consumers: 1,
                max_queue_size: 1,
                messages_per_producer: 100_000,
                notification_style: NotifyStyle::All,
                timeout: Timeout::Bounded(Duration::from_secs(1)),
                delay_seconds: 0
            );
            sanity_check_queue_timeout(
                num_producers: 1,
                num_consumers: 1,
                max_queue_size: 1,
                messages_per_producer: 100_000,
                notification_style: NotifyStyle::All,
                timeout: Timeout::Forever,
                delay_seconds: 0
            );
            new_test_without_timeout_5(
                num_producers: 1,
                num_consumers: 5,
                max_queue_size: 1,
                messages_per_producer: 100_000,
                notification_style: NotifyStyle::All,
                timeout: Timeout::Forever,
                delay_seconds: 0
            );
            one_producer_one_consumer_one_slot(
                num_producers: 1,
                num_consumers: 1,
                max_queue_size: 1,
                messages_per_producer: 100_000,
                notification_style: NotifyStyle::All,
                timeout: Timeout::Forever,
                delay_seconds: 0
            );
            one_producer_one_consumer_one_slot_timeout(
                num_producers: 1,
                num_consumers: 1,
                max_queue_size: 1,
                messages_per_producer: 100_000,
                notification_style: NotifyStyle::All,
                timeout: Timeout::Forever,
                delay_seconds: 1
            );
            one_producer_one_consumer_hundred_slots(
                num_producers: 1,
                num_consumers: 1,
                max_queue_size: 100,
                messages_per_producer: 1_000_000,
                notification_style: NotifyStyle::All,
                timeout: Timeout::Forever,
                delay_seconds: 0
            );
            ten_producers_one_consumer_one_slot(
                num_producers: 10,
                num_consumers: 1,
                max_queue_size: 1,
                messages_per_producer: 10000,
                notification_style: NotifyStyle::All,
                timeout: Timeout::Forever,
                delay_seconds: 0
            );
            ten_producers_one_consumer_hundred_slots_notify_all(
                num_producers: 10,
                num_consumers: 1,
                max_queue_size: 100,
                messages_per_producer: 10000,
                notification_style: NotifyStyle::All,
                timeout: Timeout::Forever,
                delay_seconds: 0
            );
            ten_producers_one_consumer_hundred_slots_notify_one(
                num_producers: 10,
                num_consumers: 1,
                max_queue_size: 100,
                messages_per_producer: 10000,
                notification_style: NotifyStyle::One,
                timeout: Timeout::Forever,
                delay_seconds: 0
            );
            one_producer_ten_consumers_one_slot(
                num_producers: 1,
                num_consumers: 10,
                max_queue_size: 1,
                messages_per_producer: 10000,
                notification_style: NotifyStyle::All,
                timeout: Timeout::Forever,
                delay_seconds: 0
            );
            one_producer_ten_consumers_hundred_slots_notify_all(
                num_producers: 1,
                num_consumers: 10,
                max_queue_size: 100,
                messages_per_producer: 100_000,
                notification_style: NotifyStyle::All,
                timeout: Timeout::Forever,
                delay_seconds: 0
            );
            one_producer_ten_consumers_hundred_slots_notify_one(
                num_producers: 1,
                num_consumers: 10,
                max_queue_size: 100,
                messages_per_producer: 100_000,
                notification_style: NotifyStyle::One,
                timeout: Timeout::Forever,
                delay_seconds: 0
            );
            ten_producers_ten_consumers_one_slot(
                num_producers: 10,
                num_consumers: 10,
                max_queue_size: 1,
                messages_per_producer: 50000,
                notification_style: NotifyStyle::All,
                timeout: Timeout::Forever,
                delay_seconds: 0
            );
            ten_producers_ten_consumers_hundred_slots_notify_all(
                num_producers: 10,
                num_consumers: 10,
                max_queue_size: 100,
                messages_per_producer: 50000,
                notification_style: NotifyStyle::All,
                timeout: Timeout::Forever,
                delay_seconds: 0
            );
            ten_producers_ten_consumers_hundred_slots_notify_one(
                num_producers: 10,
                num_consumers: 10,
                max_queue_size: 100,
                messages_per_producer: 50000,
                notification_style: NotifyStyle::One,
                timeout: Timeout::Forever,
                delay_seconds: 0
            );
        }
    }