pub fn pop(&mut self) -> T {
        let mut queue = self.shared_data.queue.lock().unwrap();

        // Loop until an element can be popped, waiting if necessary
        loop {
            let wait_duration = match queue.peek() {
                Some(elem) => {
                    let now = Instant::now();
                    // If there is an element and its delay is expired
                    // break out of the loop to pop it
                    if elem.delayed.delayed_until() <= now {
                        break;
                    }
                    // Otherwise, calculate the Duration until the element expires
                    elem.delayed.delayed_until() - now
                }

                // Signal that there is no element with a duration of zero
                None => Duration::from_secs(0),
            };

            // Wait until there is a new head of the queue
            // or the time to pop the current head expires
            queue = if wait_duration > Duration::from_secs(0) {
                self.shared_data
                    .condvar_new_head
                    .wait_timeout(queue, wait_duration)
                    .unwrap()
                    .0
            } else {
                self.shared_data.condvar_new_head.wait(queue).unwrap()
            };
        }

        self.force_pop(queue)
    }
/// Pops the next item from the queue, blocking if necessary until an item is available and its
/// delay has expired.
///
/// # Examples
///
/// Basic usage:
///
/// ```no_run
/// use delay_queue::{Delay, DelayQueue};
/// use std::time::{Duration, Instant};
///
/// let mut queue = DelayQueue::new();
///
/// queue.push(Delay::until_instant("1st", Instant::now()));
///
/// // The pop will not block, since the delay has expired.
/// println!("First pop: {}", queue.pop().value);
///
/// queue.push(Delay::for_duration("2nd", Duration::from_secs(5)));
///
/// // The pop will block for approximately 5 seconds before returning the item.
/// println!("Second pop: {}", queue.pop().value);
/// ```
Pops the next item from the queue, blocking if necessary until an item is available and its
delay has expired.
Pops the next item from the queue blocking if necessary until an item is available and its delay has expired .
pub fn pop(&mut self) -> T {
        let mut queue = self.shared_data.queue.lock().unwrap();
        // Loop until an element can be popped, waiting if necessary
        loop {
            let wait_duration = match queue.peek() {
                Some(elem) => {
                    let now = Instant::now();
                    // If there is an element and its delay is expired
                    // break out of the loop to pop it
                    if elem.delayed.delayed_until() <= now {
                        break;
                    }
                    // Otherwise, calculate the Duration until the element expires
                    elem.delayed.delayed_until() - now
                }
                // Signal that there is no element with a duration of zero
                None => Duration::from_secs(0),
            };
            // Wait until there is a new head of the queue
            // or the time to pop the current head expires
            queue = if wait_duration > Duration::from_secs(0) {
                self.shared_data
                    .condvar_new_head
                    .wait_timeout(queue, wait_duration)
                    .unwrap()
                    .0
            } else {
                self.shared_data.condvar_new_head.wait(queue).unwrap()
            };
        }
        self.force_pop(queue)
    }
pub fn pop ( & mut self ) -> T { let mut queue = self . shared_data . queue . lock ( ) . unwrap ( ) ; // Loop until an element can be popped, waiting if necessary loop { let wait_duration = match queue . peek ( ) { Some ( elem ) => { let now = Instant :: now ( ) ; // If there is an element and its delay is expired // break out of the loop to pop it if elem . delayed . delayed_until ( ) <= now { break ; } // Otherwise, calculate the Duration until the element expires elem . delayed . delayed_until ( ) - now } // Signal that there is no element with a duration of zero None => Duration :: from_secs ( 0 ) , } ; // Wait until there is a new head of the queue // or the time to pop the current head expires queue = if wait_duration > Duration :: from_secs ( 0 ) { self . shared_data . condvar_new_head . wait_timeout ( queue , wait_duration ) . unwrap ( ) . 0 } else { self . shared_data . condvar_new_head . wait ( queue ) . unwrap ( ) } ; } self . force_pop ( queue ) }
Pops the next item from the queue, blocking if necessary until an item is available and its
delay has expired.
Pops the next item from the queue blocking if necessary until an item is available and its delay has expired .
&mut self
examples
Basic usage.

```no_run
use delay_queue::{Delay, DelayQueue};
use std::time::{Duration, Instant}.

let mut queue = DelayQueue::new().

queue.push(Delay::until_instant("1st", Instant::now())).

The pop will not block, since the delay has expired.
println!("First pop: {}", queue.pop().value).

queue.push(Delay::for_duration("2nd", Duration::from_secs(5))).

The pop will block for approximately 5 seconds before returning the item.
Basic usage . ` ` ` no_run use delay_queue :: { Delay DelayQueue } ; use std :: time :: { Duration Instant } . let mut queue = DelayQueue :: new () . queue . push ( Delay :: until_instant ( " 1st " Instant :: now () )) . The pop will not block since the delay has expired . println! ( " First pop : {} " queue . pop () . value ) . queue . push ( Delay :: for_duration ( " 2nd " Duration :: from_secs ( 5 ))) . The pop will block for approximately 5 seconds before returning the item .