| 31 | } |
| 32 | |
| 33 | pub async fn wait_for_capacity(&self, required: u32) -> Result<(), mpsc::error::SendError<()>> { |
| 34 | loop { |
| 35 | if self.closed.load(Ordering::SeqCst) { |
| 36 | trace!("{:?} channel is closed, cannot wait for capacity", self); |
| 37 | return Err(mpsc::error::SendError(())); |
| 38 | } |
| 39 | let current = self.capacity.load(Ordering::SeqCst); |
| 40 | trace!( |
| 41 | "{:?} checking capacity: {} bytes available, required: {} bytes", |
| 42 | self, |
| 43 | current, |
| 44 | required |
| 45 | ); |
| 46 | if current >= required { |
| 47 | // Atomically subtract only if capacity hasn't changed |
| 48 | match self.capacity.compare_exchange_weak( |
| 49 | current, |
| 50 | current - required, |
| 51 | Ordering::SeqCst, |
| 52 | Ordering::SeqCst, |
| 53 | ) { |
| 54 | Ok(_) => { |
| 55 | trace!( |
| 56 | "{:?} has sufficient capacity: {} bytes available, consuming {} bytes", |
| 57 | self, |
| 58 | current, |
| 59 | required |
| 60 | ); |
| 61 | return Ok(()); |
| 62 | } |
| 63 | Err(_) => continue, // Retry if another thread modified capacity |
| 64 | } |
| 65 | } |
| 66 | |
| 67 | trace!( |
| 68 | "{:?} insufficient capacity: {} bytes available, waiting for {} more", |
| 69 | self, |
| 70 | current, |
| 71 | required |
| 72 | ); |
| 73 | |
| 74 | tokio::select! { |
| 75 | _ = self.notify.notified() => { |
| 76 | trace!("{:?} notified, checking capacity again", self); |
| 77 | } |
| 78 | _ = self.data_tx.closed() => { |
| 79 | return Err(mpsc::error::SendError(())); |
| 80 | } |
| 81 | } |
| 82 | } |
| 83 | } |
| 84 | |
| 85 | pub fn close(&self) { |
| 86 | trace!("{:?} closing channel", self); |