cancel0() — netty Function Reference

Architecture documentation for the cancel0() function in EpollIoHandler.java from the netty codebase.

Function java Buffer Telemetry called by 1

Entity Profile

Buffer→ Telemetry→ cancel0() — netty Function Reference

Dependency Diagram

graph TD
  cffd47b3_807b_103a_48bf_61da3bedfc9d["cancel0()"]
  7c12c50f_2a4c_ec3b_14e7_2e5cd5f0b5b1["DefaultEpollIoRegistration"]
  cffd47b3_807b_103a_48bf_61da3bedfc9d -->|defined in| 7c12c50f_2a4c_ec3b_14e7_2e5cd5f0b5b1
  09b97325_2b5f_bc73_43d1_758f3df9144a["cancel()"]
  09b97325_2b5f_bc73_43d1_758f3df9144a -->|calls| cffd47b3_807b_103a_48bf_61da3bedfc9d
  style cffd47b3_807b_103a_48bf_61da3bedfc9d fill:#6366f1,stroke:#818cf8,color:#fff

Relationship Graph

Source Code

transport-classes-epoll/src/main/java/io/netty/channel/epoll/EpollIoHandler.java lines 279–301

        private void cancel0() {
            int fd = handle.fd().intValue();
            DefaultEpollIoRegistration old = registrations.remove(fd);
            if (old != null) {
                if (old != this) {
                    // The Channel mapping was already replaced due FD reuse, put back the stored Channel.
                    registrations.put(fd, old);
                    return;
                } else if (old.handle instanceof AbstractEpollChannel.AbstractEpollUnsafe) {
                    numChannels--;
                }
                if (handle.fd().isOpen()) {
                    try {
                        // Remove the fd registration from epoll. This is only needed if it's still open as otherwise
                        // it will be automatically removed once the file-descriptor is closed.
                        Native.epollCtlDel(epollFd.intValue(), fd);
                    } catch (IOException e) {
                        logger.debug("Unable to remove fd {} from epoll {}", fd, epollFd.intValue());
                    }
                }
                handle.unregistered();
            }
        }