// Copyright 2017 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

// Package poll supports non-blocking I/O on file descriptors with polling. // This supports I/O operations that block only a goroutine, not a thread. // This is used by the net and os packages. // It uses a poller built into the runtime, with support from the // runtime scheduler.
package poll import ( ) // ErrNetClosing is returned when a network descriptor is used after // it has been closed. Keep this string consistent because of issue // #4373: since historically programs have not been able to detect // this error, they look for the string. var ErrNetClosing = errors.New("use of closed network connection") // ErrFileClosing is returned when a file descriptor is used after it // has been closed. var ErrFileClosing = errors.New("use of closed file") // ErrNoDeadline is returned when a request is made to set a deadline // on a file type that does not use the poller. var ErrNoDeadline = errors.New("file type does not support deadline") // Return the appropriate closing error based on isFile. func errClosing( bool) error { if { return ErrFileClosing } return ErrNetClosing } // ErrDeadlineExceeded is returned for an expired deadline. // This is exported by the os package as os.ErrDeadlineExceeded. var ErrDeadlineExceeded error = &DeadlineExceededError{} // DeadlineExceededError is returned for an expired deadline. type DeadlineExceededError struct{} // Implement the net.Error interface. // The string is "i/o timeout" because that is what was returned // by earlier Go versions. Changing it may break programs that // match on error strings. func ( *DeadlineExceededError) () string { return "i/o timeout" } func ( *DeadlineExceededError) () bool { return true } func ( *DeadlineExceededError) () bool { return true } // ErrNotPollable is returned when the file or socket is not suitable // for event notification. var ErrNotPollable = errors.New("not pollable") // consume removes data from a slice of byte slices, for writev. func consume( *[][]byte, int64) { for len(*) > 0 { := int64(len((*)[0])) if > { (*)[0] = (*)[0][:] return } -= * = (*)[1:] } } // TestHookDidWritev is a hook for testing writev. var TestHookDidWritev = func( int) {}