| // 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 ( |
| "errors" |
| ) |
| |
| // ErrClosing is returned when a descriptor is used after it has been closed. |
| var ErrClosing = errors.New("use of closed file or network connection") |
| |
| // ErrTimeout is returned for an expired deadline. |
| var ErrTimeout error = &TimeoutError{} |
| |
| // TimeoutError is returned for an expired deadline. |
| type TimeoutError struct{} |
| |
| // Implement the net.Error interface. |
| func (e *TimeoutError) Error() string { return "i/o timeout" } |
| func (e *TimeoutError) Timeout() bool { return true } |
| func (e *TimeoutError) Temporary() bool { return true } |
| |
| // consume removes data from a slice of byte slices, for writev. |
| func consume(v *[][]byte, n int64) { |
| for len(*v) > 0 { |
| ln0 := int64(len((*v)[0])) |
| if ln0 > n { |
| (*v)[0] = (*v)[0][n:] |
| return |
| } |
| n -= ln0 |
| *v = (*v)[1:] |
| } |
| } |
| |
| // TestHookDidWritev is a hook for testing writev. |
| var TestHookDidWritev = func(wrote int) {} |