1 files changed, 83 insertions, 0 deletions
diff --git a/src/internal/poll/fd.go b/src/internal/poll/fd.go
new file mode 100644
index 0000000..ef61d0c
--- /dev/null
+++ b/src/internal/poll/fd.go
@@ -0,0 +1,83 @@
+// 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"
+)
+
+// errNetClosing is the type of the variable ErrNetClosing.
+// This is used to implement the net.Error interface.
+type errNetClosing struct{}
+
+// Error returns the error message for ErrNetClosing.
+// Keep this string consistent because of issue #4373:
+// since historically programs have not been able to detect
+// this error, they look for the string.
+func (e errNetClosing) Error() string { return "use of closed network connection" }
+
+func (e errNetClosing) Timeout() bool   { return false }
+func (e errNetClosing) Temporary() bool { return false }
+
+// ErrNetClosing is returned when a network descriptor is used after
+// it has been closed.
+var ErrNetClosing = errNetClosing{}
+
+// 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(isFile bool) error {
+	if isFile {
+		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 (e *DeadlineExceededError) Error() string   { return "i/o timeout" }
+func (e *DeadlineExceededError) Timeout() bool   { return true }
+func (e *DeadlineExceededError) Temporary() 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(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)[0] = nil
+		*v = (*v)[1:]
+	}
+}
+
+// TestHookDidWritev is a hook for testing writev.
+var TestHookDidWritev = func(wrote int) {}