io: use error, add EOF, avoid os
R=r, r
CC=golang-dev
https://golang.org/cl/5311068
diff --git a/src/pkg/io/pipe.go b/src/pkg/io/pipe.go
index 00be8ef..3dcff0d 100644
--- a/src/pkg/io/pipe.go
+++ b/src/pkg/io/pipe.go
@@ -7,14 +7,14 @@
package io
-import (
- "os"
- "sync"
-)
+import "sync"
+
+// ErrClosedPipe is the error used for read or write operations on a closed pipe.
+var ErrClosedPipe = &Error{"io: read/write on closed pipe"}
type pipeResult struct {
n int
- err os.Error
+ err error
}
// A pipe is the shared pipe structure underlying PipeReader and PipeWriter.
@@ -25,11 +25,11 @@
data []byte // data remaining in pending write
rwait sync.Cond // waiting reader
wwait sync.Cond // waiting writer
- rerr os.Error // if reader closed, error to give writes
- werr os.Error // if writer closed, error to give reads
+ rerr error // if reader closed, error to give writes
+ werr error // if writer closed, error to give reads
}
-func (p *pipe) read(b []byte) (n int, err os.Error) {
+func (p *pipe) read(b []byte) (n int, err error) {
// One reader at a time.
p.rl.Lock()
defer p.rl.Unlock()
@@ -38,7 +38,7 @@
defer p.l.Unlock()
for {
if p.rerr != nil {
- return 0, os.EINVAL
+ return 0, ErrClosedPipe
}
if p.data != nil {
break
@@ -59,7 +59,7 @@
var zero [0]byte
-func (p *pipe) write(b []byte) (n int, err os.Error) {
+func (p *pipe) write(b []byte) (n int, err error) {
// pipe uses nil to mean not available
if b == nil {
b = zero[:]
@@ -82,7 +82,7 @@
break
}
if p.werr != nil {
- err = os.EINVAL
+ err = ErrClosedPipe
}
p.wwait.Wait()
}
@@ -91,9 +91,9 @@
return
}
-func (p *pipe) rclose(err os.Error) {
+func (p *pipe) rclose(err error) {
if err == nil {
- err = os.EPIPE
+ err = ErrClosedPipe
}
p.l.Lock()
defer p.l.Unlock()
@@ -102,9 +102,9 @@
p.wwait.Signal()
}
-func (p *pipe) wclose(err os.Error) {
+func (p *pipe) wclose(err error) {
if err == nil {
- err = os.EOF
+ err = EOF
}
p.l.Lock()
defer p.l.Unlock()
@@ -122,20 +122,20 @@
// it reads data from the pipe, blocking until a writer
// arrives or the write end is closed.
// If the write end is closed with an error, that error is
-// returned as err; otherwise err is os.EOF.
-func (r *PipeReader) Read(data []byte) (n int, err os.Error) {
+// returned as err; otherwise err is EOF.
+func (r *PipeReader) Read(data []byte) (n int, err error) {
return r.p.read(data)
}
// Close closes the reader; subsequent writes to the
-// write half of the pipe will return the error os.EPIPE.
-func (r *PipeReader) Close() os.Error {
+// write half of the pipe will return the error ErrClosedPipe.
+func (r *PipeReader) Close() error {
return r.CloseWithError(nil)
}
// CloseWithError closes the reader; subsequent writes
// to the write half of the pipe will return the error err.
-func (r *PipeReader) CloseWithError(err os.Error) os.Error {
+func (r *PipeReader) CloseWithError(err error) error {
r.p.rclose(err)
return nil
}
@@ -149,20 +149,20 @@
// it writes data to the pipe, blocking until readers
// have consumed all the data or the read end is closed.
// If the read end is closed with an error, that err is
-// returned as err; otherwise err is os.EPIPE.
-func (w *PipeWriter) Write(data []byte) (n int, err os.Error) {
+// returned as err; otherwise err is ErrClosedPipe.
+func (w *PipeWriter) Write(data []byte) (n int, err error) {
return w.p.write(data)
}
// Close closes the writer; subsequent reads from the
-// read half of the pipe will return no bytes and os.EOF.
-func (w *PipeWriter) Close() os.Error {
+// read half of the pipe will return no bytes and EOF.
+func (w *PipeWriter) Close() error {
return w.CloseWithError(nil)
}
// CloseWithError closes the writer; subsequent reads from the
// read half of the pipe will return no bytes and the error err.
-func (w *PipeWriter) CloseWithError(err os.Error) os.Error {
+func (w *PipeWriter) CloseWithError(err error) error {
w.p.wclose(err)
return nil
}
