internal/poll: remove named return values and naked returns

Change-Id: I283f4453e5cf8b22995b3abffccae182cfbb6945
Reviewed-on: https://go-review.googlesource.com/36970Reviewed-by: Dave Cheney <dave@cheney.net>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Run-TryBot: Dave Cheney <dave@cheney.net>
TryBot-Result: Gobot Gobot <gobot@golang.org>

src/internal/poll/fd_plan9.go

@@ -50,7 +50,7 @@ func (fd *FD) Close() error {
 	return nil
 }
 
-func (fd *FD) Read(fn func([]byte) (int, error), b []byte) (n int, err error) {
+func (fd *FD) Read(fn func([]byte) (int, error), b []byte) (int, error) {
 	if fd.rtimedout.isSet() {
 		return 0, ErrTimeout
 	}
@@ -62,7 +62,7 @@ func (fd *FD) Read(fn func([]byte) (int, error), b []byte) (n int, err error) {
 		return 0, nil
 	}
 	fd.raio = newAsyncIO(fn, b)
-	n, err = fd.raio.Wait()
+	n, err := fd.raio.Wait()
 	fd.raio = nil
 	if isHangup(err) {
 		err = io.EOF
@@ -70,10 +70,10 @@ func (fd *FD) Read(fn func([]byte) (int, error), b []byte) (n int, err error) {
 	if isInterrupted(err) {
 		err = ErrTimeout
 	}
-	return
+	return n, err
 }
 
-func (fd *FD) Write(fn func([]byte) (int, error), b []byte) (n int, err error) {
+func (fd *FD) Write(fn func([]byte) (int, error), b []byte) (int, error) {
 	if fd.wtimedout.isSet() {
 		return 0, ErrTimeout
 	}
@@ -82,12 +82,12 @@ func (fd *FD) Write(fn func([]byte) (int, error), b []byte) (n int, err error) {
 	}
 	defer fd.writeUnlock()
 	fd.waio = newAsyncIO(fn, b)
-	n, err = fd.waio.Wait()
+	n, err := fd.waio.Wait()
 	fd.waio = nil
 	if isInterrupted(err) {
 		err = ErrTimeout
 	}
-	return
+	return n, err
 }
 
 func (fd *FD) SetDeadline(t time.Time) error {

src/internal/poll/fd_unix.go

@@ -86,7 +86,7 @@ func (fd *FD) Shutdown(how int) error {
 const maxRW = 1 << 30
 
 // Read implements io.Reader.
-func (fd *FD) Read(p []byte) (n int, err error) {
+func (fd *FD) Read(p []byte) (int, error) {
 	if err := fd.readLock(); err != nil {
 		return 0, err
 	}
@@ -106,7 +106,7 @@ func (fd *FD) Read(p []byte) (n int, err error) {
 		p = p[:maxRW]
 	}
 	for {
-		n, err = syscall.Read(fd.Sysfd, p)
+		n, err := syscall.Read(fd.Sysfd, p)
 		if err != nil {
 			n = 0
 			if err == syscall.EAGAIN {
@@ -116,13 +116,12 @@ func (fd *FD) Read(p []byte) (n int, err error) {
 			}
 		}
 		err = fd.eofError(n, err)
-		break
+		return n, err
 	}
-	return
 }
 
 // Pread wraps the pread system call.
-func (fd *FD) Pread(p []byte, off int64) (n int, err error) {
+func (fd *FD) Pread(p []byte, off int64) (int, error) {
 	if err := fd.readLock(); err != nil {
 		return 0, err
 	}
@@ -134,7 +133,7 @@ func (fd *FD) Pread(p []byte, off int64) (n int, err error) {
 		p = p[:maxRW]
 	}
 	for {
-		n, err = syscall.Pread(fd.Sysfd, p, off)
+		n, err := syscall.Pread(fd.Sysfd, p, off)
 		if err != nil {
 			n = 0
 			if err == syscall.EAGAIN {
@@ -144,13 +143,12 @@ func (fd *FD) Pread(p []byte, off int64) (n int, err error) {
 			}
 		}
 		err = fd.eofError(n, err)
-		break
+		return n, err
 	}
-	return
 }
 
 // RecvFrom wraps the recvfrom network call.
-func (fd *FD) RecvFrom(p []byte) (n int, sa syscall.Sockaddr, err error) {
+func (fd *FD) RecvFrom(p []byte) (int, syscall.Sockaddr, error) {
 	if err := fd.readLock(); err != nil {
 		return 0, nil, err
 	}
@@ -159,7 +157,7 @@ func (fd *FD) RecvFrom(p []byte) (n int, sa syscall.Sockaddr, err error) {
 		return 0, nil, err
 	}
 	for {
-		n, sa, err = syscall.Recvfrom(fd.Sysfd, p, 0)
+		n, sa, err := syscall.Recvfrom(fd.Sysfd, p, 0)
 		if err != nil {
 			n = 0
 			if err == syscall.EAGAIN {
@@ -169,13 +167,12 @@ func (fd *FD) RecvFrom(p []byte) (n int, sa syscall.Sockaddr, err error) {
 			}
 		}
 		err = fd.eofError(n, err)
-		break
+		return n, sa, err
 	}
-	return
 }
 
 // ReadMsg wraps the recvmsg network call.
-func (fd *FD) ReadMsg(p []byte, oob []byte) (n, oobn, flags int, sa syscall.Sockaddr, err error) {
+func (fd *FD) ReadMsg(p []byte, oob []byte) (int, int, int, syscall.Sockaddr, error) {
 	if err := fd.readLock(); err != nil {
 		return 0, 0, 0, nil, err
 	}
@@ -184,7 +181,7 @@ func (fd *FD) ReadMsg(p []byte, oob []byte) (n, oobn, flags int, sa syscall.Sock
 		return 0, 0, 0, nil, err
 	}
 	for {
-		n, oobn, flags, sa, err = syscall.Recvmsg(fd.Sysfd, p, oob, 0)
+		n, oobn, flags, sa, err := syscall.Recvmsg(fd.Sysfd, p, oob, 0)
 		if err != nil {
 			// TODO(dfc) should n and oobn be set to 0
 			if err == syscall.EAGAIN {
@@ -194,13 +191,12 @@ func (fd *FD) ReadMsg(p []byte, oob []byte) (n, oobn, flags int, sa syscall.Sock
 			}
 		}
 		err = fd.eofError(n, err)
-		break
+		return n, oobn, flags, sa, err
 	}
-	return
 }
 
 // Write implements io.Writer.
-func (fd *FD) Write(p []byte) (nn int, err error) {
+func (fd *FD) Write(p []byte) (int, error) {
 	if err := fd.writeLock(); err != nil {
 		return 0, err
 	}
@@ -208,18 +204,18 @@ func (fd *FD) Write(p []byte) (nn int, err error) {
 	if err := fd.pd.prepareWrite(); err != nil {
 		return 0, err
 	}
+	var nn int
 	for {
-		var n int
 		max := len(p)
 		if fd.IsStream && max-nn > maxRW {
 			max = nn + maxRW
 		}
-		n, err = syscall.Write(fd.Sysfd, p[nn:max])
+		n, err := syscall.Write(fd.Sysfd, p[nn:max])
 		if n > 0 {
 			nn += n
 		}
 		if nn == len(p) {
-			break
+			return nn, err
 		}
 		if err == syscall.EAGAIN {
 			if err = fd.pd.waitWrite(); err == nil {
@@ -227,18 +223,16 @@ func (fd *FD) Write(p []byte) (nn int, err error) {
 			}
 		}
 		if err != nil {
-			break
+			return nn, err
 		}
 		if n == 0 {
-			err = io.ErrUnexpectedEOF
-			break
+			return nn, io.ErrUnexpectedEOF
 		}
 	}
-	return
 }
 
 // Pwrite wraps the pwrite system call.
-func (fd *FD) Pwrite(p []byte, off int64) (nn int, err error) {
+func (fd *FD) Pwrite(p []byte, off int64) (int, error) {
 	if err := fd.writeLock(); err != nil {
 		return 0, err
 	}
@@ -246,18 +240,18 @@ func (fd *FD) Pwrite(p []byte, off int64) (nn int, err error) {
 	if err := fd.pd.prepareWrite(); err != nil {
 		return 0, err
 	}
+	var nn int
 	for {
-		var n int
 		max := len(p)
 		if fd.IsStream && max-nn > maxRW {
 			max = nn + maxRW
 		}
-		n, err = syscall.Pwrite(fd.Sysfd, p[nn:max], off+int64(nn))
+		n, err := syscall.Pwrite(fd.Sysfd, p[nn:max], off+int64(nn))
 		if n > 0 {
 			nn += n
 		}
 		if nn == len(p) {
-			break
+			return nn, err
 		}
 		if err == syscall.EAGAIN {
 			if err = fd.pd.waitWrite(); err == nil {
@@ -265,18 +259,16 @@ func (fd *FD) Pwrite(p []byte, off int64) (nn int, err error) {
 			}
 		}
 		if err != nil {
-			break
+			return nn, err
 		}
 		if n == 0 {
-			err = io.ErrUnexpectedEOF
-			break
+			return nn, io.ErrUnexpectedEOF
 		}
 	}
-	return
 }
 
 // WriteTo wraps the sendto network call.
-func (fd *FD) WriteTo(p []byte, sa syscall.Sockaddr) (n int, err error) {
+func (fd *FD) WriteTo(p []byte, sa syscall.Sockaddr) (int, error) {
 	if err := fd.writeLock(); err != nil {
 		return 0, err
 	}
@@ -285,22 +277,21 @@ func (fd *FD) WriteTo(p []byte, sa syscall.Sockaddr) (n int, err error) {
 		return 0, err
 	}
 	for {
-		err = syscall.Sendto(fd.Sysfd, p, 0, sa)
+		err := syscall.Sendto(fd.Sysfd, p, 0, sa)
 		if err == syscall.EAGAIN {
 			if err = fd.pd.waitWrite(); err == nil {
 				continue
 			}
 		}
-		break
-	}
-	if err == nil {
-		n = len(p)
+		if err != nil {
+			return 0, err
+		}
+		return len(p), nil
 	}
-	return
 }
 
 // WriteMsg wraps the sendmsg network call.
-func (fd *FD) WriteMsg(p []byte, oob []byte, sa syscall.Sockaddr) (n int, oobn int, err error) {
+func (fd *FD) WriteMsg(p []byte, oob []byte, sa syscall.Sockaddr) (int, int, error) {
 	if err := fd.writeLock(); err != nil {
 		return 0, 0, err
 	}
@@ -309,18 +300,17 @@ func (fd *FD) WriteMsg(p []byte, oob []byte, sa syscall.Sockaddr) (n int, oobn i
 		return 0, 0, err
 	}
 	for {
-		n, err = syscall.SendmsgN(fd.Sysfd, p, oob, sa, 0)
+		n, err := syscall.SendmsgN(fd.Sysfd, p, oob, sa, 0)
 		if err == syscall.EAGAIN {
 			if err = fd.pd.waitWrite(); err == nil {
 				continue
 			}
 		}
-		break
-	}
-	if err == nil {
-		oobn = len(oob)
+		if err != nil {
+			return n, 0, err
+		}
+		return n, len(oob), err
 	}
-	return
 }
 
 // WaitWrite waits until data can be written to fd.
@@ -329,18 +319,17 @@ func (fd *FD) WaitWrite() error {
 }
 
 // Accept wraps the accept network call.
-func (fd *FD) Accept() (newfd int, rsa syscall.Sockaddr, errcall string, err error) {
-	if err = fd.readLock(); err != nil {
+func (fd *FD) Accept() (int, syscall.Sockaddr, string, error) {
+	if err := fd.readLock(); err != nil {
 		return -1, nil, "", err
 	}
 	defer fd.readUnlock()
 
-	var s int
-	if err = fd.pd.prepareRead(); err != nil {
+	if err := fd.pd.prepareRead(); err != nil {
 		return -1, nil, "", err
 	}
 	for {
-		s, rsa, errcall, err = accept(fd.Sysfd)
+		s, rsa, errcall, err := accept(fd.Sysfd)
 		if err == nil {
 			return s, rsa, "", err
 		}
@@ -360,7 +349,7 @@ func (fd *FD) Accept() (newfd int, rsa syscall.Sockaddr, errcall string, err err
 }
 
 // Seek wraps syscall.Seek.
-func (fd *FD) Seek(offset int64, whence int) (ret int64, err error) {
+func (fd *FD) Seek(offset int64, whence int) (int64, error) {
 	if err := fd.incref(); err != nil {
 		return 0, err
 	}
@@ -371,7 +360,7 @@ func (fd *FD) Seek(offset int64, whence int) (ret int64, err error) {
 // ReadDirent wraps syscall.ReadDirent.
 // We treat this like an ordinary system call rather than a call
 // that tries to fill the buffer.
-func (fd *FD) ReadDirent(buf []byte) (n int, err error) {
+func (fd *FD) ReadDirent(buf []byte) (int, error) {
 	if err := fd.incref(); err != nil {
 		return 0, err
 	}

src/internal/poll/fd_windows.go

@@ -433,7 +433,7 @@ var ReadConsole = syscall.ReadConsole // changed for testing
 // readConsole reads utf16 characters from console File,
 // encodes them into utf8 and stores them in buffer b.
 // It returns the number of utf8 bytes read and an error, if any.
-func (fd *FD) readConsole(b []byte) (n int, err error) {
+func (fd *FD) readConsole(b []byte) (int, error) {
 	if len(b) == 0 {
 		return 0, nil
 	}
@@ -503,7 +503,7 @@ func (fd *FD) readConsole(b []byte) (n int, err error) {
 	return i, nil
 }
 
-func (fd *FD) Pread(b []byte, off int64) (n int, err error) {
+func (fd *FD) Pread(b []byte, off int64) (int, error) {
 	if err := fd.readLock(); err != nil {
 		return 0, err
 	}
@@ -591,8 +591,8 @@ func (fd *FD) Write(buf []byte) (int, error) {
 
 // writeConsole writes len(b) bytes to the console File.
 // It returns the number of bytes written and an error, if any.
-func (fd *FD) writeConsole(b []byte) (n int, err error) {
-	n = len(b)
+func (fd *FD) writeConsole(b []byte) (int, error) {
+	n := len(b)
 	runes := make([]rune, 0, 256)
 	if len(fd.lastbits) > 0 {
 		b = append(fd.lastbits, b...)
@@ -622,7 +622,7 @@ func (fd *FD) writeConsole(b []byte) (n int, err error) {
 		uint16s := utf16.Encode(chunk)
 		for len(uint16s) > 0 {
 			var written uint32
-			err = syscall.WriteConsole(fd.Sysfd, &uint16s[0], uint32(len(uint16s)), &written, nil)
+			err := syscall.WriteConsole(fd.Sysfd, &uint16s[0], uint32(len(uint16s)), &written, nil)
 			if err != nil {
 				return 0, err
 			}
@@ -769,7 +769,7 @@ func (fd *FD) Accept(sysSocket func() (syscall.Handle, error)) (syscall.Handle,
 	}
 }
 
-func (fd *FD) Seek(offset int64, whence int) (ret int64, err error) {
+func (fd *FD) Seek(offset int64, whence int) (int64, error) {
 	if err := fd.incref(); err != nil {
 		return 0, err
 	}

src/internal/poll/sendfile_bsd.go

@@ -13,12 +13,14 @@ import "syscall"
 const maxSendfileSize int = 4 << 20
 
 // SendFile wraps the sendfile system call.
-func SendFile(dstFD *FD, src int, pos, remain int64) (written int64, err error) {
+func SendFile(dstFD *FD, src int, pos, remain int64) (int64, error) {
 	if err := dstFD.writeLock(); err != nil {
 		return 0, err
 	}
 	defer dstFD.writeUnlock()
 	dst := int(dstFD.Sysfd)
+	var written int64
+	var err error
 	for remain > 0 {
 		n := maxSendfileSize
 		if int64(n) > remain {

src/internal/poll/sendfile_linux.go

@@ -11,13 +11,15 @@ import "syscall"
 const maxSendfileSize int = 4 << 20
 
 // SendFile wraps the sendfile system call.
-func SendFile(dstFD *FD, src int, remain int64) (written int64, err error) {
+func SendFile(dstFD *FD, src int, remain int64) (int64, error) {
 	if err := dstFD.writeLock(); err != nil {
 		return 0, err
 	}
 	defer dstFD.writeUnlock()
 
 	dst := int(dstFD.Sysfd)
+	var written int64
+	var err error
 	for remain > 0 {
 		n := maxSendfileSize
 		if int64(n) > remain {

src/internal/poll/sendfile_solaris.go

@@ -15,13 +15,15 @@ import "syscall"
 const maxSendfileSize int = 4 << 20
 
 // SendFile wraps the sendfile system call.
-func SendFile(dstFD *FD, src int, pos, remain int64) (written int64, err error) {
+func SendFile(dstFD *FD, src int, pos, remain int64) (int64, error) {
 	if err := dstFD.writeLock(); err != nil {
 		return 0, err
 	}
 	defer dstFD.writeUnlock()
 
 	dst := int(dstFD.Sysfd)
+	var written int64
+	var err error
 	for remain > 0 {
 		n := maxSendfileSize
 		if int64(n) > remain {

src/internal/poll/writev.go

@@ -13,7 +13,7 @@ import (
 )
 
 // Writev wraps the writev system call.
-func (fd *FD) Writev(v *[][]byte) (n int64, err error) {
+func (fd *FD) Writev(v *[][]byte) (int64, error) {
 	if err := fd.writeLock(); err != nil {
 		return 0, err
 	}
@@ -31,6 +31,8 @@ func (fd *FD) Writev(v *[][]byte) (n int64, err error) {
 	// UIO_MAXIOV also seems to be 1024.
 	maxVec := 1024
 
+	var n int64
+	var err error
 	for len(*v) > 0 {
 		iovecs = iovecs[:0]
 		for _, chunk := range *v {