net: reuse channels during io

R=golang-dev, bsiegert, rsc, hectorchu
CC=golang-dev
https://golang.org/cl/5016043

diff --git a/src/pkg/net/fd_windows.go b/src/pkg/net/fd_windows.go
index f15b6c04743168bf6e10730b96541d4a9dab1b41..b025bddea0b58bf3c7f5ca523f09e6b241808ccd 100644 (file)
--- a/src/pkg/net/fd_windows.go
+++ b/src/pkg/net/fd_windows.go
@@ -52,15 +52,27 @@ type anOp struct {
        // of the struct, as our code rely on it.
        o syscall.Overlapped
 
-       resultc chan ioResult // io completion results
-       errnoc  chan int      // io submit / cancel operation errors
+       resultc chan ioResult
+       errnoc  chan int
        fd      *netFD
 }
 
-func (o *anOp) Init(fd *netFD) {
+func (o *anOp) Init(fd *netFD, mode int) {
        o.fd = fd
-       o.resultc = make(chan ioResult, 1)
-       o.errnoc = make(chan int)
+       var i int
+       if mode == 'r' {
+               i = 0
+       } else {
+               i = 1
+       }
+       if fd.resultc[i] == nil {
+               fd.resultc[i] = make(chan ioResult, 1)
+       }
+       o.resultc = fd.resultc[i]
+       if fd.errnoc[i] == nil {
+               fd.errnoc[i] = make(chan int)
+       }
+       o.errnoc = fd.errnoc[i]
 }
 
 func (o *anOp) Op() *anOp {
@@ -74,8 +86,8 @@ type bufOp struct {
        buf syscall.WSABuf
 }
 
-func (o *bufOp) Init(fd *netFD, buf []byte) {
-       o.anOp.Init(fd)
+func (o *bufOp) Init(fd *netFD, buf []byte, mode int) {
+       o.anOp.Init(fd, mode)
        o.buf.Len = uint32(len(buf))
        if len(buf) == 0 {
                o.buf.Buf = nil
@@ -208,12 +220,14 @@ type netFD struct {
        closing bool
 
        // immutable until Close
-       sysfd  syscall.Handle
-       family int
-       proto  int
-       net    string
-       laddr  Addr
-       raddr  Addr
+       sysfd   syscall.Handle
+       family  int
+       proto   int
+       net     string
+       laddr   Addr
+       raddr   Addr
+       resultc [2]chan ioResult // read/write completion results
+       errnoc  [2]chan int      // read/write submit or cancel operation errors
 
        // owned by client
        rdeadline_delta int64
@@ -325,7 +339,7 @@ func (fd *netFD) Read(buf []byte) (n int, err os.Error) {
                return 0, os.EINVAL
        }
        var o readOp
-       o.Init(fd, buf)
+       o.Init(fd, buf, 'r')
        n, err = iosrv.ExecIO(&o, fd.rdeadline_delta)
        if err == nil && n == 0 {
                err = os.EOF
@@ -365,7 +379,7 @@ func (fd *netFD) ReadFrom(buf []byte) (n int, sa syscall.Sockaddr, err os.Error)
                return 0, nil, os.EINVAL
        }
        var o readFromOp
-       o.Init(fd, buf)
+       o.Init(fd, buf, 'r')
        o.rsan = int32(unsafe.Sizeof(o.rsa))
        n, err = iosrv.ExecIO(&o, fd.rdeadline_delta)
        if err != nil {
@@ -402,7 +416,7 @@ func (fd *netFD) Write(buf []byte) (n int, err os.Error) {
                return 0, os.EINVAL
        }
        var o writeOp
-       o.Init(fd, buf)
+       o.Init(fd, buf, 'w')
        return iosrv.ExecIO(&o, fd.wdeadline_delta)
 }
 
@@ -437,7 +451,7 @@ func (fd *netFD) WriteTo(buf []byte, sa syscall.Sockaddr) (n int, err os.Error)
                return 0, os.EINVAL
        }
        var o writeToOp
-       o.Init(fd, buf)
+       o.Init(fd, buf, 'w')
        o.sa = sa
        return iosrv.ExecIO(&o, fd.wdeadline_delta)
 }
@@ -487,7 +501,7 @@ func (fd *netFD) accept(toAddr func(syscall.Sockaddr) Addr) (nfd *netFD, err os.
 
        // Submit accept request.
        var o acceptOp
-       o.Init(fd)
+       o.Init(fd, 'r')
        o.newsock = s
        _, err = iosrv.ExecIO(&o, 0)
        if err != nil {

diff --git a/src/pkg/net/sendfile_windows.go b/src/pkg/net/sendfile_windows.go
index 3772eee24900c332f557135895377386ba1ea074..d9c2f537a3db8dc4776d17e22a3f9dbf55f2ec41 100644 (file)
--- a/src/pkg/net/sendfile_windows.go
+++ b/src/pkg/net/sendfile_windows.go
@@ -54,7 +54,7 @@ func sendFile(c *netFD, r io.Reader) (written int64, err os.Error, handled bool)
        defer c.decref()
 
        var o sendfileOp
-       o.Init(c)
+       o.Init(c, 'w')
        o.n = uint32(n)
        o.src = f.Fd()
        done, err := iosrv.ExecIO(&o, 0)