Clean up message mode pipe handling, add test

pipe_test.go

@@ -2,12 +2,15 @@ package winio
 
 import (
 	"bufio"
+	"bytes"
 	"io"
 	"net"
 	"os"
+	"sync"
 	"syscall"
 	"testing"
 	"time"
+	"unsafe"
 )
 
 var testPipeName = `\\.\pipe\winiotestpipe`
@@ -451,3 +454,63 @@ func TestConnectRace(t *testing.T) {
 		c.Close()
 	}
 }
+
+func TestMessageReadMode(t *testing.T) {
+	var wg sync.WaitGroup
+	defer wg.Wait()
+
+	l, err := ListenPipe(testPipeName, &PipeConfig{MessageMode: true})
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer l.Close()
+
+	msg := ([]byte)("hello world")
+
+	wg.Add(1)
+	go func() {
+		defer wg.Done()
+		s, err := l.Accept()
+		if err != nil {
+			t.Fatal(err)
+		}
+		_, err = s.Write(msg)
+		if err != nil {
+			t.Fatal(err)
+		}
+		s.Close()
+	}()
+
+	c, err := DialPipe(testPipeName, nil)
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer c.Close()
+
+	setNamedPipeHandleState := syscall.NewLazyDLL("kernel32.dll").NewProc("SetNamedPipeHandleState")
+
+	p := c.(*win32MessageBytePipe)
+	mode := uint32(cPIPE_READMODE_MESSAGE)
+	if s, _, err := setNamedPipeHandleState.Call(uintptr(p.handle), uintptr(unsafe.Pointer(&mode)), 0, 0); s == 0 {
+		t.Fatal(err)
+	}
+
+	ch := make([]byte, 1)
+	var vmsg []byte
+	for {
+		n, err := c.Read(ch)
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			t.Fatal(err)
+		}
+		if n != 1 {
+			t.Fatal("expected 1: ", n)
+		}
+		vmsg = append(vmsg, ch[0])
+	}
+	if !bytes.Equal(msg, vmsg) {
+		t.Fatalf("expected %s: %s", msg, vmsg)
+	}
+}