Removed goselect dependency in favor of sys/unix

Author: cmaglie

go.mod

@@ -3,7 +3,6 @@ module go.bug.st/serial
 go 1.17
 
 require (
-	github.com/creack/goselect v0.1.2
 	github.com/stretchr/testify v1.8.4
 	golang.org/x/sys v0.17.0
 )

go.sum

@@ -1,5 +1,3 @@
-github.com/creack/goselect v0.1.2 h1:2DNy14+JPjRBgPzAd1thbQp4BSIihxcBf0IXhQXDRa0=
-github.com/creack/goselect v0.1.2/go.mod h1:a/NhLweNvqIYMuxcMOuWY516Cimucms3DglDzQP3hKY=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=

serial_unix.go

@@ -281,12 +281,12 @@ func nativeOpen(portName string, mode *Mode) (*unixPort, error) {
 	port.acquireExclusiveAccess()
 
 	// This pipe is used as a signal to cancel blocking Read
-	pipe := &unixutils.Pipe{}
-	if err := pipe.Open(); err != nil {
+	if pipe, err := unixutils.NewPipe(); err != nil {
 		port.Close()
 		return nil, &PortError{code: InvalidSerialPort, causedBy: fmt.Errorf("error opening signaling pipe: %w", err)}
+	} else {
+		port.closeSignal = pipe
 	}
-	port.closeSignal = pipe
 
 	return port, nil
 }

unixutils/pipe.go

@@ -10,7 +10,8 @@ package unixutils
 
 import (
 	"fmt"
-	"syscall"
+
+	"golang.org/x/sys/unix"
 )
 
 // Pipe represents a unix-pipe
@@ -20,16 +21,17 @@ type Pipe struct {
 	wr     int
 }
 
-// Open creates a new pipe
-func (p *Pipe) Open() error {
+// NewPipe creates a new pipe
+func NewPipe() (*Pipe, error) {
 	fds := []int{0, 0}
-	if err := syscall.Pipe(fds); err != nil {
-		return err
+	if err := unix.Pipe(fds); err != nil {
+		return nil, err
 	}
-	p.rd = fds[0]
-	p.wr = fds[1]
-	p.opened = true
-	return nil
+	return &Pipe{
+		rd:     fds[0],
+		wr:     fds[1],
+		opened: true,
+	}, nil
 }
 
 // ReadFD returns the file handle for the read side of the pipe.
@@ -53,24 +55,24 @@ func (p *Pipe) Write(data []byte) (int, error) {
 	if !p.opened {
 		return 0, fmt.Errorf("Pipe not opened")
 	}
-	return syscall.Write(p.wr, data)
+	return unix.Write(p.wr, data)
 }
 
 // Read from the pipe into the data array. Returns the number of bytes read.
 func (p *Pipe) Read(data []byte) (int, error) {
 	if !p.opened {
 		return 0, fmt.Errorf("Pipe not opened")
 	}
-	return syscall.Read(p.rd, data)
+	return unix.Read(p.rd, data)
 }
 
 // Close the pipe
 func (p *Pipe) Close() error {
 	if !p.opened {
 		return fmt.Errorf("Pipe not opened")
 	}
-	err1 := syscall.Close(p.rd)
-	err2 := syscall.Close(p.wr)
+	err1 := unix.Close(p.rd)
+	err2 := unix.Close(p.wr)
 	p.opened = false
 	if err1 != nil {
 		return err1

unixutils/select.go

@@ -11,13 +11,13 @@ package unixutils
 import (
 	"time"
 
-	"github.com/creack/goselect"
+	"golang.org/x/sys/unix"
 )
 
 // FDSet is a set of file descriptors suitable for a select call
 type FDSet struct {
-	set goselect.FDSet
-	max uintptr
+	set unix.FdSet
+	max int
 }
 
 // NewFDSet creates a set of file descriptors suitable for a Select call.
@@ -30,34 +30,33 @@ func NewFDSet(fds ...int) *FDSet {
 // Add adds the file descriptors passed as parameter to the FDSet.
 func (s *FDSet) Add(fds ...int) {
 	for _, fd := range fds {
-		f := uintptr(fd)
-		s.set.Set(f)
-		if f > s.max {
-			s.max = f
+		s.set.Set(fd)
+		if fd > s.max {
+			s.max = fd
 		}
 	}
 }
 
 // FDResultSets contains the result of a Select operation.
 type FDResultSets struct {
-	readable  *goselect.FDSet
-	writeable *goselect.FDSet
-	errors    *goselect.FDSet
+	readable  *unix.FdSet
+	writeable *unix.FdSet
+	errors    *unix.FdSet
 }
 
 // IsReadable test if a file descriptor is ready to be read.
 func (r *FDResultSets) IsReadable(fd int) bool {
-	return r.readable.IsSet(uintptr(fd))
+	return r.readable.IsSet(fd)
 }
 
 // IsWritable test if a file descriptor is ready to be written.
 func (r *FDResultSets) IsWritable(fd int) bool {
-	return r.writeable.IsSet(uintptr(fd))
+	return r.writeable.IsSet(fd)
 }
 
 // IsError test if a file descriptor is in error state.
 func (r *FDResultSets) IsError(fd int) bool {
-	return r.errors.IsSet(uintptr(fd))
+	return r.errors.IsSet(fd)
 }
 
 // Select performs a select system call,
@@ -68,7 +67,7 @@ func (r *FDResultSets) IsError(fd int) bool {
 // The function return an FDResultSets that contains all the file descriptor
 // that have a pending read/write/error event.
 func Select(rd, wr, er *FDSet, timeout time.Duration) (*FDResultSets, error) {
-	max := uintptr(0)
+	max := 0
 	res := &FDResultSets{}
 	if rd != nil {
 		// fdsets are copied so the parameters are left untouched
@@ -96,6 +95,12 @@ func Select(rd, wr, er *FDSet, timeout time.Duration) (*FDResultSets, error) {
 		}
 	}
 
-	err := goselect.Select(int(max+1), res.readable, res.writeable, res.errors, timeout)
+	var err error
+	if timeout != -1 {
+		t := unix.NsecToTimeval(timeout.Nanoseconds())
+		_, err = unix.Select(max+1, res.readable, res.writeable, res.errors, &t)
+	} else {
+		_, err = unix.Select(max+1, res.readable, res.writeable, res.errors, nil)
+	}
 	return res, err
 }