Added test to detect correct behaviour in Close and Read ops

.github/workflows/test.yaml

@@ -22,8 +22,12 @@ jobs:
       - name: Build native
         run: GOARCH=amd64 go build -v ./...
         shell: bash
+      - name: Install socat
+        if: matrix.os == 'ubuntu-latest'
+        run: sudo apt-get install socat
+        shell: bash
       - name: Run unit tests
-        run: go test -v ./...
+        run: go test -v -race ./...
         shell: bash
       - name: Cross-build for 386
         if: matrix.os != 'macOS-latest'

go.sum

@@ -9,6 +9,7 @@ github.com/stretchr/testify v1.4.0 h1:2E4SXV/wtOkTonXsotYi4li6zVWxYlZuYNCXe9XRJy
 github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
 golang.org/x/sys v0.0.0-20191128015809-6d18c012aee9 h1:ZBzSG/7F4eNKz2L3GE9o300RX0Az1Bw5HF7PDraD+qU=
 golang.org/x/sys v0.0.0-20191128015809-6d18c012aee9/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v2 v2.2.2 h1:ZCJp+EgiOT7lHqUV2J862kp8Qj64Jo6az82+3Td9dZw=
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=

serial_linux_test.go

@@ -0,0 +1,41 @@
+//
+// Copyright 2014-2020 Cristian Maglie. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+//
+// Testing code idea and fix thanks to @angri
+// https://github.com/bugst/go-serial/pull/42
+//
+
+package serial
+
+import (
+	"context"
+	"os/exec"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestSerialReadAndCloseConcurrency(t *testing.T) {
+
+	// Run this test with race detector to actually test that
+	// the correct multitasking behaviour is happening.
+
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+	cmd := exec.CommandContext(ctx, "socat", "STDIO", "pty,link=/tmp/faketty")
+	require.NoError(t, cmd.Start())
+	go cmd.Wait()
+	// let our fake serial port node to appear
+	time.Sleep(time.Millisecond * 100)
+
+	port, err := Open("/tmp/faketty", &Mode{})
+	require.NoError(t, err)
+	buf := make([]byte, 100)
+	go port.Read(buf)
+	// let port.Read to start
+	time.Sleep(time.Millisecond * 1)
+	port.Close()
+}