Add a retract version for v2.1.0+incompatible. (#109)

This will avoid listing this version in "go list -m -versions", which
is used by GitHub's dependabot. The "go list" is expected to list
versions oldest to newest, but it doesn't exclude the "+incompatible"
versions and treats v2.1.0 as the newest. We don't want that, 1.1 is the
latest at the moment.

.appveyor/install.sh

@@ -1,15 +0,0 @@
-#!/usr/bin/env bash
-
-export PATH="/mingw64/bin:${PATH}"
-export PKG_CONFIG_PATH="/mingw64/lib/pkgconfig:${PKG_CONFIG_PATH}"
-export GOROOT=/mingw64/lib/go
-export GOPATH=/go
-export CGO_ENABLED=1
-
-pacman --noconfirm -S \
-    mingw64/mingw-w64-x86_64-go \
-    mingw64/mingw-w64-x86_64-libusb
-
-go version
-go get -t github.com/google/gousb/...
-go test github.com/google/gousb/...

.github/test-coverage.sh

@@ -0,0 +1,4 @@
+#!/bin/sh
+echo 'mode: count' > coverage.merged &&\
+        go list -f '{{.Dir}}' ./... | xargs -n1 -I'{}' sh -c ': > coverage.tmp; go test -v -covermode=count -coverprofile=coverage.tmp {} && tail -n +2 coverage.tmp >> coverage.merged' &&\
+        rm coverage.tmp

.github/workflows/build-and-test.yaml

@@ -0,0 +1,35 @@
+name: build-and-test
+on: [pull_request, push]
+jobs:
+  linux:
+    runs-on: ubuntu-20.04
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-go@v2
+        with:
+          go-version: 1.17
+      - run: DIFF="$( find . -name '*.go' -print0 | xargs -0 gofmt -l )"; if [ -n "$DIFF" ]; then echo "Files not formatted, run gofmt:"; echo "$DIFF"; exit 1; fi
+      - run: sudo apt-get install libusb-1.0-0-dev
+      - run: go install golang.org/x/tools/cmd/cover@latest
+      - run: go install golang.org/x/lint/golint@latest
+      - run: $HOME/go/bin/golint -set_exit_status ./...
+      - run: sh ./.github/test-coverage.sh
+      - uses: shogo82148/actions-goveralls@v1
+        with:
+          path-to-profile: coverage.merged
+          ignore: libusb.go,error.go
+  windows:
+    runs-on: windows-2022
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/setup-go@v2
+        with:
+          go-version: 1.17
+      - uses: msys2/setup-msys2@v2
+        with:
+          install: |-
+            mingw64/mingw-w64-x86_64-libusb
+            mingw64/mingw-w64-x86_64-pkg-config
+      - run: echo "D:\a\_temp\msys64\mingw64\bin" | Out-File -FilePath $env:GITHUB_PATH -Encoding utf8 -Append
+      - run: go test ./...
+      - run: go run ./lsusb

.travis.yml

@@ -1,30 +0,0 @@
-language: go
-dist: trusty
-
-go:
-  - 1.7.x
-  - 1.8.x
-  - 1.9.x
-  - 1.10.x
-  - tip
-
-addons:
-  apt:
-    packages:
-      libusb-1.0-0-dev
-
-install:
-  - go get golang.org/x/tools/cmd/cover
-  # Golint requires Go 1.9 or later.
-  - if ! [[ "$TRAVIS_GO_VERSION" =~ ^1\.7\.([0-9]+|x)$ || "$TRAVIS_GO_VERSION" =~ ^1\.8\.([0-9]+|x)$ ]]; then go get golang.org/x/lint/golint; fi
-  - go get github.com/mattn/goveralls
-
-script:
-  # a workaround for go test not supporting coverage for multiple packages in a single invocation.
-  # If goveralls upload fails, ignore the result.
-  # Golint requires Go 1.9 or later.
-  - if ! [[ "$TRAVIS_GO_VERSION" =~ ^1\.7\.([0-9]+|x)+$ || "$TRAVIS_GO_VERSION" =~ ^1\.8\.([0-9]+|x)$ ]]; then $HOME/gopath/bin/golint ./...; fi
-  - |-
-    echo 'mode: count' > coverage.merged && go list ./... | xargs -n1 -I{} sh -c ': > coverage.tmp; go test -v -covermode=count -coverprofile=coverage.tmp {} && tail -n +2 coverage.tmp >> coverage.merged' && rm coverage.tmp
-  - |-
-    $HOME/gopath/bin/goveralls -coverprofile=coverage.merged -service=travis-ci -ignore libusb.go,error.go || true

README.md

@@ -4,7 +4,6 @@ Introduction
 [![Build Status][ciimg]][ci]
 [![GoDoc][docimg]][doc]
 [![Coverage Status][coverimg]][cover]
-[![Build status][appveimg]][appveyor]
 
 
 The gousb package is an attempt at wrapping the libusb library into a Go-like binding.
@@ -21,12 +20,10 @@ As of 2017-07-13 the 2.0 API is considered stable and 1.0 is deprecated.
 
 [coverimg]: https://coveralls.io/repos/github/google/gousb/badge.svg
 [cover]:    https://coveralls.io/github/google/gousb
-[ciimg]:    https://travis-ci.org/google/gousb.svg
-[ci]:       https://travis-ci.org/google/gousb
+[ciimg]:    https://github.com/google/gousb/actions/workflows/build-and-test.yaml/badge.svg
+[ci]:       https://github.com/google/gousb/actions/workflows/build-and-test.yaml
 [docimg]:   https://godoc.org/github.com/google/gousb?status.svg
 [doc]:      https://godoc.org/github.com/google/gousb
-[appveimg]: https://ci.appveyor.com/api/projects/status/661qp7x33o3wqe4o?svg=true
-[appveyor]: https://ci.appveyor.com/project/zagrodzki/gousb
 
 Documentation
 =============

appveyor.yml

@@ -1,8 +0,0 @@
-platform: x64
-
-clone_folder: C:\msys64\go\src\github.com\google\gousb
-
-install:
-  - C:\msys64\usr\bin\bash.exe -lc "cd /go/src/github.com/google/gousb/ && .appveyor/./install.sh"
-
-build: off

device.go

@@ -24,11 +24,22 @@ import (
 
 // DeviceDesc is a representation of a USB device descriptor.
 type DeviceDesc struct {
-	// Bus information
-	Bus     int   // The bus on which the device was detected
-	Address int   // The address of the device on the bus
-	Speed   Speed // The negotiated operating speed for the device
-	Port    int   // The usb port on which the device was detected
+	// The bus on which the device was detected
+	Bus int
+	// The address of the device on the bus
+	Address int
+	// The negotiated operating speed for the device
+	Speed Speed
+	// The pyhsical port on the parent hub on which the device is connected.
+	// Ports are numbered from 1, excepting root hub devices which are always 0.
+	Port int
+	// Physical path of connected parent ports, starting at the root hub device.
+	// A path length of 0 represents a root hub device,
+	// a path length of 1 represents a device directly connected to a root hub,
+	// a path length of 2 or more are connected to intermediate hub devices.
+	// e.g. [1,2,3] represents a device connected to port 3 of a hub connected
+	// to port 2 of a hub connected to port 1 of a root hub.
+	Path []int
 
 	// Version information
 	Spec   BCD // USB Specification Release Number
@@ -209,7 +220,7 @@ func (d *Device) Close() error {
 	if d.claimed != nil {
 		return fmt.Errorf("can't release the device %s, it has an open config %d", d, d.claimed.Desc.Number)
 	}
-	d.ctx.libusb.close(d.handle)
+	d.ctx.closeDev(d)
 	d.handle = nil
 	return nil
 }

fakelibusb_test.go

@@ -98,7 +98,7 @@ type fakeLibusb struct {
 	claims map[*libusbDevice]map[uint8]bool
 }
 
-func (f *fakeLibusb) init() (*libusbContext, error)                       { return new(libusbContext), nil }
+func (f *fakeLibusb) init() (*libusbContext, error)                       { return newContextPointer(), nil }
 func (f *fakeLibusb) handleEvents(c *libusbContext, done <-chan struct{}) { <-done }
 func (f *fakeLibusb) getDevices(*libusbContext) ([]*libusbDevice, error) {
 	ret := make([]*libusbDevice, 0, len(fakeDevices))
@@ -128,7 +128,7 @@ func (f *fakeLibusb) getDeviceDesc(d *libusbDevice) (*DeviceDesc, error) {
 	return nil, fmt.Errorf("invalid USB device %p", d)
 }
 func (f *fakeLibusb) open(d *libusbDevice) (*libusbDevHandle, error) {
-	h := new(libusbDevHandle)
+	h := newDevHandlePointer()
 	f.mu.Lock()
 	defer f.mu.Unlock()
 	f.handles[h] = d

go.mod

@@ -0,0 +1,6 @@
+module github.com/google/gousb
+
+go 1.16
+
+// Released in error, v1.* remains the current version.
+retract v2.1.0+incompatible

libusb.go

@@ -209,7 +209,7 @@ func (libusbImpl) getDevices(ctx *libusbContext) ([]*libusbDevice, error) {
 	for _, d := range devs {
 		ret = append(ret, (*libusbDevice)(d))
 	}
-	// devices will be dereferenced later, during close.
+	// devices must be dereferenced by the caller to prevent memory leaks.
 	C.libusb_free_device_list(list, 0)
 	return ret, nil
 }
@@ -224,14 +224,26 @@ func (libusbImpl) setDebug(c *libusbContext, lvl int) {
 }
 
 func (libusbImpl) getDeviceDesc(d *libusbDevice) (*DeviceDesc, error) {
-	var desc C.struct_libusb_device_descriptor
+	var (
+		desc     C.struct_libusb_device_descriptor
+		pathData [8]uint8
+		path     []int
+		port     int
+	)
 	if err := fromErrNo(C.libusb_get_device_descriptor((*C.libusb_device)(d), &desc)); err != nil {
 		return nil, err
 	}
+	pathLen := int(C.libusb_get_port_numbers((*C.libusb_device)(d), (*C.uint8_t)(&pathData[0]), 8))
+	for _, nPort := range pathData[:pathLen] {
+		port = int(nPort)
+		path = append(path, port)
+	}
+	// Defaults to port = 0, path = [] for root device
 	dev := &DeviceDesc{
 		Bus:                  int(C.libusb_get_bus_number((*C.libusb_device)(d))),
 		Address:              int(C.libusb_get_device_address((*C.libusb_device)(d))),
-		Port:                 int(C.libusb_get_port_number((*C.libusb_device)(d))),
+		Port:                 port,
+		Path:                 path,
 		Speed:                Speed(C.libusb_get_device_speed((*C.libusb_device)(d))),
 		Spec:                 BCD(desc.bcdUSB),
 		Device:               BCD(desc.bcdDevice),
@@ -508,6 +520,7 @@ func libusbSetDebug(c *libusbContext, lvl int) {
 	C.gousb_set_debug((*C.libusb_context)(c), C.int(lvl))
 }
 
+// for obtaining unique CGo pointers.
 func newDevicePointer() *libusbDevice {
 	return (*libusbDevice)(unsafe.Pointer(C.malloc(1)))
 }
@@ -515,3 +528,11 @@ func newDevicePointer() *libusbDevice {
 func newFakeTransferPointer() *libusbTransfer {
 	return (*libusbTransfer)(unsafe.Pointer(C.malloc(1)))
 }
+
+func newContextPointer() *libusbContext {
+	return (*libusbContext)(unsafe.Pointer(C.malloc(1)))
+}
+
+func newDevHandlePointer() *libusbDevHandle {
+	return (*libusbDevHandle)(unsafe.Pointer(C.malloc(1)))
+}

transfer_stream.go

@@ -269,14 +269,15 @@ func (w *WriteStream) Close() error {
 	return w.CloseContext(context.Background())
 }
 
-// Close signals end of data to write. Close blocks until all transfers
-// that were sent are finished. The error returned by Close is the first
-// error encountered during writing the entire stream (if any).
-// Close returning nil indicates all transfers completed successfully.
-// After Close, the total number of bytes successfully written can be
+// CloseContext signals end of data to write. CloseContext blocks until all
+// transfers that were sent are finished or until the context is canceled. The
+// error returned by CloseContext is the first error encountered during writing
+// the entire stream (if any).
+// CloseContext returning nil indicates all transfers completed successfully.
+// After CloseContext, the total number of bytes successfully written can be
 // retrieved using Written().
-// Close may not be called concurrently with Write, Close or Written.
-// CloseContext
+// CloseContext may not be called concurrently with Write, WriteContext, Close,
+// CloseContext or Written.
 func (w *WriteStream) CloseContext(ctx context.Context) error {
 	if w.s.transfers == nil {
 		return io.ErrClosedPipe

usb.go

@@ -125,11 +125,20 @@ see the excellent "USB in a nutshell" guide: http://www.beyondlogic.org/usbnutsh
 */
 package gousb
 
+import (
+	"errors"
+	"fmt"
+	"sync"
+)
+
 // Context manages all resources related to USB device handling.
 type Context struct {
 	ctx    *libusbContext
 	done   chan struct{}
 	libusb libusbIntf
+
+	mu      sync.Mutex
+	devices map[*Device]bool
 }
 
 // Debug changes the debug level. Level 0 means no debug, higher levels
@@ -146,9 +155,10 @@ func newContextWithImpl(impl libusbIntf) *Context {
 		panic(err)
 	}
 	ctx := &Context{
-		ctx:    c,
-		done:   make(chan struct{}),
-		libusb: impl,
+		ctx:     c,
+		done:    make(chan struct{}),
+		libusb:  impl,
+		devices: make(map[*Device]bool),
 	}
 	go impl.handleEvents(ctx.ctx, ctx.done)
 	return ctx
@@ -165,6 +175,9 @@ func NewContext() *Context {
 // If there are any errors enumerating the devices,
 // the final one is returned along with any successfully opened devices.
 func (c *Context) OpenDevices(opener func(desc *DeviceDesc) bool) ([]*Device, error) {
+	if c.ctx == nil {
+		return nil, errors.New("OpenDevices called on a closed or uninitialized Context")
+	}
 	list, err := c.libusb.getDevices(c.ctx)
 	if err != nil {
 		return nil, err
@@ -174,23 +187,26 @@ func (c *Context) OpenDevices(opener func(desc *DeviceDesc) bool) ([]*Device, er
 	var ret []*Device
 	for _, dev := range list {
 		desc, err := c.libusb.getDeviceDesc(dev)
+		defer c.libusb.dereference(dev)
 		if err != nil {
-			c.libusb.dereference(dev)
 			reterr = err
 			continue
 		}
 
-		if opener(desc) {
-			handle, err := c.libusb.open(dev)
-			if err != nil {
-				c.libusb.dereference(dev)
-				reterr = err
-				continue
-			}
-			ret = append(ret, &Device{handle: handle, ctx: c, Desc: desc})
-		} else {
-			c.libusb.dereference(dev)
+		if !opener(desc) {
+			continue
 		}
+		handle, err := c.libusb.open(dev)
+		if err != nil {
+			reterr = err
+			continue
+		}
+		o := &Device{handle: handle, ctx: c, Desc: desc}
+		ret = append(ret, o)
+		c.mu.Lock()
+		c.devices[o] = true
+		c.mu.Unlock()
+
 	}
 	return ret, reterr
 }
@@ -219,13 +235,32 @@ func (c *Context) OpenDeviceWithVIDPID(vid, pid ID) (*Device, error) {
 	return devs[0], nil
 }
 
+func (c *Context) closeDev(d *Device) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	c.libusb.close(d.handle)
+	delete(c.devices, d)
+}
+
+func (c *Context) checkOpenDevs() error {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+	if l := len(c.devices); l > 0 {
+		return fmt.Errorf("Context.Close called while %d Devices are still open, Close may be called only after all previously opened devices were successfuly closed", l)
+	}
+	return nil
+}
+
 // Close releases the Context and all associated resources.
 func (c *Context) Close() error {
-	var ret error
-	c.done <- struct{}{}
-	if c.ctx != nil {
-		ret = c.libusb.exit(c.ctx)
+	if c.ctx == nil {
+		return nil
 	}
+	if err := c.checkOpenDevs(); err != nil {
+		return err
+	}
+	c.done <- struct{}{}
+	err := c.libusb.exit(c.ctx)
 	c.ctx = nil
-	return ret
+	return err
 }

usb_test.go

@@ -41,6 +41,11 @@ func TestOPenDevices(t *testing.T) {
 		t.Fatalf("OpenDevices(): %s", err)
 	}
 
+	// attempt to Close() should fail because of open devices
+	if err := c.Close(); err == nil {
+		t.Fatal("Context.Close succeeded while some devices were still open")
+	}
+
 	if got, want := len(devs), len(fakeDevices); got != want {
 		t.Fatalf("len(devs) = %d, want %d (based on num fake devs)", got, want)
 	}