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Merge pull request #28 from kylelemons/async_transfers_everywhere

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Use async transfer API everywhere
This commit is contained in:
zagrodzki
2017-02-15 18:31:12 +01:00
committed by GitHub
parent 8f68b3d966 ef932806ed
commit 09150fc318
6 changed files with 171 additions and 236 deletions
Download Patch File Download Diff File Expand all files Collapse all files

9
usb/config.go
View File

@@ -38,14 +38,17 @@ func (e EndpointInfo) Number() int {
return int(e.Address) & ENDPOINT_NUM_MASK
}
func (e EndpointInfo) TransferType() TransferType {
return TransferType(e.Attributes) & TRANSFER_TYPE_MASK
}
func (e EndpointInfo) Direction() EndpointDirection {
return EndpointDirection(e.Address) & ENDPOINT_DIR_MASK
}
func (e EndpointInfo) String() string {
return fmt.Sprintf("Endpoint %d %-3s %s - %s %s [%d %d]",
e.Number(), e.Direction(),
TransferType(e.Attributes)&TRANSFER_TYPE_MASK,
e.Number(), e.Direction(), e.TransferType(),
IsoSyncType(e.Attributes)&ISO_SYNC_TYPE_MASK,
IsoUsageType(e.Attributes)&ISO_USAGE_TYPE_MASK,
e.MaxPacketSize, e.MaxIsoPacket,
@@ -135,7 +138,7 @@ func newConfig(dev *C.libusb_device, cfg *C.struct_libusb_config_descriptor) Con
RefreshRate: uint8(end.bRefresh),
SynchAddress: uint8(end.bSynchAddress),
}
if TransferType(ei.Attributes)&TRANSFER_TYPE_MASK == TRANSFER_TYPE_ISOCHRONOUS {
if ei.TransferType() == TRANSFER_TYPE_ISOCHRONOUS {
// bits 0-10 identify the packet size, bits 11-12 are the number of additional transactions per microframe.
// Don't use libusb_get_max_iso_packet_size, as it has a bug where it returns the same value
// regardless of alternative setting used, where different alternative settings might define different

10
usb/device.go
View File

@@ -151,16 +151,6 @@ func (d *Device) OpenEndpoint(conf, iface, setup, epoint uint8) (Endpoint, error
}
end.InterfaceSetup = s
end.EndpointInfo = e
switch tt := TransferType(e.Attributes) & TRANSFER_TYPE_MASK; tt {
case TRANSFER_TYPE_BULK:
end.xfer = bulk_xfer
case TRANSFER_TYPE_INTERRUPT:
end.xfer = interrupt_xfer
case TRANSFER_TYPE_ISOCHRONOUS:
end.xfer = isochronous_xfer
default:
return nil, fmt.Errorf("usb: %s transfer is unsupported", tt)
}
goto found
}
return nil, fmt.Errorf("usb: unknown endpoint %02x", epoint)

55
usb/endpoint.go
View File

@@ -20,9 +20,8 @@ import "C"
import (
"fmt"
"reflect"
"log"
"time"
"unsafe"
)
type Endpoint interface {
@@ -36,7 +35,6 @@ type endpoint struct {
*Device
InterfaceSetup
EndpointInfo
xfer func(*endpoint, []byte, time.Duration) (int, error)
}
func (e *endpoint) Read(buf []byte) (int, error) {
@@ -44,7 +42,7 @@ func (e *endpoint) Read(buf []byte) (int, error) {
return 0, fmt.Errorf("usb: read: not an IN endpoint")
}
return e.xfer(e, buf, e.ReadTimeout)
return e.transfer(buf, e.ReadTimeout)
}
func (e *endpoint) Write(buf []byte) (int, error) {
@@ -52,50 +50,33 @@ func (e *endpoint) Write(buf []byte) (int, error) {
return 0, fmt.Errorf("usb: write: not an OUT endpoint")
}
return e.xfer(e, buf, e.WriteTimeout)
return e.transfer(buf, e.WriteTimeout)
}
func (e *endpoint) Interface() InterfaceSetup { return e.InterfaceSetup }
func (e *endpoint) Info() EndpointInfo { return e.EndpointInfo }
// TODO(kevlar): (*Endpoint).Close
func bulk_xfer(e *endpoint, buf []byte, timeout time.Duration) (int, error) {
func (e *endpoint) transfer(buf []byte, timeout time.Duration) (int, error) {
if len(buf) == 0 {
return 0, nil
}
data := (*reflect.SliceHeader)(unsafe.Pointer(&buf)).Data
var cnt C.int
if errno := C.libusb_bulk_transfer(
e.handle,
C.uchar(e.Address),
(*C.uchar)(unsafe.Pointer(data)),
C.int(len(buf)),
&cnt,
C.uint(timeout/time.Millisecond)); errno < 0 {
return 0, usbError(errno)
tt := e.TransferType()
t, err := newUSBTransfer(e.Device.handle, e.EndpointInfo, buf, timeout)
if err != nil {
return 0, err
}
return int(cnt), nil
defer t.free()
if err := t.submit(); err != nil {
log.Printf("bulk: %s failed to submit: %s", tt, err)
return 0, err
}
func interrupt_xfer(e *endpoint, buf []byte, timeout time.Duration) (int, error) {
if len(buf) == 0 {
return 0, nil
n, err := t.wait()
if err != nil {
log.Printf("bulk: %s failed: %s", tt, err)
return 0, err
}
data := (*reflect.SliceHeader)(unsafe.Pointer(&buf)).Data
var cnt C.int
if errno := C.libusb_interrupt_transfer(
e.handle,
C.uchar(e.Address),
(*C.uchar)(unsafe.Pointer(data)),
C.int(len(buf)),
&cnt,
C.uint(timeout/time.Millisecond)); errno < 0 {
return 0, usbError(errno)
}
return int(cnt), nil
return n, err
}

150
usb/iso.go
View File

@@ -1,150 +0,0 @@
// Copyright 2013 Google Inc. All rights reserved.
// Copyright 2016 the gousb Authors. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package usb
/*
#include <libusb.h>
int submit(struct libusb_transfer *xfer);
void print_xfer(struct libusb_transfer *xfer);
int extract_data(struct libusb_transfer *xfer, void *data, int max, unsigned char *status);
*/
import "C"
import (
"fmt"
"log"
"time"
"unsafe"
)
//export iso_callback
func iso_callback(cptr unsafe.Pointer) {
ch := *(*chan struct{})(cptr)
close(ch)
}
func (end *endpoint) allocTransfer(maxLen int) *Transfer {
isoPacketSize := end.EndpointInfo.MaxIsoPacket
// the larget the input buffer, the more packets we use in a single
// transfer.
numIsoPackets := maxLen / int(isoPacketSize)
if numIsoPackets*int(isoPacketSize) < maxLen {
numIsoPackets++
}
xfer := C.libusb_alloc_transfer(C.int(numIsoPackets))
if xfer == nil {
log.Printf("usb: transfer allocation failed?!")
return nil
}
buf := make([]byte, numIsoPackets*int(end.EndpointInfo.MaxIsoPacket))
done := make(chan struct{}, 1)
xfer.dev_handle = end.Device.handle
xfer.endpoint = C.uchar(end.Address)
xfer._type = C.LIBUSB_TRANSFER_TYPE_ISOCHRONOUS
xfer.buffer = (*C.uchar)((unsafe.Pointer)(&buf[0]))
xfer.length = C.int(len(buf))
xfer.num_iso_packets = C.int(numIsoPackets)
C.libusb_set_iso_packet_lengths(xfer, C.uint(end.EndpointInfo.MaxIsoPacket))
/*
pkts := *(*[]C.struct_libusb_packet_descriptor)(unsafe.Pointer(&reflect.SliceHeader{
Data: uintptr(unsafe.Pointer(&xfer.iso_packet_desc)),
Len: iso_packets,
Cap: iso_packets,
}))
*/
t := &Transfer{
xfer: xfer,
done: done,
buf: buf,
}
xfer.user_data = (unsafe.Pointer)(&t.done)
return t
}
type Transfer struct {
xfer *C.struct_libusb_transfer
pkts []*C.struct_libusb_packet_descriptor
done chan struct{}
buf []byte
}
func (t *Transfer) Submit(timeout time.Duration) error {
//log.Printf("iso: submitting %#v", t.xfer)
t.xfer.timeout = C.uint(timeout / time.Millisecond)
if errno := C.submit(t.xfer); errno < 0 {
return usbError(errno)
}
return nil
}
func (t *Transfer) Wait(b []byte) (n int, err error) {
select {
case <-time.After(10 * time.Second):
return 0, fmt.Errorf("wait timed out after 10s")
case <-t.done:
}
// Non-iso transfers:
//n = int(t.xfer.actual_length)
//copy(b, ((*[1 << 16]byte)(unsafe.Pointer(t.xfer.buffer)))[:n])
//C.print_xfer(t.xfer)
/*
buf, offset := ((*[1 << 16]byte)(unsafe.Pointer(t.xfer.buffer))), 0
for i, pkt := range *t.pkts {
log.Printf("Type is %T", t.pkts)
n += copy(b[n:], buf[offset:][:pkt.actual_length])
offset += pkt.Length
if pkt.status != 0 && err == nil {
err = error(TransferStatus(pkt.status))
}
}
*/
var status uint8
n = int(C.extract_data(t.xfer, unsafe.Pointer(&b[0]), C.int(len(b)), (*C.uchar)(unsafe.Pointer(&status))))
if status != 0 {
err = TransferStatus(status)
}
return n, err
}
func (t *Transfer) Close() error {
C.libusb_free_transfer(t.xfer)
return nil
}
func isochronous_xfer(e *endpoint, buf []byte, timeout time.Duration) (int, error) {
t := e.allocTransfer(len(buf))
defer t.Close()
if err := t.Submit(timeout); err != nil {
log.Printf("iso: xfer failed to submit: %s", err)
return 0, err
}
n, err := t.Wait(buf)
if err != nil {
log.Printf("iso: xfer failed: %s", err)
return 0, err
}
return n, err
}

54
usb/iso.c → usb/transfer.c
View File

@@ -18,25 +18,15 @@
#include <string.h>
void print_xfer(struct libusb_transfer *xfer);
void iso_callback(void *);
void xfer_callback(void *);
void callback(struct libusb_transfer *xfer) {
//printf("Callback!\n");
//print_xfer(xfer);
iso_callback(xfer->user_data);
xfer_callback(xfer->user_data);
}
int submit(struct libusb_transfer *xfer) {
xfer->callback = (libusb_transfer_cb_fn)(&callback);
xfer->status = -1;
//print_xfer(xfer);
//printf("Transfer submitted\n");
/* fake
strcpy(xfer->buffer, "hello");
xfer->actual_length = 5;
callback(xfer);
return 0; */
return libusb_submit_transfer(xfer);
}
@@ -64,35 +54,27 @@ void print_xfer(struct libusb_transfer *xfer) {
}
}
int extract_data(struct libusb_transfer *xfer, void *raw, int max, unsigned char *status) {
// compact the data in an isochronous transfer. The contents of individual
// iso packets are shifted left, so that no gaps are left between them.
// Status is set to the first non-zero status of an iso packet.
int compact_iso_data(struct libusb_transfer *xfer, unsigned char *status) {
int i;
int copied = 0;
int sum = 0;
unsigned char *in = xfer->buffer;
unsigned char *out = raw;
unsigned char *out = xfer->buffer;
for (i = 0; i < xfer->num_iso_packets; i++) {
struct libusb_iso_packet_descriptor pkt = xfer->iso_packet_desc[i];
// Copy the data
int len = pkt.actual_length;
if (copied + len > max) {
len = max - copied;
}
memcpy(out, in, len);
copied += len;
// Increment offsets
in += pkt.length;
out += len;
if (copied == max) {
if (pkt.status != 0) {
*status = pkt.status;
break;
}
// Extract first error
if (pkt.status == 0 || *status != 0) {
continue;
// Copy the data
int len = pkt.actual_length;
memmove(out, in, len);
// Increment offsets
sum += len;
in += pkt.length;
out += len;
}
*status = pkt.status;
}
return copied;
return sum;
}

129
usb/transfer.go Normal file
View File

@@ -0,0 +1,129 @@
// Copyright 2016 the gousb Authors. All rights reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package usb
/*
#include <libusb.h>
int compact_iso_data(struct libusb_transfer *xfer, unsigned char *status);
int submit(struct libusb_transfer *xfer);
*/
import "C"
import (
"fmt"
"time"
"unsafe"
)
//export xfer_callback
func xfer_callback(cptr unsafe.Pointer) {
ch := *(*chan struct{})(cptr)
close(ch)
}
type usbTransfer struct {
// xfer is the allocated libusb_transfer.
xfer *C.struct_libusb_transfer
// buf is the buffer allocated for the transfer. Both buf and xfer.buffer
// point to the same piece of memory.
buf []byte
// done is blocking until the transfer is complete and data and transfer
// status are available.
done chan struct{}
}
// submits the transfer. After submit() the transfer is in flight and is owned by libusb.
// It's not safe to access the contents of the transfer until wait() returns.
// Once wait() returns, it's ok to re-use the same transfer structure by calling submit() again.
func (t *usbTransfer) submit() error {
t.done = make(chan struct{})
t.xfer.user_data = (unsafe.Pointer)(&t.done)
if errno := C.submit(t.xfer); errno < 0 {
return usbError(errno)
}
return nil
}
// wait waits for libusb to signal the release of transfer data.
// After wait returns, the transfer contents are safe to access
// via t.buf. The number returned by wait indicates how many bytes
// of the buffer were read or written by libusb, and it can be
// smaller than the length of t.buf.
func (t *usbTransfer) wait() (n int, err error) {
select {
case <-time.After(10 * time.Second):
return 0, fmt.Errorf("wait timed out after 10s")
case <-t.done:
}
var status TransferStatus
switch TransferType(t.xfer._type) {
case TRANSFER_TYPE_ISOCHRONOUS:
n = int(C.compact_iso_data(t.xfer, (*C.uchar)(unsafe.Pointer(&status))))
default:
n = int(t.xfer.length)
status = TransferStatus(t.xfer.status)
}
if status != LIBUSB_TRANSFER_COMPLETED {
return 0, status
}
return n, err
}
// free releases the memory allocated for the transfer.
// free should be called only if the transfer is not used by libusb,
// i.e. it should not be called after submit() and before wait() returns.
func (t *usbTransfer) free() error {
C.libusb_free_transfer(t.xfer)
t.xfer = nil
t.buf = nil
t.done = nil
return nil
}
type deviceHandle *C.libusb_device_handle
// newUSBTransfer allocates a new transfer structure for communication with a
// given device/endpoint, with buf as the underlying transfer buffer.
func newUSBTransfer(dev deviceHandle, ei EndpointInfo, buf []byte, timeout time.Duration) (*usbTransfer, error) {
var isoPackets int
tt := ei.TransferType()
if tt == TRANSFER_TYPE_ISOCHRONOUS {
isoPackets = len(buf) / int(ei.MaxIsoPacket)
}
xfer := C.libusb_alloc_transfer(C.int(isoPackets))
if xfer == nil {
return nil, fmt.Errorf("libusb_alloc_transfer(%d) failed", isoPackets)
}
xfer.dev_handle = dev
xfer.timeout = C.uint(timeout / time.Millisecond)
xfer.endpoint = C.uchar(ei.Address)
xfer._type = C.uchar(tt)
xfer.buffer = (*C.uchar)((unsafe.Pointer)(&buf[0]))
xfer.length = C.int(len(buf))
if tt == TRANSFER_TYPE_ISOCHRONOUS {
xfer.num_iso_packets = C.int(isoPackets)
C.libusb_set_iso_packet_lengths(xfer, C.uint(ei.MaxIsoPacket))
}
return &usbTransfer{
xfer: xfer,
buf: buf,
}, nil
}