added partial CancelIoEx emulation for XP and earlierr207

also added warning when CancelIo tries to cancel I/O started
from another thread

2 files changed, 40 insertions, 10 deletions

diff --git a/libusb/os/poll_windows.c b/libusb/os/poll_windows.c
index 0fa2dce..0d8d487 100644
--- a/libusb/os/poll_windows.c
+++ b/libusb/os/poll_windows.c
@@ -123,7 +123,9 @@ struct winfd poll_fd[MAX_FDS];
 struct {
 	CRITICAL_SECTION mutex; // lock for fds
 	BYTE marker;            // 1st byte of a usbi_read operation gets stored here
-
+	// Additional variables for XP CancelIoEx partial emulation
+	HANDLE original_handle;
+	DWORD thread_id;
 } _poll_fd[MAX_FDS];
 
 // globals
@@ -146,11 +148,19 @@ __inline BOOL cancel_io(int index)
 	if ((index < 0) || (index >= MAX_FDS)) {
 		return FALSE;
 	}
+
+	if ( (poll_fd[index].fd < 0) || (poll_fd[index].handle == INVALID_HANDLE_VALUE)
+	  || (poll_fd[index].handle == 0) || (poll_fd[index].overlapped == NULL) ) {
+		return TRUE;
+	}
 	if (pCancelIoEx != NULL) {
 		return (*pCancelIoEx)(poll_fd[index].handle, poll_fd[index].overlapped);
-	} else {
+	}
+	if (_poll_fd[index].thread_id == GetCurrentThreadId()) {
 		return CancelIo(poll_fd[index].handle);
 	}
+	usbi_warn(NULL, "Unable to cancel I/O that was started from another thread");
+	return FALSE;
 }
 
 // Init
@@ -169,6 +179,8 @@ void init_polling(void)
 		for (i=0; i<MAX_FDS; i++) {
 			poll_fd[i] = INVALID_WINFD;
 			_poll_fd[i].marker = 0;
+			_poll_fd[i].original_handle = INVALID_HANDLE_VALUE;
+			_poll_fd[i].thread_id = 0;
 			InitializeCriticalSection(&_poll_fd[i].mutex);
 		}
 #if defined(DYNAMIC_FDS)
@@ -470,7 +482,19 @@ struct winfd usbi_create_fd(HANDLE handle, int access_mode)
 				continue;
 			}
 			wfd.fd = fd;
-			wfd.handle = handle;
+			// Attempt to emulate some of the CancelIoEx behaviour on platforms
+			// that don't have it
+			if (pCancelIoEx == NULL) {
+				_poll_fd[i].thread_id = GetCurrentThreadId();
+				_poll_fd[i].original_handle = handle;
+				if (!DuplicateHandle(GetCurrentProcess(), handle, GetCurrentProcess(),
+					&wfd.handle, 0, TRUE, DUPLICATE_SAME_ACCESS)) {
+					usbi_warn(NULL, "could not duplicate handle for CancelIo - using orignal one");
+					wfd.handle = handle;
+				}
+			} else {
+				wfd.handle = handle;
+			}
 			wfd.overlapped = overlapped;
 			memcpy(&poll_fd[i], &wfd, sizeof(struct winfd));
 			LeaveCriticalSection(&_poll_fd[i].mutex);
@@ -499,6 +523,9 @@ void _free_index(int index)
 		_close(poll_fd[index].fd);
 	}
 	free_overlapped(poll_fd[index].overlapped);
+	CloseHandle(_poll_fd[index].original_handle);
+	_poll_fd[index].original_handle = INVALID_HANDLE_VALUE;
+	_poll_fd[index].thread_id = 0;
 	poll_fd[index] = INVALID_WINFD;
 }
 
diff --git a/libusb/os/windows_usb.c b/libusb/os/windows_usb.c
index 53a6a96..8bd1344 100644
--- a/libusb/os/windows_usb.c
+++ b/libusb/os/windows_usb.c
@@ -2555,6 +2555,7 @@ static int winusb_submit_control_transfer(struct usbi_transfer *itransfer)
 	winusb_handle = handle_priv->interface_handle[current_interface].api_handle;
 
 	wfd = usbi_create_fd(winusb_handle, _O_RDONLY);
+	// Always use the handle returned from usbi_create_fd (wfd.handle)
 	if (wfd.fd < 0) {
 		return LIBUSB_ERROR_NO_MEM;
 	}
@@ -2631,16 +2632,17 @@ static int winusb_submit_bulk_transfer(struct usbi_transfer *itransfer)
 	direction_in = transfer->endpoint & LIBUSB_ENDPOINT_IN;
 
 	wfd = usbi_create_fd(winusb_handle, direction_in?_O_RDONLY:_O_WRONLY);
+	// Always use the handle returned from usbi_create_fd (wfd.handle)
 	if (wfd.fd < 0) {
 		return LIBUSB_ERROR_NO_MEM;
 	}
 
 	if (direction_in) {
 		usbi_dbg("reading %d bytes", transfer->length);
-		ret = WinUsb_ReadPipe(winusb_handle, transfer->endpoint, transfer->buffer, transfer->length, NULL, wfd.overlapped);
+		ret = WinUsb_ReadPipe(wfd.handle, transfer->endpoint, transfer->buffer, transfer->length, NULL, wfd.overlapped);
 	} else {
 		usbi_dbg("writing %d bytes", transfer->length);
-		ret = WinUsb_WritePipe(winusb_handle, transfer->endpoint, transfer->buffer, transfer->length, NULL, wfd.overlapped);
+		ret = WinUsb_WritePipe(wfd.handle, transfer->endpoint, transfer->buffer, transfer->length, NULL, wfd.overlapped);
 	}
 	if (!ret) {
 		if(GetLastError() != ERROR_IO_PENDING) {
@@ -3593,7 +3595,7 @@ static int hid_submit_control_transfer(struct usbi_transfer *itransfer)
 
 	usbi_dbg("will use interface %d", current_interface);
 	hid_handle = handle_priv->interface_handle[current_interface].api_handle;
-
+	// Always use the handle returned from usbi_create_fd (wfd.handle)
 	wfd = usbi_create_fd(hid_handle, _O_RDONLY);
 	if (wfd.fd < 0) {
 		return LIBUSB_ERROR_NO_MEM;
@@ -3603,7 +3605,7 @@ static int hid_submit_control_transfer(struct usbi_transfer *itransfer)
 	case LIBUSB_REQUEST_TYPE_STANDARD:
 		switch(setup->request) {
 		case LIBUSB_REQUEST_GET_DESCRIPTOR:
-			r = _hid_get_descriptor(priv->hid, hid_handle, LIBUSB_REQ_RECIPIENT(setup->request_type), 
+			r = _hid_get_descriptor(priv->hid, wfd.handle, LIBUSB_REQ_RECIPIENT(setup->request_type), 
 				(setup->value >> 8) & 0xFF, setup->value & 0xFF, transfer->buffer + LIBUSB_CONTROL_SETUP_SIZE, &size);
 			break;
 		case LIBUSB_REQUEST_GET_CONFIGURATION:
@@ -3638,7 +3640,7 @@ static int hid_submit_control_transfer(struct usbi_transfer *itransfer)
 		}
 		break;
     case LIBUSB_REQUEST_TYPE_CLASS:
-      r =_hid_class_request(priv->hid, hid_handle, setup->request_type, setup->request, setup->value,
+      r =_hid_class_request(priv->hid, wfd.handle, setup->request_type, setup->request, setup->value,
 		  setup->index, transfer->buffer + LIBUSB_CONTROL_SETUP_SIZE, transfer_priv,
 		  &size, wfd.overlapped);
       break;
@@ -3697,6 +3699,7 @@ static int hid_submit_bulk_transfer(struct usbi_transfer *itransfer) {
 	direction_in = transfer->endpoint & LIBUSB_ENDPOINT_IN;
 
 	wfd = usbi_create_fd(hid_handle, direction_in?_O_RDONLY:_O_WRONLY);
+	// Always use the handle returned from usbi_create_fd (wfd.handle)
 	if (wfd.fd < 0) {
 		return LIBUSB_ERROR_NO_MEM;
 	}
@@ -3709,13 +3712,13 @@ static int hid_submit_bulk_transfer(struct usbi_transfer *itransfer) {
 	if (direction_in) {
 		transfer_priv->hid_buffer[0] = priv->hid->input_report_id;
 		usbi_dbg("reading %d bytes (report ID: 0x%02X)", transfer->length+1, transfer_priv->hid_buffer[0]);
-		ret = ReadFile(hid_handle, transfer_priv->hid_buffer, transfer->length+1, &size, wfd.overlapped);
+		ret = ReadFile(wfd.handle, transfer_priv->hid_buffer, transfer->length+1, &size, wfd.overlapped);
 	} else {
 		transfer_priv->hid_buffer[0] = priv->hid->output_report_id;
 		memcpy(transfer_priv->hid_buffer+1, transfer->buffer, transfer->length);
 		usbi_dbg("writing %d bytes (report ID: 0x%02X)", transfer->length+1, transfer_priv->hid_buffer[0]);
 		transfer_priv->hid_buffer[0] = 0;
-		ret = WriteFile(hid_handle, transfer_priv->hid_buffer, transfer->length+1, &size, wfd.overlapped);
+		ret = WriteFile(wfd.handle, transfer_priv->hid_buffer, transfer->length+1, &size, wfd.overlapped);
 	}
 	if (!ret) {
 		if (GetLastError() != ERROR_IO_PENDING) {