[linux-minidisc] [PATCH 03/14] Export methods to release resources.
- From: Vincent Pelletier <plr.vincent@gmail.com>
- To: <linux-minidisc@lists.fu-berlin.de>
- Date: Thu, 11 Feb 2010 21:47:36 -0000
- Domainkey-signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:in-reply-to:references:from:date:subject:to:mime-version :content-type:x-length:x-uid; b=EuYbZ4texlKY/JrtYHY7p18QEnqbifHTbZevUjeK2eCY/CGkvZxCvzF1PsxfD4snlj emokREhS3g+DAsfQk5R11x3PS2NGPAUJY5GoGhC2zjrX1R45bClmz9EKeH/SCL0z2mBv 594a3iEz8M8meAOpCSrt3VMe58HseDnB2zssQ=
- Subject: [linux-minidisc] [PATCH 03/14] Export methods to release resources.
This allows user to work-around race conditions in interpreter shutdown,
where context might be freed before handle - for example.
---
netmd/usb1.py | 243 ++-------------------------------------------------------
1 files changed, 6 insertions(+), 237 deletions(-)
diff --git a/netmd/usb1.py b/netmd/usb1.py
index cd0711b..d22f52a 100644
--- a/netmd/usb1.py
+++ b/netmd/usb1.py
@@ -1,6 +1,6 @@
# pyusb compatibility layer for libus-1.0
import libusb1
-from ctypes import byref, create_string_buffer, c_int, sizeof, POINTER
+from ctypes import byref, create_string_buffer, c_int
from cStringIO import StringIO
__all__ = ['LibUSBContext']
@@ -8,136 +8,10 @@ __all__ = ['LibUSBContext']
# Default string length
STRING_LENGTH = 256
-EVENT_CALLBACK_SET = frozenset((
- libusb1.LIBUSB_TRANSFER_COMPLETED,
- libusb1.LIBUSB_TRANSFER_ERROR,
- libusb1.LIBUSB_TRANSFER_TIMED_OUT,
- libusb1.LIBUSB_TRANSFER_CANCELLED,
- libusb1.LIBUSB_TRANSFER_STALL,
- libusb1.LIBUSB_TRANSFER_NO_DEVICE,
- libusb1.LIBUSB_TRANSFER_OVERFLOW,
-))
-
-DEFAULT_ASYNC_TRANSFER_ERROR_CALLBACK = lambda x, y: False
-
-class USBAsyncReaderBase(object):
- _handle = None
- _submited = False
-
- def __init__(self, handle, endpoint, size, user_data=None, timeout=0):
- data = create_string_buffer(size)
- self._data = data
- self._transfer = self._getTransfer(
- handle,
- endpoint,
- data,
- self._callbackDispatcher,
- user_data,
- timeout,
- )
- # XXX: set _handle *after* _transfer, so __del__ doesn't get an
- # exception if called during constructor execution.
- self._handle = handle
- self._event_callback_dict = {}
- self._errorCallback = DEFAULT_ASYNC_TRANSFER_ERROR_CALLBACK
-
- def submit(self):
- self._submited = True
- self._handle.submitTransfer(self._transfer)
-
- def cancel(self):
- self._handle.cancelTransfer(self._transfer)
- self._submited = False
-
- def setEventCallback(self, event, callback):
- if event not in EVENT_CALLBACK_SET:
- raise ValueError, 'Unknown event %r.' % (event, )
- self._event_callback_dict[event] = callback
-
- def setDefaultCallback(self, callback):
- self._errorCallback = callback
-
- def getEventCallback(self, event, default=None):
- return self._event_callback_dict.get(event, default)
-
- def _callbackDispatcher(self, transfer_p):
- transfer = self._transfer.contents #transfer_p.contents
- if self.getEventCallback(transfer.status, self._errorCallback)(
- transfer, self._data):
- self.submit()
- else:
- self._submited = False
-
- def isSubmited(self):
- return self._submited
-
- def __del__(self):
- if self._handle is not None:
- try:
- self.cancel()
- except libusb1.USBError, exception:
- if exception.value != libusb1.LIBUSB_ERROR_NOT_FOUND:
- raise
-
-class USBAsyncBulkReader(USBAsyncReaderBase):
- def _getTransfer(self, handle, *args, **kw):
- return handle.getBulkTransfer(*args, **kw)
-
-class USBAsyncInterruptReader(USBAsyncReaderBase):
- def _getTransfer(self, handle, *args, **kw):
- return handle.getInterruptTransfer(*args, **kw)
-
-class USBPoller(object):
- def __init__(self, context, poller):
- self.context = context
- self.poller = poller
- fd_set = set()
- self.fd_set = fd_set
- context.setPollFDNotifiers(self._registerFD, self._unregisterFD)
- for fd, events in context.getPollFDList():
- self._registerFD(fd, events)
-
- def poll(self, timeout=None):
- fd_set = self.fd_set
- next_usb_timeout = self.context.getNextTimeout()
- if next_usb_timeout == 0:
- next_usb_timeout = None
- if timeout is None:
- usb_timeout = next_usb_timeout
- else:
- usb_timeout = min(next_usb_timeout or timeout, timeout)
- event_list = self.poller.poll(usb_timeout)
- event_list_len = len(event_list)
- if event_list_len:
- result = [(x, y) for x, y in event_list if x not in fd_set]
- if len(result) != event_list_len:
- self.context.handleEventsTimeout()
- else:
- result = event_list
- self.context.handleEventsTimeout()
- return result
-
- def register(self, fd, events):
- self.poller.register(fd, events)
-
- def unregister(self, fd):
- self.poller.unregister(fd)
-
- def _registerFD(self, fd, events, user_data=None):
- self.fd_set.add(fd)
- self.register(fd, events)
-
- def _unregisterFD(self, fd, user_data=None):
- self.unregister(fd)
- self.sd_set.discard(fd)
-
class USBDeviceHandle(object):
handle = None
- def __init__(self, context, handle):
- # XXX Context parameter is just here as a hint for garbage collector:
- # It must collect USBDeviceHandle instance before their LibUSBContext.
- self.context = context
+ def __init__(self, handle):
self.handle = handle
def __del__(self):
@@ -288,78 +162,11 @@ class USBDeviceHandle(object):
transferred = self._interruptTransfer(endpoint, data, length, timeout)
return data.raw[:transferred]
- def _getTransfer(self, iso_packets=0):
- result = libusb1.libusb_alloc_transfer(iso_packets)
- if not result:
- raise libusb1.USBError, 'Unable to get a transfer object'
- return result
-
- def fillBulkTransfer(self, transfer, endpoint, string_buffer,
- callback, user_data, timeout):
- libusb1.libusb_fill_bulk_transfer(transfer, self.handle,
- endpoint, string_buffer, sizeof(string_buffer),
- libusb1.libusb_transfer_cb_fn_p(callback), user_data,
- timeout)
-
- def getBulkTransfer(self, endpoint, string_buffer, callback,
- user_data=None, timeout=0):
- result = self._getTransfer()
- self.fillBulkTransfer(result, endpoint, string_buffer, callback,
- user_data, timeout)
- return result
-
- def fillInterruptTransfer(self, transfer, endpoint, string_buffer,
- callback, user_data, timeout):
- libusb1.libusb_fill_interrupt_transfer(transfer, self.handle,
- endpoint, string_buffer, sizeof(string_buffer),
- libusb1.libusb_transfer_cb_fn_p(callback), user_data,
- timeout)
-
- def getInterruptTransfer(self, endpoint, string_buffer, callback,
- user_data=None, timeout=0):
- result = self._getTransfer()
- self.fillInterruptTransfer(result, endpoint, string_buffer,
- callback, user_data, timeout)
- return result
-
- def fillControlSetup(self, string_buffer, request_type, request, value,
- index, length):
- libusb1.libusb_fill_control_setup(string_buffer, request_type,
- request, value, index, length)
-
- def fillControlTransfer(self, transfer, setup, callback,
- user_data, timeout):
- libusb1.libusb_fill_control_transfer(transfer, self.handle,
- setup, libusb1.libusb_transfer_cb_fn_p(callback), user_data,
- timeout)
-
- def getControlTransfer(self, setup, callback, user_data=None, timeout=0):
- result = self._getTransfer()
- self.fillControlTransfer(result, setup, callback, user_data, timeout)
- return result
-
- def fillISOTransfer(self, *args, **kw):
- raise NotImplementedError
-
- def getISOTransfer(self, *args, **kw):
- raise NotImplementedError
-
- def submitTransfer(self, transfer):
- result = libusb1.libusb_submit_transfer(transfer)
- if result:
- raise libusb1.USBError, result
-
- def cancelTransfer(self, transfer):
- result = libusb1.libusb_cancel_transfer(transfer)
- if result:
- raise libusb1.USBError, result
-
class USBDevice(object):
configuration_descriptor_list = None
- def __init__(self, context, device_p):
- self.context = context
+ def __init__(self, device_p):
libusb1.libusb_ref_device(device_p)
self.device_p = device_p
# Fetch device descriptor
@@ -500,7 +307,7 @@ class USBDevice(object):
result = libusb1.libusb_open(self.device_p, byref(handle))
if result:
raise libusb1.USBError, result
- return USBDeviceHandle(self.context, handle)
+ return USBDeviceHandle(handle)
class LibUSBContext(object):
@@ -526,7 +333,7 @@ class LibUSBContext(object):
device_p_p = libusb1.libusb_device_p_p()
device_list_len = libusb1.libusb_get_device_list(self.context_p,
byref(device_p_p))
- result = [USBDevice(self, x) for x in device_p_p[:device_list_len]]
+ result = [USBDevice(x) for x in device_p_p[:device_list_len]]
# XXX: causes problems, why ?
#libusb1.libusb_free_device_list(device_p_p, 1)
return result
@@ -535,46 +342,8 @@ class LibUSBContext(object):
handle_p = libusb1.libusb_open_device_with_vid_pid(self.context_p,
vendor_id, product_id)
if handle_p:
- result = USBDeviceHandle(self, handle_p)
+ result = USBDeviceHandle(handle_p)
else:
result = None
return result
- def getPollFDList(self):
- pollfd_p_p = libusb1.libusb_get_pollfds(self.context_p)
- result = []
- append = result.append
- fd_index = 0
- while pollfd_p_p[fd_index]:
- append((pollfd_p_p[fd_index].contents.fd,
- pollfd_p_p[fd_index].contents.events))
- fd_index += 1
- return result
-
- def handleEvents(self):
- result = libusb1.libusb_handle_events(self.context_p)
- if result:
- raise libusb1.USBError, result
-
- def handleEventsTimeout(self, tv=None):
- assert tv is None, 'tv parameter is not supported yet'
- tv = libusb1.timeval(0, 0)
- result = libusb1.libusb_handle_events_timeout(self.context_p, byref(tv))
- if result:
- raise libusb1.USBError, result
-
- def setPollFDNotifiers(self, added_cb=None, removed_cb=None, user_data=None):
- if added_cb is None:
- added_cb = POINTER(None)
- else:
- added_cb = libusb1.libusb_pollfd_added_cb_p(added_cb)
- if removed_cb is None:
- removed_cb = POINTER(None)
- else:
- removed_cb = libusb1.libusb_pollfd_removed_cb_p(removed_cb)
- libusb1.libusb_set_pollfd_notifiers(self.context_p, added_cb,
- removed_cb, user_data)
-
- def getNextTimeout(self):
- return libusb1.libusb_get_next_timeout(self.context_p, None)
-
