# -*- coding: utf-8 -*- # # Xlib.protocol.display -- core display communication # # Copyright (C) 2000-2002 Peter Liljenberg # # This library is free software; you can redistribute it and/or # modify it under the terms of the GNU Lesser General Public License # as published by the Free Software Foundation; either version 2.1 # of the License, or (at your option) any later version. # # This library is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. # See the GNU Lesser General Public License for more details. # # You should have received a copy of the GNU Lesser General Public # License along with this library; if not, write to the # Free Software Foundation, Inc., # 59 Temple Place, # Suite 330, # Boston, MA 02111-1307 USA # Standard modules import errno import math import select import socket import struct import sys # Python 2/3 compatibility. from six import PY3, byte2int, indexbytes # Xlib modules from .. import error from ..ext import ge from ..support import lock, connect # Xlib.protocol modules from . import rq from . import event if PY3: class bytesview(object): def __init__(self, data, offset=0, size=None): if size is None: size = len(data)-offset if isinstance(data, bytes): view = memoryview(data) elif isinstance(data, bytesview): view = data.view else: raise TypeError('unsupported type: {}'.format(type(data))) self.view = view[offset:offset+size] def __len__(self): return len(self.view) def __getitem__(self, key): if isinstance(key, slice): return bytes(self.view[key]) return self.view[key] else: def bytesview(data, offset=0, size=None): if not isinstance(data, (bytes, buffer)): raise TypeError('unsupported type: {}'.format(type(data))) if size is None: size = len(data)-offset return buffer(data, offset, size) class Display(object): extension_major_opcodes = {} error_classes = error.xerror_class.copy() event_classes = event.event_class.copy() def __init__(self, display = None): name, protocol, host, displayno, screenno = connect.get_display(display) self.display_name = name self.default_screen = screenno self.socket = connect.get_socket(name, protocol, host, displayno) auth_name, auth_data = connect.get_auth(self.socket, name, protocol, host, displayno) # Internal structures for communication, grouped # by their function and locks # Socket error indicator, set when the socket is closed # in one way or another self.socket_error_lock = lock.allocate_lock() self.socket_error = None # Event queue self.event_queue_read_lock = lock.allocate_lock() self.event_queue_write_lock = lock.allocate_lock() self.event_queue = [] # Unsent request queue and sequence number counter self.request_queue_lock = lock.allocate_lock() self.request_serial = 1 self.request_queue = [] # Send-and-receive loop, see function send_and_receive # for a detailed explanation self.send_recv_lock = lock.allocate_lock() self.send_active = 0 self.recv_active = 0 self.event_waiting = 0 self.event_wait_lock = lock.allocate_lock() self.request_waiting = 0 self.request_wait_lock = lock.allocate_lock() # Calculate optimal default buffer size for recv. buffer_size = self.socket.getsockopt(socket.SOL_SOCKET, socket.SO_RCVBUF) buffer_size = math.pow(2, math.floor(math.log(buffer_size, 2))) self.recv_buffer_size = int(buffer_size) # Data used by the send-and-receive loop self.sent_requests = [] self.recv_packet_len = 0 self.data_send = b'' self.data_recv = b'' self.data_sent_bytes = 0 # Resource ID structures self.resource_id_lock = lock.allocate_lock() self.resource_ids = {} self.last_resource_id = 0 # Use an default error handler, one which just prints the error self.error_handler = None # Right, now we're all set up for the connection setup # request with the server. # Figure out which endianness the hardware uses self.big_endian = struct.unpack('BB', struct.pack('H', 0x0100))[0] if self.big_endian: order = 0x42 else: order = 0x6c # Send connection setup r = ConnectionSetupRequest(self, byte_order = order, protocol_major = 11, protocol_minor = 0, auth_prot_name = auth_name, auth_prot_data = auth_data) # Did connection fail? if r.status != 1: raise error.DisplayConnectionError(self.display_name, r.reason) # Set up remaining info self.info = r self.default_screen = min(self.default_screen, len(self.info.roots) - 1) # # Public interface # def get_display_name(self): return self.display_name def get_default_screen(self): return self.default_screen def fileno(self): self.check_for_error() return self.socket.fileno() def next_event(self): self.check_for_error() # Main lock, so that only one thread at a time performs the # event waiting code. This at least guarantees that the first # thread calling next_event() will get the next event, although # no order is guaranteed among other threads calling next_event() # while the first is blocking. self.event_queue_read_lock.acquire() # Lock event queue, so we can check if it is empty self.event_queue_write_lock.acquire() # We have too loop until we get an event, as # we might be woken up when there is no event. while not self.event_queue: # Lock send_recv so no send_and_receive # can start or stop while we're checking # whether there are one active. self.send_recv_lock.acquire() # Release event queue to allow an send_and_recv to # insert any now. self.event_queue_write_lock.release() # Call send_and_recv, which will return when # something has occured self.send_and_recv(event = 1) # Before looping around, lock the event queue against # modifications. self.event_queue_write_lock.acquire() # Whiew, we have an event! Remove it from # the event queue and relaese its write lock. event = self.event_queue[0] del self.event_queue[0] self.event_queue_write_lock.release() # Finally, allow any other threads which have called next_event() # while we were waiting to proceed. self.event_queue_read_lock.release() # And return the event! return event def pending_events(self): self.check_for_error() # Make a send_and_recv pass, receiving any events self.send_recv_lock.acquire() self.send_and_recv(recv = 1) # Lock the queue, get the event count, and unlock again. self.event_queue_write_lock.acquire() count = len(self.event_queue) self.event_queue_write_lock.release() return count def flush(self): self.check_for_error() self.send_recv_lock.acquire() self.send_and_recv(flush = 1) def close(self): self.flush() self.close_internal('client') def set_error_handler(self, handler): self.error_handler = handler def allocate_resource_id(self): """id = d.allocate_resource_id() Allocate a new X resource id number ID. Raises ResourceIDError if there are no free resource ids. """ self.resource_id_lock.acquire() try: i = self.last_resource_id while i in self.resource_ids: i = i + 1 if i > self.info.resource_id_mask: i = 0 if i == self.last_resource_id: raise error.ResourceIDError('out of resource ids') self.resource_ids[i] = None self.last_resource_id = i return self.info.resource_id_base | i finally: self.resource_id_lock.release() def free_resource_id(self, rid): """d.free_resource_id(rid) Free resource id RID. Attempts to free a resource id which isn't allocated by us are ignored. """ self.resource_id_lock.acquire() try: i = rid & self.info.resource_id_mask # Attempting to free a resource id outside our range if rid - i != self.info.resource_id_base: return None try: del self.resource_ids[i] except KeyError: pass finally: self.resource_id_lock.release() def get_resource_class(self, class_name, default = None): """class = d.get_resource_class(class_name, default = None) Return the class to be used for X resource objects of type CLASS_NAME, or DEFAULT if no such class is set. """ return self.resource_classes.get(class_name, default) def set_extension_major(self, extname, major): self.extension_major_opcodes[extname] = major def get_extension_major(self, extname): return self.extension_major_opcodes[extname] def add_extension_event(self, code, evt, subcode=None): if subcode == None: self.event_classes[code] = evt else: if not code in self.event_classes: self.event_classes[code] = {subcode: evt} else: self.event_classes[code][subcode] = evt def add_extension_error(self, code, err): self.error_classes[code] = err # # Private functions # def check_for_error(self): self.socket_error_lock.acquire() err = self.socket_error self.socket_error_lock.release() if err: raise err def send_request(self, request, wait_for_response): if self.socket_error: raise self.socket_error self.request_queue_lock.acquire() request._serial = self.request_serial self.request_serial = (self.request_serial + 1) % 65536 self.request_queue.append((request, wait_for_response)) qlen = len(self.request_queue) self.request_queue_lock.release() # if qlen > 10: # self.flush() def close_internal(self, whom): # Clear out data structures self.request_queue = None self.sent_requests = None self.event_queue = None self.data_send = None self.data_recv = None # Close the connection self.socket.close() # Set a connection closed indicator self.socket_error_lock.acquire() self.socket_error = error.ConnectionClosedError(whom) self.socket_error_lock.release() def send_and_recv(self, flush = None, event = None, request = None, recv = None): """send_and_recv(flush = None, event = None, request = None, recv = None) Perform I/O, or wait for some other thread to do it for us. send_recv_lock MUST be LOCKED when send_and_recv is called. It will be UNLOCKED at return. Exactly or one of the parameters flush, event, request and recv must be set to control the return condition. To attempt to send all requests in the queue, flush should be true. Will return immediately if another thread is already doing send_and_recv. To wait for an event to be received, event should be true. To wait for a response to a certain request (either an error or a response), request should be set the that request's serial number. To just read any pending data from the server, recv should be true. It is not guaranteed that the return condition has been fulfilled when the function returns, so the caller has to loop until it is finished. """ # We go to sleep if there is already a thread doing what we # want to do: # If flushing, we want to send # If waiting for a response to a request, we want to send # (to ensure that the request was sent - we alway recv # when we get to the main loop, but sending is the important # thing here) # If waiting for an event, we want to recv # If just trying to receive anything we can, we want to recv # FIXME: It would be good if we could also sleep when we're waiting on # a response to a request that has already been sent. if (((flush or request is not None) and self.send_active) or ((event or recv) and self.recv_active)): # Signal that we are waiting for something. These locks # together with the *_waiting variables are used as # semaphores. When an event or a request response arrives, # it will zero the *_waiting and unlock the lock. The # locks will also be unlocked when an active send_and_recv # finishes to signal the other waiting threads that one of # them has to take over the send_and_recv function. # All this makes these locks and variables a part of the # send_and_recv control logic, and hence must be modified # only when we have the send_recv_lock locked. if event: wait_lock = self.event_wait_lock if not self.event_waiting: self.event_waiting = 1 wait_lock.acquire() elif request is not None: wait_lock = self.request_wait_lock if not self.request_waiting: self.request_waiting = 1 wait_lock.acquire() # Release send_recv, allowing a send_and_recive # to terminate or other threads to queue up self.send_recv_lock.release() # Return immediately if flushing, even if that # might mean that not necessarily all requests # have been sent. if flush or recv: return # Wait for something to happen, as the wait locks are # unlocked either when what we wait for has arrived (not # necessarily the exact object we're waiting for, though), # or when an active send_and_recv exits. # Release it immediately afterwards as we're only using # the lock for synchonization. Since we're not modifying # event_waiting or request_waiting here we don't have # to lock send_and_recv_lock. In fact, we can't do that # or we trigger a dead-lock. wait_lock.acquire() wait_lock.release() # Return to caller to let it check whether it has # got the data it was waiting for return # There's no thread doing what we need to do. Find out exactly # what to do # There must always be some thread receiving data, but it must not # necessarily be us if not self.recv_active: receiving = 1 self.recv_active = 1 else: receiving = 0 flush_bytes = None sending = 0 # Loop, receiving and sending data. while 1: # We might want to start sending data if sending or not self.send_active: # Turn all requests on request queue into binary form # and append them to self.data_send self.request_queue_lock.acquire() for req, wait in self.request_queue: self.data_send = self.data_send + req._binary if wait: self.sent_requests.append(req) del self.request_queue[:] self.request_queue_lock.release() # If there now is data to send, mark us as senders if self.data_send: self.send_active = 1 sending = 1 else: self.send_active = 0 sending = 0 # We've done all setup, so release the lock and start waiting # for the network to fire up self.send_recv_lock.release() # There's no longer anything useful we can do here. if not (sending or receiving): break # If we're flushing, figure out how many bytes we # have to send so that we're not caught in an interminable # loop if other threads continuously append requests. if flush and flush_bytes is None: flush_bytes = self.data_sent_bytes + len(self.data_send) try: # We're only checking for the socket to be writable # if we're the sending thread. We always check for it # to become readable: either we are the receiving thread # and should take care of the data, or the receiving thread # might finish receiving after having read the data if sending: writeset = [self.socket] else: writeset = [] # Timeout immediately if we're only checking for # something to read or if we're flushing, otherwise block if recv or flush: timeout = 0 else: timeout = None rs, ws, es = select.select([self.socket], writeset, [], timeout) # Ignore errors caused by a signal received while blocking. # All other errors are re-raised. except select.error as err: if isinstance(err, OSError): code = err.errno else: code = err[0] if code != errno.EINTR: raise # We must lock send_and_recv before we can loop to # the start of the loop self.send_recv_lock.acquire() continue # Socket is ready for sending data, send as much as possible. if ws: try: i = self.socket.send(self.data_send) except socket.error as err: self.close_internal('server: %s' % err) raise self.socket_error self.data_send = self.data_send[i:] self.data_sent_bytes = self.data_sent_bytes + i # There is data to read gotreq = 0 if rs: # We're the receiving thread, parse the data if receiving: try: count = self.recv_packet_len - len(self.data_recv) count = max(self.recv_buffer_size, count) bytes_recv = self.socket.recv(count) except socket.error as err: self.close_internal('server: %s' % err) raise self.socket_error if not bytes_recv: # Clear up, set a connection closed indicator and raise it self.close_internal('server') raise self.socket_error self.data_recv = bytes(self.data_recv) + bytes_recv gotreq = self.parse_response(request) # Otherwise return, allowing the calling thread to figure # out if it has got the data it needs else: # We must be a sending thread if we're here, so reset # that indicator. self.send_recv_lock.acquire() self.send_active = 0 self.send_recv_lock.release() # And return to the caller return # There are three different end of send-recv-loop conditions. # However, we don't leave the loop immediately, instead we # try to send and receive any data that might be left. We # do this by giving a timeout of 0 to select to poll # the socket. # When flushing: all requests have been sent if flush and flush_bytes >= self.data_sent_bytes: break # When waiting for an event: an event has been read if event and self.event_queue: break # When processing a certain request: got its reply if request is not None and gotreq: break # Always break if we just want to receive as much as possible if recv: break # Else there's may still data which must be sent, or # we haven't got the data we waited for. Lock and loop self.send_recv_lock.acquire() # We have accomplished the callers request. # Record that there are now no active send_and_recv, # and wake up all waiting thread self.send_recv_lock.acquire() if sending: self.send_active = 0 if receiving: self.recv_active = 0 if self.event_waiting: self.event_waiting = 0 self.event_wait_lock.release() if self.request_waiting: self.request_waiting = 0 self.request_wait_lock.release() self.send_recv_lock.release() def parse_response(self, request): """Internal method. Parse data received from server. If REQUEST is not None true is returned if the request with that serial number was received, otherwise false is returned. If REQUEST is -1, we're parsing the server connection setup response. """ if request == -1: return self.parse_connection_setup() # Parse ordinary server response gotreq = 0 while 1: if self.data_recv: # Check the first byte to find out what kind of response it is rtype = byte2int(self.data_recv) # Are we're waiting for additional data for the current packet? if self.recv_packet_len: if len(self.data_recv) < self.recv_packet_len: return gotreq if rtype == 1: gotreq = self.parse_request_response(request) or gotreq continue elif rtype & 0x7f == ge.GenericEventCode: self.parse_event_response(rtype) continue else: raise AssertionError(rtype) # Every response is at least 32 bytes long, so don't bother # until we have received that much if len(self.data_recv) < 32: return gotreq # Error response if rtype == 0: gotreq = self.parse_error_response(request) or gotreq # Request response or generic event. elif rtype == 1 or rtype & 0x7f == ge.GenericEventCode: # Set reply length, and loop around to see if # we have got the full response rlen = int(struct.unpack('=L', self.data_recv[4:8])[0]) self.recv_packet_len = 32 + rlen * 4 # Else non-generic event else: self.parse_event_response(rtype) def parse_error_response(self, request): # Code is second byte code = indexbytes(self.data_recv, 1) # Fetch error class estruct = self.error_classes.get(code, error.XError) e = estruct(self, self.data_recv[:32]) self.data_recv = bytesview(self.data_recv, 32) # print 'recv Error:', e req = self.get_waiting_request(e.sequence_number) # Error for a request whose response we are waiting for, # or which have an error handler. However, if the error # handler indicates that it hasn't taken care of the # error, pass it on to the default error handler if req and req._set_error(e): # If this was a ReplyRequest, unlock any threads waiting # for a request to finish if isinstance(req, rq.ReplyRequest): self.send_recv_lock.acquire() if self.request_waiting: self.request_waiting = 0 self.request_wait_lock.release() self.send_recv_lock.release() return request == e.sequence_number # Else call the error handler else: if self.error_handler: rq.call_error_handler(self.error_handler, e, None) else: self.default_error_handler(e) return 0 def default_error_handler(self, err): sys.stderr.write('X protocol error:\n%s\n' % err) def parse_request_response(self, request): req = self.get_waiting_replyrequest() # Sequence number is always data[2:4] # Do sanity check before trying to parse the data sno = struct.unpack('=H', self.data_recv[2:4])[0] if sno != req._serial: raise RuntimeError("Expected reply for request %s, but got %s. Can't happen!" % (req._serial, sno)) req._parse_response(self.data_recv[:self.recv_packet_len]) # print 'recv Request:', req self.data_recv = bytesview(self.data_recv, self.recv_packet_len) self.recv_packet_len = 0 # Unlock any response waiting threads self.send_recv_lock.acquire() if self.request_waiting: self.request_waiting = 0 self.request_wait_lock.release() self.send_recv_lock.release() return req.sequence_number == request def parse_event_response(self, etype): # Skip bit 8, that is set if this event came from an SendEvent etype = etype & 0x7f if etype == ge.GenericEventCode: length = self.recv_packet_len else: length = 32 estruct = self.event_classes.get(etype, event.AnyEvent) if type(estruct) == dict: subcode = self.data_recv[1] # Python2 compatibility if type(subcode) == str: subcode = ord(subcode) # this etype refers to a set of sub-events with individual subcodes estruct = estruct[subcode] e = estruct(display = self, binarydata = self.data_recv[:length]) if etype == ge.GenericEventCode: self.recv_packet_len = 0 self.data_recv = bytesview(self.data_recv, length) # Drop all requests having an error handler, # but which obviously succeded. # Decrement it by one, so that we don't remove the request # that generated these events, if there is such a one. # Bug reported by Ilpo Nyyssönen # Note: not all events have a sequence_number field! # (e.g. KeymapNotify). if hasattr(e, 'sequence_number'): self.get_waiting_request((e.sequence_number - 1) % 65536) # print 'recv Event:', e # Insert the event into the queue self.event_queue_write_lock.acquire() self.event_queue.append(e) self.event_queue_write_lock.release() # Unlock any event waiting threads self.send_recv_lock.acquire() if self.event_waiting: self.event_waiting = 0 self.event_wait_lock.release() self.send_recv_lock.release() def get_waiting_request(self, sno): if not self.sent_requests: return None # Normalize sequence numbers, even if they have wrapped. # This ensures that # sno <= last_serial # and # self.sent_requests[0]._serial <= last_serial if self.sent_requests[0]._serial > self.request_serial: last_serial = self.request_serial + 65536 if sno < self.request_serial: sno = sno + 65536 else: last_serial = self.request_serial if sno > self.request_serial: sno = sno - 65536 # No matching events at all if sno < self.sent_requests[0]._serial: return None # Find last req <= sno req = None reqpos = len(self.sent_requests) adj = 0 last = 0 for i in range(0, len(self.sent_requests)): rno = self.sent_requests[i]._serial + adj # Did serial numbers just wrap around? if rno < last: adj = 65536 rno = rno + adj last = rno if sno == rno: req = self.sent_requests[i] reqpos = i + 1 break elif sno < rno: req = None reqpos = i break # Delete all request such as req <= sno del self.sent_requests[:reqpos] return req def get_waiting_replyrequest(self): for i in range(0, len(self.sent_requests)): if hasattr(self.sent_requests[i], '_reply'): req = self.sent_requests[i] del self.sent_requests[:i + 1] return req # Reply for an unknown request? No, that can't happen. else: raise RuntimeError("Request reply to unknown request. Can't happen!") def parse_connection_setup(self): """Internal function used to parse connection setup response. """ # Only the ConnectionSetupRequest has been sent so far r = self.sent_requests[0] while 1: # print 'data_send:', repr(self.data_send) # print 'data_recv:', repr(self.data_recv) if r._data: alen = r._data['additional_length'] * 4 # The full response haven't arrived yet if len(self.data_recv) < alen: return 0 # Connection failed or further authentication is needed. # Set reason to the reason string if r._data['status'] != 1: r._data['reason'] = self.data_recv[:r._data['reason_length']] # Else connection succeeded, parse the reply else: x, d = r._success_reply.parse_binary(self.data_recv[:alen], self, rawdict = 1) r._data.update(x) del self.sent_requests[0] self.data_recv = self.data_recv[alen:] return 1 else: # The base reply is 8 bytes long if len(self.data_recv) < 8: return 0 r._data, d = r._reply.parse_binary(self.data_recv[:8], self, rawdict = 1) self.data_recv = self.data_recv[8:] # Loop around to see if we have got the additional data # already PixmapFormat = rq.Struct( rq.Card8('depth'), rq.Card8('bits_per_pixel'), rq.Card8('scanline_pad'), rq.Pad(5) ) VisualType = rq.Struct ( rq.Card32('visual_id'), rq.Card8('visual_class'), rq.Card8('bits_per_rgb_value'), rq.Card16('colormap_entries'), rq.Card32('red_mask'), rq.Card32('green_mask'), rq.Card32('blue_mask'), rq.Pad(4) ) Depth = rq.Struct( rq.Card8('depth'), rq.Pad(1), rq.LengthOf('visuals', 2), rq.Pad(4), rq.List('visuals', VisualType) ) Screen = rq.Struct( rq.Window('root'), rq.Colormap('default_colormap'), rq.Card32('white_pixel'), rq.Card32('black_pixel'), rq.Card32('current_input_mask'), rq.Card16('width_in_pixels'), rq.Card16('height_in_pixels'), rq.Card16('width_in_mms'), rq.Card16('height_in_mms'), rq.Card16('min_installed_maps'), rq.Card16('max_installed_maps'), rq.Card32('root_visual'), rq.Card8('backing_store'), rq.Card8('save_unders'), rq.Card8('root_depth'), rq.LengthOf('allowed_depths', 1), rq.List('allowed_depths', Depth) ) class ConnectionSetupRequest(rq.GetAttrData): _request = rq.Struct( rq.Set('byte_order', 1, (0x42, 0x6c)), rq.Pad(1), rq.Card16('protocol_major'), rq.Card16('protocol_minor'), rq.LengthOf('auth_prot_name', 2), rq.LengthOf('auth_prot_data', 2), rq.Pad(2), rq.String8('auth_prot_name'), rq.String8('auth_prot_data') ) _reply = rq.Struct ( rq.Card8('status'), rq.Card8('reason_length'), rq.Card16('protocol_major'), rq.Card16('protocol_minor'), rq.Card16('additional_length') ) _success_reply = rq.Struct( rq.Card32('release_number'), rq.Card32('resource_id_base'), rq.Card32('resource_id_mask'), rq.Card32('motion_buffer_size'), rq.LengthOf('vendor', 2), rq.Card16('max_request_length'), rq.LengthOf('roots', 1), rq.LengthOf('pixmap_formats', 1), rq.Card8('image_byte_order'), rq.Card8('bitmap_format_bit_order'), rq.Card8('bitmap_format_scanline_unit'), rq.Card8('bitmap_format_scanline_pad'), rq.Card8('min_keycode'), rq.Card8('max_keycode'), rq.Pad(4), rq.String8('vendor'), rq.List('pixmap_formats', PixmapFormat), rq.List('roots', Screen), ) def __init__(self, display, *args, **keys): self._binary = self._request.to_binary(*args, **keys) self._data = None # Don't bother about locking, since no other threads have # access to the display yet display.request_queue.append((self, 1)) # However, we must lock send_and_recv, but we don't have # to loop. display.send_recv_lock.acquire() display.send_and_recv(request = -1)