Ticket #3286: 0001-sl-3286.patch

File 0001-sl-3286.patch, 3.3 KB (added by ajay_garg, 12 years ago)

  • src/jarabe/model/filetransfer.py 

    From fb4ec2586d34d936613abf015de34e5913d2a294 Mon Sep 17 00:00:00 2001
From: Ajay Garg <ajay@activitycentral.com>
Date: Sat, 28 Jan 2012 14:08:56 +0530
Subject: [PATCH sugar v2] sl#3286: race condition fixed by making the read- and
 write- calls pseudo synchronous.
Organization: Sugar Labs Foundation
Signed-off-by: Ajay Garg <ajay@activitycentral.com>

---

Note that this patch is to be applied in full, and not over version-1 patch.



Changes of version-2 over version-1 :
-------------------------------------

a. Corrected the patch description (courtesy Sascha).

 src/jarabe/model/filetransfer.py |   37 +++++++++++++++++--------------------
 1 files changed, 17 insertions(+), 20 deletions(-)

diff --git a/src/jarabe/model/filetransfer.py b/src/jarabe/model/filetransfer.py
index 710c3a4..447a74a 100644
    a b class StreamSplicer(gobject.GObject): 
    7070
    7171        self._input_stream = input_stream
    7272        self._output_stream = output_stream
    73         self._pending_buffers = []
    7473
    7574    def start(self):
    7675        self._input_stream.read_async(self._CHUNK_SIZE, self.__read_async_cb,
    7776                                      gobject.PRIORITY_LOW)
    7877
     78    """
     79    Fix for bug sl#3286.
     80
     81    The workflow to read and write data has been made
     82    pseudo-synchronous.
     83    The "write_async" call is executed, after the execution
     84    of "read_async" call; and the "next" "read_async" call
     85    is executed, after the "current" "write_async" call has
     86    been completed.
     87    """
    7988    def __read_async_cb(self, input_stream, result):
    8089        data = input_stream.read_finish(result)
    8190
    8291        if not data:
    8392            logging.debug('closing input stream')
    8493            self._input_stream.close()
    85         else:
    86             self._pending_buffers.append(data)
    87             self._input_stream.read_async(self._CHUNK_SIZE,
    88                                             self.__read_async_cb,
    89                                             gobject.PRIORITY_LOW)
    90         self._write_next_buffer()
    91 
    92     def __write_async_cb(self, output_stream, result, user_data):
    93         count_ = output_stream.write_finish(result)
    94 
    95         if not self._pending_buffers and \
    96                 not self._output_stream.has_pending() and \
    97                 not self._input_stream.has_pending():
    9894            logging.debug('closing output stream')
    99             output_stream.close()
     95            self._output_stream.close()
    10096            self.emit('finished')
    10197        else:
    102             self._write_next_buffer()
    103 
    104     def _write_next_buffer(self):
    105         if self._pending_buffers and not self._output_stream.has_pending():
    106             data = self._pending_buffers.pop(0)
    10798            # TODO: we pass the buffer as user_data because of
    10899            # http://bugzilla.gnome.org/show_bug.cgi?id=564102
    109100            self._output_stream.write_async(data, self.__write_async_cb,
    110101                                            gobject.PRIORITY_LOW,
    111102                                            user_data=data)
    112103
     104    def __write_async_cb(self, output_stream, result, user_data):
     105        output_stream.write_finish(result)
     106        self._input_stream.read_async(self._CHUNK_SIZE,
     107                                      self.__read_async_cb,
     108                                      gobject.PRIORITY_LOW)
     109
    113110
    114111class BaseFileTransfer(gobject.GObject):
    115112