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# Copyright (C) 2007 Canonical Ltd
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# Copyright (C) 2007, 2009, 2010 Canonical Ltd
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# Authors: Robert Collins <robert.collins@canonical.com>
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# This program is free software; you can redistribute it and/or modify
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# You should have received a copy of the GNU General Public License
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# along with this program; if not, write to the Free Software
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# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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"""Support for running strace against the current process."""
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from __future__ import absolute_import
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# this is currently test-focused, so importing bzrlib.tests is ok. We might
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# want to move feature to its own module though.
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from bzrlib.tests import Feature
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from bzrlib import errors
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def strace(function, *args, **kwargs):
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:return: a tuple: function-result, a StraceResult.
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return strace_detailed(function, args, kwargs)
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def strace_detailed(function, args, kwargs, follow_children=True):
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# FIXME: strace is buggy
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# (https://bugs.launchpad.net/ubuntu/+source/strace/+bug/103133) and the
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# test suite hangs if the '-f' is given to strace *and* more than one
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# thread is running. Using follow_children=False allows the test suite to
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# disable fork following to work around the bug.
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# capture strace output to a file
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log_file = tempfile.NamedTemporaryFile()
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log_file_fd = log_file.fileno()
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err_file = tempfile.NamedTemporaryFile()
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proc = subprocess.Popen(['strace',
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'-f', '-r', '-tt', '-p', str(pid), '-o', log_file.name
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stdout=subprocess.PIPE,
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stderr=subprocess.STDOUT)
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strace_cmd = ['strace', '-r', '-tt', '-p', str(pid), '-o', log_file.name]
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strace_cmd.append('-f')
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# need to catch both stdout and stderr to work around
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proc = subprocess.Popen(strace_cmd,
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stdout=subprocess.PIPE,
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stderr=err_file.fileno())
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# Wait for strace to attach
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attached_notice = proc.stdout.readline()
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# Run the function to strace
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log = log_file.read()
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return result, StraceResult(log)
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err_messages = err_file.read()
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if err_messages.startswith("attach: ptrace(PTRACE_ATTACH,"):
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raise StraceError(err_messages=err_messages)
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return result, StraceResult(log, err_messages)
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class StraceError(errors.BzrError):
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_fmt = "strace failed: %(err_messages)s"
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class StraceResult(object):
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"""The result of stracing a function."""
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def __init__(self, raw_log):
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def __init__(self, raw_log, err_messages):
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"""Create a StraceResult.
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:param raw_log: The output that strace created.
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self.raw_log = raw_log
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class _StraceFeature(Feature):
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proc = subprocess.Popen(['strace'],
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stderr=subprocess.PIPE,
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stdout=subprocess.PIPE)
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if e.errno == errno.ENOENT:
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# strace is not installed
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def feature_name(self):
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StraceFeature = _StraceFeature()
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self.err_messages = err_messages