mirror of https://github.com/python/cpython
gh-89480: Document the gdb helpers (GH-115657)
Content adapted from https://devguide.python.org/development-tools/gdb/# and https://wiki.python.org/moin/DebuggingWithGdb. The original content on the Wiki page came from gdb debug help used by the Launchpad (https://launchpad.net/) team. Thanks to Anatoly Techtonik and user `rmf` for substantial improvements to the Wiki page. The history of the Devguide page follows (with log entries expanded for major content contributions): Hugo van Kemenade, Sat Dec 30 21:22:04 2023 +0200 Hugo van Kemenade, Fri Dec 8 12:04:32 2023 +0200 Erlend E. Aasland & Hugo van Kemenade, Tue Aug 8 22:05:34 2023 +0200 Satish Mishra, Sat Feb 11 13:54:57 2023 +0530 Hugo van Kemenade, Fri Dec 23 17:33:33 2022 +0200 Skip Montanaro, Hugo, Erlend, & Ezio, Fri Nov 4 05:04:23 2022 -0500 Add a GDB tips section to Advanced Tools (#977) Adam Turner, Wed Jun 15 21:19:23 2022 +0100 Adam Turner, Tue Jun 14 11:12:26 2022 +0100 Suriyaa, Fri Jun 8 19:39:23 2018 +0200 Jeff Allen, Tue Oct 24 18:12:53 2017 +0100 Jeff Allen, Fri Oct 13 13:43:43 2017 +0100 Mariatta, Wed Jan 4 09:14:55 2017 -0800 Carol Willing, Mon Sep 26 14:50:54 2016 -0700 Zachary Ware, Thu Jul 21 10:42:23 2016 -0500 Georg Brandl, Mon Nov 3 11:28:19 2014 +0100 Add instruction how to activate python-gdb.py Georg Brandl, Sun Mar 9 10:32:01 2014 +0100 Georg Brandl, Tue Apr 3 09:12:53 2012 +0200 Georg Brandl, Sat Mar 5 17:32:35 2011 +0100 Dave Malcolm, Fri Jan 21 12:34:09 2011 -0500 Add documentation on the gdb extension commands provided in libpython.py I adapted this from documentation I wrote for the Fedora wiki: https://fedoraproject.org/wiki/Features/EasierPythonDebugging#New_gdb_commands reformatting it as rst, and making other minor changes Brett Cannon, Thu Jan 20 15:16:52 2011 -0800 Dave Malcolm, Thu Jan 20 16:17:23 2011 -0500 Add some notes on the gdb pretty-printer hooks Antoine Pitrou, Thu Jan 20 21:17:49 2011 +0100 Give an example backtrace Antoine Pitrou, Thu Jan 20 21:03:06 2011 +0100 Expand explanations about gdb support Brett Cannon, Thu Jan 20 11:33:36 2011 -0800 Tweak the gdb support title to fit in better with the devguide. Brett Cannon, Mon Jan 17 21:12:54 2011 +0000 Short README on gdb support. Co-authored-by: Adam Turner <9087854+aa-turner@users.noreply.github.com> Co-authored-by: anatoly techtonik <techtonik@gmail.com> Co-authored-by: Antoine Pitrou <solipsis@pitrou.net> Co-authored-by: Brett Cannon <brett@python.org> Co-authored-by: Carol Willing <carolcode@willingconsulting.com> Co-authored-by: Dave Malcolm <dmalcolm@redhat.com> Co-authored-by: Erlend E. Aasland <erlend.aasland@protonmail.com> Co-authored-by: Ezio Melotti <ezio.melotti@gmail.com> Co-authored-by: Georg Brandl <georg@python.org> Co-authored-by: Hugo van Kemenade <1324225+hugovk@users.noreply.github.com> Co-authored-by: Jeff Allen <ja.py@farowl.co.uk> Co-authored-by: Mariatta <Mariatta@users.noreply.github.com> Co-authored-by: Petr Viktorin <encukou@gmail.com> Co-authored-by: Satish Mishra <7506satish@gmail.com> Co-authored-by: Skip Montanaro <skip.montanaro@gmail.com> Co-authored-by: Suriyaa <isc.suriyaa@gmail.com> Co-authored-by: Zachary Ware <zachary.ware@gmail.com>
This commit is contained in:
Pablo Galindo Salgado
GitHub
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.. _gdb:
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=========================================================
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Debugging C API extensions and CPython Internals with GDB
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=========================================================
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.. highlight:: none
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This document explains how the Python GDB extension, ``python-gdb.py``, can
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be used with the GDB debugger to debug CPython extensions and the
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CPython interpreter itself.
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When debugging low-level problems such as crashes or deadlocks, a low-level
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debugger, such as GDB, is useful to diagnose and correct the issue.
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By default, GDB (or any of its front-ends) doesn't support high-level
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information specific to the CPython interpreter.
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The ``python-gdb.py`` extension adds CPython interpreter information to GDB.
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The extension helps introspect the stack of currently executing Python functions.
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Given a Python object represented by a :c:expr:`PyObject *` pointer,
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the extension surfaces the type and value of the object.
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Developers who are working on CPython extensions or tinkering with parts
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of CPython that are written in C can use this document to learn how to use the
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``python-gdb.py`` extension with GDB.
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.. note::
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This document assumes that you are familiar with the basics of GDB and the
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CPython C API. It consolidates guidance from the
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`devguide <https://devguide.python.org>`_ and the
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`Python wiki <https://wiki.python.org/moin/DebuggingWithGdb>`_.
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Prerequisites
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=============
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You need to have:
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- GDB 7 or later. (For earlier versions of GDB, see ``Misc/gdbinit`` in the
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sources of Python 3.11 or earlier.)
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- GDB-compatible debugging information for Python and any extension you are
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debugging.
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- The ``python-gdb.py`` extension.
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The extension is built with Python, but might be distributed separately or
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not at all. Below, we include tips for a few common systems as examples.
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Note that even if the instructions match your system, they might be outdated.
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Setup with Python built from source
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-----------------------------------
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When you build CPython from source, debugging information should be available,
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and the build should add a ``python-gdb.py`` file to the root directory of
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your repository.
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To activate support, you must add the directory containing ``python-gdb.py``
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to GDB's "auto-load-safe-path".
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If you haven't done this, recent versions of GDB will print out a warning
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with instructions on how to do this.
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.. note::
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If you do not see instructions for your version of GDB, put this in your
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configuration file (``~/.gdbinit`` or ``~/.config/gdb/gdbinit``)::
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add-auto-load-safe-path /path/to/cpython
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You can also add multiple paths, separated by ``:``.
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Setup for Python from a Linux distro
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------------------------------------
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Most Linux systems provide debug information for the system Python
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in a package called ``python-debuginfo``, ``python-dbg`` or similar.
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For example:
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- Fedora:
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.. code-block:: shell
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sudo dnf install gdb
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sudo dnf debuginfo-install python3
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- Ubuntu:
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.. code-block:: shell
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sudo apt install gdb python3-dbg
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On several recent Linux systems, GDB can download debugging symbols
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automatically using *debuginfod*.
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However, this will not install the ``python-gdb.py`` extension;
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you generally do need to install the debug info package separately.
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Using the Debug build and Development mode
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==========================================
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For easier debugging, you might want to:
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- Use a :ref:`debug build <debug-build>` of Python. (When building from source,
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use ``configure --with-pydebug``. On Linux distros, install and run a package
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like ``python-debug`` or ``python-dbg``, if available.)
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- Use the runtime :ref:`development mode <devmode>` (``-X dev``).
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Both enable extra assertions and disable some optimizations.
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Sometimes this hides the bug you are trying to find, but in most cases they
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make the process easier.
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Using the ``python-gdb`` extension
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==================================
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When the extension is loaded, it provides two main features:
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pretty printers for Python values, and additional commands.
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Pretty-printers
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---------------
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This is what a GDB backtrace looks like (truncated) when this extension is
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enabled::
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#0 0x000000000041a6b1 in PyObject_Malloc (nbytes=Cannot access memory at address 0x7fffff7fefe8
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) at Objects/obmalloc.c:748
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#1 0x000000000041b7c0 in _PyObject_DebugMallocApi (id=111 'o', nbytes=24) at Objects/obmalloc.c:1445
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#2 0x000000000041b717 in _PyObject_DebugMalloc (nbytes=24) at Objects/obmalloc.c:1412
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#3 0x000000000044060a in _PyUnicode_New (length=11) at Objects/unicodeobject.c:346
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#4 0x00000000004466aa in PyUnicodeUCS2_DecodeUTF8Stateful (s=0x5c2b8d "__lltrace__", size=11, errors=0x0, consumed=
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0x0) at Objects/unicodeobject.c:2531
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#5 0x0000000000446647 in PyUnicodeUCS2_DecodeUTF8 (s=0x5c2b8d "__lltrace__", size=11, errors=0x0)
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at Objects/unicodeobject.c:2495
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#6 0x0000000000440d1b in PyUnicodeUCS2_FromStringAndSize (u=0x5c2b8d "__lltrace__", size=11)
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at Objects/unicodeobject.c:551
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#7 0x0000000000440d94 in PyUnicodeUCS2_FromString (u=0x5c2b8d "__lltrace__") at Objects/unicodeobject.c:569
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#8 0x0000000000584abd in PyDict_GetItemString (v=
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{'Yuck': <type at remote 0xad4730>, '__builtins__': <module at remote 0x7ffff7fd5ee8>, '__file__': 'Lib/test/crashers/nasty_eq_vs_dict.py', '__package__': None, 'y': <Yuck(i=0) at remote 0xaacd80>, 'dict': {0: 0, 1: 1, 2: 2, 3: 3}, '__cached__': None, '__name__': '__main__', 'z': <Yuck(i=0) at remote 0xaace60>, '__doc__': None}, key=
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0x5c2b8d "__lltrace__") at Objects/dictobject.c:2171
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Notice how the dictionary argument to ``PyDict_GetItemString`` is displayed
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as its ``repr()``, rather than an opaque ``PyObject *`` pointer.
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The extension works by supplying a custom printing routine for values of type
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``PyObject *``. If you need to access lower-level details of an object, then
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cast the value to a pointer of the appropriate type. For example::
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(gdb) p globals
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$1 = {'__builtins__': <module at remote 0x7ffff7fb1868>, '__name__':
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'__main__', 'ctypes': <module at remote 0x7ffff7f14360>, '__doc__': None,
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'__package__': None}
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(gdb) p *(PyDictObject*)globals
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$2 = {ob_refcnt = 3, ob_type = 0x3dbdf85820, ma_fill = 5, ma_used = 5,
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ma_mask = 7, ma_table = 0x63d0f8, ma_lookup = 0x3dbdc7ea70
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<lookdict_string>, ma_smalltable = {{me_hash = 7065186196740147912,
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me_key = '__builtins__', me_value = <module at remote 0x7ffff7fb1868>},
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{me_hash = -368181376027291943, me_key = '__name__',
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me_value ='__main__'}, {me_hash = 0, me_key = 0x0, me_value = 0x0},
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{me_hash = 0, me_key = 0x0, me_value = 0x0},
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{me_hash = -9177857982131165996, me_key = 'ctypes',
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me_value = <module at remote 0x7ffff7f14360>},
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{me_hash = -8518757509529533123, me_key = '__doc__', me_value = None},
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{me_hash = 0, me_key = 0x0, me_value = 0x0}, {
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me_hash = 6614918939584953775, me_key = '__package__', me_value = None}}}
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Note that the pretty-printers do not actually call ``repr()``.
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For basic types, they try to match its result closely.
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An area that can be confusing is that the custom printer for some types look a
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lot like GDB's built-in printer for standard types. For example, the
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pretty-printer for a Python ``int`` (:c:expr:`PyLongObject *`)
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gives a representation that is not distinguishable from one of a
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regular machine-level integer::
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(gdb) p some_machine_integer
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$3 = 42
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(gdb) p some_python_integer
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$4 = 42
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The internal structure can be revealed with a cast to :c:expr:`PyLongObject *`:
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(gdb) p *(PyLongObject*)some_python_integer
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$5 = {ob_base = {ob_base = {ob_refcnt = 8, ob_type = 0x3dad39f5e0}, ob_size = 1},
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ob_digit = {42}}
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A similar confusion can arise with the ``str`` type, where the output looks a
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lot like gdb's built-in printer for ``char *``::
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(gdb) p ptr_to_python_str
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$6 = '__builtins__'
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The pretty-printer for ``str`` instances defaults to using single-quotes (as
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does Python's ``repr`` for strings) whereas the standard printer for ``char *``
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values uses double-quotes and contains a hexadecimal address::
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(gdb) p ptr_to_char_star
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$7 = 0x6d72c0 "hello world"
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Again, the implementation details can be revealed with a cast to
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:c:expr:`PyUnicodeObject *`::
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(gdb) p *(PyUnicodeObject*)$6
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$8 = {ob_base = {ob_refcnt = 33, ob_type = 0x3dad3a95a0}, length = 12,
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str = 0x7ffff2128500, hash = 7065186196740147912, state = 1, defenc = 0x0}
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``py-list``
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-----------
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The extension adds a ``py-list`` command, which
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lists the Python source code (if any) for the current frame in the selected
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thread. The current line is marked with a ">"::
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(gdb) py-list
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901 if options.profile:
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902 options.profile = False
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903 profile_me()
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904 return
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905
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>906 u = UI()
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907 if not u.quit:
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908 try:
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909 gtk.main()
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910 except KeyboardInterrupt:
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911 # properly quit on a keyboard interrupt...
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Use ``py-list START`` to list at a different line number within the Python
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source, and ``py-list START,END`` to list a specific range of lines within
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the Python source.
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``py-up`` and ``py-down``
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-------------------------
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The ``py-up`` and ``py-down`` commands are analogous to GDB's regular ``up``
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and ``down`` commands, but try to move at the level of CPython frames, rather
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than C frames.
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GDB is not always able to read the relevant frame information, depending on
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the optimization level with which CPython was compiled. Internally, the
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commands look for C frames that are executing the default frame evaluation
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function (that is, the core bytecode interpreter loop within CPython) and
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look up the value of the related ``PyFrameObject *``.
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They emit the frame number (at the C level) within the thread.
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For example::
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(gdb) py-up
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#37 Frame 0x9420b04, for file /usr/lib/python2.6/site-packages/
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gnome_sudoku/main.py, line 906, in start_game ()
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u = UI()
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(gdb) py-up
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#40 Frame 0x948e82c, for file /usr/lib/python2.6/site-packages/
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gnome_sudoku/gnome_sudoku.py, line 22, in start_game(main=<module at remote 0xb771b7f4>)
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main.start_game()
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(gdb) py-up
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Unable to find an older python frame
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so we're at the top of the Python stack.
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The frame numbers correspond to those displayed by GDB's standard
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``backtrace`` command.
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The command skips C frames which are not executing Python code.
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Going back down::
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(gdb) py-down
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#37 Frame 0x9420b04, for file /usr/lib/python2.6/site-packages/gnome_sudoku/main.py, line 906, in start_game ()
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u = UI()
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(gdb) py-down
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#34 (unable to read python frame information)
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(gdb) py-down
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#23 (unable to read python frame information)
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(gdb) py-down
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#19 (unable to read python frame information)
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(gdb) py-down
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#14 Frame 0x99262ac, for file /usr/lib/python2.6/site-packages/gnome_sudoku/game_selector.py, line 201, in run_swallowed_dialog (self=<NewOrSavedGameSelector(new_game_model=<gtk.ListStore at remote 0x98fab44>, puzzle=None, saved_games=[{'gsd.auto_fills': 0, 'tracking': {}, 'trackers': {}, 'notes': [], 'saved_at': 1270084485, 'game': '7 8 0 0 0 0 0 5 6 0 0 9 0 8 0 1 0 0 0 4 6 0 0 0 0 7 0 6 5 0 0 0 4 7 9 2 0 0 0 9 0 1 0 0 0 3 9 7 6 0 0 0 1 8 0 6 0 0 0 0 2 8 0 0 0 5 0 4 0 6 0 0 2 1 0 0 0 0 0 4 5\n7 8 0 0 0 0 0 5 6 0 0 9 0 8 0 1 0 0 0 4 6 0 0 0 0 7 0 6 5 1 8 3 4 7 9 2 0 0 0 9 0 1 0 0 0 3 9 7 6 0 0 0 1 8 0 6 0 0 0 0 2 8 0 0 0 5 0 4 0 6 0 0 2 1 0 0 0 0 0 4 5', 'gsd.impossible_hints': 0, 'timer.__absolute_start_time__': <float at remote 0x984b474>, 'gsd.hints': 0, 'timer.active_time': <float at remote 0x984b494>, 'timer.total_time': <float at remote 0x984b464>}], dialog=<gtk.Dialog at remote 0x98faaa4>, saved_game_model=<gtk.ListStore at remote 0x98fad24>, sudoku_maker=<SudokuMaker(terminated=False, played=[], batch_siz...(truncated)
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swallower.run_dialog(self.dialog)
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(gdb) py-down
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#11 Frame 0x9aead74, for file /usr/lib/python2.6/site-packages/gnome_sudoku/dialog_swallower.py, line 48, in run_dialog (self=<SwappableArea(running=<gtk.Dialog at remote 0x98faaa4>, main_page=0) at remote 0x98fa6e4>, d=<gtk.Dialog at remote 0x98faaa4>)
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gtk.main()
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(gdb) py-down
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#8 (unable to read python frame information)
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(gdb) py-down
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Unable to find a newer python frame
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and we're at the bottom of the Python stack.
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Note that in Python 3.12 and newer, the same C stack frame can be used for
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multiple Python stack frames. This means that ``py-up`` and ``py-down``
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may move multiple Python frames at once. For example::
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(gdb) py-up
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#6 Frame 0x7ffff7fb62b0, for file /tmp/rec.py, line 5, in recursive_function (n=0)
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time.sleep(5)
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#6 Frame 0x7ffff7fb6240, for file /tmp/rec.py, line 7, in recursive_function (n=1)
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recursive_function(n-1)
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#6 Frame 0x7ffff7fb61d0, for file /tmp/rec.py, line 7, in recursive_function (n=2)
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recursive_function(n-1)
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#6 Frame 0x7ffff7fb6160, for file /tmp/rec.py, line 7, in recursive_function (n=3)
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recursive_function(n-1)
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#6 Frame 0x7ffff7fb60f0, for file /tmp/rec.py, line 7, in recursive_function (n=4)
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recursive_function(n-1)
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#6 Frame 0x7ffff7fb6080, for file /tmp/rec.py, line 7, in recursive_function (n=5)
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recursive_function(n-1)
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#6 Frame 0x7ffff7fb6020, for file /tmp/rec.py, line 9, in <module> ()
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recursive_function(5)
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(gdb) py-up
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Unable to find an older python frame
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``py-bt``
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---------
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The ``py-bt`` command attempts to display a Python-level backtrace of the
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current thread.
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For example::
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(gdb) py-bt
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#8 (unable to read python frame information)
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#11 Frame 0x9aead74, for file /usr/lib/python2.6/site-packages/gnome_sudoku/dialog_swallower.py, line 48, in run_dialog (self=<SwappableArea(running=<gtk.Dialog at remote 0x98faaa4>, main_page=0) at remote 0x98fa6e4>, d=<gtk.Dialog at remote 0x98faaa4>)
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gtk.main()
|
||||
#14 Frame 0x99262ac, for file /usr/lib/python2.6/site-packages/gnome_sudoku/game_selector.py, line 201, in run_swallowed_dialog (self=<NewOrSavedGameSelector(new_game_model=<gtk.ListStore at remote 0x98fab44>, puzzle=None, saved_games=[{'gsd.auto_fills': 0, 'tracking': {}, 'trackers': {}, 'notes': [], 'saved_at': 1270084485, 'game': '7 8 0 0 0 0 0 5 6 0 0 9 0 8 0 1 0 0 0 4 6 0 0 0 0 7 0 6 5 0 0 0 4 7 9 2 0 0 0 9 0 1 0 0 0 3 9 7 6 0 0 0 1 8 0 6 0 0 0 0 2 8 0 0 0 5 0 4 0 6 0 0 2 1 0 0 0 0 0 4 5\n7 8 0 0 0 0 0 5 6 0 0 9 0 8 0 1 0 0 0 4 6 0 0 0 0 7 0 6 5 1 8 3 4 7 9 2 0 0 0 9 0 1 0 0 0 3 9 7 6 0 0 0 1 8 0 6 0 0 0 0 2 8 0 0 0 5 0 4 0 6 0 0 2 1 0 0 0 0 0 4 5', 'gsd.impossible_hints': 0, 'timer.__absolute_start_time__': <float at remote 0x984b474>, 'gsd.hints': 0, 'timer.active_time': <float at remote 0x984b494>, 'timer.total_time': <float at remote 0x984b464>}], dialog=<gtk.Dialog at remote 0x98faaa4>, saved_game_model=<gtk.ListStore at remote 0x98fad24>, sudoku_maker=<SudokuMaker(terminated=False, played=[], batch_siz...(truncated)
|
||||
swallower.run_dialog(self.dialog)
|
||||
#19 (unable to read python frame information)
|
||||
#23 (unable to read python frame information)
|
||||
#34 (unable to read python frame information)
|
||||
#37 Frame 0x9420b04, for file /usr/lib/python2.6/site-packages/gnome_sudoku/main.py, line 906, in start_game ()
|
||||
u = UI()
|
||||
#40 Frame 0x948e82c, for file /usr/lib/python2.6/site-packages/gnome_sudoku/gnome_sudoku.py, line 22, in start_game (main=<module at remote 0xb771b7f4>)
|
||||
main.start_game()
|
||||
|
||||
The frame numbers correspond to those displayed by GDB's standard
|
||||
``backtrace`` command.
|
||||
|
||||
``py-print``
|
||||
------------
|
||||
|
||||
The ``py-print`` command looks up a Python name and tries to print it.
|
||||
It looks in locals within the current thread, then globals, then finally
|
||||
builtins::
|
||||
|
||||
(gdb) py-print self
|
||||
local 'self' = <SwappableArea(running=<gtk.Dialog at remote 0x98faaa4>,
|
||||
main_page=0) at remote 0x98fa6e4>
|
||||
(gdb) py-print __name__
|
||||
global '__name__' = 'gnome_sudoku.dialog_swallower'
|
||||
(gdb) py-print len
|
||||
builtin 'len' = <built-in function len>
|
||||
(gdb) py-print scarlet_pimpernel
|
||||
'scarlet_pimpernel' not found
|
||||
|
||||
If the current C frame corresponds to multiple Python frames, ``py-print``
|
||||
only considers the first one.
|
||||
|
||||
``py-locals``
|
||||
-------------
|
||||
|
||||
The ``py-locals`` command looks up all Python locals within the current
|
||||
Python frame in the selected thread, and prints their representations::
|
||||
|
||||
(gdb) py-locals
|
||||
self = <SwappableArea(running=<gtk.Dialog at remote 0x98faaa4>,
|
||||
main_page=0) at remote 0x98fa6e4>
|
||||
d = <gtk.Dialog at remote 0x98faaa4>
|
||||
|
||||
If the current C frame corresponds to multiple Python frames, locals from
|
||||
all of them will be shown::
|
||||
|
||||
(gdb) py-locals
|
||||
Locals for recursive_function
|
||||
n = 0
|
||||
Locals for recursive_function
|
||||
n = 1
|
||||
Locals for recursive_function
|
||||
n = 2
|
||||
Locals for recursive_function
|
||||
n = 3
|
||||
Locals for recursive_function
|
||||
n = 4
|
||||
Locals for recursive_function
|
||||
n = 5
|
||||
Locals for <module>
|
||||
|
||||
|
||||
Use with GDB commands
|
||||
=====================
|
||||
|
||||
The extension commands complement GDB's built-in commands.
|
||||
For example, you can use a frame numbers shown by ``py-bt`` with the ``frame``
|
||||
command to go a specific frame within the selected thread, like this::
|
||||
|
||||
(gdb) py-bt
|
||||
(output snipped)
|
||||
#68 Frame 0xaa4560, for file Lib/test/regrtest.py, line 1548, in <module> ()
|
||||
main()
|
||||
(gdb) frame 68
|
||||
#68 0x00000000004cd1e6 in PyEval_EvalFrameEx (f=Frame 0xaa4560, for file Lib/test/regrtest.py, line 1548, in <module> (), throwflag=0) at Python/ceval.c:2665
|
||||
2665 x = call_function(&sp, oparg);
|
||||
(gdb) py-list
|
||||
1543 # Run the tests in a context manager that temporary changes the CWD to a
|
||||
1544 # temporary and writable directory. If it's not possible to create or
|
||||
1545 # change the CWD, the original CWD will be used. The original CWD is
|
||||
1546 # available from test_support.SAVEDCWD.
|
||||
1547 with test_support.temp_cwd(TESTCWD, quiet=True):
|
||||
>1548 main()
|
||||
|
||||
The ``info threads`` command will give you a list of the threads within the
|
||||
process, and you can use the ``thread`` command to select a different one::
|
||||
|
||||
(gdb) info threads
|
||||
105 Thread 0x7fffefa18710 (LWP 10260) sem_wait () at ../nptl/sysdeps/unix/sysv/linux/x86_64/sem_wait.S:86
|
||||
104 Thread 0x7fffdf5fe710 (LWP 10259) sem_wait () at ../nptl/sysdeps/unix/sysv/linux/x86_64/sem_wait.S:86
|
||||
* 1 Thread 0x7ffff7fe2700 (LWP 10145) 0x00000038e46d73e3 in select () at ../sysdeps/unix/syscall-template.S:82
|
||||
|
||||
You can use ``thread apply all COMMAND`` or (``t a a COMMAND`` for short) to run
|
||||
a command on all threads. With ``py-bt``, this lets you see what every
|
||||
thread is doing at the Python level::
|
||||
|
||||
(gdb) t a a py-bt
|
||||
|
||||
Thread 105 (Thread 0x7fffefa18710 (LWP 10260)):
|
||||
#5 Frame 0x7fffd00019d0, for file /home/david/coding/python-svn/Lib/threading.py, line 155, in _acquire_restore (self=<_RLock(_Verbose__verbose=False, _RLock__owner=140737354016512, _RLock__block=<thread.lock at remote 0x858770>, _RLock__count=1) at remote 0xd7ff40>, count_owner=(1, 140737213728528), count=1, owner=140737213728528)
|
||||
self.__block.acquire()
|
||||
#8 Frame 0x7fffac001640, for file /home/david/coding/python-svn/Lib/threading.py, line 269, in wait (self=<_Condition(_Condition__lock=<_RLock(_Verbose__verbose=False, _RLock__owner=140737354016512, _RLock__block=<thread.lock at remote 0x858770>, _RLock__count=1) at remote 0xd7ff40>, acquire=<instancemethod at remote 0xd80260>, _is_owned=<instancemethod at remote 0xd80160>, _release_save=<instancemethod at remote 0xd803e0>, release=<instancemethod at remote 0xd802e0>, _acquire_restore=<instancemethod at remote 0xd7ee60>, _Verbose__verbose=False, _Condition__waiters=[]) at remote 0xd7fd10>, timeout=None, waiter=<thread.lock at remote 0x858a90>, saved_state=(1, 140737213728528))
|
||||
self._acquire_restore(saved_state)
|
||||
#12 Frame 0x7fffb8001a10, for file /home/david/coding/python-svn/Lib/test/lock_tests.py, line 348, in f ()
|
||||
cond.wait()
|
||||
#16 Frame 0x7fffb8001c40, for file /home/david/coding/python-svn/Lib/test/lock_tests.py, line 37, in task (tid=140737213728528)
|
||||
f()
|
||||
|
||||
Thread 104 (Thread 0x7fffdf5fe710 (LWP 10259)):
|
||||
#5 Frame 0x7fffe4001580, for file /home/david/coding/python-svn/Lib/threading.py, line 155, in _acquire_restore (self=<_RLock(_Verbose__verbose=False, _RLock__owner=140737354016512, _RLock__block=<thread.lock at remote 0x858770>, _RLock__count=1) at remote 0xd7ff40>, count_owner=(1, 140736940992272), count=1, owner=140736940992272)
|
||||
self.__block.acquire()
|
||||
#8 Frame 0x7fffc8002090, for file /home/david/coding/python-svn/Lib/threading.py, line 269, in wait (self=<_Condition(_Condition__lock=<_RLock(_Verbose__verbose=False, _RLock__owner=140737354016512, _RLock__block=<thread.lock at remote 0x858770>, _RLock__count=1) at remote 0xd7ff40>, acquire=<instancemethod at remote 0xd80260>, _is_owned=<instancemethod at remote 0xd80160>, _release_save=<instancemethod at remote 0xd803e0>, release=<instancemethod at remote 0xd802e0>, _acquire_restore=<instancemethod at remote 0xd7ee60>, _Verbose__verbose=False, _Condition__waiters=[]) at remote 0xd7fd10>, timeout=None, waiter=<thread.lock at remote 0x858860>, saved_state=(1, 140736940992272))
|
||||
self._acquire_restore(saved_state)
|
||||
#12 Frame 0x7fffac001c90, for file /home/david/coding/python-svn/Lib/test/lock_tests.py, line 348, in f ()
|
||||
cond.wait()
|
||||
#16 Frame 0x7fffac0011c0, for file /home/david/coding/python-svn/Lib/test/lock_tests.py, line 37, in task (tid=140736940992272)
|
||||
f()
|
||||
|
||||
Thread 1 (Thread 0x7ffff7fe2700 (LWP 10145)):
|
||||
#5 Frame 0xcb5380, for file /home/david/coding/python-svn/Lib/test/lock_tests.py, line 16, in _wait ()
|
||||
time.sleep(0.01)
|
||||
#8 Frame 0x7fffd00024a0, for file /home/david/coding/python-svn/Lib/test/lock_tests.py, line 378, in _check_notify (self=<ConditionTests(_testMethodName='test_notify', _resultForDoCleanups=<TestResult(_original_stdout=<cStringIO.StringO at remote 0xc191e0>, skipped=[], _mirrorOutput=False, testsRun=39, buffer=False, _original_stderr=<file at remote 0x7ffff7fc6340>, _stdout_buffer=<cStringIO.StringO at remote 0xc9c7f8>, _stderr_buffer=<cStringIO.StringO at remote 0xc9c790>, _moduleSetUpFailed=False, expectedFailures=[], errors=[], _previousTestClass=<type at remote 0x928310>, unexpectedSuccesses=[], failures=[], shouldStop=False, failfast=False) at remote 0xc185a0>, _threads=(0,), _cleanups=[], _type_equality_funcs={<type at remote 0x7eba00>: <instancemethod at remote 0xd750e0>, <type at remote 0x7e7820>: <instancemethod at remote 0xd75160>, <type at remote 0x7e30e0>: <instancemethod at remote 0xd75060>, <type at remote 0x7e7d20>: <instancemethod at remote 0xd751e0>, <type at remote 0x7f19e0...(truncated)
|
||||
_wait()
|
||||
|
|
@ -16,6 +16,7 @@ Currently, the HOWTOs are:
|
|||
cporting.rst
|
||||
curses.rst
|
||||
descriptor.rst
|
||||
gdb_helpers.rst
|
||||
enum.rst
|
||||
functional.rst
|
||||
logging.rst
|
||||
|
|
|
|||
Loading…
Reference in New Issue