view .hgignore @ 44226:cb52e619c99e stable

worker: Use buffered input from the pickle stream

On Python 3, "pickle.load" will raise an exception ("_pickle.UnpicklingError:
pickle data was truncated") when it gets a short read, i.e. it receives fewer
bytes than it requested.

On our build machine, Mercurial seems to frequently hit this problem while
updating a mozilla-central clone iff it gets scheduled in batch mode. It is easy
to trigger with:

    #wipe the workdir
    rm -rf *
    hg update null

    chrt -b 0 hg update default

I've also written the following program, which demonstrates the core problem:

    from __future__ import print_function

    import io
    import os
    import pickle
    import time

    obj = {"a": 1, "b": 2}
    obj_data = pickle.dumps(obj)
    assert len(obj_data) > 10

    rfd, wfd = os.pipe()

    pid = os.fork()
    if pid == 0:
        os.close(rfd)

        for _ in range(4):
            time.sleep(0.5)
            print("First write")
            os.write(wfd, obj_data[:10])

            time.sleep(0.5)
            print("Second write")
            os.write(wfd, obj_data[10:])

        os._exit(0)

    try:
        os.close(wfd)

        rfile = os.fdopen(rfd, "rb", 0)

        print("Reading")
        while True:
            try:
                obj_copy = pickle.load(rfile)
                assert obj == obj_copy
            except EOFError:
                break
        print("Success")
    finally:
        os.kill(pid, 15)

The program reliably fails with Python 3.8 and succeeds with Python 2.7.

Providing the unpickler with a buffered reader fixes the issue, so let
"os.fdopen" create one.

https://bugzilla.mozilla.org/show_bug.cgi?id=1604486

Differential Revision: https://phab.mercurial-scm.org/D8051

syntax: glob

*.elc
*.tmp
*.orig
*.rej
*~
*.mergebackup
*.o
*.so
*.dll
*.exe
*.pyd
*.pyc
*.pyo
*$py.class
*.swp
*.prof
*.zip
\#*\#
.\#*
tests/artifacts/cache/big-file-churn.hg
tests/.coverage*
tests/.testtimes*
tests/.hypothesis
tests/hypothesis-generated
tests/annotated
tests/exceptions
tests/*.err
tests/htmlcov
build
contrib/chg/chg
contrib/hgsh/hgsh
contrib/vagrant/.vagrant
dist
packages
doc/common.txt
doc/*.[0-9]
doc/*.[0-9].txt
doc/*.[0-9].gendoc.txt
doc/*.[0-9].{x,ht}ml
MANIFEST
MANIFEST.in
patches
mercurial/__modulepolicy__.py
mercurial/__version__.py
mercurial/hgpythonlib.h
mercurial.egg-info
.DS_Store
tags
cscope.*
.idea/*
.asv/*
.pytype/*
i18n/hg.pot
locale/*/LC_MESSAGES/hg.mo
hgext/__index__.py

rust/target/
rust/*/target/

# Generated wheels
wheelhouse/

syntax: regexp
^\.pc/
^\.(pydev)?project

# hackable windows distribution additions
^hg-python
^hg.py$