##// END OF EJS Templates
worker: Use buffered input from the pickle stream...
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

File last commit:

r26421:4b0fc75f default
r44718:cb52e619 stable
Show More
README
39 lines | 1.7 KiB | text/plain | TextLexer
Mercurial for Plan 9 from Bell Labs
===================================
This directory contains support for Mercurial on Plan 9 from Bell Labs
platforms. It is assumed that the version of Python running on these
systems supports the ANSI/POSIX Environment (APE). At the time of this
writing, the bichued/python port is the most commonly installed version
of Python on these platforms. If a native port of Python is ever made,
some minor modification will need to be made to support some of the more
esoteric requirements of the platform rather than those currently made
(cf. posix.py).
By default, installations will have the factotum extension enabled; this
extension permits factotum(4) to act as an authentication agent for
HTTP repositories. Additionally, an extdiff command named 9diff is
enabled which generates diff(1) compatible output suitable for use with
the plumber(4).
Commit messages are plumbed using E if no editor is defined; users must
update the plumbed file to continue, otherwise the hg process must be
interrupted.
Some work remains with regard to documentation. Section 5 manual page
references for hgignore and hgrc need to be re-numbered to section 6 (file
formats) and a new man page writer should be written to support the
Plan 9 man macro set. Until these issues can be resolved, manual pages
are elided from the installation.
Basic install:
% mk install # do a system-wide install
% hg debuginstall # sanity-check setup
% hg # see help
A proto(2) file is included in this directory as an example of how a
binary distribution could be packaged, ostensibly with contrib(1).
See https://mercurial-scm.org/ for detailed installation
instructions, platform-specific notes, and Mercurial user information.