Mercurial > hg
view tests/test-pull-pull-corruption.t @ 31063:18fb3cf572b4 stable
worker: ignore meaningless exit status indication returned by os.waitpid()
Before this patch, worker implementation assumes that os.waitpid()
with os.WNOHANG returns '(0, 0)' for still running child process. This
is explicitly specified as below in Python API document.
os.WNOHANG
The option for waitpid() to return immediately if no child
process status is available immediately. The function returns
(0, 0) in this case.
On the other hand, POSIX specification doesn't define the "stat_loc"
value returned by waitpid() with WNOHANG for such child process.
http://pubs.opengroup.org/onlinepubs/9699919799/functions/waitpid.html
CPython implementation for os.waitpid() on POSIX doesn't take any care
of this gap, and this may cause unexpected "exit status indication"
even on POSIX conformance platform.
For example, os.waitpid() with os.WNOHANG returns non-zero "exit
status indication" on FreeBSD. This implies os.kill() with own pid or
sys.exit() with non-zero exit code, even if no child process fails.
To ignore meaningless exit status indication returned by os.waitpid(),
this patch skips subsequent steps forcibly, if os.waitpid() returns 0
as pid.
This patch also arranges examination of 'p' value for readability.
FYI, there are some issues below about this behavior reported for
CPython.
https://bugs.python.org/issue21791
https://bugs.python.org/issue27808
author | FUJIWARA Katsunori <foozy@lares.dti.ne.jp> |
---|---|
date | Sat, 25 Feb 2017 01:07:52 +0900 |
parents | f2719b387380 |
children | eb586ed5d8ce |
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Corrupt an hg repo with two pulls. create one repo with a long history $ hg init source1 $ cd source1 $ touch foo $ hg add foo $ for i in 1 2 3 4 5 6 7 8 9 10; do > echo $i >> foo > hg ci -m $i > done $ cd .. create one repo with a shorter history $ hg clone -r 0 source1 source2 adding changesets adding manifests adding file changes added 1 changesets with 1 changes to 1 files updating to branch default 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ cd source2 $ echo a >> foo $ hg ci -m a $ cd .. create a third repo to pull both other repos into it $ hg init corrupted $ cd corrupted use a hook to make the second pull start while the first one is still running $ echo '[hooks]' >> .hg/hgrc $ echo 'prechangegroup = sleep 5' >> .hg/hgrc start a pull... $ hg pull ../source1 > pull.out 2>&1 & ... and start another pull before the first one has finished $ sleep 1 $ hg pull ../source2 2>/dev/null pulling from ../source2 searching for changes adding changesets adding manifests adding file changes added 1 changesets with 1 changes to 1 files (+1 heads) (run 'hg heads' to see heads, 'hg merge' to merge) $ cat pull.out pulling from ../source1 requesting all changes adding changesets adding manifests adding file changes added 10 changesets with 10 changes to 1 files (run 'hg update' to get a working copy) see the result $ wait $ hg verify checking changesets checking manifests crosschecking files in changesets and manifests checking files 1 files, 11 changesets, 11 total revisions $ cd ..