Mercurial > hg
view tests/test-double-merge.t @ 30521:86cd09bc13ba
worker: use os._exit for posix worker in all cases
Like commandserver, the worker should never run other resource cleanup logic.
Previously this is not true for workers if they have exceptions other than
KeyboardInterrupt.
This actually caused a real-world deadlock with remotefilelog:
1. remotefilelog/fileserverclient creates a sshpeer. pipei/o/e get created.
2. worker inherits that sshpeer's pipei/o/e.
3. worker runs sshpeer.cleanup (only happens without os._exit)
4. worker closes pipeo/i, which will normally make the sshpeer read EOF from
its stdin and exit. But the master process still have pipeo, so no EOF.
5. worker reads pipee (stderr of sshpeer), which never completes because
the ssh process does not exit, does not close its stderr.
6. master waits for all workers, which never completes because they never
complete sshpeer.cleanup.
This could also be addressed by closing these fds after fork, which is not
easy because Python 2.x does not have an official "afterfork" hook. Hacking
os.fork is also ugly. Besides, sshpeer is probably not the only troublemarker.
The patch changes _posixworker so all its code paths will use os._exit to
avoid running unwanted resource clean-ups.
author | Jun Wu <quark@fb.com> |
---|---|
date | Thu, 24 Nov 2016 01:15:34 +0000 |
parents | 564a354f7f35 |
children | 91a0bc50b288 |
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$ hg init repo $ cd repo $ echo line 1 > foo $ hg ci -qAm 'add foo' copy foo to bar and change both files $ hg cp foo bar $ echo line 2-1 >> foo $ echo line 2-2 >> bar $ hg ci -m 'cp foo bar; change both' in another branch, change foo in a way that doesn't conflict with the other changes $ hg up -qC 0 $ echo line 0 > foo $ hg cat foo >> foo $ hg ci -m 'change foo' created new head we get conflicts that shouldn't be there $ hg merge -P changeset: 1:484bf6903104 user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: cp foo bar; change both $ hg merge --debug searching for copies back to rev 1 unmatched files in other: bar all copies found (* = to merge, ! = divergent, % = renamed and deleted): src: 'foo' -> dst: 'bar' * checking for directory renames resolving manifests branchmerge: True, force: False, partial: False ancestor: e6dc8efe11cc, local: 6a0df1dad128+, remote: 484bf6903104 preserving foo for resolve of bar preserving foo for resolve of foo starting 4 threads for background file closing (?) bar: remote copied from foo -> m (premerge) picked tool ':merge' for bar (binary False symlink False changedelete False) merging foo and bar to bar my bar@6a0df1dad128+ other bar@484bf6903104 ancestor foo@e6dc8efe11cc premerge successful foo: versions differ -> m (premerge) picked tool ':merge' for foo (binary False symlink False changedelete False) merging foo my foo@6a0df1dad128+ other foo@484bf6903104 ancestor foo@e6dc8efe11cc premerge successful 0 files updated, 2 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) contents of foo $ cat foo line 0 line 1 line 2-1 contents of bar $ cat bar line 0 line 1 line 2-2 $ cd ..