Re: [PATCH 1 of 2 stable] worker: do not suppress EINTR
On 25/05/2022 14.55, Yuya Nishihara wrote: On Wed, 25 May 2022 02:30:29 +0200, Manuel Jacob wrote: # HG changeset patch # User Manuel Jacob # Date 1653433864 -7200 # Wed May 25 01:11:04 2022 +0200 # Branch stable # Node ID d058898bdd462b03c5bff38ad40d1f855ea51c23 # Parent 477b5145e1a02715f846ce017b460858a58e03b1 # EXP-Topic worker-pickle-load-EINTR worker: do not suppress EINTR Before this change, when IOError with errno EINTR was raised during pickle.load(), the error was suppressed and loading from other file descriptors was continued. On Python 3, system calls failing with EINTR are retried (PEP 475). Therefore, the removal of this code should not make any difference. On Python 2, this is not generally the case. CPickle has no handling of EINTR. In one place it misinterprets it as EOF. In another place, it will raise IOError. However, this could happen in the middle of the stream. In this case, if pickle tries to load from the stream later, it will behave wrongly (usually it will raise an error, but loading of incorrect data or interpreter crashes are thinkable). Do we want this (and the partial write fix) on stable? The problem could occur if the payload were quite large, but I think it's unlikely. Since writer issues a single os.write() in the original code, reader wouldn't be interrupted in the middle of pickle message in general. Yes, the problems fixed by the two series exist, but we can assume that they are very unlikely (at least nobody complained so far). I would be fine either way. We don't have to think about Python 2 on default, so the patches will get simplified. This patch series is essentially no-op on default, except for removing the unnecessary (basically dead code) EINTR handling. ___ Mercurial-devel mailing list Mercurial-devel@mercurial-scm.org https://www.mercurial-scm.org/mailman/listinfo/mercurial-devel
Re: [PATCH 1 of 2 stable] worker: do not suppress EINTR
On Wed, 25 May 2022 02:30:29 +0200, Manuel Jacob wrote: > # HG changeset patch > # User Manuel Jacob > # Date 1653433864 -7200 > # Wed May 25 01:11:04 2022 +0200 > # Branch stable > # Node ID d058898bdd462b03c5bff38ad40d1f855ea51c23 > # Parent 477b5145e1a02715f846ce017b460858a58e03b1 > # EXP-Topic worker-pickle-load-EINTR > worker: do not suppress EINTR > > Before this change, when IOError with errno EINTR was raised during > pickle.load(), the error was suppressed and loading from other file > descriptors > was continued. > > On Python 3, system calls failing with EINTR are retried (PEP 475). Therefore, > the removal of this code should not make any difference. > > On Python 2, this is not generally the case. CPickle has no handling of EINTR. > In one place it misinterprets it as EOF. In another place, it will raise > IOError. However, this could happen in the middle of the stream. In this case, > if pickle tries to load from the stream later, it will behave wrongly (usually > it will raise an error, but loading of incorrect data or interpreter crashes > are thinkable). Do we want this (and the partial write fix) on stable? The problem could occur if the payload were quite large, but I think it's unlikely. Since writer issues a single os.write() in the original code, reader wouldn't be interrupted in the middle of pickle message in general. We don't have to think about Python 2 on default, so the patches will get simplified. ___ Mercurial-devel mailing list Mercurial-devel@mercurial-scm.org https://www.mercurial-scm.org/mailman/listinfo/mercurial-devel
Re: [PATCH 1 of 2 stable] worker: do not suppress EINTR
Before I review these (and your previous series), is there a reason why you use the ML instead of Heptapod (as per https://www.mercurial-scm.org/pipermail/mercurial-devel/2022-May/148466.html ) considering you're already using it for your pre-submission CI? On 5/25/22 02:30, Manuel Jacob wrote: # HG changeset patch # User Manuel Jacob # Date 1653433864 -7200 # Wed May 25 01:11:04 2022 +0200 # Branch stable # Node ID d058898bdd462b03c5bff38ad40d1f855ea51c23 # Parent 477b5145e1a02715f846ce017b460858a58e03b1 # EXP-Topic worker-pickle-load-EINTR worker: do not suppress EINTR Before this change, when IOError with errno EINTR was raised during pickle.load(), the error was suppressed and loading from other file descriptors was continued. On Python 3, system calls failing with EINTR are retried (PEP 475). Therefore, the removal of this code should not make any difference. On Python 2, this is not generally the case. CPickle has no handling of EINTR. In one place it misinterprets it as EOF. In another place, it will raise IOError. However, this could happen in the middle of the stream. In this case, if pickle tries to load from the stream later, it will behave wrongly (usually it will raise an error, but loading of incorrect data or interpreter crashes are thinkable). diff --git a/mercurial/worker.py b/mercurial/worker.py --- a/mercurial/worker.py +++ b/mercurial/worker.py @@ -301,10 +301,6 @@ selector.unregister(key.fileobj) key.fileobj.close() openpipes -= 1 -except IOError as e: -if e.errno == errno.EINTR: -continue -raise except: # re-raises killworkers() cleanup() ___ Mercurial-devel mailing list Mercurial-devel@mercurial-scm.org https://www.mercurial-scm.org/mailman/listinfo/mercurial-devel ___ Mercurial-devel mailing list Mercurial-devel@mercurial-scm.org https://www.mercurial-scm.org/mailman/listinfo/mercurial-devel
[PATCH 1 of 2 stable] worker: do not suppress EINTR
# HG changeset patch # User Manuel Jacob # Date 1653433864 -7200 # Wed May 25 01:11:04 2022 +0200 # Branch stable # Node ID d058898bdd462b03c5bff38ad40d1f855ea51c23 # Parent 477b5145e1a02715f846ce017b460858a58e03b1 # EXP-Topic worker-pickle-load-EINTR worker: do not suppress EINTR Before this change, when IOError with errno EINTR was raised during pickle.load(), the error was suppressed and loading from other file descriptors was continued. On Python 3, system calls failing with EINTR are retried (PEP 475). Therefore, the removal of this code should not make any difference. On Python 2, this is not generally the case. CPickle has no handling of EINTR. In one place it misinterprets it as EOF. In another place, it will raise IOError. However, this could happen in the middle of the stream. In this case, if pickle tries to load from the stream later, it will behave wrongly (usually it will raise an error, but loading of incorrect data or interpreter crashes are thinkable). diff --git a/mercurial/worker.py b/mercurial/worker.py --- a/mercurial/worker.py +++ b/mercurial/worker.py @@ -301,10 +301,6 @@ selector.unregister(key.fileobj) key.fileobj.close() openpipes -= 1 -except IOError as e: -if e.errno == errno.EINTR: -continue -raise except: # re-raises killworkers() cleanup() ___ Mercurial-devel mailing list Mercurial-devel@mercurial-scm.org https://www.mercurial-scm.org/mailman/listinfo/mercurial-devel
