Re: multiprocessing module backport from 3 to 2.7 - spawn feature

2015-01-30 Thread Sturla Molden
On 30/01/15 23:25, Marko Rauhamaa wrote: Sturla Molden : Only a handful of POSIX functions are required to be "fork safe", i.e. callable on each side of a fork without an exec. That is a pretty surprising statement. Forking without an exec is a routine way to do multiprocessing. I understand

Re: multiprocessing module backport from 3 to 2.7 - spawn feature

2015-01-30 Thread Marko Rauhamaa
Sturla Molden : > Only a handful of POSIX functions are required to be "fork safe", i.e. > callable on each side of a fork without an exec. That is a pretty surprising statement. Forking without an exec is a routine way to do multiprocessing. I understand there are things to consider, but all sy

Re: multiprocessing module backport from 3 to 2.7 - spawn feature

2015-01-30 Thread Sturla Molden
Andres Riancho wrote: > Spawn, and I took that from the multiprocessing 3 documentation, will > create a new process without using fork(). > This means that no memory > is shared between the MainProcess and the spawn'ed sub-process created > by multiprocessing. If you memory map a segment with

Re: multiprocessing module backport from 3 to 2.7 - spawn feature

2015-01-30 Thread Sturla Molden
Skip Montanaro wrote: > Can you explain what you see as the difference between "spawn" and "fork" > in this context? Are you using Windows perhaps? I don't know anything > obviously different between the two terms on Unix systems. spawn is fork + exec. Only a handful of POSIX functions are requ

Re: multiprocessing module backport from 3 to 2.7 - spawn feature

2015-01-29 Thread Andres Riancho
On Wed, Jan 28, 2015 at 3:06 PM, Skip Montanaro wrote: > > On Wed, Jan 28, 2015 at 7:07 AM, Andres Riancho > wrote: >> >> The feature I'm specially interested in is the ability to spawn >> processes [1] instead of forking, which is not present in the 2.7 >> version of the module. > > > Can you ex

Re: multiprocessing module backport from 3 to 2.7 - spawn feature

2015-01-28 Thread Devin Jeanpierre
On Wed, Jan 28, 2015 at 10:06 AM, Skip Montanaro wrote: > On Wed, Jan 28, 2015 at 7:07 AM, Andres Riancho > wrote: >> The feature I'm specially interested in is the ability to spawn >> processes [1] instead of forking, which is not present in the 2.7 >> version of the module. > > Can you explain

Re: multiprocessing module backport from 3 to 2.7 - spawn feature

2015-01-28 Thread Skip Montanaro
On Wed, Jan 28, 2015 at 7:07 AM, Andres Riancho wrote: > The feature I'm specially interested in is the ability to spawn > processes [1] instead of forking, which is not present in the 2.7 > version of the module. > Can you explain what you see as the difference between "spawn" and "fork" in thi

multiprocessing module backport from 3 to 2.7 - spawn feature

2015-01-28 Thread Andres Riancho
List, I've been searching around for a multiprocessing module backport from 3 to 2.7.x and the closest thing I've found was celery's billiard [0] which seems to be a work in progress. The feature I'm specially interested in is the ability to spawn processes [1] instead of forking, which is not pr