[Python-ideas] Re: Support for atomic types in Python

Hi Antoine, As you said there can be lot of possible use cases for the proposed feature, since there are lot’s of use cases for a lock. I can tell you some cases which I am facing. Let’s say I have a parent process which spawns lots of worker processes to serve some requests. Now the parent pr

[Python-ideas] Re: Support for atomic types in Python

Hi Vinay, I see. I agree agregating statistics is a reasonable use case. Still, maintaining atomic types in the standard library sounds non-trivial for a rather niche feature. Perhaps you want to implement them as a third-party project and publish it on PyPI? multiprocessing already provides sh

[Python-ideas] Re: Support for atomic types in Python

On 13/09/2019 14:32, Vinay Sharma via Python-ideas wrote: As you said there can be lot of possible use cases for the proposed feature, since there are lot’s of use cases for a lock. I can tell you some cases which I am facing. I don't in principle object to having language support for tricky o

[Python-ideas] Re: Support for atomic types in Python

Please see my second mail in this thread, where I have comprehensively explained what I mean by atomic types. It is nothing but multiprocessing.Value, which can have an Atomic variant to be used across processes. >>> On 13-Sep-2019, at 8:37 PM, Rhodri James wrote: >> On 13/09/2019 14:32, Vinay

[Python-ideas] Re: Support for atomic types in Python

On 13/09/2019 17:07, Vinay Sharma wrote: Please see my second mail in this thread, where I have comprehensively explained what I mean by atomic types. It is nothing but multiprocessing.Value, which can have an Atomic variant to be used across processes. Doesn't multiprocessing.Value already h

[Python-ideas] Re: Support for atomic types in Python

multiprocessing.Value can be synchronised using a lock, but if I have multiple multiprocessing.Value(s) which I want to synchronise between two processes, then I will have to pass a lock for each multiprocessing.Value. Therefore having a multiprocessing.AtomicValue could prove handy in these cas

[Python-ideas] Re: Support for atomic types in Python

If you see my first mail, I have mentioned that gcc has support for atomic builtins, which can be used to support atomic behaviour. You can refer gcc’s documentation for the same at https://gcc.gnu.org/onlinedocs/gcc-5.2.0/gcc/_005f_005fsync-Builtins.html#g_t_005f_005fsync-Builtins

[Python-ideas] Re: Support for atomic types in Python

On Fri, Sep 13, 2019 at 6:27 PM Rhodri James wrote: > On 13/09/2019 17:07, Vinay Sharma wrote: > > Please see my second mail in this thread, where I have comprehensively > explained what I mean by atomic types. > > It is nothing but multiprocessing.Value, which can have an Atomic > variant to be

[Python-ideas] Re: Support for atomic types in Python

On 13/09/2019 17:31, Vinay Sharma wrote: multiprocessing.Value can be synchronised using a lock, but if I have multiple multiprocessing.Value(s) which I want to synchronise between two processes, then I will have to pass a lock for each multiprocessing.Value. Therefore having a multiprocessing

[Python-ideas] Re: Support for atomic types in Python

On Fri, Sep 13, 2019 at 6:56 PM Rhodri James wrote: > I repeat, how does this work? If you want atomicity across processes, > you need some kind of lock at some level. > For the atomic operations the lock is on the hardware level (i.e. implemented in the CPU, across the mem BUS, cache, etc.), f

[Python-ideas] Re: Support for atomic types in Python

First, I’m pretty sure that, contrary to your claims, C++ does not support this. C++ doesn’t even support shared memory out of the box. The third-party Boost library does provide it—as long as you only care about systems that correctly supports POSIX shared memory, and Windows, and as long as yo

[Python-ideas] Re: Support for atomic types in Python

On Sep 13, 2019, at 09:31, Vinay Sharma via Python-ideas wrote: > > multiprocessing.Value can be synchronised using a lock, but if I have > multiple multiprocessing.Value(s) which I want to synchronise between two > processes, then I will have to pass a lock for each multiprocessing.Value. Th

[Python-ideas] Re: Support for atomic types in Python

On Fri, 13 Sep 2019 10:27:10 -0700 Andrew Barnert via Python-ideas wrote: > > (If you want a shiny modern solution instead, this looks like one of the few > cases where hardware TM support can probably speed things up relatively > easily, which would be a fun project to work on…) Hardware tran

[Python-ideas] Re: Support for atomic types in Python

On Sep 13, 2019, at 10:11, Richard Musil wrote: > > For the atomic operations the lock is on the hardware level (i.e. implemented > in the CPU, across the mem BUS, cache, etc.), from the user perspective, it > looks only like executing a particular (atomic) op-code. > (https://software.intel.c

[Python-ideas] Re: Support for atomic types in Python

On Sep 13, 2019, at 10:42, Antoine Pitrou wrote: > > On Fri, 13 Sep 2019 10:27:10 -0700 > Andrew Barnert via Python-ideas > wrote: >> >> (If you want a shiny modern solution instead, this looks like one of the few >> cases where hardware TM support can probably speed things up relatively >> e

[Python-ideas] Re: Support for atomic types in Python

On Fri, Sep 13, 2019 at 7:28 PM Andrew Barnert via Python-ideas < [email protected]> wrote: > First, I’m pretty sure that, contrary to your claims, C++ does not support > this. C++ doesn’t even support shared memory out of the box. The > third-party Boost library does provide it—as long as y

[Python-ideas] Re: Support for atomic types in Python

> On Sep 13, 2019, at 12:21, Richard Musil wrote: > >> On Fri, Sep 13, 2019 at 7:28 PM Andrew Barnert via Python-ideas >> wrote: > >> First, I’m pretty sure that, contrary to your claims, C++ does not support >> this. C++ doesn’t even support shared memory out of the box. The third-party >>