----- Original Message ----- From: "Ion Gaztañaga" <igaztanaga@gmail.com> To: <boost@lists.boost.org> Sent: Tuesday, February 17, 2009 5:57 PM Subject: Re: [boost] [future|interprocess] Could futures live in shared memory and synchronize process? vicente.botet wrote:
Hi,
As a future is a synchronization mechanism, I was wondering if futures are intrisic of mutil-threaded programs and so they live in the protected process memory or if the concept can be used in a multi-process context and have futures/promises living on shared memory.
I don't see why do we want to have a future in shared memory. Do you see any use case for this?
I was just requesting the same thing. Well, it could be a way to communicate a value between a producer process and a consumer process, so ... the door is open.
A future is a handle of a concurrency unit that has spawned another concurrency unit. A future for processes would be interesting, but passing/returning values between processes is not easy and using shared memory consumes at least 1 memory page.
However, I can find useful a future returning "int", just because main returns int and a process could spawn other processes and obtain futures to them (Boost.Process child is a an example of this approach).
Yes, I see but the future needed in this case will be internal to the spawning process, isnt't it?
Passing objects between processes is not easy, but there are OS mechanisms that do similar things like Solaris Doors.
I'll take a look. Thanks, Vicente