4 ms·

Can Pharo/Squeak programs utilize multiple cores? Last I checked, they used green threads and there weren't any plans to add true multi-threading.

needusername 12y ago
> Last I checked, they used green threads and there weren't any plans to add true multi-threading. That is correct. My understanding is that supporting multiple hardware threads would require major work in the VM and the development of a memory model. There's some quite critical code in there relies on certain things not being a point for a possible context switch.
- echoless 12y ago
  Isn't that a big setback for adoption though? The world is moving to multiple-cores, albeit slowly.
  - needusername 12y ago
    It's hard to tell. If you compare yourself with traditional scripting languages like CRuby, CPython, JavaScript, Perl, PHP, Lua, … — they all use green threads as well. If you compare yourself to C++, C#, Java then things look differently. It's probably a bigger issue for the commercial Smalltalk vendors. I would assume for a free, open source project this can be "forgiven" more easily.
    - dragonwriter 12y ago
      > It's hard to tell. If you compare yourself with traditional scripting languages like CRuby, CPython, JavaScript, Perl, PHP, Lua, … — they all use green threads as well. "CRuby" (MRI) since 1.9 and "CPython" (forever, as far as I know) use native threads with a global runtime lock so only one thread running Ruby/Python code (but possibly more running native code in the same process) runs at any given time. AFAIK, most JS environments don't provide threads (green or otherwise).
Mikeb85 12y ago
Smalltalk uses multiple cores by forking processes and passing messages, just like JavaScript, Ruby, Python, etc...
- Rockslide 12y ago
  It is true that you can fork in Smalltalk. It is not true that such a fork results in multiple cores being used by the same VM concurrently. At least not in any of the "mainstream" Smalltalk implementations I know (which would be Squeak, Pharo and VisualWorks).
shaunxcode 12y ago
Check out the work on roar vm https://github.com/smarr/RoarVM https://github.com/smarr/RoarVM if you are interested in such things. There are rad videos here too: http://stefan-marr.de/renaissance/ http://stefan-marr.de/renaissance/

needusername 12y ago

> Last I checked, they used green threads and there weren't any plans to add true multi-threading. That is correct. My understanding is that supporting multiple hardware threads would require major work in the VM and the development of a memory model. There's some quite critical code in there relies on certain things not being a point for a possible context switch.

echoless 12y ago
Isn't that a big setback for adoption though? The world is moving to multiple-cores, albeit slowly.
- needusername 12y ago
  It's hard to tell. If you compare yourself with traditional scripting languages like CRuby, CPython, JavaScript, Perl, PHP, Lua, … — they all use green threads as well. If you compare yourself to C++, C#, Java then things look differently. It's probably a bigger issue for the commercial Smalltalk vendors. I would assume for a free, open source project this can be "forgiven" more easily.
  - dragonwriter 12y ago
    > It's hard to tell. If you compare yourself with traditional scripting languages like CRuby, CPython, JavaScript, Perl, PHP, Lua, … — they all use green threads as well. "CRuby" (MRI) since 1.9 and "CPython" (forever, as far as I know) use native threads with a global runtime lock so only one thread running Ruby/Python code (but possibly more running native code in the same process) runs at any given time. AFAIK, most JS environments don't provide threads (green or otherwise).

Mikeb85 12y ago

Smalltalk uses multiple cores by forking processes and passing messages, just like JavaScript, Ruby, Python, etc...

Rockslide 12y ago
It is true that you can fork in Smalltalk. It is not true that such a fork results in multiple cores being used by the same VM concurrently. At least not in any of the "mainstream" Smalltalk implementations I know (which would be Squeak, Pharo and VisualWorks).

shaunxcode 12y ago

Check out the work on roar vm https://github.com/smarr/RoarVM https://github.com/smarr/RoarVM if you are interested in such things. There are rad videos here too: http://stefan-marr.de/renaissance/ http://stefan-marr.de/renaissance/