5 ms·

> Add new data by wrapping it into a tuple and tossing it into the pile In David Gelernter's original work, it's not just data. In Linda, it's possible to put

> Add new data by wrapping it into a tuple and tossing it into the pile In David Gelernter's original work, it's not just data. In Linda, it's possible to put Objects in, which are little executable (`eval` in Linda terms) which a processor can manipulate through whatever interface the tuple type exposes.

Jupe 4y ago
That does not sound very secure. Also, what's to stop another processor "finding" the Object before the intended recipient?
- cratermoon 4y ago
  1. Just bare like that, it's not. Unless, of course, the object requires a key to allow a processor to execute it. See for example Capability-Based Access Control 2. In TupleWorld, there's no concept of "the" intended recipient. The tuple's properties determine what kind of processor would match. If those properties happen to only match a single processor, you'd get that 1:1 mapping you want, but that's missing the point of tuple spaces.
  - Jupe 4y ago
    Just coordinating the 1:1 mapping I might want is fraught with challenges. Network delays, out-of-order execution, stampeding herd situations, poison objects, processors crashing (or being rebooted) at random times... I'm not seeing the benefit of a "bag" of objects to be processed whenever by whoever or whatever. Perhaps this is attempting to solve a problem I've not come across. While it sounds interesting, I'm not sure I see the benefit? (Probably me just being short-sighted).
    - cratermoon 4y ago
      It's a way of doing massively parallel computations in a scatter/gather system. I suggest looking up the paper "Linda in Context. I'd provide a link but I'm on my phone.
      - Jtsummers 4y ago
        Here you go (not on mobile): https://dl.acm.org/doi/10.1145/63334.63337 https://dl.acm.org/doi/10.1145/63334.63337 (free access)
        cratermoon 4y ago
        Also worth reading are the "Linda Letters" from Communications of the ACM, October 1989, vol 32, no 10, p 1244. I found an excerpt at https://web.archive.org/web/20160901000000*/https://www.cypherpunks.to/erights/history/clp/linda-letters.pdf https://web.archive.org/web/20160901000000*/https://www.cyph..., starting on page 4 of the PDF
    - infinite8s 4y ago
      Somehow this model works to build complex organisms in embryology...
      - dllthomas 4y ago
        Still have a problem with viruses, though...
    - cratermoon 4y ago
      Also, on "poison objects". We execute Javascript all the time in our browsers. Sandboxing and other measures keep the executable objects from exploiting our computers. It's imperfect, of course, and there are still exploits, but that's the general approach. Things like out-of-order execution and so forth require careful parallel design, but that's pretty much the bread-and-butter of things like SETI@Home
infinite8s 4y ago
This exactly. Sadly the idea went through a low pass filter and just became a way to pass around dumb data objects.
- cratermoon 4y ago
  It's not unlike the Blackboard system pattern (https://en.wikipedia.org/wiki/Blackboard_system#Metaphor https://en.wikipedia.org/wiki/Blackboard_system#Metaphor) in that respect, but Gelertner had something more ambitious in mind.
- brazzy 4y ago
  Honestly, I suspect the other, fancier parts of the idea were more like a solution in search of a problem.

Jupe 4y ago

That does not sound very secure. Also, what's to stop another processor "finding" the Object before the intended recipient?

cratermoon 4y ago
1. Just bare like that, it's not. Unless, of course, the object requires a key to allow a processor to execute it. See for example Capability-Based Access Control 2. In TupleWorld, there's no concept of "the" intended recipient. The tuple's properties determine what kind of processor would match. If those properties happen to only match a single processor, you'd get that 1:1 mapping you want, but that's missing the point of tuple spaces.
- Jupe 4y ago
  Just coordinating the 1:1 mapping I might want is fraught with challenges. Network delays, out-of-order execution, stampeding herd situations, poison objects, processors crashing (or being rebooted) at random times... I'm not seeing the benefit of a "bag" of objects to be processed whenever by whoever or whatever. Perhaps this is attempting to solve a problem I've not come across. While it sounds interesting, I'm not sure I see the benefit? (Probably me just being short-sighted).
  - cratermoon 4y ago
    It's a way of doing massively parallel computations in a scatter/gather system. I suggest looking up the paper "Linda in Context. I'd provide a link but I'm on my phone.
    - Jtsummers 4y ago
      Here you go (not on mobile): https://dl.acm.org/doi/10.1145/63334.63337 https://dl.acm.org/doi/10.1145/63334.63337 (free access)
      - cratermoon 4y ago
        Also worth reading are the "Linda Letters" from Communications of the ACM, October 1989, vol 32, no 10, p 1244. I found an excerpt at https://web.archive.org/web/20160901000000*/https://www.cypherpunks.to/erights/history/clp/linda-letters.pdf https://web.archive.org/web/20160901000000*/https://www.cyph..., starting on page 4 of the PDF
  - infinite8s 4y ago
    Somehow this model works to build complex organisms in embryology...
    - dllthomas 4y ago
      Still have a problem with viruses, though...
  - cratermoon 4y ago
    Also, on "poison objects". We execute Javascript all the time in our browsers. Sandboxing and other measures keep the executable objects from exploiting our computers. It's imperfect, of course, and there are still exploits, but that's the general approach. Things like out-of-order execution and so forth require careful parallel design, but that's pretty much the bread-and-butter of things like SETI@Home

infinite8s 4y ago

This exactly. Sadly the idea went through a low pass filter and just became a way to pass around dumb data objects.

cratermoon 4y ago
It's not unlike the Blackboard system pattern (https://en.wikipedia.org/wiki/Blackboard_system#Metaphor https://en.wikipedia.org/wiki/Blackboard_system#Metaphor) in that respect, but Gelertner had something more ambitious in mind.
brazzy 4y ago
Honestly, I suspect the other, fancier parts of the idea were more like a solution in search of a problem.