2 ms·

The problem is that regardless of the amount of confrontation it does not have an answer for any infinite run time event-loop based program, other than "allocat

The problem is that regardless of the amount of confrontation it does not have an answer for any infinite run time event-loop based program, other than "allocate all of memory into a buffer at startup and implement your own memory manager inside that". Which just punts the problem from a mature and tested runtime library to some code you just make up on the spot.

int_19h 2y ago
Heap was invented for a reason, and some tasks are naturally easier to model with it. The problem is that once it's there, people start using it as the proverbial hammer, and everything looks like a nail even if it isn't. Note though that ""allocate all of memory into a buffer at startup" is a lot more viable if you scope it not to the start of the app, but to the entrypoint of some code that needs to make a complicated calculation. It's actually not all that uncommon to need something heap-like to store temporary data as you compute - e.g. a list or map to cache intermediary results - but which shouldn't outlive the computation. Ada access types give you exactly that - declare them inside the top-level function that's your entrypoint, allocate as needed in nested functions as they get called, and know that it'll all be cleaned up once the top-level function returns.
- brucehoult 2y ago
  That works for something where the events being handled are like "serve a web page" or "compile a C function". It doesn't work for a spreadsheet or word processor or a web browser.
  - duskwuff 2y ago
    I'm not convinced it even works very well for either of those cases. It's common in many applications to return the result of a computation as an object in memory, like an array or string of arbitrary length or a treelike structure. Without the ability to allocate memory which exists after a function exits, I'm not sure how you'd do that (short of solutions which create arbitrary limits, like writing to a fixed-size buffer).
    - brucehoult 2y ago
      Well, yes, but I'm trying to be generous to the PoV. My preferred solution is definitely to use the GC. With some help if you want. You can GC the nursery each time around the event loop. You can create and destroy arenas.
  - int_19h 2y ago
    It would be more accurate to say that it doesn't work for some of the allocations in a spreadsheet or word processor app. Which is why you still have the global heap, but the point is that not everything needs to be on the same heap that has the same overall lifetime. That spreadsheet might still be running some algorithm that can do what it needs to do with a local heap. And that aside, there are still many apps that are more like "serve a web page". Most console apps are like that. Many daemons are, too.

int_19h 2y ago

Heap was invented for a reason, and some tasks are naturally easier to model with it. The problem is that once it's there, people start using it as the proverbial hammer, and everything looks like a nail even if it isn't. Note though that ""allocate all of memory into a buffer at startup" is a lot more viable if you scope it not to the start of the app, but to the entrypoint of some code that needs to make a complicated calculation. It's actually not all that uncommon to need something heap-like to store temporary data as you compute - e.g. a list or map to cache intermediary results - but which shouldn't outlive the computation. Ada access types give you exactly that - declare them inside the top-level function that's your entrypoint, allocate as needed in nested functions as they get called, and know that it'll all be cleaned up once the top-level function returns.

brucehoult 2y ago
That works for something where the events being handled are like "serve a web page" or "compile a C function". It doesn't work for a spreadsheet or word processor or a web browser.
- duskwuff 2y ago
  I'm not convinced it even works very well for either of those cases. It's common in many applications to return the result of a computation as an object in memory, like an array or string of arbitrary length or a treelike structure. Without the ability to allocate memory which exists after a function exits, I'm not sure how you'd do that (short of solutions which create arbitrary limits, like writing to a fixed-size buffer).
  - brucehoult 2y ago
    Well, yes, but I'm trying to be generous to the PoV. My preferred solution is definitely to use the GC. With some help if you want. You can GC the nursery each time around the event loop. You can create and destroy arenas.
- int_19h 2y ago
  It would be more accurate to say that it doesn't work for some of the allocations in a spreadsheet or word processor app. Which is why you still have the global heap, but the point is that not everything needs to be on the same heap that has the same overall lifetime. That spreadsheet might still be running some algorithm that can do what it needs to do with a local heap. And that aside, there are still many apps that are more like "serve a web page". Most console apps are like that. Many daemons are, too.