Does std.process.Init.environ_map allocate memory or not?

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1

The doc comment for it says “Environment variables, initialized with gpa" so when I used it first time I did the following

const environ_map = init.environ_map;
defer environ_map.deinit();

But it failed …

thread 16198 panic: integer overflow
Unwind error at address `./development:0x2dc2f6` (unwind info unavailable), remaining frames may be incorrect
???:?:?: 0x3e12ff in multi_array_list.MultiArrayList(array_hash_map.Custom([ ]const u8,[ ]const u8,process.Environ.Map.EnvNameHashContext,false).Data).slice (./development)
???:?:?: 0x3e1ff0 in multi_array_list.MultiArrayList(array_hash_map.Custom([ ]const u8,[ ]const u8,process.Environ.Map.EnvNameHashContext,false).Data).items__anon_24407 (./development)
???:?:?: 0x3e1f28 in array_hash_map.Custom([ ]const u8,[ ]const u8,process.Environ.Map.EnvNameHashContext,false).keys (./development)
???:?:?: 0x3e1df6 in process.Environ.Map.keys (./development)
???:?:?: 0x44761e in process.Environ.Map.deinit (./development)
???:?:?: 0x442e83 in start.posixCallMainAndExit (./development)
???:?:?: 0x441bf1 in start.\_start (./development)
zsh: abort      ./development

I removed the deinit part and it was fine(I also tried making environ_map mutable).
Another thing that added to the confusion is …

const environ = init.minimal.environ;
var environ_map = environ.createMap(gpa);
defer environ_map.deinit();

So, does it allocate?
If so, then how come that it didn’t accept an allocator parameter?
If not, then what is the significance of the part of the doc comment that says “initialized with gpa”?

2

Hi @Ahmad , welcome to Ziggit!

Juicy main does the deinit for you. So the ones passed into main will be initialized with GPA and should handle the deinit as well.

For the second example, because you are creating the map, you are in charge of deallocating. That’s why the deinit works fine.

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3

The source of all this for me is that I didn’t pass an allocator parameter, but if I understand correctly this is the first exception to that rule.

4

A general rule of thumb is if you didn’t ever pass an allocator, then you don’t have to call deinit.

This is a special case of that rule. Juicy main did the allocation, so you don’t have to.
The special case is that since juicy main does the deallocation, you don’t have to worry about it, even if you call one of the apis and pass in an allocator.