alt Hacker News> It's not clear to me what you mean by this.
TigerBeetle calculates all the memory it needs at startup. It allocates that much memory once. It does not allocate memory dynamically.
This only works for very specific use cases, like a fixed server size where you know exactly how much memory you want to allocate to a process.
It’s not portable to general purpose computing, where it’s expected that apps aren’t allocating the maximum amount of memory they might use at startup. Their memory usage grows and shrinks as you open and close files or as your documents get longer.
> and the approach more commonly used in Rust (allocate wherever and whenever) is non-idiomatic in Zig
Allocating memory as needed isn’t a Rust-specific idiom. Most programming involves dynamic memory allocation.
I don’t think the Zig developers would go as far as saying Zig isn’t a good fit for dynamic memory allocation. If it was that simple this entire debacle could have been written off as “Bun requires dynamic memory allocation by nature, therefore Zig isn’t a good fit”. That’s not what Andrew Kelley is trying to say though.
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> This only works for very specific use cases, like a fixed server size where you know exactly how much memory you want to allocate to a process.
So, like, the JVM with its "initial heap size" setting? After reserving that space from the OS on startup, pieces of the space are then handed out by the JVM's internal allocator, where and when needed.
If initial heap size and max heap size are the same, that initial one is the only malloc() call that ever happens. Not as common for desktop software, but a common best practice when deploying JVM applications to servers.
(I think we're perhaps tripping over two different meanings of "allocate" - you can "allocate" in the sense of calling malloc(), and you can "allocate" a piece of that reserved memory to a particular scope/function/object without actually calling malloc.)
> Allocating memory as needed isn’t a Rust-specific idiom.
I never said that.
It works really well for a ton of use cases (e.g. any data acquisition task, which is mostly what I use C for...)