5 ms·

In C, I can just write the whole program without calling malloc. I write my own allocator tuned for my programs behavior, I even have multiple allocators if nee

In C, I can just write the whole program without calling malloc. I write my own allocator tuned for my programs behavior, I even have multiple allocators if needed. I just have a lot more control available. If you can't do this in a language, you can't claim its performance is close to C. Performance is about control.

neonsunset 2y ago
It's as if you didn't bother reading my previous comment. Incredible.
- waqar144 2y ago
  You keep ignoring the point. Show me how can I write a program in C# that works with a fixed size memory region, lets say 512KB. It should not do any dynamic memory allocation. Here's a library that does this in C in case you are wondering: https://github.com/rxi/microui https://github.com/rxi/microui.
  - neonsunset 2y ago
    Sigh. // Please, just allocate a normal array instead, there is no benefit to this if it lives throughout the whole application lifetime var bytes = (stackalloc byte[512 * 1024]); // or, but, please, at least use a span instead of C nonsense of tracking offsets by hand // it's not 1980 anymore var ptr = stackalloc byte[512 * 1024]; // byte* // or [InlineArray(256 * 1024)] struct CommandList { byte _; } var commands = new CommandList(); // or unsafe struct State { public fixed byte CommandList[256 * 1024]; } Whichever you like the most, they do have somewhat different implications - stackalloc is C alloca while struct-based definitions have the exact same meaning as in C. To avoid running into stack space limitations, you can place a fixed buffer or any of these large arrays into a static field. It gets a fixed static offset in the memory. C# goes much further and also provides zero-cost abstractions via struct generics with interface constraints. Or without - you can also apply pattern matching against a generic T struct and it will be zero-cost and evaluated at compilation (be it with RyuJIT or ILC (IL AOT Compiler)).
    - waqar144 2y ago
      Nice, thanks a lot for sharing the knowledge.

neonsunset 2y ago

It's as if you didn't bother reading my previous comment. Incredible.

waqar144 2y ago
You keep ignoring the point. Show me how can I write a program in C# that works with a fixed size memory region, lets say 512KB. It should not do any dynamic memory allocation. Here's a library that does this in C in case you are wondering: https://github.com/rxi/microui https://github.com/rxi/microui.
- neonsunset 2y ago
  Sigh. // Please, just allocate a normal array instead, there is no benefit to this if it lives throughout the whole application lifetime var bytes = (stackalloc byte[512 * 1024]); // or, but, please, at least use a span instead of C nonsense of tracking offsets by hand // it's not 1980 anymore var ptr = stackalloc byte[512 * 1024]; // byte* // or [InlineArray(256 * 1024)] struct CommandList { byte _; } var commands = new CommandList(); // or unsafe struct State { public fixed byte CommandList[256 * 1024]; } Whichever you like the most, they do have somewhat different implications - stackalloc is C alloca while struct-based definitions have the exact same meaning as in C. To avoid running into stack space limitations, you can place a fixed buffer or any of these large arrays into a static field. It gets a fixed static offset in the memory. C# goes much further and also provides zero-cost abstractions via struct generics with interface constraints. Or without - you can also apply pattern matching against a generic T struct and it will be zero-cost and evaluated at compilation (be it with RyuJIT or ILC (IL AOT Compiler)).
  - waqar144 2y ago
    Nice, thanks a lot for sharing the knowledge.