rustfs-mimalloc

High-performance mimalloc V3 global allocator for Rust.

Quick Start

[dependencies]
rustfs-mimalloc = "0.5.2"

use rustfs_mimalloc::MiMalloc;

#[global_allocator]
static GLOBAL: MiMalloc = MiMalloc;

fn main() {
    let v = vec![1, 2, 3, 4, 5];
    println!("{:?}", v);
}

Features

Feature	Description
`secure`	Heap allocation encryption (MI_SECURE=4)
`debug`	mimalloc debug checks
`debug_in_debug`	Auto-enable `debug` in Cargo debug builds
`override`	Override system `malloc`/`free`
`local_dynamic_tls`	Use local-dynamic TLS model
`no_thp`	Disable Transparent Huge Pages

API

Allocator

MiMalloc implements GlobalAlloc — all methods use mi_malloc_aligned for guaranteed alignment.

Stats & Options

use rustfs_mimalloc::MiMalloc;
use rustfs_mimalloc_sys::mi_option_t;

let version = MiMalloc::version();       // 30501 = V3.5.1
let json    = MiMalloc::stats_json();    // stats as JSON
let text    = MiMalloc::stats_print();   // stats as text
let info    = MiMalloc::process_info();  // ProcessInfo struct

MiMalloc::option_set(mi_option_t::mi_option_purge_delay, 0);

Small Free Fast Paths

MiMalloc::free_csize, free_csize_nonnull, free_small, and free_small_nonnull expose mimalloc V3.5.1's small and constant-size free fast paths. These APIs are unsafe: the pointer must come from mimalloc, and the caller must preserve the original allocation size contract.

Threadpool Hint

rustfs_mimalloc::set_current_thread_in_threadpool();

Call this from custom thread-pool worker threads to set mimalloc's current-thread threadpool marker.

Heap & Arena

use rustfs_mimalloc::heap::Heap;

let heap = Heap::new().unwrap();
unsafe {
    let ptr = heap.malloc(128);
    rustfs_mimalloc_sys::mi_free(ptr as *mut core::ffi::c_void);
}
heap.delete();

MSRV

Rust 1.96.0. Rolling support window for the latest three stable Rust releases.

License

Apache-2.0.

rustfs-mimalloc 0.5.2