Function pin_thread_arena

nodedb-mem/src/arena.rs:104–123

Pin the calling thread to a dedicated jemalloc arena. Call this once at Data Plane core startup, before any allocations. Each core should get a unique `arena_index` (typically core ID). Returns the arena index that was assigned. On wasm32 the standard allocator is used and the supplied index is returned unchanged as a no-op.

(arena_index: u32)

/// Returns the arena index that was assigned. On wasm32 the standard allocator
/// is used and the supplied index is returned unchanged as a no-op.
pub fn pin_thread_arena(arena_index: u32) -> Result<u32> {
    #[cfg(not(target_arch = "wasm32"))]
    {
        let narenas = read_narenas()?;

        let target_arena = if (arena_index as usize) < narenas {
            arena_index
        } else {
            create_arena()?
        };

        set_thread_arena(target_arena)?;
        Ok(target_arena)
    }
    #[cfg(target_arch = "wasm32")]
    {
        // wasm32 uses the standard allocator; per-thread arena pinning is a no-op.
        Ok(arena_index)
    }
}

/// Query the current number of jemalloc arenas.
#[cfg(not(target_arch = "wasm32"))]