Atomic Operations

The atomic module provides low-level synchronization primitives. These functions are implemented as bare top-level functions (no namespace wrapping) for maximum efficiency.

Getting Started

To use atomics, simply import the module.

import atomic

Atomic Functions

Chemical provides atomic operations for u64, u32, u16, and u8.

Load & Store

var value : u64 = 0

atomic_store_u64(&mut value, 42)



var current = atomic_load_u64(&value)

Compare and Exchange (CAS)

CAS operations are the building blocks of lock-free data structures.

var state : u32 = 0

var expected : u32 = 0

var desired : u32 = 1



if (atomic_compare_exchange_strong_u32(&mut state, &mut expected, desired)) {

    // Successfully changed state from 0 to 1

}

Fetch and Modify

Operations like add, sub, and, or, and xor return the previous value.

var counter : u64 = 10

var previous = atomic_fetch_add_u64(&mut counter, 5)

// counter is now 15, previous is 10

Memory Orders

You can optionally specify a memory_order. If omitted, seq_cst (Sequentially Consistent) is used.

• memory_order.relaxed
• memory_order.consume
• memory_order.acquire
• memory_order.release
• memory_order.acq_rel
• memory_order.seq_cst

atomic_store_u64(&mut value, 100, memory_order.release)

Fences

Use atomic_fence to enforce memory ordering without a specific atomic variable.

atomic_fence(memory_order.acquire)

Available Types Reference

The following functions are available for u64, u32, u16, and u8:

• atomic_load_[type]
• atomic_store_[type]
• atomic_exchange_[type]
• atomic_compare_exchange_weak_[type]
• atomic_compare_exchange_strong_[type]
• atomic_fetch_add_[type]
• atomic_fetch_sub_[type]
• atomic_fetch_and_[type]
• atomic_fetch_or_[type]
• atomic_fetch_xor_[type]

NOTE

These functions operate on raw pointers (*u64, etc.). Ensure the memory is properly aligned for your target architecture.