How do atomic.LoadInt64 and atomic.StoreInt64 ensure data consistency and memory ordering in concurrent Go programs?

Atomic LoadInt32 and StoreInt32: Understanding Their Significance

The sync/atomic package in Golang provides atomic operations to guarantee that operations on shared memory are atomic, ensuring consistency across concurrent goroutines. This becomes necessary when multiple goroutines attempt to access or modify the same variable concurrently, potentially leading to data race conditions.

LoadInt64 and StoreInt64

atomic.LoadInt64 and atomic.StoreInt64 are two specific atomic operations for reading and writing 64-bit integers, respectively. To illustrate their usage, consider the following code:

<code class="go">package main

import (
    "sync/atomic"
    "time"
)

var sharedCounter int64

func main() {
    go func() {
        for {
            v := atomic.LoadInt64(&sharedCounter) // Read sharedCounter using atomic load
            time.Sleep(10 * time.Millisecond)
            atomic.StoreInt64(&sharedCounter, v+1) // Increment sharedCounter using atomic store
        }
    }()

    go func() {
        for {
            time.Sleep(time.Second)
            v := atomic.LoadInt64(&sharedCounter) // Read sharedCounter again using atomic load
            println(v)
        }
    }()

    time.Sleep(60 * time.Second) // Keep the program running for some time to see updates
}</code>

Importance of Atomic Operations

In this example, multiple goroutines share access to the sharedCounter variable. It is crucial to perform atomic operations on it to ensure that:

1. Consistent Reading and Writing: Using atomic.LoadInt64 for reading and atomic.StoreInt64 for writing guarantees that each operation is executed as an indivisible atomic unit. This prevents data races where one goroutine could see the intermediate state of the variable being modified by another goroutine.
2. Memory Ordering: The atomic operations enforce memory ordering, ensuring that the visibility of writes to the shared variable is consistent across all goroutines. This means that v will always reflect the most recent value written to by any goroutine, even if they access it asynchronously.

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