What synchronization primitives are available for goroutines in Go? Fix the race condition example using atomic.

In Go, there are several tools for goroutine synchronization:

• Mutexes (sync.Mutex) — for locking critical sections.
• Channels (chan) — for communication and synchronization.
• The sync/atomic package — for atomic operations on variables.
• sync.WaitGroup — for waiting for a group of goroutines to finish.

Example of a race condition and its fix using atomic:

package main

import (
	"fmt"
	"sync"
	"sync/atomic"
)

func main() {
	var counter int64 = 0
	var wg sync.WaitGroup

	for i := 0; i < 1000; i++ {
		wg.Add(1)
		go func() {
			defer wg.Done()
			atomic.AddInt64(&counter, 1) // atomic increment
		}()
	}

	wg.Wait()
	fmt.Println("Counter:", counter) // Expected 1000
}

In this example, without atomic.AddInt64, there would be a race condition when incrementing counter. Using atomic guarantees correct variable updates without locks.