Is it possible to use the same buffer []byte in…

Yes, it is possible, but access synchronization must be ensured to prevent data races.

Common approaches:

Mutexes (sync.Mutex):

import "sync"

var buf []byte
var mu sync.Mutex

func processBuffer() {
    mu.Lock()
    defer mu.Unlock()
    // Safe access to buf
    // For example: buf = append(buf, data...)
}

func main() {
    // Initialize buf
    go processBuffer()
    go processBuffer()
    // ...
}

Channels (chan):

You can pass ownership of the buffer between goroutines or use a channel to coordinate access.

import "bytes"

type BufferAccess struct {
    buf *bytes.Buffer // Pointer to shared buffer
    mu  sync.Mutex    // Mutex for synchronization
}

func (ba *BufferAccess) Write(p []byte) (n int, err error) {
    ba.mu.Lock()
    defer ba.mu.Unlock()
    return ba.buf.Write(p)
}

func worker(ba *BufferAccess, data []byte) {
    ba.Write(data) // Safe write via method with mutex
}

func main() {
    sharedBuffer := &BufferAccess{buf: &bytes.Buffer{}}
    // Launch goroutines passing sharedBuffer
    go worker(sharedBuffer, []byte("hello"))
    go worker(sharedBuffer, []byte("world"))
    // ...
}

Buffer Pool (sync.Pool):

Less need for synchronization when each goroutine takes a buffer from the pool, uses it, and then returns it.

import (
    "bytes"
    "sync"
)

var bufferPool = sync.Pool{
    New: func() interface{} {
        // Default buffer size
        return bytes.NewBuffer(make([]byte, 0, 1024))
    },
}

func processData(data []byte) {
    buf := bufferPool.Get().(*bytes.Buffer)
    defer bufferPool.Put(buf) // Always return buffer to pool

    buf.Reset() // Clear buffer before use
    buf.Write(data)
    // Process data in buffer
    // ...
}

func main() {
    go processData([]byte("message1"))
    go processData([]byte("message2"))
    // ...
}

Important: Using a buffer without synchronization in a concurrent environment will lead to data race conditions, which cause unpredictable program behavior and are difficult to debug.

Is it possible to use the same buffer []byte in multiple goroutines?