Channel Types

Unbuffered Channels#

Unbuffered channels have no capacity to store values. When you send a value on an unbuffered channel, the operation will block until another goroutine is ready to receive the value.

ch := make(chan int)  // Unbuffered channel

// In goroutine 1
ch <- 42  // Blocks until goroutine 2 receives

// In goroutine 2
value := <-ch  // Blocks until goroutine 1 sends

This creates a synchronization point between goroutines, ensuring that the sending goroutine and receiving goroutine are synchronized.

Buffered Channels#

Buffered channels have a capacity to store a limited number of values. Sending to a buffered channel only blocks when the buffer is full, and receiving only blocks when the buffer is empty.

ch := make(chan int, 3)  // Buffered channel with capacity 3

ch <- 1  // Doesn't block
ch <- 2  // Doesn't block
ch <- 3  // Doesn't block
ch <- 4  // Blocks until someone receives from the channel

When to Use Each Type#

• Unbuffered channels are best when you want a guarantee that data has been received by another goroutine (synchronization)
• Buffered channels are useful when:
  • You want to decouple the sender and receiver temporally
  • You know the approximate number of values that will be sent
  • You want to batch process items
  • You’re dealing with bursty data and want to smooth out processing

Comparison of Channel Types#