buffered-unbuffered

Buffered vs Unbuffered Channels

The example shows the difference between buffered and unbuffered channels.

Channel Capacity and Length

Capacity of a channel is defined as the number of values a channel can hold. Length is defined as the number of values that are currently enqueued in the channel buffer. For example:

ch := make(chan int, 5)
ch <- 1
ch <- 2
// Output: cap: 5, len: 2
fmt.Printf("cap: %d, len: %d\n", cap(ch), len(ch))

Buffered vs Unbuffered

There are 2 types of channels:

• Buffered channel - Asynchronous channel. This means make(chan int, n) where n >= 1.
  • A goroutine that writes to a sending channel will be blocked until there is room available in the buffer.
  • A goroutine reading a value from a receiving channel will be blocked until a value is placed into the channel.
• Unbuffered channel - Synchronous channel. It has the length and capacity of 0 ie. make(chan int) is the same as make(chan int, 0). This means that channel always full and the associated goroutine will be blocked after writing to the channel unless the receiving channel reads the value.

Setup

1. Run the program.

   $ make run

Reference

• Go: Channels