> For the complete documentation index, see [llms.txt](https://ineelhere.gitbook.io/code-with-go/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://ineelhere.gitbook.io/code-with-go/28-channel-synchronization.md).

# Channel Synchronization

This Go code showcases the use of a channel (`done`) to signal the completion of work in a goroutine.

Let's break it down with inline comments:

```go
package main

import (
    "fmt"
    "time"
)

// Function representing a worker that performs some work and signals completion through a channel
func worker(done chan bool) {
    fmt.Print("working...")    // Print a message indicating work is being done
    time.Sleep(time.Second)     // Simulate work by sleeping for one second
    fmt.Println("done")         // Print a message indicating work is done

    done <- true                // Send a signal (boolean value true) through the 'done' channel
}

func main() {
    // Creating a buffered channel named 'done' with a capacity of 1
    done := make(chan bool, 1)

    // Launching a goroutine to execute the 'worker' function with the 'done' channel
    go worker(done)

    // Blocking operation: Receiving a signal from the 'done' channel, indicating that the work is complete
    <-done
}
```

#### Output

```
working...done
```

Explanation:

1. `package main`: Indicates that this Go file belongs to the main executable package.
2. `import (...)`: Imports necessary packages, including "fmt" for formatting and printing, and "time" for handling time-related operations.
3. `func worker(done chan bool) { ... }`: Defines a function `worker` that takes a channel `done` as a parameter. This function simulates work by printing messages, sleeping for one second, and then sending a signal (`true`) through the channel to indicate that the work is complete.
4. `func main() { ... }`: The main function, where the execution of the program begins.
5. `done := make(chan bool, 1)`: Creates a buffered channel named 'done' with a capacity of 1. The buffer size ensures that the channel can hold one value without requiring a corresponding receiver to be ready.
6. `go worker(done)`: Launches a new goroutine to execute the `worker` function with the `done` channel as a parameter.
7. `<-done`: Blocks the main goroutine until a value is received from the `done` channel. This serves as a synchronization point, ensuring that the main goroutine waits until the worker goroutine has completed its work and sent the signal.

In summary, this code demonstrates how to use a channel to signal the completion of work between goroutines. The main goroutine launches a worker goroutine, and the main goroutine waits for a signal from the worker before proceeding further. This pattern is commonly used for synchronization in concurrent programming.