65 Goroutines

A goroutine is a lightweight thread managed by the Go runtime.

`go f(x, y, z)`

starts a new goroutine running

`f(x, y, z)`

The evaluation of f, x, y, and z happens in the current goroutine
and the execution of f happens in the new goroutine.

Goroutines run in the same address space,
so access to shared memory must be synchronized.
The sync package provides useful primitives, although you won't need
them much in Go as there are other primitives.
66 Channels

Channels are a typed conduit through which you can send and receive values with the channel operator, <-.

```
ch <- v    // Send v to channel ch.
v := <-ch  // Receive from ch, and
// assign value to v.
(The data flows in the direction of the arrow.)
```

Like maps and slices, channels must be created before use:

```
ch := make(chan int)
```

By default, sends and receives block until the other side is ready.
his allows goroutines to synchronize without explicit locks or condition variables.
67 Buffered Channels

Channels can be buffered.
Provide the buffer length as the second argument to make to initialize a buffered channel:

```
ch := make(chan int, 100)
```

Sends to a buffered channel block only when the buffer is full.
Receives block when the buffer is empty.
Modify the example to overfill the buffer and see what happens.