<p>
The exit of a goroutine is not guaranteed to be synchronized before
any event in the program.
For example, in this program:
</p>

<pre>
var a string

func hello() {
	go func() { a = "hello" }()
	print(a)
}
</pre>

<p>
the assignment to <code>a</code> is not followed by
any synchronization event, so it is not guaranteed to be
observed by any other goroutine.