<h2 id="introduction">Introduction</h2>

<p>
The Go memory model specifies the conditions under which
reads of a variable in one goroutine can be guaranteed to
observe values produced by writes to the same variable in a different goroutine.
</p>


<h3 id="advice">Advice</h3>

<p>
Programs that modify data being simultaneously accessed by multiple goroutines
must serialize such access.
</p>

<p>

<h3 id="Uniqueness_of_identifiers">Uniqueness of identifiers</h3>

<p>
Given a set of identifiers, an identifier is called <i>unique</i> if it is
<i>different</i> from every other in the set.
Two identifiers are different if they are spelled differently, or if they
appear in different <a href="#Packages">packages</a> and are not
<a href="#Exported_identifiers">exported</a>. Otherwise, they are the same.
</p>

the name prefix distinguishes
references to the virtual stack pointer from references to the architectural
<code>SP</code> register.
That is, <code>x-8(SP)</code> and <code>-8(SP)</code>
are different memory locations:
the first refers to the virtual stack pointer pseudo-register,
while the second refers to the
hardware's <code>SP</code> register.
</p>

<p>

<p>
<code>B0</code> and <code>B1</code> are different because they are new types
created by distinct <a href="#Type_definitions">type definitions</a>;
<code>func(int, float64) *B0</code> and <code>func(x int, y float64) *[]string</code>
are different because <code>B0</code> is different from <code>[]string</code>;
and <code>P1</code> and <code>P2</code> are different because they are different
type parameters.