// The WriteCloser's Close method must be used to flush pending data to w.
// The Compressor itself must be safe to invoke from multiple goroutines
// simultaneously, but each returned writer will be used only by
// one goroutine at a time.
type Compressor func(w io.Writer) (io.WriteCloser, error)

// A Decompressor returns a new decompressing reader, reading from r.

Some, such as atomic compare-and-swap, are both read-like and write-like.
</p>

<p>
A <i>goroutine execution</i> is modeled as a set of memory operations executed by a single goroutine.
</p>

<p>
<b>Requirement 1</b>:
The memory operations in each goroutine must correspond to a correct sequential execution of that goroutine,
given the values read from and written to memory.

// panicking goroutine. Executing a call to recover inside a deferred
// function (but not any function called by it) stops the panicking sequence
// by restoring normal execution and retrieves the error value passed to the
// call of panic. If recover is called outside the deferred function it will
// not stop a panicking sequence. In this case, or when the goroutine is not
// panicking, recover returns nil.
//

<p>
The function value and parameters are
<a href="#Calls">evaluated as usual</a>
in the calling goroutine, but
unlike with a regular call, program execution does not wait
for the invoked function to complete.
Instead, the function begins executing independently
in a new goroutine.
When the function terminates, its goroutine also terminates.
If the function has any return values, they are discarded when the
function completes.

</p>

<h3 id="arm">ARM</h3>

<p>
The registers <code>R10</code> and <code>R11</code>
are reserved by the compiler and linker.
</p>

<p>
<code>R10</code> points to the <code>g</code> (goroutine) structure.
Within assembler source code, this pointer must be referred to as <code>g</code>;
the name <code>R10</code> is not recognized.
</p>

<p>

<p>
The function value and parameters are
<a href="#Calls">evaluated as usual</a>
in the calling goroutine, but
unlike with a regular call, program execution does not wait
for the invoked function to complete.
Instead, the function begins executing independently
in a new goroutine.
When the function terminates, its goroutine also terminates.
If the function has any return values, they are discarded when the
function completes.

	// passed on, the hanging adb subprocess will hold them open and
	// go test will hang forever.
	//
	// Avoid that by wrapping stderr, breaking the short circuit and
	// forcing cmd.Run to use another pipe and goroutine to pass
	// along stderr from adb.
	cmd.Stderr = struct{ io.Writer }{os.Stderr}
	err := cmd.Run()

	// Before we process err, flush any further output and get the exit code.
	exitCode, err2 := filter.Finish()

file to which the runtime should write its fatal crash report.
It may be used to construct an automated reporting mechanism for all
unexpected crashes, not just those in goroutines that explicitly use