</p>

<p>
Not allowing a single read to observe multiple values means
not reloading local variables from shared memory.
For example, a compiler must not discard <code>i</code> and reload it
a second time from <code>*p</code> in this program:
</p>

<pre>
i := *p
if i &lt; 0 || i &gt;= len(funcs) {
	panic("invalid function index")
}
... complex code ...

	cred, seedSignature, region, seedDate, errCode := calculateSeedSignature(req, trailer)
	if errCode != ErrNone {
		return nil, errCode
	}

	if trailer {
		// Discard anything unsigned.
		req.Trailer = make(http.Header)
		trailers := req.Header.Values(awsTrailerHeader)
		for _, key := range trailers {
			req.Trailer.Add(key, "")
		}
	} else {
		req.Trailer = nil
	}

	r, err := client.GetObject(ctx, bucket, object, minio.GetObjectOptions{})
	if err != nil {
		c.Fatalf("user was unable to download the object: %v", err)
	}
	defer r.Close()

	_, err = io.Copy(io.Discard, r)
	if err != nil {
		c.Fatalf("user was unable to download the object: %v", err)
	}
}

func (c *check) mustHeadObject(ctx context.Context, client *minio.Client, bucket, object string, tagCount int) {

				writer.WriteByte('(')
				stmt.AddVar(writer, v...)
				writer.WriteByte(')')
			} else {
				writer.WriteString("(NULL)")
			}
		case *DB:
			subdb := v.Session(&Session{Logger: logger.Discard, DryRun: true}).getInstance()
			if v.Statement.SQL.Len() > 0 {
				var (
					vars = subdb.Statement.Vars
					sql  = v.Statement.SQL.String()
				)

			// unconsumedTimer fires.
			select {
			// Check after a second
			case <-time.After(time.Second):
				h.mutex.Unlock()
				continue

			case <-h.ctx.Done():
				h.mutex.Unlock()
				// discard result and return.
				return errHealStopSignalled

			// Timeout if no results consumed for too long.
			case <-unconsumedTimer.C:
				h.mutex.Unlock()
				return errHealIdleTimeout
			}
		}
		break

      TYPE_GOAWAY -> readGoAway(handler, length, flags, streamId)
      TYPE_WINDOW_UPDATE -> readWindowUpdate(handler, length, flags, streamId)
      else -> source.skip(length.toLong()) // Implementations MUST discard frames of unknown types.
    }

    return true
  }

  @Throws(IOException::class)
  private fun readHeaders(
    handler: Handler,
    length: Int,
    flags: Int,
    streamId: Int,

* los datos enviados por tu programa para ser recibidos por el cliente a través de la red
* el contenido de un archivo en disco para ser leído por el sistema y entregado al programa
* los contenidos que tu programa da al sistema para ser escritos en disco
* una operación relacionada con una API remota
* una operación de base de datos
* el retorno de resultados de una consulta de base de datos
* etc.

   *
   * <p>Prefer this method instead of manually casting an exception's cause. For example, {@code
   * (IOException) e.getCause()} throws a {@link ClassCastException} that discards the original
   * exception {@code e} if the cause is not an {@link IOException}, but {@code
   * Throwables.getCauseAs(e, IOException.class)} keeps {@code e} as the {@link
   * ClassCastException}'s cause.
   *

   *
   * <p>Prefer this method instead of manually casting an exception's cause. For example, {@code
   * (IOException) e.getCause()} throws a {@link ClassCastException} that discards the original
   * exception {@code e} if the cause is not an {@link IOException}, but {@code
   * Throwables.getCauseAs(e, IOException.class)} keeps {@code e} as the {@link
   * ClassCastException}'s cause.
   *

func (b *Buffer) Cap() int { return cap(b.buf) }

// Available returns how many bytes are unused in the buffer.
func (b *Buffer) Available() int { return cap(b.buf) - len(b.buf) }

// Truncate discards all but the first n unread bytes from the buffer
// but continues to use the same allocated storage.
// It panics if n is negative or greater than the length of the buffer.
func (b *Buffer) Truncate(n int) {
	if n == 0 {