err = rb.WriteByte(buf[0])
			if err != nil {
				t.Fatalf("write failed: %v", err)
			}
			wroteBytes++
			wrote.Write(buf[:1])
			debugln("WRITE 3\t", 1, wroteBytes)

			// TryWrite
			n, err = rb.TryWrite(buf[:writeRng.Intn(len(buf))])
			if err != nil && err != ErrAcquireLock && err != ErrTooMuchDataToWrite && err != ErrIsFull {
				t.Fatalf("write failed: %v", err)
			}
			wroteBytes += n

	}
	if r.block && wrote > 0 {
		r.writeCond.Broadcast()
	}

	return wrote, r.setErr(err, true)
}

// TryWrite writes len(p) bytes from p to the underlying buf like Write, but it is not blocking.
// If it has not succeeded to acquire the lock, it return 0 as n and ErrAcquireLock.
func (r *RingBuffer) TryWrite(p []byte) (n int, err error) {
	if len(p) == 0 {
		return 0, r.setErr(nil, false)
	}
	ok := r.mu.TryLock()