| // Copyright 2024 The Go Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| package runtime_test |
| |
| import ( |
| . "runtime" |
| "testing" |
| ) |
| |
| func TestBitCursor(t *testing.T) { |
| ones := [5]byte{0xff, 0xff, 0xff, 0xff, 0xff} |
| zeros := [5]byte{0, 0, 0, 0, 0} |
| |
| for start := uintptr(0); start < 16; start++ { |
| for end := start + 1; end < 32; end++ { |
| buf := zeros |
| NewBitCursor(&buf[0]).Offset(start).Write(&ones[0], end-start) |
| |
| for i := uintptr(0); i < uintptr(len(buf)*8); i++ { |
| bit := buf[i/8] >> (i % 8) & 1 |
| if bit == 0 && i >= start && i < end { |
| t.Errorf("bit %d not set in [%d:%d]", i, start, end) |
| } |
| if bit == 1 && (i < start || i >= end) { |
| t.Errorf("bit %d is set outside [%d:%d]", i, start, end) |
| } |
| } |
| } |
| } |
| |
| for start := uintptr(0); start < 16; start++ { |
| for end := start + 1; end < 32; end++ { |
| buf := ones |
| NewBitCursor(&buf[0]).Offset(start).Write(&zeros[0], end-start) |
| |
| for i := uintptr(0); i < uintptr(len(buf)*8); i++ { |
| bit := buf[i/8] >> (i % 8) & 1 |
| if bit == 1 && i >= start && i < end { |
| t.Errorf("bit %d not cleared in [%d:%d]", i, start, end) |
| } |
| if bit == 0 && (i < start || i >= end) { |
| t.Errorf("bit %d cleared outside [%d:%d]", i, start, end) |
| } |
| } |
| } |
| } |
| } |