github.com/andy-kimball/arenaskl@v0.0.0-20200617143215-f701008588b9/arena_test.go (about) 1 /* 2 * Copyright 2017 Dgraph Labs, Inc. and Contributors 3 * Modifications copyright (C) 2017 Andy Kimball and Contributors 4 * 5 * Licensed under the Apache License, Version 2.0 (the "License"); 6 * you may not use this file except in compliance with the License. 7 * You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 18 package arenaskl 19 20 import ( 21 "math" 22 "testing" 23 24 "github.com/stretchr/testify/require" 25 ) 26 27 // TestArenaSizeOverflow tests that large allocations do not cause Arena's 28 // internal size accounting to overflow and produce incorrect results. 29 func TestArenaSizeOverflow(t *testing.T) { 30 a := NewArena(math.MaxUint32) 31 32 // Allocating under the limit throws no error. 33 offset, err := a.Alloc(math.MaxUint16, 0, Align1) 34 require.Nil(t, err) 35 require.Equal(t, uint32(1), offset) 36 require.Equal(t, uint32(math.MaxUint16)+1, a.Size()) 37 38 // Allocating over the limit could cause an accounting 39 // overflow if 32-bit arithmetic was used. It shouldn't. 40 _, err = a.Alloc(math.MaxUint32, 0, Align1) 41 require.Equal(t, ErrArenaFull, err) 42 require.Equal(t, uint32(math.MaxUint32), a.Size()) 43 44 // Continuing to allocate continues to throw an error. 45 _, err = a.Alloc(math.MaxUint16, 0, Align1) 46 require.Equal(t, ErrArenaFull, err) 47 require.Equal(t, uint32(math.MaxUint32), a.Size()) 48 }