// Copyright 2018 The gVisor Authors. // // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. // You may obtain a copy of the License at // // http://www.apache.org/licenses/LICENSE-2.0 // // Unless required by applicable law or agreed to in writing, software // distributed under the License is distributed on an "AS IS" BASIS, // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. // See the License for the specific language governing permissions and // limitations under the License. package atomicbitops import ( "runtime" "testing" "gvisor.dev/gvisor/pkg/sync" ) const iterations = 100 func detectRaces32(val, target uint32, fn func(*uint32, uint32)) bool { runtime.GOMAXPROCS(100) for n := 0; n < iterations; n++ { x := val var wg sync.WaitGroup for i := uint32(0); i < 32; i++ { wg.Add(1) go func(a *uint32, i uint32) { defer wg.Done() fn(a, uint32(1<<i)) }(&x, i) } wg.Wait() if x != target { return true } } return false } func detectRaces64(val, target uint64, fn func(*uint64, uint64)) bool { runtime.GOMAXPROCS(100) for n := 0; n < iterations; n++ { x := val var wg sync.WaitGroup for i := uint64(0); i < 64; i++ { wg.Add(1) go func(a *uint64, i uint64) { defer wg.Done() fn(a, uint64(1<<i)) }(&x, i) } wg.Wait() if x != target { return true } } return false } func TestOrUint32(t *testing.T) { if detectRaces32(0x0, 0xffffffff, OrUint32) { t.Error("Data race detected!") } } func TestAndUint32(t *testing.T) { if detectRaces32(0xf0f0f0f0, 0x00000000, AndUint32) { t.Error("Data race detected!") } } func TestXorUint32(t *testing.T) { if detectRaces32(0xf0f0f0f0, 0x0f0f0f0f, XorUint32) { t.Error("Data race detected!") } } func TestOrUint64(t *testing.T) { if detectRaces64(0x0, 0xffffffffffffffff, OrUint64) { t.Error("Data race detected!") } } func TestAndUint64(t *testing.T) { if detectRaces64(0xf0f0f0f0f0f0f0f0, 0x0, AndUint64) { t.Error("Data race detected!") } } func TestXorUint64(t *testing.T) { if detectRaces64(0xf0f0f0f0f0f0f0f0, 0x0f0f0f0f0f0f0f0f, XorUint64) { t.Error("Data race detected!") } } func TestCompareAndSwapUint32(t *testing.T) { tests := []struct { name string prev uint32 old uint32 new uint32 next uint32 }{ { name: "Successful compare-and-swap with prev == new", prev: 10, old: 10, new: 10, next: 10, }, { name: "Successful compare-and-swap with prev != new", prev: 20, old: 20, new: 22, next: 22, }, { name: "Failed compare-and-swap with prev == new", prev: 31, old: 30, new: 31, next: 31, }, { name: "Failed compare-and-swap with prev != new", prev: 41, old: 40, new: 42, next: 41, }, } for _, test := range tests { val := test.prev prev := CompareAndSwapUint32(&val, test.old, test.new) if got, want := prev, test.prev; got != want { t.Errorf("%s: incorrect returned previous value: got %d, expected %d", test.name, got, want) } if got, want := val, test.next; got != want { t.Errorf("%s: incorrect value stored in val: got %d, expected %d", test.name, got, want) } } } func TestCompareAndSwapUint64(t *testing.T) { tests := []struct { name string prev uint64 old uint64 new uint64 next uint64 }{ { name: "Successful compare-and-swap with prev == new", prev: 0x100000000, old: 0x100000000, new: 0x100000000, next: 0x100000000, }, { name: "Successful compare-and-swap with prev != new", prev: 0x200000000, old: 0x200000000, new: 0x200000002, next: 0x200000002, }, { name: "Failed compare-and-swap with prev == new", prev: 0x300000001, old: 0x300000000, new: 0x300000001, next: 0x300000001, }, { name: "Failed compare-and-swap with prev != new", prev: 0x400000001, old: 0x400000000, new: 0x400000002, next: 0x400000001, }, } for _, test := range tests { val := test.prev prev := CompareAndSwapUint64(&val, test.old, test.new) if got, want := prev, test.prev; got != want { t.Errorf("%s: incorrect returned previous value: got %d, expected %d", test.name, got, want) } if got, want := val, test.next; got != want { t.Errorf("%s: incorrect value stored in val: got %d, expected %d", test.name, got, want) } } }