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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-16 19:23:18 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-16 19:23:18 +0000 |
commit | 43a123c1ae6613b3efeed291fa552ecd909d3acf (patch) | |
tree | fd92518b7024bc74031f78a1cf9e454b65e73665 /src/runtime/internal/atomic/atomic_test.go | |
parent | Initial commit. (diff) | |
download | golang-1.20-upstream.tar.xz golang-1.20-upstream.zip |
Adding upstream version 1.20.14.upstream/1.20.14upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/runtime/internal/atomic/atomic_test.go')
-rw-r--r-- | src/runtime/internal/atomic/atomic_test.go | 386 |
1 files changed, 386 insertions, 0 deletions
diff --git a/src/runtime/internal/atomic/atomic_test.go b/src/runtime/internal/atomic/atomic_test.go new file mode 100644 index 0000000..2427bfd --- /dev/null +++ b/src/runtime/internal/atomic/atomic_test.go @@ -0,0 +1,386 @@ +// Copyright 2015 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 atomic_test + +import ( + "internal/goarch" + "runtime" + "runtime/internal/atomic" + "testing" + "unsafe" +) + +func runParallel(N, iter int, f func()) { + defer runtime.GOMAXPROCS(runtime.GOMAXPROCS(int(N))) + done := make(chan bool) + for i := 0; i < N; i++ { + go func() { + for j := 0; j < iter; j++ { + f() + } + done <- true + }() + } + for i := 0; i < N; i++ { + <-done + } +} + +func TestXadduintptr(t *testing.T) { + N := 20 + iter := 100000 + if testing.Short() { + N = 10 + iter = 10000 + } + inc := uintptr(100) + total := uintptr(0) + runParallel(N, iter, func() { + atomic.Xadduintptr(&total, inc) + }) + if want := uintptr(N*iter) * inc; want != total { + t.Fatalf("xadduintpr error, want %d, got %d", want, total) + } + total = 0 + runParallel(N, iter, func() { + atomic.Xadduintptr(&total, inc) + atomic.Xadduintptr(&total, uintptr(-int64(inc))) + }) + if total != 0 { + t.Fatalf("xadduintpr total error, want %d, got %d", 0, total) + } +} + +// Tests that xadduintptr correctly updates 64-bit values. The place where +// we actually do so is mstats.go, functions mSysStat{Inc,Dec}. +func TestXadduintptrOnUint64(t *testing.T) { + if goarch.BigEndian { + // On big endian architectures, we never use xadduintptr to update + // 64-bit values and hence we skip the test. (Note that functions + // mSysStat{Inc,Dec} in mstats.go have explicit checks for + // big-endianness.) + t.Skip("skip xadduintptr on big endian architecture") + } + const inc = 100 + val := uint64(0) + atomic.Xadduintptr((*uintptr)(unsafe.Pointer(&val)), inc) + if inc != val { + t.Fatalf("xadduintptr should increase lower-order bits, want %d, got %d", inc, val) + } +} + +func shouldPanic(t *testing.T, name string, f func()) { + defer func() { + // Check that all GC maps are sane. + runtime.GC() + + err := recover() + want := "unaligned 64-bit atomic operation" + if err == nil { + t.Errorf("%s did not panic", name) + } else if s, _ := err.(string); s != want { + t.Errorf("%s: wanted panic %q, got %q", name, want, err) + } + }() + f() +} + +// Variant of sync/atomic's TestUnaligned64: +func TestUnaligned64(t *testing.T) { + // Unaligned 64-bit atomics on 32-bit systems are + // a continual source of pain. Test that on 32-bit systems they crash + // instead of failing silently. + + if unsafe.Sizeof(int(0)) != 4 { + t.Skip("test only runs on 32-bit systems") + } + + x := make([]uint32, 4) + u := unsafe.Pointer(uintptr(unsafe.Pointer(&x[0])) | 4) // force alignment to 4 + + up64 := (*uint64)(u) // misaligned + p64 := (*int64)(u) // misaligned + + shouldPanic(t, "Load64", func() { atomic.Load64(up64) }) + shouldPanic(t, "Loadint64", func() { atomic.Loadint64(p64) }) + shouldPanic(t, "Store64", func() { atomic.Store64(up64, 0) }) + shouldPanic(t, "Xadd64", func() { atomic.Xadd64(up64, 1) }) + shouldPanic(t, "Xchg64", func() { atomic.Xchg64(up64, 1) }) + shouldPanic(t, "Cas64", func() { atomic.Cas64(up64, 1, 2) }) +} + +func TestAnd8(t *testing.T) { + // Basic sanity check. + x := uint8(0xff) + for i := uint8(0); i < 8; i++ { + atomic.And8(&x, ^(1 << i)) + if r := uint8(0xff) << (i + 1); x != r { + t.Fatalf("clearing bit %#x: want %#x, got %#x", uint8(1<<i), r, x) + } + } + + // Set every bit in array to 1. + a := make([]uint8, 1<<12) + for i := range a { + a[i] = 0xff + } + + // Clear array bit-by-bit in different goroutines. + done := make(chan bool) + for i := 0; i < 8; i++ { + m := ^uint8(1 << i) + go func() { + for i := range a { + atomic.And8(&a[i], m) + } + done <- true + }() + } + for i := 0; i < 8; i++ { + <-done + } + + // Check that the array has been totally cleared. + for i, v := range a { + if v != 0 { + t.Fatalf("a[%v] not cleared: want %#x, got %#x", i, uint8(0), v) + } + } +} + +func TestAnd(t *testing.T) { + // Basic sanity check. + x := uint32(0xffffffff) + for i := uint32(0); i < 32; i++ { + atomic.And(&x, ^(1 << i)) + if r := uint32(0xffffffff) << (i + 1); x != r { + t.Fatalf("clearing bit %#x: want %#x, got %#x", uint32(1<<i), r, x) + } + } + + // Set every bit in array to 1. + a := make([]uint32, 1<<12) + for i := range a { + a[i] = 0xffffffff + } + + // Clear array bit-by-bit in different goroutines. + done := make(chan bool) + for i := 0; i < 32; i++ { + m := ^uint32(1 << i) + go func() { + for i := range a { + atomic.And(&a[i], m) + } + done <- true + }() + } + for i := 0; i < 32; i++ { + <-done + } + + // Check that the array has been totally cleared. + for i, v := range a { + if v != 0 { + t.Fatalf("a[%v] not cleared: want %#x, got %#x", i, uint32(0), v) + } + } +} + +func TestOr8(t *testing.T) { + // Basic sanity check. + x := uint8(0) + for i := uint8(0); i < 8; i++ { + atomic.Or8(&x, 1<<i) + if r := (uint8(1) << (i + 1)) - 1; x != r { + t.Fatalf("setting bit %#x: want %#x, got %#x", uint8(1)<<i, r, x) + } + } + + // Start with every bit in array set to 0. + a := make([]uint8, 1<<12) + + // Set every bit in array bit-by-bit in different goroutines. + done := make(chan bool) + for i := 0; i < 8; i++ { + m := uint8(1 << i) + go func() { + for i := range a { + atomic.Or8(&a[i], m) + } + done <- true + }() + } + for i := 0; i < 8; i++ { + <-done + } + + // Check that the array has been totally set. + for i, v := range a { + if v != 0xff { + t.Fatalf("a[%v] not fully set: want %#x, got %#x", i, uint8(0xff), v) + } + } +} + +func TestOr(t *testing.T) { + // Basic sanity check. + x := uint32(0) + for i := uint32(0); i < 32; i++ { + atomic.Or(&x, 1<<i) + if r := (uint32(1) << (i + 1)) - 1; x != r { + t.Fatalf("setting bit %#x: want %#x, got %#x", uint32(1)<<i, r, x) + } + } + + // Start with every bit in array set to 0. + a := make([]uint32, 1<<12) + + // Set every bit in array bit-by-bit in different goroutines. + done := make(chan bool) + for i := 0; i < 32; i++ { + m := uint32(1 << i) + go func() { + for i := range a { + atomic.Or(&a[i], m) + } + done <- true + }() + } + for i := 0; i < 32; i++ { + <-done + } + + // Check that the array has been totally set. + for i, v := range a { + if v != 0xffffffff { + t.Fatalf("a[%v] not fully set: want %#x, got %#x", i, uint32(0xffffffff), v) + } + } +} + +func TestBitwiseContended8(t *testing.T) { + // Start with every bit in array set to 0. + a := make([]uint8, 16) + + // Iterations to try. + N := 1 << 16 + if testing.Short() { + N = 1 << 10 + } + + // Set and then clear every bit in the array bit-by-bit in different goroutines. + done := make(chan bool) + for i := 0; i < 8; i++ { + m := uint8(1 << i) + go func() { + for n := 0; n < N; n++ { + for i := range a { + atomic.Or8(&a[i], m) + if atomic.Load8(&a[i])&m != m { + t.Errorf("a[%v] bit %#x not set", i, m) + } + atomic.And8(&a[i], ^m) + if atomic.Load8(&a[i])&m != 0 { + t.Errorf("a[%v] bit %#x not clear", i, m) + } + } + } + done <- true + }() + } + for i := 0; i < 8; i++ { + <-done + } + + // Check that the array has been totally cleared. + for i, v := range a { + if v != 0 { + t.Fatalf("a[%v] not cleared: want %#x, got %#x", i, uint8(0), v) + } + } +} + +func TestBitwiseContended(t *testing.T) { + // Start with every bit in array set to 0. + a := make([]uint32, 16) + + // Iterations to try. + N := 1 << 16 + if testing.Short() { + N = 1 << 10 + } + + // Set and then clear every bit in the array bit-by-bit in different goroutines. + done := make(chan bool) + for i := 0; i < 32; i++ { + m := uint32(1 << i) + go func() { + for n := 0; n < N; n++ { + for i := range a { + atomic.Or(&a[i], m) + if atomic.Load(&a[i])&m != m { + t.Errorf("a[%v] bit %#x not set", i, m) + } + atomic.And(&a[i], ^m) + if atomic.Load(&a[i])&m != 0 { + t.Errorf("a[%v] bit %#x not clear", i, m) + } + } + } + done <- true + }() + } + for i := 0; i < 32; i++ { + <-done + } + + // Check that the array has been totally cleared. + for i, v := range a { + if v != 0 { + t.Fatalf("a[%v] not cleared: want %#x, got %#x", i, uint32(0), v) + } + } +} + +func TestCasRel(t *testing.T) { + const _magic = 0x5a5aa5a5 + var x struct { + before uint32 + i uint32 + after uint32 + o uint32 + n uint32 + } + + x.before = _magic + x.after = _magic + for j := 0; j < 32; j += 1 { + x.i = (1 << j) + 0 + x.o = (1 << j) + 0 + x.n = (1 << j) + 1 + if !atomic.CasRel(&x.i, x.o, x.n) { + t.Fatalf("should have swapped %#x %#x", x.o, x.n) + } + + if x.i != x.n { + t.Fatalf("wrong x.i after swap: x.i=%#x x.n=%#x", x.i, x.n) + } + + if x.before != _magic || x.after != _magic { + t.Fatalf("wrong magic: %#x _ %#x != %#x _ %#x", x.before, x.after, _magic, _magic) + } + } +} + +func TestStorepNoWB(t *testing.T) { + var p [2]*int + for i := range p { + atomic.StorepNoWB(unsafe.Pointer(&p[i]), unsafe.Pointer(new(int))) + } + if p[0] == p[1] { + t.Error("Bad escape analysis of StorepNoWB") + } +} |