package atomic_test
import (
+ "fmt"
"runtime"
+ "strings"
. "sync/atomic"
"testing"
"unsafe"
return nil
}()
+func TestSwapInt32(t *testing.T) {
+ var x struct {
+ before int32
+ i int32
+ after int32
+ }
+ x.before = magic32
+ x.after = magic32
+ var j int32
+ for delta := int32(1); delta+delta > delta; delta += delta {
+ k := SwapInt32(&x.i, delta)
+ if x.i != delta || k != j {
+ t.Fatalf("delta=%d i=%d j=%d k=%d", delta, x.i, j, k)
+ }
+ j = delta
+ }
+ if x.before != magic32 || x.after != magic32 {
+ t.Fatalf("wrong magic: %#x _ %#x != %#x _ %#x", x.before, x.after, magic32, magic32)
+ }
+}
+
+func TestSwapUint32(t *testing.T) {
+ var x struct {
+ before uint32
+ i uint32
+ after uint32
+ }
+ x.before = magic32
+ x.after = magic32
+ var j uint32
+ for delta := uint32(1); delta+delta > delta; delta += delta {
+ k := SwapUint32(&x.i, delta)
+ if x.i != delta || k != j {
+ t.Fatalf("delta=%d i=%d j=%d k=%d", delta, x.i, j, k)
+ }
+ j = delta
+ }
+ if x.before != magic32 || x.after != magic32 {
+ t.Fatalf("wrong magic: %#x _ %#x != %#x _ %#x", x.before, x.after, magic32, magic32)
+ }
+}
+
+func TestSwapInt64(t *testing.T) {
+ if test64err != nil {
+ t.Skipf("Skipping 64-bit tests: %v", test64err)
+ }
+ var x struct {
+ before int64
+ i int64
+ after int64
+ }
+ x.before = magic64
+ x.after = magic64
+ var j int64
+ for delta := int64(1); delta+delta > delta; delta += delta {
+ k := SwapInt64(&x.i, delta)
+ if x.i != delta || k != j {
+ t.Fatalf("delta=%d i=%d j=%d k=%d", delta, x.i, j, k)
+ }
+ j = delta
+ }
+ if x.before != magic64 || x.after != magic64 {
+ t.Fatalf("wrong magic: %#x _ %#x != %#x _ %#x", x.before, x.after, uint64(magic64), uint64(magic64))
+ }
+}
+
+func TestSwapUint64(t *testing.T) {
+ if test64err != nil {
+ t.Skipf("Skipping 64-bit tests: %v", test64err)
+ }
+ var x struct {
+ before uint64
+ i uint64
+ after uint64
+ }
+ x.before = magic64
+ x.after = magic64
+ var j uint64
+ for delta := uint64(1); delta+delta > delta; delta += delta {
+ k := SwapUint64(&x.i, delta)
+ if x.i != delta || k != j {
+ t.Fatalf("delta=%d i=%d j=%d k=%d", delta, x.i, j, k)
+ }
+ j = delta
+ }
+ if x.before != magic64 || x.after != magic64 {
+ t.Fatalf("wrong magic: %#x _ %#x != %#x _ %#x", x.before, x.after, uint64(magic64), uint64(magic64))
+ }
+}
+
+func TestSwapUintptr(t *testing.T) {
+ var x struct {
+ before uintptr
+ i uintptr
+ after uintptr
+ }
+ var m uint64 = magic64
+ magicptr := uintptr(m)
+ x.before = magicptr
+ x.after = magicptr
+ var j uintptr
+ for delta := uintptr(1); delta+delta > delta; delta += delta {
+ k := SwapUintptr(&x.i, delta)
+ if x.i != delta || k != j {
+ t.Fatalf("delta=%d i=%d j=%d k=%d", delta, x.i, j, k)
+ }
+ j = delta
+ }
+ if x.before != magicptr || x.after != magicptr {
+ t.Fatalf("wrong magic: %#x _ %#x != %#x _ %#x", x.before, x.after, magicptr, magicptr)
+ }
+}
+
+func TestSwapPointer(t *testing.T) {
+ var x struct {
+ before uintptr
+ i unsafe.Pointer
+ after uintptr
+ }
+ var m uint64 = magic64
+ magicptr := uintptr(m)
+ x.before = magicptr
+ x.after = magicptr
+ var j uintptr
+ for delta := uintptr(1); delta+delta > delta; delta += delta {
+ k := SwapPointer(&x.i, unsafe.Pointer(delta))
+ if uintptr(x.i) != delta || uintptr(k) != j {
+ t.Fatalf("delta=%d i=%d j=%d k=%d", delta, x.i, j, k)
+ }
+ j = delta
+ }
+ if x.before != magicptr || x.after != magicptr {
+ t.Fatalf("wrong magic: %#x _ %#x != %#x _ %#x", x.before, x.after, magicptr, magicptr)
+ }
+}
+
func TestAddInt32(t *testing.T) {
var x struct {
before int32
// uses the atomic operation to add 1 to a value. After running
// multiple hammers in parallel, check that we end with the correct
// total.
-
-var hammer32 = []struct {
- name string
- f func(*uint32, int)
-}{
- {"AddInt32", hammerAddInt32},
- {"AddUint32", hammerAddUint32},
- {"AddUintptr", hammerAddUintptr32},
- {"CompareAndSwapInt32", hammerCompareAndSwapInt32},
- {"CompareAndSwapUint32", hammerCompareAndSwapUint32},
- {"CompareAndSwapUintptr", hammerCompareAndSwapUintptr32},
- {"CompareAndSwapPointer", hammerCompareAndSwapPointer32},
+// Swap can't add 1, so it uses a different scheme.
+// The functions repeatedly generate a pseudo-random number such that
+// low bits are equal to high bits, swap, check that the old value
+// has low and high bits equal.
+
+var hammer32 = map[string]func(*uint32, int){
+ "SwapInt32": hammerSwapInt32,
+ "SwapUint32": hammerSwapUint32,
+ "SwapUintptr": hammerSwapUintptr32,
+ "SwapPointer": hammerSwapPointer32,
+ "AddInt32": hammerAddInt32,
+ "AddUint32": hammerAddUint32,
+ "AddUintptr": hammerAddUintptr32,
+ "CompareAndSwapInt32": hammerCompareAndSwapInt32,
+ "CompareAndSwapUint32": hammerCompareAndSwapUint32,
+ "CompareAndSwapUintptr": hammerCompareAndSwapUintptr32,
+ "CompareAndSwapPointer": hammerCompareAndSwapPointer32,
}
func init() {
var v uint64 = 1 << 50
if uintptr(v) != 0 {
// 64-bit system; clear uintptr tests
- hammer32[2].f = nil
- hammer32[5].f = nil
- hammer32[6].f = nil
+ delete(hammer32, "SwapUintptr")
+ delete(hammer32, "SwapPointer")
+ delete(hammer32, "AddUintptr")
+ delete(hammer32, "CompareAndSwapUintptr")
+ delete(hammer32, "CompareAndSwapPointer")
+ }
+}
+
+func hammerSwapInt32(uaddr *uint32, count int) {
+ addr := (*int32)(unsafe.Pointer(uaddr))
+ seed := int(uintptr(unsafe.Pointer(&count)))
+ for i := 0; i < count; i++ {
+ new := uint32(seed+i)<<16 | uint32(seed+i)<<16>>16
+ old := uint32(SwapInt32(addr, int32(new)))
+ if old>>16 != old<<16>>16 {
+ panic(fmt.Sprintf("SwapInt32 is not atomic: %v", old))
+ }
+ }
+}
+
+func hammerSwapUint32(addr *uint32, count int) {
+ seed := int(uintptr(unsafe.Pointer(&count)))
+ for i := 0; i < count; i++ {
+ new := uint32(seed+i)<<16 | uint32(seed+i)<<16>>16
+ old := SwapUint32(addr, new)
+ if old>>16 != old<<16>>16 {
+ panic(fmt.Sprintf("SwapUint32 is not atomic: %v", old))
+ }
+ }
+}
+
+func hammerSwapUintptr32(uaddr *uint32, count int) {
+ // only safe when uintptr is 32-bit.
+ // not called on 64-bit systems.
+ addr := (*uintptr)(unsafe.Pointer(uaddr))
+ seed := int(uintptr(unsafe.Pointer(&count)))
+ for i := 0; i < count; i++ {
+ new := uintptr(seed+i)<<16 | uintptr(seed+i)<<16>>16
+ old := SwapUintptr(addr, new)
+ if old>>16 != old<<16>>16 {
+ panic(fmt.Sprintf("SwapUintptr is not atomic: %v", old))
+ }
+ }
+}
+
+func hammerSwapPointer32(uaddr *uint32, count int) {
+ // only safe when uintptr is 32-bit.
+ // not called on 64-bit systems.
+ addr := (*unsafe.Pointer)(unsafe.Pointer(uaddr))
+ seed := int(uintptr(unsafe.Pointer(&count)))
+ for i := 0; i < count; i++ {
+ new := uintptr(seed+i)<<16 | uintptr(seed+i)<<16>>16
+ old := uintptr(SwapPointer(addr, unsafe.Pointer(new)))
+ if old>>16 != old<<16>>16 {
+ panic(fmt.Sprintf("SwapPointer is not atomic: %v", old))
+ }
}
}
}
defer runtime.GOMAXPROCS(runtime.GOMAXPROCS(p))
- for _, tt := range hammer32 {
- if tt.f == nil {
- continue
- }
+ for name, testf := range hammer32 {
c := make(chan int)
var val uint32
for i := 0; i < p; i++ {
go func() {
- tt.f(&val, n)
- c <- 1
+ defer func() {
+ if err := recover(); err != nil {
+ t.Error(err.(string))
+ }
+ c <- 1
+ }()
+ testf(&val, n)
}()
}
for i := 0; i < p; i++ {
<-c
}
- if val != uint32(n)*p {
- t.Fatalf("%s: val=%d want %d", tt.name, val, n*p)
+ if !strings.HasPrefix(name, "Swap") && val != uint32(n)*p {
+ t.Fatalf("%s: val=%d want %d", name, val, n*p)
}
}
}
-var hammer64 = []struct {
- name string
- f func(*uint64, int)
-}{
- {"AddInt64", hammerAddInt64},
- {"AddUint64", hammerAddUint64},
- {"AddUintptr", hammerAddUintptr64},
- {"CompareAndSwapInt64", hammerCompareAndSwapInt64},
- {"CompareAndSwapUint64", hammerCompareAndSwapUint64},
- {"CompareAndSwapUintptr", hammerCompareAndSwapUintptr64},
- {"CompareAndSwapPointer", hammerCompareAndSwapPointer64},
+var hammer64 = map[string]func(*uint64, int){
+ "SwapInt64": hammerSwapInt64,
+ "SwapUint64": hammerSwapUint64,
+ "SwapUintptr": hammerSwapUintptr64,
+ "SwapPointer": hammerSwapPointer64,
+ "AddInt64": hammerAddInt64,
+ "AddUint64": hammerAddUint64,
+ "AddUintptr": hammerAddUintptr64,
+ "CompareAndSwapInt64": hammerCompareAndSwapInt64,
+ "CompareAndSwapUint64": hammerCompareAndSwapUint64,
+ "CompareAndSwapUintptr": hammerCompareAndSwapUintptr64,
+ "CompareAndSwapPointer": hammerCompareAndSwapPointer64,
}
func init() {
var v uint64 = 1 << 50
if uintptr(v) == 0 {
// 32-bit system; clear uintptr tests
- hammer64[2].f = nil
- hammer64[5].f = nil
- hammer64[6].f = nil
+ delete(hammer64, "SwapUintptr")
+ delete(hammer64, "SwapPointer")
+ delete(hammer64, "AddUintptr")
+ delete(hammer64, "CompareAndSwapUintptr")
+ delete(hammer64, "CompareAndSwapPointer")
+ }
+}
+
+func hammerSwapInt64(uaddr *uint64, count int) {
+ addr := (*int64)(unsafe.Pointer(uaddr))
+ seed := int(uintptr(unsafe.Pointer(&count)))
+ for i := 0; i < count; i++ {
+ new := uint64(seed+i)<<32 | uint64(seed+i)<<32>>32
+ old := uint64(SwapInt64(addr, int64(new)))
+ if old>>32 != old<<32>>32 {
+ panic(fmt.Sprintf("SwapInt64 is not atomic: %v", old))
+ }
+ }
+}
+
+func hammerSwapUint64(addr *uint64, count int) {
+ seed := int(uintptr(unsafe.Pointer(&count)))
+ for i := 0; i < count; i++ {
+ new := uint64(seed+i)<<32 | uint64(seed+i)<<32>>32
+ old := SwapUint64(addr, new)
+ if old>>32 != old<<32>>32 {
+ panic(fmt.Sprintf("SwapUint64 is not atomic: %v", old))
+ }
+ }
+}
+
+func hammerSwapUintptr64(uaddr *uint64, count int) {
+ // only safe when uintptr is 64-bit.
+ // not called on 32-bit systems.
+ addr := (*uintptr)(unsafe.Pointer(uaddr))
+ seed := int(uintptr(unsafe.Pointer(&count)))
+ for i := 0; i < count; i++ {
+ new := uintptr(seed+i)<<32 | uintptr(seed+i)<<32>>32
+ old := SwapUintptr(addr, new)
+ if old>>32 != old<<32>>32 {
+ panic(fmt.Sprintf("SwapUintptr is not atomic: %v", old))
+ }
+ }
+}
+
+func hammerSwapPointer64(uaddr *uint64, count int) {
+ // only safe when uintptr is 64-bit.
+ // not called on 32-bit systems.
+ addr := (*unsafe.Pointer)(unsafe.Pointer(uaddr))
+ seed := int(uintptr(unsafe.Pointer(&count)))
+ for i := 0; i < count; i++ {
+ new := uintptr(seed+i)<<32 | uintptr(seed+i)<<32>>32
+ old := uintptr(SwapPointer(addr, unsafe.Pointer(new)))
+ if old>>32 != old<<32>>32 {
+ panic(fmt.Sprintf("SwapPointer is not atomic: %v", old))
+ }
}
}
}
defer runtime.GOMAXPROCS(runtime.GOMAXPROCS(p))
- for _, tt := range hammer64 {
- if tt.f == nil {
- continue
- }
+ for name, testf := range hammer64 {
c := make(chan int)
var val uint64
for i := 0; i < p; i++ {
go func() {
- tt.f(&val, n)
- c <- 1
+ defer func() {
+ if err := recover(); err != nil {
+ t.Error(err.(string))
+ }
+ c <- 1
+ }()
+ testf(&val, n)
}()
}
for i := 0; i < p; i++ {
<-c
}
- if val != uint64(n)*p {
- t.Fatalf("%s: val=%d want %d", tt.name, val, n*p)
+ if !strings.HasPrefix(name, "Swap") && val != uint64(n)*p {
+ t.Fatalf("%s: val=%d want %d", name, val, n*p)
}
}
}