diff options
| -rw-r--r-- | pkg/sync/seqatomic_unsafe.go | 17 | ||||
| -rw-r--r-- | pkg/sync/seqcount.go | 34 | ||||
| -rw-r--r-- | pkg/sync/seqcount_test.go | 53 |
3 files changed, 0 insertions, 104 deletions
diff --git a/pkg/sync/seqatomic_unsafe.go b/pkg/sync/seqatomic_unsafe.go index 2184cb5ab..780f3b8f8 100644 --- a/pkg/sync/seqatomic_unsafe.go +++ b/pkg/sync/seqatomic_unsafe.go @@ -8,20 +8,12 @@ package template import ( - "fmt" - "reflect" - "strings" "unsafe" "gvisor.dev/gvisor/pkg/sync" ) // Value is a required type parameter. -// -// Value must not contain any pointers, including interface objects, function -// objects, slices, maps, channels, unsafe.Pointer, and arrays or structs -// containing any of the above. An init() function will panic if this property -// does not hold. type Value struct{} // SeqAtomicLoad returns a copy of *ptr, ensuring that the read does not race @@ -55,12 +47,3 @@ func SeqAtomicTryLoad(seq *sync.SeqCount, epoch sync.SeqCountEpoch, ptr *Value) ok = seq.ReadOk(epoch) return } - -func init() { - var val Value - typ := reflect.TypeOf(val) - name := typ.Name() - if ptrs := sync.PointersInType(typ, name); len(ptrs) != 0 { - panic(fmt.Sprintf("SeqAtomicLoad<%s> is invalid since values %s of type %s contain pointers:\n%s", typ, name, typ, strings.Join(ptrs, "\n"))) - } -} diff --git a/pkg/sync/seqcount.go b/pkg/sync/seqcount.go index 2c5d3df99..1f025f33c 100644 --- a/pkg/sync/seqcount.go +++ b/pkg/sync/seqcount.go @@ -6,8 +6,6 @@ package sync import ( - "fmt" - "reflect" "sync/atomic" ) @@ -27,9 +25,6 @@ import ( // - SeqCount may be more flexible: correct use of SeqCount.ReadOk allows other // operations to be made atomic with reads of SeqCount-protected data. // -// - SeqCount may be less flexible: as of this writing, SeqCount-protected data -// cannot include pointers. -// // - SeqCount is more cumbersome to use; atomic reads of SeqCount-protected // data require instantiating function templates using go_generics (see // seqatomic.go). @@ -128,32 +123,3 @@ func (s *SeqCount) EndWrite() { panic("SeqCount.EndWrite outside writer critical section") } } - -// PointersInType returns a list of pointers reachable from values named -// valName of the given type. -// -// PointersInType is not exhaustive, but it is guaranteed that if typ contains -// at least one pointer, then PointersInTypeOf returns a non-empty list. -func PointersInType(typ reflect.Type, valName string) []string { - switch kind := typ.Kind(); kind { - case reflect.Bool, reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64, reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr, reflect.Float32, reflect.Float64, reflect.Complex64, reflect.Complex128: - return nil - - case reflect.Chan, reflect.Func, reflect.Interface, reflect.Map, reflect.Ptr, reflect.Slice, reflect.String, reflect.UnsafePointer: - return []string{valName} - - case reflect.Array: - return PointersInType(typ.Elem(), valName+"[]") - - case reflect.Struct: - var ptrs []string - for i, n := 0, typ.NumField(); i < n; i++ { - field := typ.Field(i) - ptrs = append(ptrs, PointersInType(field.Type, fmt.Sprintf("%s.%s", valName, field.Name))...) - } - return ptrs - - default: - return []string{fmt.Sprintf("%s (of type %s with unknown kind %s)", valName, typ, kind)} - } -} diff --git a/pkg/sync/seqcount_test.go b/pkg/sync/seqcount_test.go index 6eb7b4b59..3f5592e3e 100644 --- a/pkg/sync/seqcount_test.go +++ b/pkg/sync/seqcount_test.go @@ -6,7 +6,6 @@ package sync import ( - "reflect" "testing" "time" ) @@ -99,55 +98,3 @@ func BenchmarkSeqCountReadUncontended(b *testing.B) { } }) } - -func TestPointersInType(t *testing.T) { - for _, test := range []struct { - name string // used for both test and value name - val interface{} - ptrs []string - }{ - { - name: "EmptyStruct", - val: struct{}{}, - }, - { - name: "Int", - val: int(0), - }, - { - name: "MixedStruct", - val: struct { - b bool - I int - ExportedPtr *struct{} - unexportedPtr *struct{} - arr [2]int - ptrArr [2]*int - nestedStruct struct { - nestedNonptr int - nestedPtr *int - } - structArr [1]struct { - nonptr int - ptr *int - } - }{}, - ptrs: []string{ - "MixedStruct.ExportedPtr", - "MixedStruct.unexportedPtr", - "MixedStruct.ptrArr[]", - "MixedStruct.nestedStruct.nestedPtr", - "MixedStruct.structArr[].ptr", - }, - }, - } { - t.Run(test.name, func(t *testing.T) { - typ := reflect.TypeOf(test.val) - ptrs := PointersInType(typ, test.name) - t.Logf("Found pointers: %v", ptrs) - if (len(ptrs) != 0 || len(test.ptrs) != 0) && !reflect.DeepEqual(ptrs, test.ptrs) { - t.Errorf("Got %v, wanted %v", ptrs, test.ptrs) - } - }) - } -} |