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-rw-r--r--pkg/sync/seqatomic_unsafe.go17
-rw-r--r--pkg/sync/seqcount.go34
-rw-r--r--pkg/sync/seqcount_test.go53
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)
- }
- })
- }
-}