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-rw-r--r--pkg/refs/BUILD6
-rw-r--r--pkg/refs/refcounter.go71
-rw-r--r--pkg/refs/refcounter_test.go38
3 files changed, 89 insertions, 26 deletions
diff --git a/pkg/refs/BUILD b/pkg/refs/BUILD
index 74affc887..9888cce9c 100644
--- a/pkg/refs/BUILD
+++ b/pkg/refs/BUILD
@@ -24,6 +24,7 @@ go_library(
],
visibility = ["//:sandbox"],
deps = [
+ "//pkg/context",
"//pkg/log",
"//pkg/sync",
],
@@ -34,5 +35,8 @@ go_test(
size = "small",
srcs = ["refcounter_test.go"],
library = ":refs",
- deps = ["//pkg/sync"],
+ deps = [
+ "//pkg/context",
+ "//pkg/sync",
+ ],
)
diff --git a/pkg/refs/refcounter.go b/pkg/refs/refcounter.go
index c45ba8200..699ea8ac3 100644
--- a/pkg/refs/refcounter.go
+++ b/pkg/refs/refcounter.go
@@ -23,6 +23,7 @@ import (
"runtime"
"sync/atomic"
+ "gvisor.dev/gvisor/pkg/context"
"gvisor.dev/gvisor/pkg/log"
"gvisor.dev/gvisor/pkg/sync"
)
@@ -38,7 +39,7 @@ type RefCounter interface {
// Note that AtomicRefCounter.DecRef() does not support destructors.
// If a type has a destructor, it must implement its own DecRef()
// method and call AtomicRefCounter.DecRefWithDestructor(destructor).
- DecRef()
+ DecRef(ctx context.Context)
// TryIncRef attempts to increase the reference counter on the object,
// but may fail if all references have already been dropped. This
@@ -57,7 +58,7 @@ type RefCounter interface {
// A WeakRefUser is notified when the last non-weak reference is dropped.
type WeakRefUser interface {
// WeakRefGone is called when the last non-weak reference is dropped.
- WeakRefGone()
+ WeakRefGone(ctx context.Context)
}
// WeakRef is a weak reference.
@@ -123,7 +124,7 @@ func (w *WeakRef) Get() RefCounter {
// Drop drops this weak reference. You should always call drop when you are
// finished with the weak reference. You may not use this object after calling
// drop.
-func (w *WeakRef) Drop() {
+func (w *WeakRef) Drop(ctx context.Context) {
rc, ok := w.get()
if !ok {
// We've been zapped already. When the refcounter has called
@@ -145,7 +146,7 @@ func (w *WeakRef) Drop() {
// And now aren't on the object's list of weak references. So it won't
// zap us if this causes the reference count to drop to zero.
- rc.DecRef()
+ rc.DecRef(ctx)
// Return to the pool.
weakRefPool.Put(w)
@@ -214,6 +215,8 @@ type AtomicRefCount struct {
// LeakMode configures the leak checker.
type LeakMode uint32
+// TODO(gvisor.dev/issue/1624): Simplify down to two modes once vfs1 ref
+// counting is gone.
const (
// UninitializedLeakChecking indicates that the leak checker has not yet been initialized.
UninitializedLeakChecking LeakMode = iota
@@ -231,6 +234,41 @@ const (
LeaksLogTraces
)
+// Set implements flag.Value.
+func (l *LeakMode) Set(v string) error {
+ switch v {
+ case "disabled":
+ *l = NoLeakChecking
+ case "log-names":
+ *l = LeaksLogWarning
+ case "log-traces":
+ *l = LeaksLogTraces
+ default:
+ return fmt.Errorf("invalid ref leak mode %q", v)
+ }
+ return nil
+}
+
+// Get implements flag.Value.
+func (l *LeakMode) Get() interface{} {
+ return *l
+}
+
+// String implements flag.Value.
+func (l *LeakMode) String() string {
+ switch *l {
+ case UninitializedLeakChecking:
+ return "uninitialized"
+ case NoLeakChecking:
+ return "disabled"
+ case LeaksLogWarning:
+ return "log-names"
+ case LeaksLogTraces:
+ return "log-traces"
+ }
+ panic(fmt.Sprintf("invalid ref leak mode %d", *l))
+}
+
// leakMode stores the current mode for the reference leak checker.
//
// Values must be one of the LeakMode values.
@@ -243,6 +281,11 @@ func SetLeakMode(mode LeakMode) {
atomic.StoreUint32(&leakMode, uint32(mode))
}
+// GetLeakMode returns the current leak mode.
+func GetLeakMode() LeakMode {
+ return LeakMode(atomic.LoadUint32(&leakMode))
+}
+
const maxStackFrames = 40
type fileLine struct {
@@ -427,7 +470,7 @@ func (r *AtomicRefCount) dropWeakRef(w *WeakRef) {
// A: TryIncRef [transform speculative to real]
//
//go:nosplit
-func (r *AtomicRefCount) DecRefWithDestructor(destroy func()) {
+func (r *AtomicRefCount) DecRefWithDestructor(ctx context.Context, destroy func(context.Context)) {
switch v := atomic.AddInt64(&r.refCount, -1); {
case v < -1:
panic("Decrementing non-positive ref count")
@@ -448,7 +491,7 @@ func (r *AtomicRefCount) DecRefWithDestructor(destroy func()) {
if user != nil {
r.mu.Unlock()
- user.WeakRefGone()
+ user.WeakRefGone(ctx)
r.mu.Lock()
}
}
@@ -456,7 +499,7 @@ func (r *AtomicRefCount) DecRefWithDestructor(destroy func()) {
// Call the destructor.
if destroy != nil {
- destroy()
+ destroy(ctx)
}
}
}
@@ -464,6 +507,16 @@ func (r *AtomicRefCount) DecRefWithDestructor(destroy func()) {
// DecRef decrements this object's reference count.
//
//go:nosplit
-func (r *AtomicRefCount) DecRef() {
- r.DecRefWithDestructor(nil)
+func (r *AtomicRefCount) DecRef(ctx context.Context) {
+ r.DecRefWithDestructor(ctx, nil)
+}
+
+// OnExit is called on sandbox exit. It runs GC to enqueue refcount finalizers,
+// which check for reference leaks. There is no way to guarantee that every
+// finalizer will run before exiting, but this at least ensures that they will
+// be discovered/enqueued by GC.
+func OnExit() {
+ if LeakMode(atomic.LoadUint32(&leakMode)) != NoLeakChecking {
+ runtime.GC()
+ }
}
diff --git a/pkg/refs/refcounter_test.go b/pkg/refs/refcounter_test.go
index 1ab4a4440..6d0dd1018 100644
--- a/pkg/refs/refcounter_test.go
+++ b/pkg/refs/refcounter_test.go
@@ -18,6 +18,7 @@ import (
"reflect"
"testing"
+ "gvisor.dev/gvisor/pkg/context"
"gvisor.dev/gvisor/pkg/sync"
)
@@ -31,11 +32,11 @@ type testCounter struct {
destroyed bool
}
-func (t *testCounter) DecRef() {
- t.AtomicRefCount.DecRefWithDestructor(t.destroy)
+func (t *testCounter) DecRef(ctx context.Context) {
+ t.AtomicRefCount.DecRefWithDestructor(ctx, t.destroy)
}
-func (t *testCounter) destroy() {
+func (t *testCounter) destroy(context.Context) {
t.mu.Lock()
defer t.mu.Unlock()
t.destroyed = true
@@ -53,7 +54,7 @@ func newTestCounter() *testCounter {
func TestOneRef(t *testing.T) {
tc := newTestCounter()
- tc.DecRef()
+ tc.DecRef(context.Background())
if !tc.IsDestroyed() {
t.Errorf("object should have been destroyed")
@@ -63,8 +64,9 @@ func TestOneRef(t *testing.T) {
func TestTwoRefs(t *testing.T) {
tc := newTestCounter()
tc.IncRef()
- tc.DecRef()
- tc.DecRef()
+ ctx := context.Background()
+ tc.DecRef(ctx)
+ tc.DecRef(ctx)
if !tc.IsDestroyed() {
t.Errorf("object should have been destroyed")
@@ -74,12 +76,13 @@ func TestTwoRefs(t *testing.T) {
func TestMultiRefs(t *testing.T) {
tc := newTestCounter()
tc.IncRef()
- tc.DecRef()
+ ctx := context.Background()
+ tc.DecRef(ctx)
tc.IncRef()
- tc.DecRef()
+ tc.DecRef(ctx)
- tc.DecRef()
+ tc.DecRef(ctx)
if !tc.IsDestroyed() {
t.Errorf("object should have been destroyed")
@@ -89,19 +92,20 @@ func TestMultiRefs(t *testing.T) {
func TestWeakRef(t *testing.T) {
tc := newTestCounter()
w := NewWeakRef(tc, nil)
+ ctx := context.Background()
// Try resolving.
if x := w.Get(); x == nil {
t.Errorf("weak reference didn't resolve: expected %v, got nil", tc)
} else {
- x.DecRef()
+ x.DecRef(ctx)
}
// Try resolving again.
if x := w.Get(); x == nil {
t.Errorf("weak reference didn't resolve: expected %v, got nil", tc)
} else {
- x.DecRef()
+ x.DecRef(ctx)
}
// Shouldn't be destroyed yet. (Can't continue if this fails.)
@@ -110,7 +114,7 @@ func TestWeakRef(t *testing.T) {
}
// Drop the original reference.
- tc.DecRef()
+ tc.DecRef(ctx)
// Assert destroyed.
if !tc.IsDestroyed() {
@@ -126,7 +130,8 @@ func TestWeakRef(t *testing.T) {
func TestWeakRefDrop(t *testing.T) {
tc := newTestCounter()
w := NewWeakRef(tc, nil)
- w.Drop()
+ ctx := context.Background()
+ w.Drop(ctx)
// Just assert the list is empty.
if !tc.weakRefs.Empty() {
@@ -134,14 +139,14 @@ func TestWeakRefDrop(t *testing.T) {
}
// Drop the original reference.
- tc.DecRef()
+ tc.DecRef(ctx)
}
type testWeakRefUser struct {
weakRefGone func()
}
-func (u *testWeakRefUser) WeakRefGone() {
+func (u *testWeakRefUser) WeakRefGone(ctx context.Context) {
u.weakRefGone()
}
@@ -165,7 +170,8 @@ func TestCallback(t *testing.T) {
}})
// Drop the original reference, this must trigger the callback.
- tc.DecRef()
+ ctx := context.Background()
+ tc.DecRef(ctx)
if !called {
t.Fatalf("Callback not called")
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-23 13:06:09 +0000