diff options
Diffstat (limited to 'pkg/refs')
-rw-r--r-- | pkg/refs/BUILD | 6 | ||||
-rw-r--r-- | pkg/refs/refcounter.go | 36 | ||||
-rw-r--r-- | pkg/refs/refcounter_test.go | 38 |
3 files changed, 54 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..d9d5e6bcb 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 @@ -243,6 +246,11 @@ 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 +435,7 @@ 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 +456,7 @@ func (r *AtomicRefCount) DecRefWithDestructor(destroy func()) { if user != nil { r.mu.Unlock() - user.WeakRefGone() + user.WeakRefGone(ctx) r.mu.Lock() } } @@ -456,7 +464,7 @@ func (r *AtomicRefCount) DecRefWithDestructor(destroy func()) { // Call the destructor. if destroy != nil { - destroy() + destroy(ctx) } } } @@ -464,6 +472,16 @@ 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") |