diff options
Diffstat (limited to 'pkg/refs/refcounter.go')
| -rw-r--r-- | pkg/refs/refcounter.go | 71 |
1 files changed, 62 insertions, 9 deletions
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() + } } |