| // Copyright 2020 The gVisor Authors. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| // Package refsvfs2 defines an interface for a reference-counted object. |
| package refsvfs2 |
| |
| import ( |
| "gvisor.dev/gvisor/pkg/context" |
| ) |
| |
| // RefCounter is the interface to be implemented by objects that are reference |
| // counted. |
| type RefCounter interface { |
| // IncRef increments the reference counter on the object. |
| IncRef() |
| |
| // DecRef decrements the object's reference count. Users of refs_template.Refs |
| // may specify a destructor to be called once the reference count reaches zero. |
| DecRef(ctx context.Context) |
| } |
| |
| // TryRefCounter is like RefCounter but allow the ref increment to be tried. |
| type TryRefCounter interface { |
| RefCounter |
| |
| // TryIncRef attempts to increment the reference count, but may fail if all |
| // references have already been dropped, in which case it returns false. If |
| // true is returned, then a valid reference is now held on the object. |
| TryIncRef() bool |
| } |