github.com/metacubex/gvisor@v0.0.0-20240320004321-933faba989ec/pkg/sync/locking/locking.go (about)

     1  // Copyright 2022 The gVisor Authors.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  // Package locking implements lock primitives with the correctness validator.
    16  //
    17  // All mutexes are divided on classes and the validator check following conditions:
    18  //   - Mutexes of the same class are not taken more than once except cases when
    19  //     that is expected.
    20  //   - Mutexes are never locked in a reverse order. Lock dependencies are tracked
    21  //     on the class level.
    22  //
    23  // The validator is implemented in a very straightforward way. For each mutex
    24  // class, we maintain the ancestors list of all classes that have ever been
    25  // taken before the target one. For each goroutine, we have the list of
    26  // currently locked mutexes. And finally, all lock methods check that
    27  // ancestors of currently locked mutexes don't contain the target one.
    28  package locking