github.com/m3db/m3@v1.5.0/src/dbnode/client/rc.go (about)

     1  // Copyright (c) 2016 Uber Technologies, Inc.
     2  //
     3  // Permission is hereby granted, free of charge, to any person obtaining a copy
     4  // of this software and associated documentation files (the "Software"), to deal
     5  // in the Software without restriction, including without limitation the rights
     6  // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
     7  // copies of the Software, and to permit persons to whom the Software is
     8  // furnished to do so, subject to the following conditions:
     9  //
    10  // The above copyright notice and this permission notice shall be included in
    11  // all copies or substantial portions of the Software.
    12  //
    13  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    14  // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    15  // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    16  // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    17  // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    18  // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
    19  // THE SOFTWARE.
    20  
    21  package client
    22  
    23  import "sync/atomic"
    24  
    25  type refCounter struct {
    26  	destructorFn func()
    27  	n            int32
    28  }
    29  
    30  func (r *refCounter) incRef() {
    31  	if atomic.AddInt32(&r.n, 1) <= 0 {
    32  		panic("invalid rc state")
    33  	}
    34  }
    35  
    36  func (r *refCounter) decRef() {
    37  	if v := atomic.AddInt32(&r.n, -1); v == 0 {
    38  		r.destructorFn()
    39  	} else if v < 0 {
    40  		panic("invalid rc state")
    41  	}
    42  }