go.temporal.io/server@v1.23.0/common/channel/shutdown_once.go (about)

     1  // The MIT License
     2  //
     3  // Copyright (c) 2020 Temporal Technologies Inc.  All rights reserved.
     4  //
     5  // Copyright (c) 2020 Uber Technologies, Inc.
     6  //
     7  // Permission is hereby granted, free of charge, to any person obtaining a copy
     8  // of this software and associated documentation files (the "Software"), to deal
     9  // in the Software without restriction, including without limitation the rights
    10  // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
    11  // copies of the Software, and to permit persons to whom the Software is
    12  // furnished to do so, subject to the following conditions:
    13  //
    14  // The above copyright notice and this permission notice shall be included in
    15  // all copies or substantial portions of the Software.
    16  //
    17  // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    18  // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    19  // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    20  // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    21  // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    22  // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
    23  // THE SOFTWARE.
    24  
    25  package channel
    26  
    27  import (
    28  	"sync/atomic"
    29  )
    30  
    31  const (
    32  	shutdownOnceStatusOpen   int32 = 0
    33  	shutdownOnceStatusClosed int32 = 1
    34  )
    35  
    36  type (
    37  	ShutdownOnce interface {
    38  		// Shutdown broadcast shutdown signal
    39  		Shutdown()
    40  		// IsShutdown return true if already shutdown
    41  		IsShutdown() bool
    42  		// Channel for shutdown notification
    43  		Channel() <-chan struct{}
    44  	}
    45  
    46  	ShutdownOnceImpl struct {
    47  		status  int32
    48  		channel chan struct{}
    49  	}
    50  )
    51  
    52  func NewShutdownOnce() *ShutdownOnceImpl {
    53  	return &ShutdownOnceImpl{
    54  		status:  shutdownOnceStatusOpen,
    55  		channel: make(chan struct{}),
    56  	}
    57  }
    58  
    59  func (c *ShutdownOnceImpl) Shutdown() {
    60  	if atomic.CompareAndSwapInt32(
    61  		&c.status,
    62  		shutdownOnceStatusOpen,
    63  		shutdownOnceStatusClosed,
    64  	) {
    65  		close(c.channel)
    66  	}
    67  }
    68  
    69  func (c *ShutdownOnceImpl) IsShutdown() bool {
    70  	return atomic.LoadInt32(&c.status) == shutdownOnceStatusClosed
    71  }
    72  
    73  func (c *ShutdownOnceImpl) Channel() <-chan struct{} {
    74  	return c.channel
    75  }