github.com/mdaxf/iac@v0.0.0-20240519030858-58a061660378/integration/messagebus/glue/handler.go (about)

     1  /*
     2   *  Glue - Robust Go and Javascript Socket Library
     3   *  Copyright (C) 2015  Roland Singer <roland.singer[at]desertbit.com>
     4   *
     5   *  This program is free software: you can redistribute it and/or modify
     6   *  it under the terms of the GNU General Public License as published by
     7   *  the Free Software Foundation, either version 3 of the License, or
     8   *  (at your option) any later version.
     9   *
    10   *  This program is distributed in the hope that it will be useful,
    11   *  but WITHOUT ANY WARRANTY; without even the implied warranty of
    12   *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    13   *  GNU General Public License for more details.
    14   *
    15   *  You should have received a copy of the GNU General Public License
    16   *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
    17   */
    18  
    19  package glue
    20  
    21  import "sync"
    22  
    23  //###############//
    24  //### Handler ###//
    25  //###############//
    26  
    27  type handler struct {
    28  	stopChan       chan struct{}
    29  	stopChanClosed bool
    30  
    31  	mutex sync.Mutex
    32  }
    33  
    34  func newHandler() *handler {
    35  	return &handler{
    36  		stopChanClosed: true,
    37  	}
    38  }
    39  
    40  // New creates a new handler and stopps the previous handler if present.
    41  // A stop channel is returned, which is closed as soon as the handler is stopped.
    42  func (h *handler) New() chan struct{} {
    43  	// Lock the mutex.
    44  	h.mutex.Lock()
    45  	defer h.mutex.Unlock()
    46  
    47  	// Signal the stop request by closing the channel if open.
    48  	if !h.stopChanClosed {
    49  		close(h.stopChan)
    50  	}
    51  
    52  	// Create a new stop channel.
    53  	h.stopChan = make(chan struct{})
    54  
    55  	// Update the flag.
    56  	h.stopChanClosed = false
    57  
    58  	return h.stopChan
    59  }
    60  
    61  // Stop the handler if present.
    62  func (h *handler) Stop() {
    63  	// Lock the mutex.
    64  	h.mutex.Lock()
    65  	defer h.mutex.Unlock()
    66  
    67  	// Signal the stop request by closing the channel if open.
    68  	if !h.stopChanClosed {
    69  		close(h.stopChan)
    70  		h.stopChanClosed = true
    71  	}
    72  }