lbcwallet/signal.go
2015-05-01 12:20:05 -05:00

67 lines
2.2 KiB
Go

/*
* Copyright (c) 2013, 2014 The btcsuite developers
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
package main
import (
"os"
"os/signal"
)
// interruptChannel is used to receive SIGINT (Ctrl+C) signals.
var interruptChannel chan os.Signal
// addHandlerChannel is used to add an interrupt handler to the list of handlers
// to be invoked on SIGINT (Ctrl+C) signals.
var addHandlerChannel = make(chan func())
// mainInterruptHandler listens for SIGINT (Ctrl+C) signals on the
// interruptChannel and invokes the registered interruptCallbacks accordingly.
// It also listens for callback registration. It must be run as a goroutine.
func mainInterruptHandler() {
// interruptCallbacks is a list of callbacks to invoke when a
// SIGINT (Ctrl+C) is received.
var interruptCallbacks []func()
for {
select {
case <-interruptChannel:
log.Info("Received SIGINT (Ctrl+C). Shutting down...")
// run handlers in LIFO order.
for i := range interruptCallbacks {
idx := len(interruptCallbacks) - 1 - i
interruptCallbacks[idx]()
}
case handler := <-addHandlerChannel:
interruptCallbacks = append(interruptCallbacks, handler)
}
}
}
// addInterruptHandler adds a handler to call when a SIGINT (Ctrl+C) is
// received.
func addInterruptHandler(handler func()) {
// Create the channel and start the main interrupt handler which invokes
// all other callbacks and exits if not already done.
if interruptChannel == nil {
interruptChannel = make(chan os.Signal, 1)
signal.Notify(interruptChannel, os.Interrupt)
go mainInterruptHandler()
}
addHandlerChannel <- handler
}