signal handling code files

signal.go

@@ -0,0 +1,73 @@
+// Copyright (c) 2013-2016 The btcsuite developers
+// Use of this source code is governed by an ISC
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"os"
+	"os/signal"
+
+	log "github.com/sirupsen/logrus"
+)
+
+// shutdownRequestChannel is used to initiate shutdown from one of the
+// subsystems using the same code paths as when an interrupt signal is received.
+var shutdownRequestChannel = make(chan struct{})
+
+// interruptSignals defines the default signals to catch in order to do a proper
+// shutdown.  This may be modified during init depending on the platform.
+var interruptSignals = []os.Signal{os.Interrupt}
+
+// interruptListener listens for OS Signals such as SIGINT (Ctrl+C) and shutdown
+// requests from shutdownRequestChannel.  It returns a channel that is closed
+// when either signal is received.
+func interruptListener() <-chan struct{} {
+	c := make(chan struct{})
+	go func() {
+		interruptChannel := make(chan os.Signal, 1)
+		signal.Notify(interruptChannel, interruptSignals...)
+
+		// Listen for initial shutdown signal and close the returned
+		// channel to notify the caller.
+		select {
+		case sig := <-interruptChannel:
+			log.Infof("Received signal (%s).  Shutting down...",
+				sig)
+
+		case <-shutdownRequestChannel:
+			log.Info("Shutdown requested.  Shutting down...")
+		}
+		close(c)
+
+		// Listen for repeated signals and display a message so the user
+		// knows the shutdown is in progress and the process is not
+		// hung.
+		for {
+			select {
+			case sig := <-interruptChannel:
+				log.Infof("Received signal (%s).  Already "+
+					"shutting down...", sig)
+
+			case <-shutdownRequestChannel:
+				log.Info("Shutdown requested.  Already " +
+					"shutting down...")
+			}
+		}
+	}()
+
+	return c
+}
+
+// interruptRequested returns true when the channel returned by
+// interruptListener was closed.  This simplifies early shutdown slightly since
+// the caller can just use an if statement instead of a select.
+func interruptRequested(interrupted <-chan struct{}) bool {
+	select {
+	case <-interrupted:
+		return true
+	default:
+	}
+
+	return false
+}

signalsigterm.go

@@ -0,0 +1,17 @@
+// Copyright (c) 2016 The btcsuite developers
+// Use of this source code is governed by an ISC
+// license that can be found in the LICENSE file.
+
+//go:build darwin || dragonfly || freebsd || linux || netbsd || openbsd || solaris
+// +build darwin dragonfly freebsd linux netbsd openbsd solaris
+
+package main
+
+import (
+	"os"
+	"syscall"
+)
+
+func initsignals() {
+	interruptSignals = []os.Signal{os.Interrupt, syscall.SIGTERM}
+}