mirror of
https://github.com/FlipsideCrypto/dcrd.git
synced 2026-02-06 10:56:47 +00:00
51852570e2
This converts the signal handling and dcrdMain function to use a context with cancellation instead of a separate interrupt channel. It does not really make much of a difference yet, but the intent is to simplify the various subsystems in future commits by refactoring them to make use of the context versus manually handling start and stop in each subsystem.
72 lines
2.1 KiB
Go
72 lines
2.1 KiB
Go
// Copyright (c) 2013-2016 The btcsuite developers
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// Copyright (c) 2015-2016 The Decred developers
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// Use of this source code is governed by an ISC
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// license that can be found in the LICENSE file.
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package main
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import (
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"context"
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"os"
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"os/signal"
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)
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// shutdownRequestChannel is used to initiate shutdown from one of the
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// subsystems using the same code paths as when an interrupt signal is received.
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var shutdownRequestChannel = make(chan struct{})
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// interruptSignals defines the default signals to catch in order to do a proper
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// shutdown. This may be modified during init depending on the platform.
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var interruptSignals = []os.Signal{os.Interrupt}
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// shutdownListener listens for OS Signals such as SIGINT (Ctrl+C) and shutdown
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// requests from shutdownRequestChannel. It returns a context that is canceled
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// when either signal is received.
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func shutdownListener() context.Context {
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ctx, cancel := context.WithCancel(context.Background())
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go func() {
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interruptChannel := make(chan os.Signal, 1)
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signal.Notify(interruptChannel, interruptSignals...)
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// Listen for initial shutdown signal and cancel the returned context.
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select {
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case sig := <-interruptChannel:
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dcrdLog.Infof("Received signal (%s). Shutting down...", sig)
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case <-shutdownRequestChannel:
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dcrdLog.Infof("Shutdown requested. Shutting down...")
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}
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cancel()
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// Listen for repeated signals and display a message so the user
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// knows the shutdown is in progress and the process is not
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// hung.
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for {
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select {
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case sig := <-interruptChannel:
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dcrdLog.Infof("Received signal (%s). Already "+
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"shutting down...", sig)
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case <-shutdownRequestChannel:
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dcrdLog.Info("Shutdown requested. Already " +
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"shutting down...")
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}
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}
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}()
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return ctx
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}
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// shutdownRequested returns true when the context returned by shutdownListener
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// was canceled. This simplifies early shutdown slightly since the caller can
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// just use an if statement instead of a select.
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func shutdownRequested(ctx context.Context) bool {
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select {
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case <-ctx.Done():
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return true
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default:
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}
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return false
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}
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