nmode's Git Repositories - signal-cli/blob - src/main/java/org/asamk/signal/Shutdown.java

   1 package org.asamk.signal;
   2
   3 import org.asamk.signal.commands.exceptions.CommandException;
   4 import org.slf4j.Logger;
   5 import org.slf4j.LoggerFactory;
   6
   7 import java.util.concurrent.CompletableFuture;
   8 import java.util.concurrent.ExecutionException;
   9
  10 import sun.misc.Signal;
  11
  12 public class Shutdown {
  13
  14     private static final Logger logger = LoggerFactory.getLogger(Shutdown.class);
  15     private static final CompletableFuture<Object> shutdown = new CompletableFuture<>();
  16     private static final CompletableFuture<Void> shutdownComplete = new CompletableFuture<>();
  17     private static boolean initialized = false;
  18
  19     public static void installHandler() {
  20         if (initialized) {
  21             return;
  22         }
  23         initialized = true;
  24         Signal.handle(new Signal("INT"), Shutdown::handleSignal);
  25         Signal.handle(new Signal("TERM"), Shutdown::handleSignal);
  26         Runtime.getRuntime().addShutdownHook(Thread.ofPlatform().unstarted(() -> {
  27             logger.debug("JVM is shutting down");
  28             if (!shutdown.isDone()) {
  29                 triggerShutdown();
  30             }
  31
  32             try {
  33                 logger.debug("Waiting for app to shut down");
  34                 shutdownComplete.get();
  35                 logger.debug("Exiting");
  36             } catch (InterruptedException | ExecutionException e) {
  37                 throw new RuntimeException(e);
  38             }
  39         }));
  40     }
  41
  42     public static void triggerShutdown() {
  43         logger.debug("Triggering shutdown.");
  44         shutdown.complete(null);
  45     }
  46
  47     public static void triggerShutdown(CommandException exception) {
  48         logger.debug("Triggering shutdown with exception.", exception);
  49         shutdown.complete(exception);
  50     }
  51
  52     public static void waitForShutdown() throws InterruptedException, CommandException {
  53         try {
  54             final var result = shutdown.get();
  55             if (result instanceof CommandException e) {
  56                 throw e;
  57             }
  58         } catch (ExecutionException e) {
  59             throw new RuntimeException(e);
  60         }
  61     }
  62
  63     public static void registerShutdownListener(Runnable action) {
  64         shutdown.thenRun(action);
  65     }
  66
  67     static void shutdownComplete() {
  68         shutdownComplete.complete(null);
  69     }
  70
  71     private static void handleSignal(Signal signal) {
  72         logger.info("Received {} signal, shutting down ...", signal);
  73         triggerShutdown();
  74     }
  75 }