Removed safety shutdown hook again

base/src/main/java/de/staropensource/sosengine/base/Engine.java

@@ -32,7 +32,6 @@ import de.staropensource.sosengine.base.exceptions.dependency.UnmetDependenciesE
 import de.staropensource.sosengine.base.internal.events.InternalEngineShutdownEvent;
 import de.staropensource.sosengine.base.internal.types.DependencySubsystemVector;
 import de.staropensource.sosengine.base.logging.CrashHandler;
-import de.staropensource.sosengine.base.logging.InitLogger;
 import de.staropensource.sosengine.base.logging.Logger;
 import de.staropensource.sosengine.base.logging.LoggerInstance;
 import de.staropensource.sosengine.base.types.DependencyVector;
@@ -41,7 +40,6 @@ import de.staropensource.sosengine.base.types.immutable.ImmutableLinkedList;
 import de.staropensource.sosengine.base.utility.DependencyResolver;
 import de.staropensource.sosengine.base.utility.Miscellaneous;
 import de.staropensource.sosengine.base.utility.PlaceholderEngine;
-import lombok.AccessLevel;
 import lombok.Getter;
 import lombok.Setter;
 import org.jetbrains.annotations.NotNull;
@@ -152,41 +150,6 @@ public final class Engine extends SubsystemClass {
     @Setter
     private @NotNull ShutdownHandler shutdownHandler = new Engine.JvmShutdownHandler();
 
-    /**
-     * Contains the JVM shutdown hook thread,
-     * which ensures that the engine is fully shut
-     * down before the JVM exits.
-     *
-     * @see EngineInternals#installSafetyShutdownHook(boolean)
-     * @since v1-alpha4
-     */
-    @Getter(AccessLevel.MODULE)
-    private final @NotNull Thread safetyShutdownHook = Thread.ofPlatform()
-            .name("Engine shutdown thread")
-            .group(getThreadGroup())
-            .unstarted(() -> {
-                // To avoid race condition or something
-                try {
-                    Thread.sleep(1000);
-                } catch (InterruptedException ignored) {}
-
-                // Check if already shutting down
-                switch (state) {
-                    case UNKNOWN, SHUTDOWN, CRASHED -> {
-                        return;
-                    }
-                }
-
-                // Print warning about shutdown
-                logger.warn("Trying to shut down engine using shutdown hook.\nThis approach to shutting down the engine and JVM is NOT RECOMMENDED, please use Engine#shutdown() instead.");
-
-                // Shutdown
-                Engine.getInstance().shutdown();
-
-                // Print last message
-                InitLogger.warn(getClass(), "ENGINE", EngineInformation.getVersioningCodename(), "Engine successfully shut down using shutdown hook. PLEASE USE Engine#shutdown() INSTEAD OF System#exit() or Runtime#exit()!");
-            });
-
     /**
      * Initializes the StarOpenSource Engine.
      *
@@ -209,7 +172,6 @@ public final class Engine extends SubsystemClass {
             initializeClasses();         // Initialize classes
             if (checkEnvironment())      // Check environment
                 throw new IllegalStateException("Running in an incompatible environment");
-            ensureEnvironment();         // Prepare the environment and ensure safety
             populateCrashContent();      // Populate crash content
             cacheEvents();               // Cache event listeners
             startThreads();              // Start threads
@@ -262,15 +224,6 @@ public final class Engine extends SubsystemClass {
         return false;
     }
 
-    /**
-     * Ensures the execution safety of the environment.
-     *
-     * @since v1-alpha4
-     */
-    private void ensureEnvironment() {
-        EngineInternals.getInstance().installSafetyShutdownHook(true);
-    }
-
     /**
      * This method populates {@link CrashHandler#crashContent} with content.
      *
@@ -479,11 +432,6 @@ public final class Engine extends SubsystemClass {
         // Flush log messages
         Logger.flushLogMessages();
 
-        // Disable safety shutdown hook
-        try {
-            Runtime.getRuntime().removeShutdownHook(safetyShutdownHook);
-        } catch (Exception ignored) {}
-
         // Send events
         logger.verb("Notifiying classes about shutdown");
         new EngineShutdownEvent().callEvent();

base/src/main/java/de/staropensource/sosengine/base/EngineInternals.java

@@ -19,7 +19,6 @@
 
 package de.staropensource.sosengine.base;
 
-import de.staropensource.sosengine.base.exceptions.NoAccessException;
 import de.staropensource.sosengine.base.logging.LoggerInstance;
 import de.staropensource.sosengine.base.types.InternalAccessArea;
 import lombok.Getter;
@@ -92,26 +91,4 @@ public final class EngineInternals {
 
         restrictedAreas.add(area);
     }
-
-    /**
-     * Installs or uninstalls the JVM shutdown
-     * hook, which prevents the JVM from exiting
-     * before the engine has fully shut down.
-     * Highly recommended to keep enabled.
-     *
-     * @param status {@code true} to install, {@code false} otherwise
-     * @throws NoAccessException when restricted
-     * @since v1-alpha4
-     */
-    public void installSafetyShutdownHook(boolean status) throws NoAccessException {
-        if (restrictedAreas.contains(InternalAccessArea.SAFETY_SHUTDOWN_HOOK))
-            throw new NoAccessException("The internal access area SAFETY_SHUTDOWN_HOOK has been restricted");
-
-        try {
-            if (status)
-                Runtime.getRuntime().addShutdownHook(Engine.getInstance().getSafetyShutdownHook());
-            else
-                Runtime.getRuntime().removeShutdownHook(Engine.getInstance().getSafetyShutdownHook());
-        } catch (IllegalArgumentException | IllegalStateException ignored) {}
-    }
 }

base/src/main/java/de/staropensource/sosengine/base/types/InternalAccessArea.java

@@ -35,12 +35,4 @@ public enum InternalAccessArea {
      * @since v1-alpha4
      */
     ALL,
-
-    /**
-     * Refers to the toggling of the JVM shutdown hook, which
-     * prevents JVM shutdowns without the engine first shutting down.
-     *
-     * @since v1-alpha4
-     */
-    SAFETY_SHUTDOWN_HOOK,
 }