8315566: [JVMCI] deadlock in JVMCI startup when bad option specified

Reviewed-by: thartmann, never

Author: Doug Simon

src/jdk.internal.vm.ci/share/classes/jdk/vm/ci/hotspot/HotSpotJVMCIRuntime.java

@@ -49,6 +49,7 @@
 import java.util.Map;
 import java.util.Objects;
 import java.util.ServiceLoader;
+import java.util.concurrent.atomic.AtomicBoolean;
 import java.util.function.Predicate;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
@@ -509,18 +510,7 @@ T get() {
 
     private final Map<Class<? extends Architecture>, JVMCIBackend> backends = new HashMap<>();
 
-    private volatile List<HotSpotVMEventListener> vmEventListeners;
-
-    private Iterable<HotSpotVMEventListener> getVmEventListeners() {
-        if (vmEventListeners == null) {
-            synchronized (this) {
-                if (vmEventListeners == null) {
-                    vmEventListeners = JVMCIServiceLocator.getProviders(HotSpotVMEventListener.class);
-                }
-            }
-        }
-        return vmEventListeners;
-    }
+    private final List<HotSpotVMEventListener> vmEventListeners;
 
     @SuppressWarnings("try")
     private HotSpotJVMCIRuntime() {
@@ -580,6 +570,8 @@ private HotSpotJVMCIRuntime() {
         if (Option.PrintConfig.getBoolean()) {
             configStore.printConfig(this);
         }
+
+        vmEventListeners = JVMCIServiceLocator.getProviders(HotSpotVMEventListener.class);
     }
 
     /**
@@ -938,22 +930,21 @@ private boolean isGCSupported(int gcIdentifier) {
     }
 
     /**
-     * Guard to ensure shut down actions are performed at most once.
+     * Guard to ensure shut down actions are performed by at most one thread.
      */
-    private boolean isShutdown;
+    private final AtomicBoolean isShutdown = new AtomicBoolean();
 
     /**
      * Shuts down the runtime.
      */
     @VMEntryPoint
-    private synchronized void shutdown() throws Exception {
-        if (!isShutdown) {
-            isShutdown = true;
+    private void shutdown() throws Exception {
+        if (isShutdown.compareAndSet(false, true)) {
             // Cleaners are normally only processed when a new Cleaner is
             // instantiated so process all remaining cleaners now.
             Cleaner.clean();
 
-            for (HotSpotVMEventListener vmEventListener : getVmEventListeners()) {
+            for (HotSpotVMEventListener vmEventListener : vmEventListeners) {
                 vmEventListener.notifyShutdown();
             }
         }
@@ -964,7 +955,7 @@ private synchronized void shutdown() throws Exception {
      */
     @VMEntryPoint
     private void bootstrapFinished() throws Exception {
-        for (HotSpotVMEventListener vmEventListener : getVmEventListeners()) {
+        for (HotSpotVMEventListener vmEventListener : vmEventListeners) {
             vmEventListener.notifyBootstrapFinished();
         }
     }
@@ -977,7 +968,7 @@ private void bootstrapFinished() throws Exception {
      * @param compiledCode
      */
     void notifyInstall(HotSpotCodeCacheProvider hotSpotCodeCacheProvider, InstalledCode installedCode, CompiledCode compiledCode) {
-        for (HotSpotVMEventListener vmEventListener : getVmEventListeners()) {
+        for (HotSpotVMEventListener vmEventListener : vmEventListeners) {
             vmEventListener.notifyInstall(hotSpotCodeCacheProvider, installedCode, compiledCode);
         }
     }