8346781: [JVMCI] Limit ServiceLoader to class initializers

Reviewed-by: never, yzheng

Author: Doug Simon

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

@@ -36,7 +36,7 @@
  * referenced by this might be referenced by {@link ResolvedJavaType} which is kept alive by a
  * {@link WeakReference} so we need equivalent reference strength.
  */
-abstract class Cleaner extends WeakReference<Object> {
+public abstract class Cleaner extends WeakReference<Object> {
 
     /**
      * Head of linked list of cleaners.
@@ -107,7 +107,7 @@ private static synchronized void remove(Cleaner cl) {
     /**
      * Remove the cleaners whose referents have become weakly reachable.
      */
-    static void clean() {
+    public static void clean() {
         Cleaner c = (Cleaner) queue.poll();
         boolean oopHandleCleared = false;
         while (c != null) {

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

@@ -23,7 +23,6 @@
 package jdk.vm.ci.hotspot;
 
 import static jdk.vm.ci.common.InitTimer.timer;
-import static jdk.vm.ci.services.Services.IS_BUILDING_NATIVE_IMAGE;
 import static jdk.vm.ci.services.Services.IS_IN_NATIVE_IMAGE;
 
 import java.io.IOException;
@@ -453,33 +452,26 @@ static void parse(HotSpotJVMCIRuntime runtime) {
         }
     }
 
-    private static HotSpotJVMCIBackendFactory findFactory(String architecture) {
-        Iterable<HotSpotJVMCIBackendFactory> factories = getHotSpotJVMCIBackendFactories();
-        assert factories != null : "sanity";
-        for (HotSpotJVMCIBackendFactory factory : factories) {
-            if (factory.getArchitecture().equalsIgnoreCase(architecture)) {
-                return factory;
+    /**
+     * The backend factory for the JVMCI shared library.
+     */
+    private static final HotSpotJVMCIBackendFactory backendFactory;
+    static {
+        String arch = HotSpotVMConfig.getHostArchitectureName();
+        HotSpotJVMCIBackendFactory selected = null;
+        for (HotSpotJVMCIBackendFactory factory : ServiceLoader.load(HotSpotJVMCIBackendFactory.class)) {
+            if (factory.getArchitecture().equalsIgnoreCase(arch)) {
+                if (selected != null) {
+                    throw new JVMCIError("Multiple factories available for %s: %s and %s",
+                        arch, selected, factory);
+                }
+                selected = factory;
             }
         }
-
-        throw new JVMCIError("No JVMCI runtime available for the %s architecture", architecture);
-    }
-
-    private static volatile List<HotSpotJVMCIBackendFactory> cachedHotSpotJVMCIBackendFactories;
-
-    @SuppressFBWarnings(value = "LI_LAZY_INIT_UPDATE_STATIC", justification = "not sure about this")
-    private static Iterable<HotSpotJVMCIBackendFactory> getHotSpotJVMCIBackendFactories() {
-        if (IS_IN_NATIVE_IMAGE || cachedHotSpotJVMCIBackendFactories != null) {
-            return cachedHotSpotJVMCIBackendFactories;
+        if (selected == null) {
+            throw new JVMCIError("No JVMCI runtime available for the %s architecture", arch);
         }
-        Iterable<HotSpotJVMCIBackendFactory> result = ServiceLoader.load(HotSpotJVMCIBackendFactory.class, ClassLoader.getSystemClassLoader());
-        if (IS_BUILDING_NATIVE_IMAGE) {
-            cachedHotSpotJVMCIBackendFactories = new ArrayList<>();
-            for (HotSpotJVMCIBackendFactory factory : result) {
-                cachedHotSpotJVMCIBackendFactories.add(factory);
-            }
-        }
-        return result;
+        backendFactory = selected;
     }
 
     /**
@@ -587,15 +579,8 @@ private HotSpotJVMCIRuntime() {
         // Initialize the Option values.
         Option.parse(this);
 
-        String hostArchitecture = config.getHostArchitectureName();
-
-        HotSpotJVMCIBackendFactory factory;
-        try (InitTimer t = timer("find factory:", hostArchitecture)) {
-            factory = findFactory(hostArchitecture);
-        }
-
-        try (InitTimer t = timer("create JVMCI backend:", hostArchitecture)) {
-            hostBackend = registerBackend(factory.createJVMCIBackend(this, null));
+        try (InitTimer t = timer("create JVMCI backend:", backendFactory.getArchitecture())) {
+            hostBackend = registerBackend(backendFactory.createJVMCIBackend(this, null));
         }
 
         compilerFactory = HotSpotJVMCICompilerConfig.getCompilerFactory(this);

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

@@ -55,7 +55,7 @@ static HotSpotVMConfig config() {
      * Gets the host architecture name for the purpose of finding the corresponding
      * {@linkplain HotSpotJVMCIBackendFactory backend}.
      */
-    String getHostArchitectureName() {
+    static String getHostArchitectureName() {
         Architecture arch = Architecture.current();
         switch (arch) {
             case X64: return "amd64";

src/jdk.internal.vm.ci/share/classes/jdk/vm/ci/services/JVMCIServiceLocator.java

@@ -22,8 +22,6 @@
  */
 package jdk.vm.ci.services;
 
-import static jdk.vm.ci.services.Services.IS_BUILDING_NATIVE_IMAGE;
-
 import java.util.ArrayList;
 import java.util.List;
 import java.util.ServiceLoader;
@@ -71,24 +69,12 @@ protected JVMCIServiceLocator() {
      */
     protected abstract <S> S getProvider(Class<S> service);
 
-    private static volatile List<JVMCIServiceLocator> cachedLocators;
-
-    private static Iterable<JVMCIServiceLocator> getJVMCIServiceLocators() {
-        Iterable<JVMCIServiceLocator> result = cachedLocators;
-        if (result != null) {
-            return result;
-        }
-        result = ServiceLoader.load(JVMCIServiceLocator.class, ClassLoader.getSystemClassLoader());
-        if (IS_BUILDING_NATIVE_IMAGE) {
-            ArrayList<JVMCIServiceLocator> l = new ArrayList<>();
-            for (JVMCIServiceLocator locator : result) {
-                l.add(locator);
-            }
-            l.trimToSize();
-            cachedLocators = l;
-            return l;
-        }
-        return result;
+    /**
+     * The available set of locators.
+     */
+    private static final List<JVMCIServiceLocator> locators = new ArrayList<>();
+    static {
+        ServiceLoader.load(JVMCIServiceLocator.class).forEach(locators::add);
     }
 
     /**
@@ -106,7 +92,7 @@ public static <S> List<S> getProviders(Class<S> service) {
             sm.checkPermission(new JVMCIPermission());
         }
         List<S> providers = new ArrayList<>();
-        for (JVMCIServiceLocator access : getJVMCIServiceLocators()) {
+        for (JVMCIServiceLocator access : locators) {
             S provider = access.getProvider(service);
             if (provider != null) {
                 providers.add(provider);

src/jdk.internal.vm.ci/share/classes/jdk/vm/ci/services/Services.java

@@ -22,13 +22,10 @@
  */
 package jdk.vm.ci.services;
 
-import java.util.ArrayList;
-import java.util.Formatter;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
-import java.util.ServiceLoader;
 import java.util.Set;
 import java.util.function.Consumer;
 import java.util.function.Supplier;
@@ -44,13 +41,6 @@
  */
 public final class Services {
 
-    /**
-     * Guards code that should be run when building an JVMCI shared library but should be excluded
-     * from (being compiled into) the library. Such code must be directly guarded by an {@code if}
-     * statement on this field - the guard cannot be behind a method call.
-     */
-    public static final boolean IS_BUILDING_NATIVE_IMAGE = Boolean.parseBoolean(VM.getSavedProperty("jdk.vm.ci.services.aot"));
-
     /**
      * Guards code that should only be run in a JVMCI shared library. Such code must be directly
      * guarded by an {@code if} statement on this field - the guard cannot be behind a method call.
@@ -131,34 +121,6 @@ public static void initializeJVMCI() {
         }
     }
 
-    private static final Map<Class<?>, List<?>> servicesCache = IS_BUILDING_NATIVE_IMAGE ? new HashMap<>() : null;
-
-    @SuppressWarnings("unchecked")
-    private static <S> Iterable<S> load0(Class<S> service) {
-        if (IS_IN_NATIVE_IMAGE || IS_BUILDING_NATIVE_IMAGE) {
-            List<?> list = servicesCache.get(service);
-            if (list != null) {
-                return (Iterable<S>) list;
-            }
-            if (IS_IN_NATIVE_IMAGE) {
-                throw new InternalError(String.format("No %s providers found when building native image", service.getName()));
-            }
-        }
-
-        Iterable<S> providers = ServiceLoader.load(service, ClassLoader.getSystemClassLoader());
-        if (IS_BUILDING_NATIVE_IMAGE) {
-            synchronized (servicesCache) {
-                ArrayList<S> providersList = new ArrayList<>();
-                for (S provider : providers) {
-                    providersList.add(provider);
-                }
-                servicesCache.put(service, providersList);
-                providers = providersList;
-            }
-        }
-        return providers;
-    }
-
     /**
      * Opens all JVMCI packages to {@code otherModule}.
      */
@@ -175,57 +137,6 @@ static void openJVMCITo(Module otherModule) {
         }
     }
 
-    /**
-     * Gets an {@link Iterable} of the JVMCI providers available for a given service.
-     *
-     * @throws SecurityException if a security manager is present and it denies <tt>
-     *             {@link RuntimePermission}("jvmci")</tt>
-     */
-    public static <S> Iterable<S> load(Class<S> service) {
-        @SuppressWarnings("removal")
-        SecurityManager sm = System.getSecurityManager();
-        if (sm != null) {
-            sm.checkPermission(new JVMCIPermission());
-        }
-        return load0(service);
-    }
-
-    /**
-     * Gets the JVMCI provider for a given service for which at most one provider must be available.
-     *
-     * @param service the service whose provider is being requested
-     * @param required specifies if an {@link InternalError} should be thrown if no provider of
-     *            {@code service} is available
-     * @throws SecurityException if a security manager is present and it denies <tt>
-     *             {@link RuntimePermission}("jvmci")</tt>
-     */
-    public static <S> S loadSingle(Class<S> service, boolean required) {
-        @SuppressWarnings("removal")
-        SecurityManager sm = System.getSecurityManager();
-        if (sm != null) {
-            sm.checkPermission(new JVMCIPermission());
-        }
-        Iterable<S> providers = load0(service);
-
-        S singleProvider = null;
-        for (S provider : providers) {
-            if (singleProvider != null) {
-                throw new InternalError(String.format("Multiple %s providers found: %s, %s", service.getName(), singleProvider.getClass().getName(), provider.getClass().getName()));
-            }
-            singleProvider = provider;
-        }
-        if (singleProvider == null && required) {
-            String javaHome = Services.getSavedProperty("java.home");
-            String vmName = Services.getSavedProperty("java.vm.name");
-            Formatter errorMessage = new Formatter();
-            errorMessage.format("The VM does not expose required service %s.%n", service.getName());
-            errorMessage.format("Currently used Java home directory is %s.%n", javaHome);
-            errorMessage.format("Currently used VM configuration is: %s", vmName);
-            throw new UnsupportedOperationException(errorMessage.toString());
-        }
-        return singleProvider;
-    }
-
     /**
      * Creates a thread-local variable that notifies {@code onThreadTermination} when a thread
      * terminates and it has been initialized in the terminating thread (even if it was initialized

test/hotspot/jtreg/compiler/jvmci/events/JvmciShutdownEventListener.java

@@ -31,11 +31,13 @@ public class JvmciShutdownEventListener extends JVMCIServiceLocator implements H
     public static final String MESSAGE = "Shutdown notified";
     public static final String GOT_INTERNAL_ERROR = "Got internal error";
 
-    public static void main(String args[]) {
-        try {
-            HotSpotJVMCIRuntime.runtime(); // let's trigger that lazy jvmci init
-        } catch (Error e) {
-            System.out.println(GOT_INTERNAL_ERROR);
+    public static class Main {
+        public static void main(String args[]) {
+            try {
+                HotSpotJVMCIRuntime.runtime(); // let's trigger that lazy jvmci init
+            } catch (Error e) {
+                System.out.println(GOT_INTERNAL_ERROR);
+            }
         }
     }
 

test/hotspot/jtreg/compiler/jvmci/events/JvmciShutdownEventTest.java

@@ -53,11 +53,11 @@
 import jdk.test.lib.cli.CommandLineOptionTest;
 
 public class JvmciShutdownEventTest {
-    private final static String[] MESSAGE = new String[]{
+    private final static String[] MESSAGE = {
         JvmciShutdownEventListener.MESSAGE
     };
 
-    private final static String[] ERROR_MESSAGE = new String[]{
+    private final static String[] ERROR_MESSAGE = {
         JvmciShutdownEventListener.GOT_INTERNAL_ERROR
     };
 
@@ -68,15 +68,15 @@ public static void main(String args[]) throws Throwable {
                 "Unexpected output with +EnableJVMCI", ExitCode.OK,
                 addTestVMOptions, "-XX:+UnlockExperimentalVMOptions",
                 "-XX:+EnableJVMCI", "-XX:-UseJVMCICompiler", "-Xbootclasspath/a:.",
-                JvmciShutdownEventListener.class.getName()
+                JvmciShutdownEventListener.Main.class.getName()
         );
 
         CommandLineOptionTest.verifyJVMStartup(ERROR_MESSAGE, MESSAGE,
                 "Unexpected exit code with -EnableJVMCI",
                 "Unexpected output with -EnableJVMCI", ExitCode.OK,
                 addTestVMOptions, "-XX:+UnlockExperimentalVMOptions",
                 "-XX:-EnableJVMCI", "-XX:-UseJVMCICompiler", "-Xbootclasspath/a:.",
-                JvmciShutdownEventListener.class.getName()
+                JvmciShutdownEventListener.Main.class.getName()
         );
     }
 }