diff --git a/api/src/main/java/io/github/karlatemp/unsafeaccessor/Unsafe.java b/api/src/main/java/io/github/karlatemp/unsafeaccessor/Unsafe.java
index 90f0566..ce6092e 100644
--- a/api/src/main/java/io/github/karlatemp/unsafeaccessor/Unsafe.java
+++ b/api/src/main/java/io/github/karlatemp/unsafeaccessor/Unsafe.java
@@ -52,7 +52,8 @@
  */
 @SuppressWarnings({"unused", "BooleanMethodIsAlwaysInverted", "RedundantSuppression", "Since15", "DefaultAnnotationParam", "JavaDoc"})
 public abstract class Unsafe {
-    private static Unsafe theUnsafe;
+    static Unsafe theUnsafe;
+    static final Unsafe INSTANCE = getUnsafe0();
 
     /**
      * is Java9+
@@ -92,12 +93,12 @@ public boolean isJava9() {
     @Contract(pure = false)
     public static Unsafe getUnsafe() {
         SecurityCheck.LIMITER.preGetUnsafe();
-        return getUnsafe0();
+        return INSTANCE;
     }
 
     static Unsafe getUnsafe0() {
         if (theUnsafe == null) {
-            return theUnsafe = (Unsafe) UsfAccessor.allocateUnsafe();
+            UsfAccessor.initialize();
         }
         return theUnsafe;
     }
diff --git a/api/src/main/java/io/github/karlatemp/unsafeaccessor/UsfAccessor.java b/api/src/main/java/io/github/karlatemp/unsafeaccessor/UsfAccessor.java
index 7ab4667..ecec1f9 100644
--- a/api/src/main/java/io/github/karlatemp/unsafeaccessor/UsfAccessor.java
+++ b/api/src/main/java/io/github/karlatemp/unsafeaccessor/UsfAccessor.java
@@ -5,7 +5,7 @@
 // internal
 public class UsfAccessor {
     static abstract class UsfAccessorSpi {
-        abstract Object allocateUnsafe();
+        abstract void initialize();
 
         abstract Consumer<Object> allocateObjectInitializer();
     }
@@ -27,8 +27,8 @@ static UsfAccessorSpi spi() {
     }
 
     // Internal service for load Unsafe.
-    protected static Object allocateUnsafe() {
-        return spi().allocateUnsafe();
+    protected static void initialize() {
+        spi().initialize();
     }
 
     protected static Consumer<Object> allocateObjectInitializer() {
diff --git a/gradle/wrapper/gradle-wrapper.properties b/gradle/wrapper/gradle-wrapper.properties
index 1c728b8..f08e1fa 100644
--- a/gradle/wrapper/gradle-wrapper.properties
+++ b/gradle/wrapper/gradle-wrapper.properties
@@ -1,12 +1,4 @@
-#
-# Copyright 2019-2021 Mamoe Technologies and contributors.
-#
-#  此源代码的使用受 GNU AFFERO GENERAL PUBLIC LICENSE version 3 许可证的约束, 可以在以下链接找到该许可证.
-#  Use of this source code is governed by the GNU AGPLv3 license that can be found through the following link.
-#
-#  https://github.com/mamoe/mirai/blob/master/LICENSE
-#
-distributionUrl=https\://services.gradle.org/distributions/gradle-6.8-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-7.1-all.zip
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStorePath=wrapper/dists
diff --git a/impl/codegen/build.gradle b/impl/codegen/build.gradle
index 96e669c..5c2d79b 100644
--- a/impl/codegen/build.gradle
+++ b/impl/codegen/build.gradle
@@ -6,16 +6,17 @@ dependencies {
     implementation(project(':api'))
 
     // https://mvnrepository.com/artifact/org.ow2.asm/asm
-    testCompile group: 'org.ow2.asm', name: 'asm', version: '9.1'
-    testCompile group: 'org.ow2.asm', name: 'asm-commons', version: '9.1'
-    testCompile group: 'org.ow2.asm', name: 'asm-util', version: '9.1'
-    testCompile group: 'org.ow2.asm', name: 'asm-tree', version: '9.1'
+    testImplementation group: 'org.ow2.asm', name: 'asm', version: '9.2'
+    testImplementation group: 'org.ow2.asm', name: 'asm-commons', version: '9.2'
+    testImplementation group: 'org.ow2.asm', name: 'asm-util', version: '9.2'
+    testImplementation group: 'org.ow2.asm', name: 'asm-tree', version: '9.2'
 
 }
 
 task runCodeGen(type: JavaExec) {
     dependsOn(':impl.jdk8:classes')
     dependsOn(':impl.jdk9:classes')
+    dependsOn(':impl.jdk17:classes')
 
     classpath = sourceSets.test.runtimeClasspath
     main = 'io.github.karlatemp.unsafeaccessor.RunCodeGen'
diff --git a/impl/jdk17/build.gradle b/impl/jdk17/build.gradle
new file mode 100644
index 0000000..96a1e7b
--- /dev/null
+++ b/impl/jdk17/build.gradle
@@ -0,0 +1,21 @@
+plugins {
+    id 'java'
+    id 'java-library'
+}
+
+println("JDK 17")
+
+ext.set('versionOverrided', true)
+
+compileJava {
+    sourceCompatibility = JavaVersion.VERSION_16
+    targetCompatibility = JavaVersion.VERSION_16
+    options.compilerArgs.addAll([
+            '--add-exports', 'java.base/jdk.internal.misc=ALL-UNNAMED',
+            '--add-exports', 'java.base/jdk.internal.access=ALL-UNNAMED'
+    ])
+}
+
+dependencies {
+    api(project(':impl.jdk9'))
+}
diff --git a/impl/jdk17/src/main/java/io/github/karlatemp/unsafeaccessor/UsfAllocImpl17.java b/impl/jdk17/src/main/java/io/github/karlatemp/unsafeaccessor/UsfAllocImpl17.java
new file mode 100644
index 0000000..6063432
--- /dev/null
+++ b/impl/jdk17/src/main/java/io/github/karlatemp/unsafeaccessor/UsfAllocImpl17.java
@@ -0,0 +1,19 @@
+package io.github.karlatemp.unsafeaccessor;
+
+class UsfAllocImpl17 extends UsfAllocImpl9 {
+    @SuppressWarnings("JavaReflectionMemberAccess")
+    @Override
+    UsfAlloc checkSelectedRequirement() throws Exception {
+        try {
+            Class.forName("jdk.internal.misc.Unsafe").getMethod(
+                    "defineAnonymousClass",
+                    Class.class,
+                    byte[].class,
+                    Object[].class
+            );
+        } catch (NoSuchMethodException ignore) {
+            return this;
+        }
+        return null;
+    }
+}
diff --git a/impl/jdk17/src/main/java/io/github/karlatemp/unsafeaccessor/UsfImpl17.java b/impl/jdk17/src/main/java/io/github/karlatemp/unsafeaccessor/UsfImpl17.java
new file mode 100644
index 0000000..ada6b3b
--- /dev/null
+++ b/impl/jdk17/src/main/java/io/github/karlatemp/unsafeaccessor/UsfImpl17.java
@@ -0,0 +1,18 @@
+package io.github.karlatemp.unsafeaccessor;
+
+import java.lang.invoke.MethodHandles;
+
+class UsfImpl17 extends Impl9 {
+    @Override
+    public Class<?> defineAnonymousClass(Class<?> hostClass, byte[] data, Object[] cpPatches) {
+        try {
+            MethodHandles.Lookup lookup = Root.RootLookupHolder.trustedIn(hostClass).in(hostClass);
+            if (cpPatches == null) {
+                return lookup.defineHiddenClass(data, false).lookupClass();
+            }
+            return lookup.defineHiddenClassWithClassData(data, cpPatches, false).lookupClass();
+        } catch (IllegalAccessException e) {
+            throw new RuntimeException(e);
+        }
+    }
+}
diff --git a/impl/jdk8/build.gradle b/impl/jdk8/build.gradle
index 97cac3e..6a55150 100644
--- a/impl/jdk8/build.gradle
+++ b/impl/jdk8/build.gradle
@@ -1,7 +1,8 @@
 plugins {
     id 'java'
+    id 'java-library'
 }
 
 dependencies {
-    implementation(project(':api'))
+    api(project(':api'))
 }
diff --git a/api/src/main/java/io/github/karlatemp/unsafeaccessor/ModuleAccessImpl.java b/impl/jdk8/src/main/java/io/github/karlatemp/unsafeaccessor/ModuleAccessImpl.java
similarity index 100%
rename from api/src/main/java/io/github/karlatemp/unsafeaccessor/ModuleAccessImpl.java
rename to impl/jdk8/src/main/java/io/github/karlatemp/unsafeaccessor/ModuleAccessImpl.java
diff --git a/impl/jdk8/src/main/java/io/github/karlatemp/unsafeaccessor/UsfAlloc.java b/impl/jdk8/src/main/java/io/github/karlatemp/unsafeaccessor/UsfAlloc.java
new file mode 100644
index 0000000..911fc00
--- /dev/null
+++ b/impl/jdk8/src/main/java/io/github/karlatemp/unsafeaccessor/UsfAlloc.java
@@ -0,0 +1,25 @@
+package io.github.karlatemp.unsafeaccessor;
+
+abstract class UsfAlloc {
+
+    Unsafe newUnsafe(UsfAllocCtx ctx) throws Exception {
+        return ctx.newUsfImpl(this);
+    }
+
+    void prepare(UsfAllocCtx ctx) throws Exception {
+    }
+
+    void destroyLimit(UsfAllocCtx ctx) throws Exception {
+    }
+
+    void completed(UsfAllocCtx ctx) throws Exception {
+    }
+
+    ModuleAccess newModuleAccess(UsfAllocCtx ctx) throws Exception {
+        return new ModuleAccessImpl.Noop();
+    }
+
+    UsfAlloc checkSelectedRequirement() throws Exception {
+        return this;
+    }
+}
diff --git a/impl/jdk8/src/main/java/io/github/karlatemp/unsafeaccessor/UsfAllocCtx.java b/impl/jdk8/src/main/java/io/github/karlatemp/unsafeaccessor/UsfAllocCtx.java
new file mode 100644
index 0000000..65df81e
--- /dev/null
+++ b/impl/jdk8/src/main/java/io/github/karlatemp/unsafeaccessor/UsfAllocCtx.java
@@ -0,0 +1,56 @@
+package io.github.karlatemp.unsafeaccessor;
+
+import java.util.function.Consumer;
+import java.util.function.Supplier;
+
+class UsfAllocCtx {
+    private DynClassLoader loader;
+
+    void putUnsafeInstance(Unsafe usf) {
+        Unsafe.theUnsafe = usf;
+    }
+
+    void putModuleAccess(ModuleAccess ma) {
+        Root.Secret.MACCESS = ma;
+    }
+
+    DynClassLoader loader() {
+        if (loader == null)
+            return loader = new DynClassLoader();
+        return loader;
+    }
+
+    @SuppressWarnings("rawtypes")
+    static class DynClassLoader extends ClassLoader implements Supplier, Consumer {
+        Object env;
+
+        DynClassLoader() {
+            super(DynClassLoader.class.getClassLoader());
+        }
+
+        @Override
+        public Object get() {
+            return env;
+        }
+
+        @Override
+        public void accept(Object o) {
+            env = o;
+        }
+
+        Class<?> define(byte[] code) {
+            return defineClass(null, code, 0, code.length, null);
+        }
+
+        Class<?> defineAndLoad(byte[] data) throws ClassNotFoundException {
+            return Class.forName(define(data).getName(), true, this);
+        }
+    }
+
+    String namespace;
+    Class<?>[] ACCESS_C;
+
+    Unsafe newUsfImpl(UsfAlloc thiz) throws Exception {
+        throw new UnsupportedOperationException();
+    }
+}
diff --git a/impl/jdk8/src/main/java/io/github/karlatemp/unsafeaccessor/UsfAllocImpl8.java b/impl/jdk8/src/main/java/io/github/karlatemp/unsafeaccessor/UsfAllocImpl8.java
new file mode 100644
index 0000000..479aa07
--- /dev/null
+++ b/impl/jdk8/src/main/java/io/github/karlatemp/unsafeaccessor/UsfAllocImpl8.java
@@ -0,0 +1,4 @@
+package io.github.karlatemp.unsafeaccessor;
+
+class UsfAllocImpl8 extends UsfAlloc {
+}
diff --git a/impl/jdk9/build.gradle b/impl/jdk9/build.gradle
index 5e49ca4..556ec12 100644
--- a/impl/jdk9/build.gradle
+++ b/impl/jdk9/build.gradle
@@ -1,5 +1,6 @@
 plugins {
     id 'java'
+    id 'java-library'
 }
 
 println("JDK 9")
@@ -16,5 +17,5 @@ compileJava {
 }
 
 dependencies {
-    implementation(project(':api'))
+    api(project(':impl.jdk8'))
 }
diff --git a/impl/jdk9/src/main/java/io/github/karlatemp/unsafeaccessor/ModuleAccessImpl$JDK9.java b/impl/jdk9/src/main/java/io/github/karlatemp/unsafeaccessor/ModuleAccessImpl$JDK9.java
index c4c13f2..e6fa107 100644
--- a/impl/jdk9/src/main/java/io/github/karlatemp/unsafeaccessor/ModuleAccessImpl$JDK9.java
+++ b/impl/jdk9/src/main/java/io/github/karlatemp/unsafeaccessor/ModuleAccessImpl$JDK9.java
@@ -124,7 +124,9 @@ public void addOpensToAllUnnamed(Object m, String pkg) {
 
     @Override
     public void addOpensToAllUnnamed(Object m, Iterator<String> packages) {
-        JLA.addOpensToAllUnnamed((Module) m, packages);
+        while (packages.hasNext()) {
+            JLA.addOpensToAllUnnamed((Module) m, packages.next());
+        }
     }
 
     @Override
diff --git a/impl/jdk9/src/main/java/io/github/karlatemp/unsafeaccessor/Open9.java b/impl/jdk9/src/main/java/io/github/karlatemp/unsafeaccessor/Open9.java
deleted file mode 100644
index 7222977..0000000
--- a/impl/jdk9/src/main/java/io/github/karlatemp/unsafeaccessor/Open9.java
+++ /dev/null
@@ -1,154 +0,0 @@
-package io.github.karlatemp.unsafeaccessor;
-
-import jdk.internal.access.JavaLangAccess;
-import jdk.internal.access.SharedSecrets;
-
-import java.io.InputStream;
-import java.lang.reflect.Proxy;
-import java.security.AllPermission;
-import java.security.ProtectionDomain;
-import java.util.function.Consumer;
-import java.util.function.Supplier;
-
-import static io.github.karlatemp.unsafeaccessor.BytecodeUtil.replace;
-
-class Open9 extends ClassLoader implements Supplier<Object>, Consumer<Object> {
-    private static Object env = null;
-
-    @Override
-    public void accept(Object o) {
-        env = o;
-    }
-
-    @Override
-    public Object get() {
-        return env;
-    }
-
-    private Open9() {
-        super(Open9.class.getClassLoader());
-    }
-
-    static class Injector {
-        static {
-            Class<?> klass = Injector.class;
-            Module module = klass.getModule();
-            Module open = klass.getClassLoader().getClass().getModule();
-            module.addExports(klass.getPackageName(), open);
-            module.addOpens(klass.getPackageName(), open);
-            JavaLangAccess javaLangAccess = SharedSecrets.getJavaLangAccess();
-            javaLangAccess.addExports(Object.class.getModule(), "jdk.internal.misc", open);
-            javaLangAccess.addExports(open, "io.github.karlatemp.unsafeaccessor", module);
-            javaLangAccess.addReads(module, open);
-        }
-    }
-
-    Class<?> define(byte[] code) {
-        ProtectionDomain domain = new ProtectionDomain(null,
-                new AllPermission().newPermissionCollection()
-        );
-        return defineClass(null, code, 0, code.length, domain);
-    }
-
-    static Class<?> findSS() throws ClassNotFoundException {
-        String[] classpath = {
-                "jdk.internal.access.SharedSecrets",
-                "jdk.internal.misc.SharedSecrets",
-        };
-        return findClass(classpath);
-    }
-
-    static Class<?> findClass(String[] classpath) throws ClassNotFoundException {
-        ClassNotFoundException cnfe = null;
-        ClassLoader loader = ClassLoader.getSystemClassLoader();
-        for (String s : classpath) {
-            try {
-                return Class.forName(s, true, loader);
-            } catch (ClassNotFoundException ce) {
-                if (cnfe == null) cnfe = ce;
-                else cnfe.addSuppressed(ce);
-            }
-        }
-        assert cnfe != null;
-        throw cnfe;
-    }
-
-    static Class<?> findJLA() throws ClassNotFoundException {
-        String[] classpath = {
-                "jdk.internal.access.JavaLangAccess",
-                "jdk.internal.misc.JavaLangAccess",
-        };
-        return findClass(classpath);
-    }
-
-    static Class<?> findJLMA() throws ClassNotFoundException {
-        String[] classpath = {
-                "jdk.internal.access.JavaLangModuleAccess",
-                "jdk.internal.misc.JavaLangModuleAccess",
-        };
-        return findClass(classpath);
-    }
-
-    static byte[] doRemap(
-            byte[] data,
-            Class<?>... accessClasses
-    ) {
-
-        for (Class<?> c : accessClasses) {
-            data = replace(data, "jdk/internal/access/" + c.getSimpleName(), c.getName().replace('.', '/'));
-            data = replace(data, "Ljdk/internal/access/" + c.getSimpleName() + ";", "L" + c.getName().replace('.', '/') + ";");
-            data = replace(data, "()Ljdk/internal/access/" + c.getSimpleName() + ";", "()L" + c.getName().replace('.', '/') + ";");
-        }
-        return data;
-    }
-
-
-    @SuppressWarnings("UnnecessarySemicolon")
-    static Unsafe open() throws NoSuchMethodException {
-        Open9 loader = new Open9();
-        try (InputStream source = Open9.class.getResourceAsStream("Open9$Injector.class");
-             InputStream mai9 = Open9.class.getResourceAsStream("ModuleAccessImpl$JDK9.class");
-        ) {
-            byte[] data;
-            Class<?> JLA = findJLA();
-            Class<?>[] ACCESS_CLASSES = {
-                    JLA, findSS(), findJLMA()
-            };
-
-            Object proxy = Proxy.newProxyInstance(loader, new Class[]{JLA}, (proxy0, method, args) -> null);
-            String namespace = proxy.getClass().getPackageName();
-            {
-                data = source.readAllBytes();
-                String targetName = namespace + ".Injector",
-                        targetJvmName = targetName.replace('.', '/');
-                data = replace(data, "io/github/karlatemp/unsafeaccessor/Open9$Injector", targetJvmName);
-                data = replace(data, "Lio/github/karlatemp/unsafeaccessor/Open9$Injector;", "L" + targetJvmName + ";");
-
-                data = doRemap(data, ACCESS_CLASSES);
-
-                Class<?> injectorClass = loader.define(data);
-                Class.forName(injectorClass.getName(), true, loader);
-            }
-            {
-                String targetName = namespace + ".ModuleAccessImpl$JDK9",
-                        targetJvmName = targetName.replace('.', '/');
-
-                data = mai9.readAllBytes();
-                data = replace(data, "io/github/karlatemp/unsafeaccessor/ModuleAccessImpl$JDK9", targetJvmName);
-                data = replace(data, "Lio/github/karlatemp/unsafeaccessor/ModuleAccessImpl$JDK9;", "L" + targetJvmName + ";");
-
-                data = doRemap(data, ACCESS_CLASSES);
-                env = (Supplier) () -> UnsafeAccess.INSTANCE;
-
-                Class.forName(loader.define(data).getName(), true, loader);
-                Root.Secret.MACCESS = (ModuleAccess) env;
-                env = null;
-            }
-        } catch (Exception exception) {
-            throw new ExceptionInInitializerError(exception);
-        }
-        //noinspection ResultOfMethodCallIgnored
-        jdk.internal.misc.Unsafe.class.getDeclaredMethod("getReference", Object.class, long.class);
-        return new Impl9();
-    }
-}
diff --git a/impl/jdk9/src/main/java/io/github/karlatemp/unsafeaccessor/UsfAllocImpl9.java b/impl/jdk9/src/main/java/io/github/karlatemp/unsafeaccessor/UsfAllocImpl9.java
new file mode 100644
index 0000000..ace4b97
--- /dev/null
+++ b/impl/jdk9/src/main/java/io/github/karlatemp/unsafeaccessor/UsfAllocImpl9.java
@@ -0,0 +1,131 @@
+package io.github.karlatemp.unsafeaccessor;
+
+import jdk.internal.access.JavaLangAccess;
+import jdk.internal.access.SharedSecrets;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.lang.reflect.Proxy;
+import java.util.function.Supplier;
+
+import static io.github.karlatemp.unsafeaccessor.BytecodeUtil.replace;
+
+class UsfAllocImpl9 extends UsfAlloc {
+    Class<?> usfClass() {
+        return jdk.internal.misc.Unsafe.class;
+    }
+
+    static class Injector {
+        static {
+            Class<?> klass = Injector.class;
+            Module module = klass.getModule();
+            Module open = klass.getClassLoader().getClass().getModule();
+            module.addExports(klass.getPackageName(), open);
+            module.addOpens(klass.getPackageName(), open);
+            JavaLangAccess javaLangAccess = SharedSecrets.getJavaLangAccess();
+            javaLangAccess.addExports(Object.class.getModule(), "jdk.internal.misc", open);
+            javaLangAccess.addExports(open, "io.github.karlatemp.unsafeaccessor", module);
+            javaLangAccess.addReads(module, open);
+        }
+    }
+
+    static byte[] doRemap(
+            byte[] data,
+            Class<?>... accessClasses
+    ) {
+        for (Class<?> c : accessClasses) {
+            data = replace(data, "jdk/internal/access/" + c.getSimpleName(), c.getName().replace('.', '/'));
+            data = replace(data, "Ljdk/internal/access/" + c.getSimpleName() + ";", "L" + c.getName().replace('.', '/') + ";");
+            data = replace(data, "()Ljdk/internal/access/" + c.getSimpleName() + ";", "()L" + c.getName().replace('.', '/') + ";");
+        }
+        return data;
+    }
+
+    static byte[] inNamespace(byte[] data, String name, String namespace) {
+        String targetJvmName = namespace.replace('.', '/') + "/UsfI_" + name;
+        data = BytecodeUtil.replace(data, "io/github/karlatemp/unsafeaccessor/" + name, targetJvmName);
+        data = BytecodeUtil.replace(data, "Lio/github/karlatemp/unsafeaccessor/" + name + ";", "L" + targetJvmName + ";");
+        return data;
+    }
+
+    static Class<?> findSS() throws ClassNotFoundException {
+        String[] classpath = {
+                "jdk.internal.access.SharedSecrets",
+                "jdk.internal.misc.SharedSecrets",
+        };
+        return findClass(classpath);
+    }
+
+    static Class<?> findClass(String[] classpath) throws ClassNotFoundException {
+        ClassNotFoundException cnfe = null;
+        ClassLoader loader = ClassLoader.getSystemClassLoader();
+        for (String s : classpath) {
+            try {
+                return Class.forName(s, true, loader);
+            } catch (ClassNotFoundException ce) {
+                if (cnfe == null) cnfe = ce;
+                else cnfe.addSuppressed(ce);
+            }
+        }
+        assert cnfe != null;
+        throw cnfe;
+    }
+
+    static Class<?> findJLA() throws ClassNotFoundException {
+        String[] classpath = {
+                "jdk.internal.access.JavaLangAccess",
+                "jdk.internal.misc.JavaLangAccess",
+        };
+        return findClass(classpath);
+    }
+
+    static Class<?> findJLMA() throws ClassNotFoundException {
+        String[] classpath = {
+                "jdk.internal.access.JavaLangModuleAccess",
+                "jdk.internal.misc.JavaLangModuleAccess",
+        };
+        return findClass(classpath);
+    }
+
+    static byte[] readC(String name) throws IOException {
+        try (InputStream is = UsfAllocImpl9.class.getResourceAsStream(name)) {
+            return is.readAllBytes();
+        }
+    }
+
+    @Override
+    void destroyLimit(UsfAllocCtx ctx) throws Exception {
+        Class<?>[] ACCESS_CLASSES = {
+                findJLA(), findSS(), findJLMA()
+        };
+        Object proxy = Proxy.newProxyInstance(
+                ctx.loader(),
+                new Class[]{ACCESS_CLASSES[0]},
+                (proxy1, method, args) -> null
+        );
+        String namespace = ctx.namespace = proxy.getClass().getPackageName();
+        ctx.ACCESS_C = ACCESS_CLASSES;
+
+        { // Injector
+            byte[] data = readC("UsfAllocImpl9$Injector.class");
+            data = inNamespace(data, "UsfAllocImpl9$Injector", namespace);
+            data = doRemap(data, ACCESS_CLASSES);
+            ctx.loader().defineAndLoad(data);
+        }
+    }
+
+    @Override
+    Unsafe newUnsafe(UsfAllocCtx ctx) throws Exception {
+        return ctx.newUsfImpl(this);
+    }
+
+    @Override
+    ModuleAccess newModuleAccess(UsfAllocCtx ctx) throws Exception {
+        byte[] data = readC("ModuleAccessImpl$JDK9.class");
+        data = inNamespace(data, "ModuleAccessImpl$JDK9", ctx.namespace);
+        data = doRemap(data, ctx.ACCESS_C);
+        ctx.loader().env = ((Supplier<Object>) () -> UnsafeAccess.INSTANCE);
+        ctx.loader().defineAndLoad(data);
+        return (ModuleAccess) ctx.loader().env;
+    }
+}
diff --git a/impl/loader/build.gradle b/impl/loader/build.gradle
index cee76f0..f893228 100644
--- a/impl/loader/build.gradle
+++ b/impl/loader/build.gradle
@@ -17,21 +17,23 @@ task sourcesJar(type: Jar) {
     from(project(':api').sourceSets.main.allSource)
     from(project(':impl.jdk8').sourceSets.main.allSource)
     from(project(':impl.jdk9').sourceSets.main.allSource)
+    from(project(':impl.jdk17').sourceSets.main.allSource)
     from(project.sourceSets.main.allSource)
 }
 
 dependencies {
     implementation(project(':api'))
-    implementation(project(':impl.jdk8'))
 
+    implementation(files(new File(project(':impl.jdk8').buildDir, "classes/java/main")))
     implementation(files(new File(project(':impl.jdk9').buildDir, "classes/java/main")))
+    implementation(files(new File(project(':impl.jdk17').buildDir, "classes/java/main")))
     implementation(files("generated"))
 
     // https://mvnrepository.com/artifact/org.ow2.asm/asm
-    testCompile group: 'org.ow2.asm', name: 'asm', version: '9.1'
-    testCompile group: 'org.ow2.asm', name: 'asm-commons', version: '9.1'
-    testCompile group: 'org.ow2.asm', name: 'asm-util', version: '9.1'
-    testCompile group: 'org.ow2.asm', name: 'asm-tree', version: '9.1'
+    testImplementation group: 'org.ow2.asm', name: 'asm', version: '9.2'
+    testImplementation group: 'org.ow2.asm', name: 'asm-commons', version: '9.2'
+    testImplementation group: 'org.ow2.asm', name: 'asm-util', version: '9.2'
+    testImplementation group: 'org.ow2.asm', name: 'asm-tree', version: '9.2'
 
 }
 
diff --git a/impl/loader/src/main/java/io/github/karlatemp/unsafeaccessor/UsfAccessorImpl.java b/impl/loader/src/main/java/io/github/karlatemp/unsafeaccessor/UsfAccessorImpl.java
index cbd7d64..1f0a367 100644
--- a/impl/loader/src/main/java/io/github/karlatemp/unsafeaccessor/UsfAccessorImpl.java
+++ b/impl/loader/src/main/java/io/github/karlatemp/unsafeaccessor/UsfAccessorImpl.java
@@ -7,19 +7,83 @@
 
 @SuppressWarnings("unchecked")
 class UsfAccessorImpl extends UsfAccessor.UsfAccessorSpi {
-    Object allocateUnsafe() {
-        try {
-            Class.forName("java.lang.Module");
-            Root.Secret.MACCESS = new ModuleAccessImpl.PendingInit();
 
+    static class UsfACtxImpl extends UsfAllocCtx {
+        @Override
+        Unsafe newUsfImpl(UsfAlloc alloc) throws Exception {
+            return (Unsafe) newUsf(alloc);
+        }
+
+        Object newUsf(UsfAlloc alloc) throws Exception {
+            if (alloc instanceof UsfAllocImpl8) {
+                return new SunMiscUnsafeImpl();
+            }
+            return newUsf9(alloc);
+        }
+
+        @SuppressWarnings("SwitchStatementWithTooFewBranches")
+        Object newUsf9(UsfAlloc $$$$$$$$$$$$$$$$) throws Exception {
+            UsfAllocImpl9 alloc = (UsfAllocImpl9) $$$$$$$$$$$$$$$$;
+            boolean isGetObj;
             try {
-                return Open9.open();
+                alloc.usfClass().getMethod("getObject", Object.class, long.class);
+                isGetObj = true;
             } catch (NoSuchMethodException ignored) {
-                return new Impl9Obj();
+                isGetObj = false;
+            }
+
+            String cname = alloc.getClass().getSimpleName();
+            String sname = null;
+            switch (cname) {
+                case "UsfAllocImpl17":
+                    return new UsfImpl17();
+                default:
+                    return isGetObj ? new Impl9Obj() : new Impl9();
+            }
+        }
+
+    }
+
+    static UsfAlloc findImpl9() {
+        ExceptionInInitializerError e = new ExceptionInInitializerError("no any provider found");
+        for (String k : new String[]{
+                "17",
+                "9",
+                "8",
+        }) {
+            try {
+                UsfAlloc alloc = Class.forName("io.github.karlatemp.unsafeaccessor.UsfAllocImpl" + k)
+                        .asSubclass(UsfAlloc.class)
+                        .getDeclaredConstructor()
+                        .newInstance()
+                        .checkSelectedRequirement();
+                if (alloc != null) return alloc;
+            } catch (Throwable ex) {
+                e.addSuppressed(ex);
             }
+        }
+        throw e;
+    }
+
+    void initialize() {
+        Root.Secret.MACCESS = new ModuleAccessImpl.PendingInit();
+        UsfAlloc alloc;
+        try {
+            Class.forName("java.lang.Module");
+            alloc = findImpl9();
         } catch (ClassNotFoundException ignored) {
-            Root.Secret.MACCESS = new ModuleAccessImpl.Noop();
-            return new SunMiscUnsafeImpl();
+            alloc = new UsfAllocImpl8();
+        }
+        try {
+            UsfAllocCtx ctx = new UsfACtxImpl();
+            alloc.prepare(ctx);
+            alloc.destroyLimit(ctx);
+
+            ctx.putUnsafeInstance(alloc.newUnsafe(ctx));
+
+            ctx.putModuleAccess(alloc.newModuleAccess(ctx));
+        } catch (Throwable throwable) {
+            throw new ExceptionInInitializerError(throwable);
         }
     }
 
diff --git a/impl/testunit/build.gradle b/impl/testunit/build.gradle
index ab921e5..4ae26df 100644
--- a/impl/testunit/build.gradle
+++ b/impl/testunit/build.gradle
@@ -2,20 +2,21 @@ plugins {
     id 'java'
     id 'io.github.karlatemp.publication-sign'
     id("maven-publish")
+    id 'java-library'
 }
 
 dependencies {
     compileOnly(project(':api'))
 
-    compile group: 'org.ow2.asm', name: 'asm', version: '9.1'
-    compile group: 'org.ow2.asm', name: 'asm-commons', version: '9.1'
-    compile group: 'org.ow2.asm', name: 'asm-util', version: '9.1'
-    compile group: 'org.ow2.asm', name: 'asm-tree', version: '9.1'
-    compile 'com.google.code.gson:gson:2.8.8'
-    compile 'org.apache.commons:commons-lang3:3.12.0'
-    compile'org.apache.commons:commons-text:1.9'
+    api group: 'org.ow2.asm', name: 'asm', version: '9.2'
+    api group: 'org.ow2.asm', name: 'asm-commons', version: '9.2'
+    api group: 'org.ow2.asm', name: 'asm-util', version: '9.2'
+    api group: 'org.ow2.asm', name: 'asm-tree', version: '9.2'
+    api 'com.google.code.gson:gson:2.8.8'
+    api 'org.apache.commons:commons-lang3:3.12.0'
+    api 'org.apache.commons:commons-text:1.9'
 
-    compile 'org.junit.jupiter:junit-jupiter-api:5.6.0'
+    api 'org.junit.jupiter:junit-jupiter-api:5.6.0'
 
 }
 
diff --git a/settings.gradle b/settings.gradle
index 660b985..3d0390e 100644
--- a/settings.gradle
+++ b/settings.gradle
@@ -12,6 +12,7 @@ include(':api')
 
 importImpl('jdk8')
 importImpl('jdk9')
+importImpl('jdk17')
 
 importImpl('codegen')