diff --git a/core/java/android/os/Build.java b/core/java/android/os/Build.java
index 30d2dec..3c3a4fd 100644
--- a/core/java/android/os/Build.java
+++ b/core/java/android/os/Build.java
@@ -36,8 +36,6 @@
 import android.util.Slog;
 import android.view.View;
 
-import com.android.internal.ravenwood.RavenwoodEnvironment;
-
 import dalvik.system.VMRuntime;
 
 import java.util.ArrayList;
@@ -51,10 +49,6 @@
  */
 @RavenwoodKeepWholeClass
 public class Build {
-    static {
-        // Set up the default system properties.
-        RavenwoodEnvironment.ensureRavenwoodInitialized();
-    }
     private static final String TAG = "Build";
 
     /** Value used for when a build property is unknown. */
diff --git a/core/java/android/os/ParcelFileDescriptor.java b/core/java/android/os/ParcelFileDescriptor.java
index e80efd2..60eeb2b 100644
--- a/core/java/android/os/ParcelFileDescriptor.java
+++ b/core/java/android/os/ParcelFileDescriptor.java
@@ -41,7 +41,6 @@
 import android.net.Uri;
 import android.os.MessageQueue.OnFileDescriptorEventListener;
 import android.ravenwood.annotation.RavenwoodKeepWholeClass;
-import android.ravenwood.annotation.RavenwoodReplace;
 import android.ravenwood.annotation.RavenwoodThrow;
 import android.system.ErrnoException;
 import android.system.Os;
@@ -51,8 +50,6 @@
 import android.util.Log;
 import android.util.Slog;
 
-import com.android.internal.ravenwood.RavenwoodEnvironment;
-
 import dalvik.system.VMRuntime;
 
 import libcore.io.IoUtils;
@@ -1254,15 +1251,10 @@
         }
     }
 
-    @RavenwoodReplace
     private static boolean isAtLeastQ() {
         return (VMRuntime.getRuntime().getTargetSdkVersion() >= Build.VERSION_CODES.Q);
     }
 
-    private static boolean isAtLeastQ$ravenwood() {
-        return RavenwoodEnvironment.workaround().isTargetSdkAtLeastQ();
-    }
-
     private static int ifAtLeastQ(int value) {
         return isAtLeastQ() ? value : 0;
     }
diff --git a/core/java/android/os/Process.java b/core/java/android/os/Process.java
index cd8788d..851953a 100644
--- a/core/java/android/os/Process.java
+++ b/core/java/android/os/Process.java
@@ -29,6 +29,11 @@
 import android.annotation.UptimeMillisLong;
 import android.compat.annotation.UnsupportedAppUsage;
 import android.os.Build.VERSION_CODES;
+import android.ravenwood.annotation.RavenwoodKeep;
+import android.ravenwood.annotation.RavenwoodKeepPartialClass;
+import android.ravenwood.annotation.RavenwoodRedirect;
+import android.ravenwood.annotation.RavenwoodRedirectionClass;
+import android.ravenwood.annotation.RavenwoodReplace;
 import android.sysprop.MemoryProperties;
 import android.system.ErrnoException;
 import android.system.Os;
@@ -37,8 +42,6 @@
 import android.util.Pair;
 import android.webkit.WebViewZygote;
 
-import com.android.internal.os.SomeArgs;
-import com.android.internal.util.Preconditions;
 import com.android.sdksandbox.flags.Flags;
 
 import dalvik.system.VMDebug;
@@ -55,6 +58,8 @@
 /**
  * Tools for managing OS processes.
  */
+@RavenwoodKeepPartialClass
+@RavenwoodRedirectionClass("Process_ravenwood")
 public class Process {
     private static final String LOG_TAG = "Process";
 
@@ -672,7 +677,6 @@
      */
     public static final ZygoteProcess ZYGOTE_PROCESS = new ZygoteProcess();
 
-
     /**
      * The process name set via {@link #setArgV0(String)}.
      */
@@ -846,47 +850,20 @@
     /**
      * Returns true if the current process is a 64-bit runtime.
      */
-    @android.ravenwood.annotation.RavenwoodKeep
+    @RavenwoodKeep
     public static final boolean is64Bit() {
         return VMRuntime.getRuntime().is64Bit();
     }
 
-    private static volatile ThreadLocal<SomeArgs> sIdentity$ravenwood;
-
-    /** @hide */
-    @android.ravenwood.annotation.RavenwoodKeep
-    public static void init$ravenwood(final int uid, final int pid) {
-        sIdentity$ravenwood = ThreadLocal.withInitial(() -> {
-            final SomeArgs args = SomeArgs.obtain();
-            args.argi1 = uid;
-            args.argi2 = pid;
-            args.argi3 = Long.hashCode(Thread.currentThread().getId());
-            args.argi4 = THREAD_PRIORITY_DEFAULT;
-            args.arg1 = Boolean.TRUE; // backgroundOk
-            return args;
-        });
-    }
-
-    /** @hide */
-    @android.ravenwood.annotation.RavenwoodKeep
-    public static void reset$ravenwood() {
-        sIdentity$ravenwood = null;
-    }
-
     /**
      * Returns the identifier of this process, which can be used with
      * {@link #killProcess} and {@link #sendSignal}.
      */
-    @android.ravenwood.annotation.RavenwoodReplace
+    @RavenwoodKeep
     public static final int myPid() {
         return Os.getpid();
     }
 
-    /** @hide */
-    public static final int myPid$ravenwood() {
-        return Preconditions.requireNonNullViaRavenwoodRule(sIdentity$ravenwood).get().argi2;
-    }
-
     /**
      * Returns the identifier of this process' parent.
      * @hide
@@ -900,39 +877,29 @@
      * Returns the identifier of the calling thread, which be used with
      * {@link #setThreadPriority(int, int)}.
      */
-    @android.ravenwood.annotation.RavenwoodReplace
+    @RavenwoodKeep
     public static final int myTid() {
         return Os.gettid();
     }
 
-    /** @hide */
-    public static final int myTid$ravenwood() {
-        return Preconditions.requireNonNullViaRavenwoodRule(sIdentity$ravenwood).get().argi3;
-    }
-
     /**
      * Returns the identifier of this process's uid.  This is the kernel uid
      * that the process is running under, which is the identity of its
      * app-specific sandbox.  It is different from {@link #myUserHandle} in that
      * a uid identifies a specific app sandbox in a specific user.
      */
-    @android.ravenwood.annotation.RavenwoodReplace
+    @RavenwoodKeep
     public static final int myUid() {
         return Os.getuid();
     }
 
-    /** @hide */
-    public static final int myUid$ravenwood() {
-        return Preconditions.requireNonNullViaRavenwoodRule(sIdentity$ravenwood).get().argi1;
-    }
-
     /**
      * Returns this process's user handle.  This is the
      * user the process is running under.  It is distinct from
      * {@link #myUid()} in that a particular user will have multiple
      * distinct apps running under it each with their own uid.
      */
-    @android.ravenwood.annotation.RavenwoodKeep
+    @RavenwoodKeep
     public static UserHandle myUserHandle() {
         return UserHandle.of(UserHandle.getUserId(myUid()));
     }
@@ -941,7 +908,7 @@
      * Returns whether the given uid belongs to a system core component or not.
      * @hide
      */
-    @android.ravenwood.annotation.RavenwoodKeep
+    @RavenwoodKeep
     public static boolean isCoreUid(int uid) {
         return UserHandle.isCore(uid);
     }
@@ -952,7 +919,7 @@
      * @return Whether the uid corresponds to an application sandbox running in
      *     a specific user.
      */
-    @android.ravenwood.annotation.RavenwoodKeep
+    @RavenwoodKeep
     public static boolean isApplicationUid(int uid) {
         return UserHandle.isApp(uid);
     }
@@ -960,7 +927,7 @@
     /**
      * Returns whether the current process is in an isolated sandbox.
      */
-    @android.ravenwood.annotation.RavenwoodKeep
+    @RavenwoodKeep
     public static final boolean isIsolated() {
         return isIsolated(myUid());
     }
@@ -972,7 +939,7 @@
     @Deprecated
     @UnsupportedAppUsage(maxTargetSdk = Build.VERSION_CODES.TIRAMISU,
             publicAlternatives = "Use {@link #isIsolatedUid(int)} instead.")
-    @android.ravenwood.annotation.RavenwoodKeep
+    @RavenwoodKeep
     public static final boolean isIsolated(int uid) {
         return isIsolatedUid(uid);
     }
@@ -980,7 +947,7 @@
     /**
      * Returns whether the process with the given {@code uid} is an isolated sandbox.
      */
-    @android.ravenwood.annotation.RavenwoodKeep
+    @RavenwoodKeep
     public static final boolean isIsolatedUid(int uid) {
         uid = UserHandle.getAppId(uid);
         return (uid >= FIRST_ISOLATED_UID && uid <= LAST_ISOLATED_UID)
@@ -992,7 +959,7 @@
      * @see android.app.sdksandbox.SdkSandboxManager
      */
     @SuppressLint("UnflaggedApi") // promoting from @SystemApi.
-    @android.ravenwood.annotation.RavenwoodKeep
+    @RavenwoodKeep
     public static final boolean isSdkSandboxUid(int uid) {
         uid = UserHandle.getAppId(uid);
         return (uid >= FIRST_SDK_SANDBOX_UID && uid <= LAST_SDK_SANDBOX_UID);
@@ -1008,7 +975,7 @@
      * @throws IllegalArgumentException if input is not an sdk sandbox uid
      */
     @SuppressLint("UnflaggedApi") // promoting from @SystemApi.
-    @android.ravenwood.annotation.RavenwoodKeep
+    @RavenwoodKeep
     public static final int getAppUidForSdkSandboxUid(int uid) {
         if (!isSdkSandboxUid(uid)) {
             throw new IllegalArgumentException("Input UID is not an SDK sandbox UID");
@@ -1024,7 +991,7 @@
      */
     @SystemApi(client = MODULE_LIBRARIES)
     @TestApi
-    @android.ravenwood.annotation.RavenwoodKeep
+    @RavenwoodKeep
     // TODO(b/318651609): Deprecate once Process#getSdkSandboxUidForAppUid is rolled out to 100%
     public static final int toSdkSandboxUid(int uid) {
         return uid + (FIRST_SDK_SANDBOX_UID - FIRST_APPLICATION_UID);
@@ -1040,7 +1007,7 @@
      * @throws IllegalArgumentException if input is not an app uid
      */
     @FlaggedApi(Flags.FLAG_SDK_SANDBOX_UID_TO_APP_UID_API)
-    @android.ravenwood.annotation.RavenwoodKeep
+    @RavenwoodKeep
     public static final int getSdkSandboxUidForAppUid(int uid) {
         if (!isApplicationUid(uid)) {
             throw new IllegalArgumentException("Input UID is not an app UID");
@@ -1051,7 +1018,7 @@
     /**
      * Returns whether the current process is a sdk sandbox process.
      */
-    @android.ravenwood.annotation.RavenwoodKeep
+    @RavenwoodKeep
     public static final boolean isSdkSandbox() {
         return isSdkSandboxUid(myUid());
     }
@@ -1128,28 +1095,11 @@
      * not have permission to modify the given thread, or to use the given
      * priority.
      */
-    @android.ravenwood.annotation.RavenwoodReplace
+    @RavenwoodRedirect
     public static final native void setThreadPriority(int tid,
             @IntRange(from = -20, to = THREAD_PRIORITY_LOWEST) int priority)
             throws IllegalArgumentException, SecurityException;
 
-    /** @hide */
-    public static final void setThreadPriority$ravenwood(int tid, int priority) {
-        final SomeArgs args =
-                Preconditions.requireNonNullViaRavenwoodRule(sIdentity$ravenwood).get();
-        if (args.argi3 == tid) {
-            boolean backgroundOk = (args.arg1 == Boolean.TRUE);
-            if (priority >= THREAD_PRIORITY_BACKGROUND && !backgroundOk) {
-                throw new IllegalArgumentException(
-                        "Priority " + priority + " blocked by setCanSelfBackground()");
-            }
-            args.argi4 = priority;
-        } else {
-            throw new UnsupportedOperationException(
-                    "Cross-thread priority management not yet available in Ravenwood");
-        }
-    }
-
     /**
      * Call with 'false' to cause future calls to {@link #setThreadPriority(int)} to
      * throw an exception if passed a background-level thread priority.  This is only
@@ -1157,16 +1107,9 @@
      *
      * @hide
      */
-    @android.ravenwood.annotation.RavenwoodReplace
+    @RavenwoodRedirect
     public static final native void setCanSelfBackground(boolean backgroundOk);
 
-    /** @hide */
-    public static final void setCanSelfBackground$ravenwood(boolean backgroundOk) {
-        final SomeArgs args =
-                Preconditions.requireNonNullViaRavenwoodRule(sIdentity$ravenwood).get();
-        args.arg1 = Boolean.valueOf(backgroundOk);
-    }
-
     /**
      * Sets the scheduling group for a thread.
      * @hide
@@ -1295,13 +1238,12 @@
      *
      * @see #setThreadPriority(int, int)
      */
-    @android.ravenwood.annotation.RavenwoodReplace
+    @RavenwoodReplace
     public static final native void setThreadPriority(
             @IntRange(from = -20, to = THREAD_PRIORITY_LOWEST) int priority)
             throws IllegalArgumentException, SecurityException;
 
-    /** @hide */
-    public static final void setThreadPriority$ravenwood(int priority) {
+    private static void setThreadPriority$ravenwood(int priority) {
         setThreadPriority(myTid(), priority);
     }
 
@@ -1318,23 +1260,11 @@
      * @throws IllegalArgumentException Throws IllegalArgumentException if
      * <var>tid</var> does not exist.
      */
-    @android.ravenwood.annotation.RavenwoodReplace
+    @RavenwoodRedirect
     @IntRange(from = -20, to = THREAD_PRIORITY_LOWEST)
     public static final native int getThreadPriority(int tid)
             throws IllegalArgumentException;
 
-    /** @hide */
-    public static final int getThreadPriority$ravenwood(int tid) {
-        final SomeArgs args =
-                Preconditions.requireNonNullViaRavenwoodRule(sIdentity$ravenwood).get();
-        if (args.argi3 == tid) {
-            return args.argi4;
-        } else {
-            throw new UnsupportedOperationException(
-                    "Cross-thread priority management not yet available in Ravenwood");
-        }
-    }
-
     /**
      * Return the current scheduling policy of a thread, based on Linux.
      *
diff --git a/core/java/com/android/internal/ravenwood/RavenwoodEnvironment.java b/core/java/com/android/internal/ravenwood/RavenwoodEnvironment.java
index 30b160a..a69d2e4 100644
--- a/core/java/com/android/internal/ravenwood/RavenwoodEnvironment.java
+++ b/core/java/com/android/internal/ravenwood/RavenwoodEnvironment.java
@@ -28,19 +28,9 @@
 public final class RavenwoodEnvironment {
     public static final String TAG = "RavenwoodEnvironment";
 
-    private static final RavenwoodEnvironment sInstance;
-    private static final Workaround sWorkaround;
+    private static RavenwoodEnvironment sInstance = new RavenwoodEnvironment();
 
-    private RavenwoodEnvironment() {
-    }
-
-    static {
-        sInstance = new RavenwoodEnvironment();
-        sWorkaround = new Workaround();
-        ensureRavenwoodInitialized();
-    }
-
-    public static RuntimeException notSupportedOnDevice() {
+    private static RuntimeException notSupportedOnDevice() {
         return new UnsupportedOperationException("This method can only be used on Ravenwood");
     }
 
@@ -52,15 +42,6 @@
     }
 
     /**
-     * Initialize the ravenwood environment if it hasn't happened already, if running on Ravenwood.
-     *
-     * No-op if called on the device side.
-     */
-    @RavenwoodRedirect
-    public static void ensureRavenwoodInitialized() {
-    }
-
-    /**
      * USE IT SPARINGLY! Returns true if it's running on Ravenwood, hostside test environment.
      *
      * <p>Using this allows code to behave differently on a real device and on Ravenwood, but
@@ -91,38 +72,10 @@
     }
 
     /**
-     * See {@link Workaround}. It's only usable on Ravenwood.
-     */
-    @RavenwoodReplace
-    public static Workaround workaround() {
-        throw notSupportedOnDevice();
-    }
-
-    private static Workaround workaround$ravenwood() {
-        return sWorkaround;
-    }
-
-    /**
      * @return the "ravenwood-runtime" directory.
      */
     @RavenwoodRedirect
     public String getRavenwoodRuntimePath() {
         throw notSupportedOnDevice();
     }
-
-    /**
-     * A set of APIs used to work around missing features on Ravenwood. Ideally, this class should
-     * be empty, and all its APIs should be able to be implemented properly.
-     */
-    public static class Workaround {
-        Workaround() {
-        }
-
-        /**
-         * @return whether the app's target SDK level is at least Q.
-         */
-        public boolean isTargetSdkAtLeastQ() {
-            return true;
-        }
-    }
 }
diff --git a/ravenwood/junit-impl-src/android/platform/test/ravenwood/RavenwoodRuntimeEnvironmentController.java b/ravenwood/junit-impl-src/android/platform/test/ravenwood/RavenwoodRuntimeEnvironmentController.java
index 0f16352..9752ff3 100644
--- a/ravenwood/junit-impl-src/android/platform/test/ravenwood/RavenwoodRuntimeEnvironmentController.java
+++ b/ravenwood/junit-impl-src/android/platform/test/ravenwood/RavenwoodRuntimeEnvironmentController.java
@@ -40,6 +40,7 @@
 import android.os.Bundle;
 import android.os.HandlerThread;
 import android.os.Looper;
+import android.os.Process_ravenwood;
 import android.os.ServiceManager;
 import android.os.SystemProperties;
 import android.provider.DeviceConfig_host;
@@ -52,6 +53,7 @@
 import com.android.hoststubgen.hosthelper.HostTestUtils;
 import com.android.internal.os.RuntimeInit;
 import com.android.ravenwood.RavenwoodRuntimeNative;
+import com.android.ravenwood.RavenwoodRuntimeState;
 import com.android.ravenwood.common.RavenwoodCommonUtils;
 import com.android.ravenwood.common.RavenwoodRuntimeException;
 import com.android.ravenwood.common.SneakyThrow;
@@ -223,7 +225,9 @@
             Thread.setDefaultUncaughtExceptionHandler(sUncaughtExceptionHandler);
         }
 
-        android.os.Process.init$ravenwood(config.mUid, config.mPid);
+        RavenwoodRuntimeState.sUid = config.mUid;
+        RavenwoodRuntimeState.sPid = config.mPid;
+        RavenwoodRuntimeState.sTargetSdkLevel = config.mTargetSdkLevel;
         sOriginalIdentityToken = Binder.clearCallingIdentity();
         reinit();
         setSystemProperties(config.mSystemProperties);
@@ -350,8 +354,8 @@
         if (sOriginalIdentityToken != -1) {
             Binder.restoreCallingIdentity(sOriginalIdentityToken);
         }
-        android.os.Process.reset$ravenwood();
-
+        RavenwoodRuntimeState.reset();
+        Process_ravenwood.reset();
         DeviceConfig_host.reset();
 
         try {
diff --git a/ravenwood/junit-src/android/platform/test/ravenwood/RavenwoodConfig.java b/ravenwood/junit-src/android/platform/test/ravenwood/RavenwoodConfig.java
index 37b0abc..d8f2b70 100644
--- a/ravenwood/junit-src/android/platform/test/ravenwood/RavenwoodConfig.java
+++ b/ravenwood/junit-src/android/platform/test/ravenwood/RavenwoodConfig.java
@@ -23,6 +23,7 @@
 import android.annotation.Nullable;
 import android.app.Instrumentation;
 import android.content.Context;
+import android.os.Build;
 
 import java.lang.annotation.ElementType;
 import java.lang.annotation.Retention;
@@ -67,7 +68,7 @@
     String mTargetPackageName;
 
     int mMinSdkLevel;
-    int mTargetSdkLevel;
+    int mTargetSdkLevel = Build.VERSION_CODES.CUR_DEVELOPMENT;
 
     boolean mProvideMainThread = false;
 
diff --git a/ravenwood/runtime-helper-src/framework/android/os/Process_ravenwood.java b/ravenwood/runtime-helper-src/framework/android/os/Process_ravenwood.java
new file mode 100644
index 0000000..3c6a4d7
--- /dev/null
+++ b/ravenwood/runtime-helper-src/framework/android/os/Process_ravenwood.java
@@ -0,0 +1,70 @@
+/*
+ * Copyright (C) 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package android.os;
+
+import android.util.Pair;
+
+public class Process_ravenwood {
+
+    private static volatile ThreadLocal<Pair<Integer, Boolean>> sThreadPriority;
+
+    static {
+        reset();
+    }
+
+    public static void reset() {
+        // Reset the thread local variable
+        sThreadPriority = ThreadLocal.withInitial(
+                () -> Pair.create(Process.THREAD_PRIORITY_DEFAULT, true));
+    }
+
+    /**
+     * Called by {@link Process#setThreadPriority(int, int)}
+     */
+    public static void setThreadPriority(int tid, int priority) {
+        if (Process.myTid() == tid) {
+            boolean backgroundOk = sThreadPriority.get().second;
+            if (priority >= Process.THREAD_PRIORITY_BACKGROUND && !backgroundOk) {
+                throw new IllegalArgumentException(
+                        "Priority " + priority + " blocked by setCanSelfBackground()");
+            }
+            sThreadPriority.set(Pair.create(priority, backgroundOk));
+        } else {
+            throw new UnsupportedOperationException(
+                    "Cross-thread priority management not yet available in Ravenwood");
+        }
+    }
+
+    /**
+     * Called by {@link Process#setCanSelfBackground(boolean)}
+     */
+    public static void setCanSelfBackground(boolean backgroundOk) {
+        int priority = sThreadPriority.get().first;
+        sThreadPriority.set(Pair.create(priority, backgroundOk));
+    }
+
+    /**
+     * Called by {@link Process#getThreadPriority(int)}
+     */
+    public static int getThreadPriority(int tid) {
+        if (Process.myTid() == tid) {
+            return sThreadPriority.get().first;
+        } else {
+            throw new UnsupportedOperationException(
+                    "Cross-thread priority management not yet available in Ravenwood");
+        }
+    }
+}
diff --git a/ravenwood/runtime-helper-src/framework/com/android/internal/ravenwood/RavenwoodEnvironment_host.java b/ravenwood/runtime-helper-src/framework/com/android/internal/ravenwood/RavenwoodEnvironment_host.java
index e12ff24..b65668b 100644
--- a/ravenwood/runtime-helper-src/framework/com/android/internal/ravenwood/RavenwoodEnvironment_host.java
+++ b/ravenwood/runtime-helper-src/framework/com/android/internal/ravenwood/RavenwoodEnvironment_host.java
@@ -23,14 +23,6 @@
     }
 
     /**
-     * Called from {@link RavenwoodEnvironment#ensureRavenwoodInitialized()}.
-     */
-    public static void ensureRavenwoodInitialized() {
-        // Initialization is now done by RavenwoodAwareTestRunner.
-        // Should we remove it?
-    }
-
-    /**
      * Called from {@link RavenwoodEnvironment#getRavenwoodRuntimePath()}.
      */
     public static String getRavenwoodRuntimePath(RavenwoodEnvironment env) {
diff --git a/ravenwood/runtime-helper-src/libcore-fake/android/system/Os.java b/ravenwood/runtime-helper-src/libcore-fake/android/system/Os.java
index c94ef31..0298171 100644
--- a/ravenwood/runtime-helper-src/libcore-fake/android/system/Os.java
+++ b/ravenwood/runtime-helper-src/libcore-fake/android/system/Os.java
@@ -16,6 +16,7 @@
 package android.system;
 
 import com.android.ravenwood.RavenwoodRuntimeNative;
+import com.android.ravenwood.RavenwoodRuntimeState;
 import com.android.ravenwood.common.JvmWorkaround;
 
 import java.io.FileDescriptor;
@@ -97,4 +98,16 @@
     public static void setenv(String name, String value, boolean overwrite) throws ErrnoException {
         RavenwoodRuntimeNative.setenv(name, value, overwrite);
     }
+
+    public static int getpid() {
+        return RavenwoodRuntimeState.sPid;
+    }
+
+    public static int getuid() {
+        return RavenwoodRuntimeState.sUid;
+    }
+
+    public static int gettid() {
+        return RavenwoodRuntimeNative.gettid();
+    }
 }
diff --git a/ravenwood/runtime-helper-src/libcore-fake/com/android/ravenwood/RavenwoodRuntimeNative.java b/ravenwood/runtime-helper-src/libcore-fake/com/android/ravenwood/RavenwoodRuntimeNative.java
index f13189f..7b940b4 100644
--- a/ravenwood/runtime-helper-src/libcore-fake/com/android/ravenwood/RavenwoodRuntimeNative.java
+++ b/ravenwood/runtime-helper-src/libcore-fake/com/android/ravenwood/RavenwoodRuntimeNative.java
@@ -58,6 +58,8 @@
 
     public static native void clearSystemProperties();
 
+    public static native int gettid();
+
     public static long lseek(FileDescriptor fd, long offset, int whence) throws ErrnoException {
         return nLseek(JvmWorkaround.getInstance().getFdInt(fd), offset, whence);
     }
diff --git a/ravenwood/runtime-helper-src/libcore-fake/com/android/ravenwood/RavenwoodRuntimeState.java b/ravenwood/runtime-helper-src/libcore-fake/com/android/ravenwood/RavenwoodRuntimeState.java
new file mode 100644
index 0000000..175e020
--- /dev/null
+++ b/ravenwood/runtime-helper-src/libcore-fake/com/android/ravenwood/RavenwoodRuntimeState.java
@@ -0,0 +1,35 @@
+/*
+ * Copyright (C) 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.android.ravenwood;
+
+public class RavenwoodRuntimeState {
+    // This must match VMRuntime.SDK_VERSION_CUR_DEVELOPMENT.
+    public static final int CUR_DEVELOPMENT = 10000;
+
+    public static volatile int sUid;
+    public static volatile int sPid;
+    public static volatile int sTargetSdkLevel;
+
+    static {
+        reset();
+    }
+
+    public static void reset() {
+        sUid = -1;
+        sPid = -1;
+        sTargetSdkLevel = CUR_DEVELOPMENT;
+    }
+}
diff --git a/ravenwood/runtime-helper-src/libcore-fake/dalvik/system/VMRuntime.java b/ravenwood/runtime-helper-src/libcore-fake/dalvik/system/VMRuntime.java
index ba89f71..eaadac6 100644
--- a/ravenwood/runtime-helper-src/libcore-fake/dalvik/system/VMRuntime.java
+++ b/ravenwood/runtime-helper-src/libcore-fake/dalvik/system/VMRuntime.java
@@ -19,6 +19,7 @@
 // The original is here:
 // $ANDROID_BUILD_TOP/libcore/libart/src/main/java/dalvik/system/VMRuntime.java
 
+import com.android.ravenwood.RavenwoodRuntimeState;
 import com.android.ravenwood.common.JvmWorkaround;
 
 import java.lang.reflect.Array;
@@ -52,4 +53,8 @@
     public long addressOf(Object obj) {
         return JvmWorkaround.getInstance().addressOf(obj);
     }
+
+    public int getTargetSdkVersion() {
+        return RavenwoodRuntimeState.sTargetSdkLevel;
+    }
 }
diff --git a/ravenwood/runtime-jni/ravenwood_runtime.cpp b/ravenwood/runtime-jni/ravenwood_runtime.cpp
index 2a3c26e..5b75e98 100644
--- a/ravenwood/runtime-jni/ravenwood_runtime.cpp
+++ b/ravenwood/runtime-jni/ravenwood_runtime.cpp
@@ -17,6 +17,7 @@
 #include <fcntl.h>
 #include <string.h>
 #include <sys/stat.h>
+#include <sys/syscall.h>
 #include <unistd.h>
 #include <utils/misc.h>
 
@@ -173,6 +174,12 @@
     throwIfMinusOne(env, "setenv", setenv(name.c_str(), value.c_str(), overwrite ? 1 : 0));
 }
 
+
+static jint Linux_gettid(JNIEnv* env, jobject) {
+    // gettid(2() was added in glibc 2.30 but Android uses an older version in prebuilt.
+    return syscall(__NR_gettid);
+}
+
 static void maybeRedirectLog() {
     auto ravenwoodLogOut = getenv("RAVENWOOD_LOG_OUT");
     if (ravenwoodLogOut == NULL) {
@@ -207,6 +214,7 @@
     { "stat", "(Ljava/lang/String;)Landroid/system/StructStat;", (void*)Linux_stat },
     { "nOpen", "(Ljava/lang/String;II)I", (void*)Linux_open },
     { "setenv", "(Ljava/lang/String;Ljava/lang/String;Z)V", (void*)Linux_setenv },
+    { "gettid", "()I", (void*)Linux_gettid },
 };
 
 extern "C" jint JNI_OnLoad(JavaVM* vm, void* /* reserved */) {
diff --git a/ravenwood/tests/runtime-test/Android.bp b/ravenwood/tests/runtime-test/Android.bp
index 4102920..0c0df1f 100644
--- a/ravenwood/tests/runtime-test/Android.bp
+++ b/ravenwood/tests/runtime-test/Android.bp
@@ -10,6 +10,9 @@
 android_ravenwood_test {
     name: "RavenwoodRuntimeTest",
 
+    libs: [
+        "ravenwood-helper-runtime",
+    ],
     static_libs: [
         "androidx.annotation_annotation",
         "androidx.test.ext.junit",
diff --git a/ravenwood/tests/runtime-test/test/com/android/ravenwoodtest/runtimetest/IdentityTest.java b/ravenwood/tests/runtime-test/test/com/android/ravenwoodtest/runtimetest/IdentityTest.java
new file mode 100644
index 0000000..8e04b69
--- /dev/null
+++ b/ravenwood/tests/runtime-test/test/com/android/ravenwoodtest/runtimetest/IdentityTest.java
@@ -0,0 +1,66 @@
+/*
+ * Copyright (C) 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.android.ravenwoodtest.runtimetest;
+
+import static android.os.Build.VERSION_CODES.UPSIDE_DOWN_CAKE;
+import static android.os.Process.FIRST_APPLICATION_UID;
+
+import static org.junit.Assert.assertEquals;
+
+import android.os.Binder;
+import android.os.Build;
+import android.os.Process;
+import android.platform.test.ravenwood.RavenwoodConfig;
+import android.system.Os;
+
+import com.android.ravenwood.RavenwoodRuntimeState;
+
+import dalvik.system.VMRuntime;
+
+import org.junit.Test;
+
+public class IdentityTest {
+
+    @RavenwoodConfig.Config
+    public static final RavenwoodConfig sConfig =
+            new RavenwoodConfig.Builder()
+                    .setTargetSdkLevel(UPSIDE_DOWN_CAKE)
+                    .setProcessApp()
+                    .build();
+
+    @Test
+    public void testUid() {
+        assertEquals(FIRST_APPLICATION_UID, RavenwoodRuntimeState.sUid);
+        assertEquals(FIRST_APPLICATION_UID, Os.getuid());
+        assertEquals(FIRST_APPLICATION_UID, Process.myUid());
+        assertEquals(FIRST_APPLICATION_UID, Binder.getCallingUid());
+    }
+
+    @Test
+    public void testPid() {
+        int pid = RavenwoodRuntimeState.sPid;
+        assertEquals(pid, Os.getpid());
+        assertEquals(pid, Process.myPid());
+        assertEquals(pid, Binder.getCallingPid());
+    }
+
+    @Test
+    public void testTargetSdkLevel() {
+        assertEquals(Build.VERSION_CODES.CUR_DEVELOPMENT, RavenwoodRuntimeState.CUR_DEVELOPMENT);
+        assertEquals(UPSIDE_DOWN_CAKE, RavenwoodRuntimeState.sTargetSdkLevel);
+        assertEquals(UPSIDE_DOWN_CAKE, VMRuntime.getRuntime().getTargetSdkVersion());
+    }
+}
diff --git a/ravenwood/tests/runtime-test/test/com/android/ravenwoodtest/runtimetest/OsTest.java b/ravenwood/tests/runtime-test/test/com/android/ravenwoodtest/runtimetest/OsTest.java
index c2230c7..c55506a 100644
--- a/ravenwood/tests/runtime-test/test/com/android/ravenwoodtest/runtimetest/OsTest.java
+++ b/ravenwood/tests/runtime-test/test/com/android/ravenwoodtest/runtimetest/OsTest.java
@@ -24,6 +24,8 @@
 import static android.system.OsConstants.S_ISSOCK;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotEquals;
+import static org.junit.Assert.assertTrue;
 
 import static java.nio.file.LinkOption.NOFOLLOW_LINKS;
 
@@ -51,10 +53,12 @@
 import java.nio.file.attribute.PosixFilePermission;
 import java.util.HashSet;
 import java.util.Set;
+import java.util.concurrent.CountDownLatch;
 import java.util.concurrent.TimeUnit;
 
 @RunWith(AndroidJUnit4.class)
 public class OsTest {
+
     public interface ConsumerWithThrow<T> {
         void accept(T var1) throws Exception;
     }
@@ -165,6 +169,35 @@
         });
     }
 
+    private static class TestThread extends Thread {
+
+        final CountDownLatch mLatch = new CountDownLatch(1);
+        int mTid;
+
+        TestThread() {
+            setDaemon(true);
+        }
+
+        @Override
+        public void run() {
+            mTid = Os.gettid();
+            mLatch.countDown();
+        }
+    }
+
+    @Test
+    public void testGetTid() throws InterruptedException {
+        var t1 = new TestThread();
+        var t2 = new TestThread();
+        t1.start();
+        t2.start();
+        // Wait for thread execution
+        assertTrue(t1.mLatch.await(1, TimeUnit.SECONDS));
+        assertTrue(t2.mLatch.await(1, TimeUnit.SECONDS));
+        // Make sure the tid is unique per-thread
+        assertNotEquals(t1.mTid, t2.mTid);
+    }
+
     // Verify StructStat values from libcore against native JVM PosixFileAttributes
     private static void assertAttributesEqual(PosixFileAttributes attr, StructStat stat) {
         assertEquals(attr.lastModifiedTime(), convertTimespecToFileTime(stat.st_mtim));
diff --git a/ravenwood/tests/runtime-test/test/com/android/ravenwoodtest/runtimetest/ProcessTest.java b/ravenwood/tests/runtime-test/test/com/android/ravenwoodtest/runtimetest/ProcessTest.java
new file mode 100644
index 0000000..d25b5c1
--- /dev/null
+++ b/ravenwood/tests/runtime-test/test/com/android/ravenwoodtest/runtimetest/ProcessTest.java
@@ -0,0 +1,54 @@
+/*
+ * Copyright (C) 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.android.ravenwoodtest.runtimetest;
+
+import static android.os.Process.THREAD_PRIORITY_BACKGROUND;
+import static android.os.Process.THREAD_PRIORITY_DEFAULT;
+import static android.os.Process.THREAD_PRIORITY_FOREGROUND;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertThrows;
+
+import android.os.Process;
+import android.system.Os;
+
+import org.junit.Test;
+
+public class ProcessTest {
+
+    @Test
+    public void testGetUidPidTid() {
+        assertEquals(Os.getuid(), Process.myUid());
+        assertEquals(Os.getpid(), Process.myPid());
+        assertEquals(Os.gettid(), Process.myTid());
+    }
+
+    @Test
+    public void testThreadPriority() {
+        assertThrows(UnsupportedOperationException.class,
+                () -> Process.getThreadPriority(Process.myTid() + 1));
+        assertThrows(UnsupportedOperationException.class,
+                () -> Process.setThreadPriority(Process.myTid() + 1, THREAD_PRIORITY_DEFAULT));
+        assertEquals(THREAD_PRIORITY_DEFAULT, Process.getThreadPriority(Process.myTid()));
+        Process.setThreadPriority(THREAD_PRIORITY_FOREGROUND);
+        assertEquals(THREAD_PRIORITY_FOREGROUND, Process.getThreadPriority(Process.myTid()));
+        Process.setCanSelfBackground(false);
+        Process.setThreadPriority(THREAD_PRIORITY_DEFAULT);
+        assertEquals(THREAD_PRIORITY_DEFAULT, Process.getThreadPriority(Process.myTid()));
+        assertThrows(IllegalArgumentException.class,
+                () -> Process.setThreadPriority(THREAD_PRIORITY_BACKGROUND));
+    }
+}