diff --git a/apct-tests/perftests/core/src/android/os/ParcelStringPerfTest.java b/apct-tests/perftests/core/src/android/os/ParcelStringPerfTest.java
new file mode 100644
index 0000000000000..2b861cb668909
--- /dev/null
+++ b/apct-tests/perftests/core/src/android/os/ParcelStringPerfTest.java
@@ -0,0 +1,70 @@
+/*
+ * Copyright (C) 2020 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.perftests.utils.BenchmarkState;
+import android.perftests.utils.PerfStatusReporter;
+
+import androidx.test.filters.LargeTest;
+
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+
+import java.util.Arrays;
+import java.util.Collection;
+
+@LargeTest
+@RunWith(Parameterized.class)
+public class ParcelStringPerfTest {
+    @Rule
+    public PerfStatusReporter mPerfStatusReporter = new PerfStatusReporter();
+
+    @Parameterized.Parameter(0)
+    public String mName;
+    @Parameterized.Parameter(1)
+    public String mValue;
+
+    @Parameterized.Parameters(name = "{0}")
+    public static Collection<Object[]> getParameters() {
+        return Arrays.asList(new Object[][] {
+                { "simple", "com.example.typical_package_name" },
+                { "complex", "從不喜歡孤單一個 - 蘇永康／吳雨霏" },
+        });
+    }
+
+    @Test
+    public void timeWriteString8() {
+        final Parcel parcel = Parcel.obtain();
+        final BenchmarkState state = mPerfStatusReporter.getBenchmarkState();
+        while (state.keepRunning()) {
+            parcel.setDataPosition(0);
+            parcel.writeString8(mValue);
+        }
+    }
+
+    @Test
+    public void timeWriteString16() {
+        final Parcel parcel = Parcel.obtain();
+        final BenchmarkState state = mPerfStatusReporter.getBenchmarkState();
+        while (state.keepRunning()) {
+            parcel.setDataPosition(0);
+            parcel.writeString16(mValue);
+        }
+    }
+}
diff --git a/core/jni/android_os_Parcel.cpp b/core/jni/android_os_Parcel.cpp
index 355ef0cd6b3f9..f05c6a42c5f72 100644
--- a/core/jni/android_os_Parcel.cpp
+++ b/core/jni/android_os_Parcel.cpp
@@ -252,20 +252,25 @@ static void android_os_Parcel_nativeSignalExceptionForError(JNIEnv* env, jclass
     signalExceptionForError(env, clazz, err);
 }
 
-static void android_os_Parcel_writeString8(JNIEnv* env, jclass clazz, jlong nativePtr, jstring val)
-{
+static void android_os_Parcel_writeString8(JNIEnv *env, jclass clazz, jlong nativePtr,
+        jstring val) {
     Parcel* parcel = reinterpret_cast<Parcel*>(nativePtr);
-    if (parcel != NULL) {
-        status_t err = NO_MEMORY;
+    if (parcel != nullptr) {
+        status_t err = NO_ERROR;
         if (val) {
-            const size_t len = env->GetStringUTFLength(val);
-            const char* str = env->GetStringUTFChars(val, 0);
-            if (str) {
-                err = parcel->writeString8(str, len);
-                env->ReleaseStringUTFChars(val, str);
+            // NOTE: Keep this logic in sync with Parcel.cpp
+            const size_t len = env->GetStringLength(val);
+            const size_t allocLen = env->GetStringUTFLength(val);
+            err = parcel->writeInt32(allocLen);
+            char *data = reinterpret_cast<char*>(parcel->writeInplace(allocLen + sizeof(char)));
+            if (data != nullptr) {
+                env->GetStringUTFRegion(val, 0, len, data);
+                *(data + allocLen) = 0;
+            } else {
+                err = NO_MEMORY;
             }
         } else {
-            err = parcel->writeString8(NULL, 0);
+            err = parcel->writeString8(nullptr, 0);
         }
         if (err != NO_ERROR) {
             signalExceptionForError(env, clazz, err);
@@ -273,21 +278,25 @@ static void android_os_Parcel_writeString8(JNIEnv* env, jclass clazz, jlong nati
     }
 }
 
-static void android_os_Parcel_writeString16(JNIEnv* env, jclass clazz, jlong nativePtr, jstring val)
-{
+static void android_os_Parcel_writeString16(JNIEnv *env, jclass clazz, jlong nativePtr,
+        jstring val) {
     Parcel* parcel = reinterpret_cast<Parcel*>(nativePtr);
-    if (parcel != NULL) {
-        status_t err = NO_MEMORY;
+    if (parcel != nullptr) {
+        status_t err = NO_ERROR;
         if (val) {
-            const jchar* str = env->GetStringCritical(val, 0);
-            if (str) {
-                err = parcel->writeString16(
-                    reinterpret_cast<const char16_t*>(str),
-                    env->GetStringLength(val));
-                env->ReleaseStringCritical(val, str);
+            // NOTE: Keep this logic in sync with Parcel.cpp
+            const size_t len = env->GetStringLength(val);
+            const size_t allocLen = len * sizeof(char16_t);
+            err = parcel->writeInt32(len);
+            char *data = reinterpret_cast<char*>(parcel->writeInplace(allocLen + sizeof(char16_t)));
+            if (data != nullptr) {
+                env->GetStringRegion(val, 0, len, reinterpret_cast<jchar*>(data));
+                *reinterpret_cast<char16_t*>(data + allocLen) = 0;
+            } else {
+                err = NO_MEMORY;
             }
         } else {
-            err = parcel->writeString16(NULL, 0);
+            err = parcel->writeString16(nullptr, 0);
         }
         if (err != NO_ERROR) {
             signalExceptionForError(env, clazz, err);