stagefright: add test for MediaCodec::reclaim/release race

- Minor MediaCodec refactoring to allow dependency injection
- Introduce MediaTestHelper to access private methods
  from the test code

Bug: 154678891
Test: atest mediacodecTest
Merged-In: I14c23eeabc288b43ad2be6ded0f8858ce22844c4
Change-Id: I14c23eeabc288b43ad2be6ded0f8858ce22844c4
diff --git a/media/libstagefright/MediaCodec.cpp b/media/libstagefright/MediaCodec.cpp
index dfd3118..298a3f9 100644
--- a/media/libstagefright/MediaCodec.cpp
+++ b/media/libstagefright/MediaCodec.cpp
@@ -614,7 +614,10 @@
     return new PersistentSurface(bufferProducer, bufferSource);
 }
 
-MediaCodec::MediaCodec(const sp<ALooper> &looper, pid_t pid, uid_t uid)
+MediaCodec::MediaCodec(
+        const sp<ALooper> &looper, pid_t pid, uid_t uid,
+        std::function<sp<CodecBase>(const AString &, const char *)> getCodecBase,
+        std::function<status_t(const AString &, sp<MediaCodecInfo> *)> getCodecInfo)
     : mState(UNINITIALIZED),
       mReleasedByResourceManager(false),
       mLooper(looper),
@@ -639,7 +642,9 @@
       mNumLowLatencyDisables(0),
       mIsLowLatencyModeOn(false),
       mIndexOfFirstFrameWhenLowLatencyOn(-1),
-      mInputBufferCounter(0) {
+      mInputBufferCounter(0),
+      mGetCodecBase(getCodecBase),
+      mGetCodecInfo(getCodecInfo) {
     if (uid == kNoUid) {
         mUid = AIBinder_getCallingUid();
     } else {
@@ -647,6 +652,33 @@
     }
     mResourceManagerProxy = new ResourceManagerServiceProxy(pid, mUid,
             ::ndk::SharedRefBase::make<ResourceManagerClient>(this));
+    if (!mGetCodecBase) {
+        mGetCodecBase = [](const AString &name, const char *owner) {
+            return GetCodecBase(name, owner);
+        };
+    }
+    if (!mGetCodecInfo) {
+        mGetCodecInfo = [](const AString &name, sp<MediaCodecInfo> *info) -> status_t {
+            *info = nullptr;
+            const sp<IMediaCodecList> mcl = MediaCodecList::getInstance();
+            if (!mcl) {
+                return NO_INIT;  // if called from Java should raise IOException
+            }
+            AString tmp = name;
+            if (tmp.endsWith(".secure")) {
+                tmp.erase(tmp.size() - 7, 7);
+            }
+            for (const AString &codecName : { name, tmp }) {
+                ssize_t codecIdx = mcl->findCodecByName(codecName.c_str());
+                if (codecIdx < 0) {
+                    continue;
+                }
+                *info = mcl->getCodecInfo(codecIdx);
+                return OK;
+            }
+            return NAME_NOT_FOUND;
+        };
+    }
 
     initMediametrics();
 }
@@ -1090,40 +1122,30 @@
     bool secureCodec = false;
     const char *owner = "";
     if (!name.startsWith("android.filter.")) {
-        AString tmp = name;
-        if (tmp.endsWith(".secure")) {
-            secureCodec = true;
-            tmp.erase(tmp.size() - 7, 7);
-        }
-        const sp<IMediaCodecList> mcl = MediaCodecList::getInstance();
-        if (mcl == NULL) {
+        status_t err = mGetCodecInfo(name, &mCodecInfo);
+        if (err != OK) {
             mCodec = NULL;  // remove the codec.
-            return NO_INIT; // if called from Java should raise IOException
-        }
-        for (const AString &codecName : { name, tmp }) {
-            ssize_t codecIdx = mcl->findCodecByName(codecName.c_str());
-            if (codecIdx < 0) {
-                continue;
-            }
-            mCodecInfo = mcl->getCodecInfo(codecIdx);
-            Vector<AString> mediaTypes;
-            mCodecInfo->getSupportedMediaTypes(&mediaTypes);
-            for (size_t i = 0; i < mediaTypes.size(); i++) {
-                if (mediaTypes[i].startsWith("video/")) {
-                    mIsVideo = true;
-                    break;
-                }
-            }
-            break;
+            return err;
         }
         if (mCodecInfo == nullptr) {
+            ALOGE("Getting codec info with name '%s' failed", name.c_str());
             return NAME_NOT_FOUND;
         }
+        secureCodec = name.endsWith(".secure");
+        Vector<AString> mediaTypes;
+        mCodecInfo->getSupportedMediaTypes(&mediaTypes);
+        for (size_t i = 0; i < mediaTypes.size(); ++i) {
+            if (mediaTypes[i].startsWith("video/")) {
+                mIsVideo = true;
+                break;
+            }
+        }
         owner = mCodecInfo->getOwnerName();
     }
 
-    mCodec = GetCodecBase(name, owner);
+    mCodec = mGetCodecBase(name, owner);
     if (mCodec == NULL) {
+        ALOGE("Getting codec base with name '%s' (owner='%s') failed", name.c_str(), owner);
         return NAME_NOT_FOUND;
     }
 
diff --git a/media/libstagefright/TEST_MAPPING b/media/libstagefright/TEST_MAPPING
index 8b36ea5..5e537dd 100644
--- a/media/libstagefright/TEST_MAPPING
+++ b/media/libstagefright/TEST_MAPPING
@@ -17,6 +17,9 @@
           "exclude-filter": "android.media.cts.AudioRecordTest"
         }
       ]
+    },
+    {
+      "name": "mediacodecTest"
     }
   ],
   "postsubmit": [
diff --git a/media/libstagefright/include/media/stagefright/MediaCodec.h b/media/libstagefright/include/media/stagefright/MediaCodec.h
index 35de612..823677a 100644
--- a/media/libstagefright/include/media/stagefright/MediaCodec.h
+++ b/media/libstagefright/include/media/stagefright/MediaCodec.h
@@ -429,7 +429,10 @@
 
     std::shared_ptr<BufferChannelBase> mBufferChannel;
 
-    MediaCodec(const sp<ALooper> &looper, pid_t pid, uid_t uid);
+    MediaCodec(
+            const sp<ALooper> &looper, pid_t pid, uid_t uid,
+            std::function<sp<CodecBase>(const AString &, const char *)> getCodecBase = nullptr,
+            std::function<status_t(const AString &, sp<MediaCodecInfo> *)> getCodecInfo = nullptr);
 
     static sp<CodecBase> GetCodecBase(const AString &name, const char *owner = nullptr);
 
@@ -576,6 +579,10 @@
 
     Histogram mLatencyHist;
 
+    std::function<sp<CodecBase>(const AString &, const char *)> mGetCodecBase;
+    std::function<status_t(const AString &, sp<MediaCodecInfo> *)> mGetCodecInfo;
+    friend class MediaTestHelper;
+
     DISALLOW_EVIL_CONSTRUCTORS(MediaCodec);
 };
 
diff --git a/media/libstagefright/include/media/stagefright/MediaCodecListWriter.h b/media/libstagefright/include/media/stagefright/MediaCodecListWriter.h
index f53b23e..bf85d7e 100644
--- a/media/libstagefright/include/media/stagefright/MediaCodecListWriter.h
+++ b/media/libstagefright/include/media/stagefright/MediaCodecListWriter.h
@@ -19,7 +19,6 @@
 #define MEDIA_CODEC_LIST_WRITER_H_
 
 #include <media/stagefright/foundation/ABase.h>
-#include <media/stagefright/MediaCodecListWriter.h>
 #include <media/MediaCodecInfo.h>
 
 #include <utils/Errors.h>
@@ -65,6 +64,7 @@
     std::vector<sp<MediaCodecInfo>> mCodecInfos;
 
     friend struct MediaCodecList;
+    friend class MediaTestHelper;
 };
 
 /**
diff --git a/media/libstagefright/tests/mediacodec/Android.bp b/media/libstagefright/tests/mediacodec/Android.bp
new file mode 100644
index 0000000..006864e
--- /dev/null
+++ b/media/libstagefright/tests/mediacodec/Android.bp
@@ -0,0 +1,57 @@
+/*
+ * 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.
+ */
+
+cc_test {
+    name: "mediacodecTest",
+    gtest: true,
+
+    srcs: [
+        "MediaCodecTest.cpp",
+        "MediaTestHelper.cpp",
+    ],
+
+    shared_libs: [
+        "libmedia",
+        "libmedia_codeclist",
+        "libmediametrics",
+        "libmediandk",
+        "libstagefright",
+        "libstagefright_codecbase",
+        "libstagefright_foundation",
+        "libutils",
+    ],
+
+    static_libs: [
+        "libgmock",
+    ],
+
+    cflags: [
+        "-Werror",
+        "-Wall",
+    ],
+
+    sanitize: {
+        cfi: true,
+        misc_undefined: [
+            "unsigned-integer-overflow",
+            "signed-integer-overflow",
+        ],
+    },
+
+    test_suites: [
+        "general-tests",
+    ],
+}
diff --git a/media/libstagefright/tests/mediacodec/MediaCodecTest.cpp b/media/libstagefright/tests/mediacodec/MediaCodecTest.cpp
new file mode 100644
index 0000000..baa86c1
--- /dev/null
+++ b/media/libstagefright/tests/mediacodec/MediaCodecTest.cpp
@@ -0,0 +1,268 @@
+/*
+ * 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.
+ */
+
+#include <future>
+#include <thread>
+
+#include <gmock/gmock.h>
+#include <gtest/gtest.h>
+
+#include <media/stagefright/CodecBase.h>
+#include <media/stagefright/MediaCodec.h>
+#include <media/stagefright/MediaCodecListWriter.h>
+#include <media/MediaCodecInfo.h>
+
+#include "MediaTestHelper.h"
+
+namespace android {
+
+class MockBufferChannel : public BufferChannelBase {
+public:
+    ~MockBufferChannel() override = default;
+
+    MOCK_METHOD(void, setCrypto, (const sp<ICrypto> &crypto), (override));
+    MOCK_METHOD(void, setDescrambler, (const sp<IDescrambler> &descrambler), (override));
+    MOCK_METHOD(status_t, queueInputBuffer, (const sp<MediaCodecBuffer> &buffer), (override));
+    MOCK_METHOD(status_t, queueSecureInputBuffer,
+            (const sp<MediaCodecBuffer> &buffer,
+             bool secure,
+             const uint8_t *key,
+             const uint8_t *iv,
+             CryptoPlugin::Mode mode,
+             CryptoPlugin::Pattern pattern,
+             const CryptoPlugin::SubSample *subSamples,
+             size_t numSubSamples,
+             AString *errorDetailMsg),
+            (override));
+    MOCK_METHOD(status_t, attachBuffer,
+            (const std::shared_ptr<C2Buffer> &c2Buffer, const sp<MediaCodecBuffer> &buffer),
+            (override));
+    MOCK_METHOD(status_t, attachEncryptedBuffer,
+            (const sp<hardware::HidlMemory> &memory,
+             bool secure,
+             const uint8_t *key,
+             const uint8_t *iv,
+             CryptoPlugin::Mode mode,
+             CryptoPlugin::Pattern pattern,
+             size_t offset,
+             const CryptoPlugin::SubSample *subSamples,
+             size_t numSubSamples,
+             const sp<MediaCodecBuffer> &buffer),
+            (override));
+    MOCK_METHOD(status_t, renderOutputBuffer,
+            (const sp<MediaCodecBuffer> &buffer, int64_t timestampNs),
+            (override));
+    MOCK_METHOD(status_t, discardBuffer, (const sp<MediaCodecBuffer> &buffer), (override));
+    MOCK_METHOD(void, getInputBufferArray, (Vector<sp<MediaCodecBuffer>> *array), (override));
+    MOCK_METHOD(void, getOutputBufferArray, (Vector<sp<MediaCodecBuffer>> *array), (override));
+};
+
+class MockCodec : public CodecBase {
+public:
+    MockCodec(std::function<void(const std::shared_ptr<MockBufferChannel> &)> mock) {
+        mMockBufferChannel = std::make_shared<MockBufferChannel>();
+        mock(mMockBufferChannel);
+    }
+    ~MockCodec() override = default;
+
+    MOCK_METHOD(void, initiateAllocateComponent, (const sp<AMessage> &msg), (override));
+    MOCK_METHOD(void, initiateConfigureComponent, (const sp<AMessage> &msg), (override));
+    MOCK_METHOD(void, initiateCreateInputSurface, (), (override));
+    MOCK_METHOD(void, initiateSetInputSurface, (const sp<PersistentSurface> &surface), (override));
+    MOCK_METHOD(void, initiateStart, (), (override));
+    MOCK_METHOD(void, initiateShutdown, (bool keepComponentAllocated), (override));
+    MOCK_METHOD(void, onMessageReceived, (const sp<AMessage> &msg), (override));
+    MOCK_METHOD(status_t, setSurface, (const sp<Surface> &surface), (override));
+    MOCK_METHOD(void, signalFlush, (), (override));
+    MOCK_METHOD(void, signalResume, (), (override));
+    MOCK_METHOD(void, signalRequestIDRFrame, (), (override));
+    MOCK_METHOD(void, signalSetParameters, (const sp<AMessage> &msg), (override));
+    MOCK_METHOD(void, signalEndOfInputStream, (), (override));
+
+    std::shared_ptr<BufferChannelBase> getBufferChannel() override {
+        return mMockBufferChannel;
+    }
+
+    const std::unique_ptr<CodecCallback> &callback() {
+        return mCallback;
+    }
+
+    std::shared_ptr<MockBufferChannel> mMockBufferChannel;
+};
+
+class Counter {
+public:
+    Counter() = default;
+    explicit Counter(int32_t initCount) : mCount(initCount) {}
+    ~Counter() = default;
+
+    int32_t advance() {
+        std::unique_lock<std::mutex> lock(mMutex);
+        ++mCount;
+        mCondition.notify_all();
+        return mCount;
+    }
+
+    template <typename Rep, typename Period, typename ...Args>
+    int32_t waitFor(const std::chrono::duration<Rep, Period> &duration, Args... values) {
+        std::initializer_list<int32_t> list = {values...};
+        std::unique_lock<std::mutex> lock(mMutex);
+        mCondition.wait_for(
+                lock,
+                duration,
+                [&list, this]{
+                    return std::find(list.begin(), list.end(), mCount) != list.end();
+                });
+        return mCount;
+    }
+
+    template <typename ...Args>
+    int32_t wait(Args... values) {
+        std::initializer_list<int32_t> list = {values...};
+        std::unique_lock<std::mutex> lock(mMutex);
+        mCondition.wait(
+                lock,
+                [&list, this]{
+                    return std::find(list.begin(), list.end(), mCount) != list.end();
+                });
+        return mCount;
+    }
+
+private:
+    std::mutex mMutex;
+    std::condition_variable mCondition;
+    int32_t mCount = 0;
+};
+
+}  // namespace android
+
+using namespace android;
+using ::testing::_;
+
+TEST(MediaCodecTest, ReclaimReleaseRace) {
+    // Test scenario:
+    //
+    // 1) ResourceManager thread calls reclaim(), message posted to
+    //    MediaCodec looper thread.
+    // 2) MediaCodec looper thread calls initiateShutdown(), shutdown being
+    //    handled at the component thread.
+    // 3) Client thread calls release(), message posted to & handle at
+    //    MediaCodec looper thread.
+    // 4) MediaCodec looper thread may call initiateShutdown().
+    // 5) initiateShutdown() from 2) is handled at onReleaseComplete() event
+    //    posted to MediaCodec looper thread.
+    // 6) If called, initiateShutdown() from 4) is handled and
+    //    onReleaseComplete() event posted to MediaCodec looper thread.
+
+    static const AString kCodecName{"test.codec"};
+    static const AString kCodecOwner{"nobody"};
+    static const AString kMediaType{"video/x-test"};
+
+    enum {
+        kInit,
+        kShutdownFromReclaimReceived,
+        kReleaseCalled,
+    };
+    Counter counter{kInit};
+    sp<MockCodec> mockCodec;
+    std::function<sp<CodecBase>(const AString &name, const char *owner)> getCodecBase =
+        [&mockCodec, &counter](const AString &, const char *) {
+            mockCodec = new MockCodec([](const std::shared_ptr<MockBufferChannel> &) {
+                // No mock setup, as we don't expect any buffer operations
+                // in this scenario.
+            });
+            ON_CALL(*mockCodec, initiateAllocateComponent(_))
+                .WillByDefault([mockCodec](const sp<AMessage> &) {
+                    mockCodec->callback()->onComponentAllocated(kCodecName.c_str());
+                });
+            ON_CALL(*mockCodec, initiateShutdown(_))
+                .WillByDefault([mockCodec, &counter](bool) {
+                    int32_t stage = counter.wait(kInit, kReleaseCalled);
+                    if (stage == kInit) {
+                        // Mark that 2) happened, so test can proceed to 3)
+                        counter.advance();
+                    } else if (stage == kReleaseCalled) {
+                        // Handle 6)
+                        mockCodec->callback()->onReleaseCompleted();
+                    }
+                });
+            return mockCodec;
+        };
+
+    std::shared_ptr<MediaCodecListWriter> listWriter =
+        MediaTestHelper::CreateCodecListWriter();
+    std::unique_ptr<MediaCodecInfoWriter> infoWriter = listWriter->addMediaCodecInfo();
+    infoWriter->setName(kCodecName.c_str());
+    infoWriter->setOwner(kCodecOwner.c_str());
+    infoWriter->addMediaType(kMediaType.c_str());
+    std::vector<sp<MediaCodecInfo>> codecInfos;
+    MediaTestHelper::WriteCodecInfos(listWriter, &codecInfos);
+    std::function<status_t(const AString &, sp<MediaCodecInfo> *)> getCodecInfo =
+        [codecInfos](const AString &name, sp<MediaCodecInfo> *info) -> status_t {
+            auto it = std::find_if(
+                    codecInfos.begin(), codecInfos.end(),
+                    [&name](const sp<MediaCodecInfo> &info) {
+                        return name.equalsIgnoreCase(info->getCodecName());
+                    });
+
+            *info = (it == codecInfos.end()) ? nullptr : *it;
+            return (*info) ? OK : NAME_NOT_FOUND;
+        };
+
+    sp<ALooper> looper{new ALooper};
+    looper->start();
+    sp<MediaCodec> codec = MediaTestHelper::CreateCodec(
+            kCodecName, looper, getCodecBase, getCodecInfo);
+    ASSERT_NE(nullptr, codec) << "Codec must not be null";
+    ASSERT_NE(nullptr, mockCodec) << "MockCodec must not be null";
+    std::promise<void> reclaimCompleted;
+    std::promise<void> releaseCompleted;
+    Counter threadExitCounter;
+    std::thread([codec, &reclaimCompleted]{
+        // Simulate ResourceManager thread. Proceed with 1)
+        MediaTestHelper::Reclaim(codec, true /* force */);
+        reclaimCompleted.set_value();
+    }).detach();
+    std::thread([codec, &counter, &releaseCompleted]{
+        // Simulate client thread. Wait until 2) is complete
+        (void)counter.wait(kShutdownFromReclaimReceived);
+        // Proceed to 3), and mark that 5) is ready to happen.
+        // NOTE: it's difficult to pinpoint when 4) happens, so we will sleep
+        //       to meet the timing.
+        counter.advance();
+        codec->release();
+        releaseCompleted.set_value();
+    }).detach();
+    std::thread([mockCodec, &counter]{
+        // Simulate component thread. Wait until 3) is complete
+        (void)counter.wait(kReleaseCalled);
+        // We want 4) to complete before moving forward, but it is hard to
+        // wait for this exact event. Just sleep so that the other thread can
+        // proceed and complete 4).
+        std::this_thread::sleep_for(std::chrono::milliseconds(100));
+        // Proceed to 5).
+        mockCodec->callback()->onReleaseCompleted();
+    }).detach();
+    EXPECT_EQ(
+            std::future_status::ready,
+            reclaimCompleted.get_future().wait_for(std::chrono::seconds(5)))
+        << "reclaim timed out";
+    EXPECT_EQ(
+            std::future_status::ready,
+            releaseCompleted.get_future().wait_for(std::chrono::seconds(5)))
+        << "release timed out";
+    looper->stop();
+}
diff --git a/media/libstagefright/tests/mediacodec/MediaTestHelper.cpp b/media/libstagefright/tests/mediacodec/MediaTestHelper.cpp
new file mode 100644
index 0000000..bbe3c05
--- /dev/null
+++ b/media/libstagefright/tests/mediacodec/MediaTestHelper.cpp
@@ -0,0 +1,55 @@
+/*
+ * 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.
+ */
+
+#include <media/stagefright/MediaCodec.h>
+#include <media/stagefright/MediaCodecListWriter.h>
+
+#include "MediaTestHelper.h"
+
+namespace android {
+
+// static
+sp<MediaCodec> MediaTestHelper::CreateCodec(
+        const AString &name,
+        const sp<ALooper> &looper,
+        std::function<sp<CodecBase>(const AString &, const char *)> getCodecBase,
+        std::function<status_t(const AString &, sp<MediaCodecInfo> *)> getCodecInfo) {
+    sp<MediaCodec> codec = new MediaCodec(
+            looper, MediaCodec::kNoPid, MediaCodec::kNoUid, getCodecBase, getCodecInfo);
+    if (codec->init(name) != OK) {
+        return nullptr;
+    }
+    return codec;
+}
+
+// static
+void MediaTestHelper::Reclaim(const sp<MediaCodec> &codec, bool force) {
+    codec->reclaim(force);
+}
+
+// static
+std::shared_ptr<MediaCodecListWriter> MediaTestHelper::CreateCodecListWriter() {
+    return std::shared_ptr<MediaCodecListWriter>(new MediaCodecListWriter);
+}
+
+// static
+void MediaTestHelper::WriteCodecInfos(
+        const std::shared_ptr<MediaCodecListWriter> &writer,
+        std::vector<sp<MediaCodecInfo>> *codecInfos) {
+    writer->writeCodecInfos(codecInfos);
+}
+
+}  // namespace android
diff --git a/media/libstagefright/tests/mediacodec/MediaTestHelper.h b/media/libstagefright/tests/mediacodec/MediaTestHelper.h
new file mode 100644
index 0000000..f3d6110
--- /dev/null
+++ b/media/libstagefright/tests/mediacodec/MediaTestHelper.h
@@ -0,0 +1,51 @@
+/*
+ * Copyright 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.
+ */
+
+#ifndef MEDIA_TEST_HELPER_H_
+
+#define MEDIA_TEST_HELPER_H_
+
+#include <media/stagefright/foundation/AString.h>
+#include <utils/StrongPointer.h>
+
+namespace android {
+
+struct ALooper;
+struct CodecBase;
+struct MediaCodec;
+struct MediaCodecInfo;
+struct MediaCodecListWriter;
+
+class MediaTestHelper {
+public:
+    // MediaCodec
+    static sp<MediaCodec> CreateCodec(
+            const AString &name,
+            const sp<ALooper> &looper,
+            std::function<sp<CodecBase>(const AString &, const char *)> getCodecBase,
+            std::function<status_t(const AString &, sp<MediaCodecInfo> *)> getCodecInfo);
+    static void Reclaim(const sp<MediaCodec> &codec, bool force);
+
+    // MediaCodecListWriter
+    static std::shared_ptr<MediaCodecListWriter> CreateCodecListWriter();
+    static void WriteCodecInfos(
+            const std::shared_ptr<MediaCodecListWriter> &writer,
+            std::vector<sp<MediaCodecInfo>> *codecInfos);
+};
+
+}  // namespace android
+
+#endif  // MEDIA_TEST_HELPER_H_