Merge changes I37ee51b1,I86ea29a8,I2a43d22d,I832d274b into main

* changes:
  libgui: Add a test server utility for unit tests.
  view::Surface: Add toString()
  libui/libui: Remove extraneous semicolons
  libgui: Expose methods to Surface API to support Camera3StreamSplitter

17 files changed, 783 insertions, 18 deletions

diff --git a/libs/gui/include/gui/FrameTimestamps.h b/libs/gui/include/gui/FrameTimestamps.h
index 3d1be4d2eb..462081bfd2 100644
--- a/libs/gui/include/gui/FrameTimestamps.h
+++ b/libs/gui/include/gui/FrameTimestamps.h
@@ -116,7 +116,7 @@ public:
     // Public for testing.
     static nsecs_t snapToNextTick(
             nsecs_t timestamp, nsecs_t tickPhase, nsecs_t tickInterval);
-    nsecs_t getReportedCompositeDeadline() const { return mCompositorTiming.deadline; };
+    nsecs_t getReportedCompositeDeadline() const { return mCompositorTiming.deadline; }
 
     nsecs_t getNextCompositeDeadline(const nsecs_t now) const;
     nsecs_t getCompositeInterval() const { return mCompositorTiming.interval; }
diff --git a/libs/gui/include/gui/IGraphicBufferProducer.h b/libs/gui/include/gui/IGraphicBufferProducer.h
index 8fca9460aa..3aac457a09 100644
--- a/libs/gui/include/gui/IGraphicBufferProducer.h
+++ b/libs/gui/include/gui/IGraphicBufferProducer.h
@@ -867,6 +867,6 @@ class BnGraphicBufferProducer : public IGraphicBufferProducer {
 #endif
 
 // ----------------------------------------------------------------------------
-}; // namespace android
+} // namespace android
 
 #endif // ANDROID_GUI_IGRAPHICBUFFERPRODUCER_H
diff --git a/libs/gui/include/gui/Surface.h b/libs/gui/include/gui/Surface.h
index 39207f835f..0f51f2dc13 100644
--- a/libs/gui/include/gui/Surface.h
+++ b/libs/gui/include/gui/Surface.h
@@ -194,6 +194,14 @@ public:
      * in <system/window.h>. */
     int setScalingMode(int mode);
 
+    virtual int setBuffersTimestamp(int64_t timestamp);
+    virtual int setBuffersDataSpace(ui::Dataspace dataSpace);
+    virtual int setCrop(Rect const* rect);
+    virtual int setBuffersTransform(uint32_t transform);
+    virtual int setBuffersStickyTransform(uint32_t transform);
+    virtual int setBuffersFormat(PixelFormat format);
+    virtual int setUsage(uint64_t reqUsage);
+
     // See IGraphicBufferProducer::setDequeueTimeout
     status_t setDequeueTimeout(nsecs_t timeout);
 
@@ -354,16 +362,9 @@ protected:
     virtual int connect(int api);
     virtual int setBufferCount(int bufferCount);
     virtual int setBuffersUserDimensions(uint32_t width, uint32_t height);
-    virtual int setBuffersFormat(PixelFormat format);
-    virtual int setBuffersTransform(uint32_t transform);
-    virtual int setBuffersStickyTransform(uint32_t transform);
-    virtual int setBuffersTimestamp(int64_t timestamp);
-    virtual int setBuffersDataSpace(ui::Dataspace dataSpace);
     virtual int setBuffersSmpte2086Metadata(const android_smpte2086_metadata* metadata);
     virtual int setBuffersCta8613Metadata(const android_cta861_3_metadata* metadata);
     virtual int setBuffersHdr10PlusMetadata(const size_t size, const uint8_t* metadata);
-    virtual int setCrop(Rect const* rect);
-    virtual int setUsage(uint64_t reqUsage);
     virtual void setSurfaceDamage(android_native_rect_t* rects, size_t numRects);
 
 public:
diff --git a/libs/gui/include/gui/view/Surface.h b/libs/gui/include/gui/view/Surface.h
index b7aba2b9dc..7ddac8139a 100644
--- a/libs/gui/include/gui/view/Surface.h
+++ b/libs/gui/include/gui/view/Surface.h
@@ -59,8 +59,9 @@ class Surface : public Parcelable {
     // of the full parceling to happen on its native side.
     status_t readFromParcel(const Parcel* parcel, bool nameAlreadyRead);
 
-  private:
+    std::string toString() const;
 
+private:
     static String16 readMaybeEmptyString16(const Parcel* parcel);
 };
 
diff --git a/libs/gui/tests/Android.bp b/libs/gui/tests/Android.bp
index 1b216e9063..f07747f32f 100644
--- a/libs/gui/tests/Android.bp
+++ b/libs/gui/tests/Android.bp
@@ -12,6 +12,34 @@ package {
     default_applicable_licenses: ["frameworks_native_license"],
 }
 
+aidl_interface {
+    name: "libgui_test_server_aidl",
+    unstable: true,
+    srcs: ["testserver/aidl/**/*.aidl"],
+    local_include_dir: "testserver/aidl",
+    include_dirs: [
+        "frameworks/native/aidl/gui",
+    ],
+    backend: {
+        cpp: {
+            enabled: true,
+            additional_shared_libraries: [
+                "libgui",
+                "libui",
+            ],
+        },
+        java: {
+            enabled: false,
+        },
+        ndk: {
+            enabled: false,
+        },
+        rust: {
+            enabled: false,
+        },
+    },
+}
+
 cc_test {
     name: "libgui_test",
     test_suites: ["device-tests"],
@@ -30,7 +58,6 @@ cc_test {
     ],
 
     srcs: [
-        "LibGuiMain.cpp", // Custom gtest entrypoint
         "BLASTBufferQueue_test.cpp",
         "BufferItemConsumer_test.cpp",
         "BufferQueue_test.cpp",
@@ -38,24 +65,29 @@ cc_test {
         "Choreographer_test.cpp",
         "CompositorTiming_test.cpp",
         "CpuConsumer_test.cpp",
-        "EndToEndNativeInputTest.cpp",
-        "FrameRateUtilsTest.cpp",
-        "DisplayInfo_test.cpp",
         "DisplayedContentSampling_test.cpp",
+        "DisplayInfo_test.cpp",
+        "EndToEndNativeInputTest.cpp",
         "FillBuffer.cpp",
+        "FrameRateUtilsTest.cpp",
         "GLTest.cpp",
         "IGraphicBufferProducer_test.cpp",
+        "LibGuiMain.cpp", // Custom gtest entrypoint
         "Malicious.cpp",
         "MultiTextureConsumer_test.cpp",
         "RegionSampling_test.cpp",
         "StreamSplitter_test.cpp",
+        "Surface_test.cpp",
         "SurfaceTextureClient_test.cpp",
         "SurfaceTextureFBO_test.cpp",
+        "SurfaceTextureGL_test.cpp",
         "SurfaceTextureGLThreadToGL_test.cpp",
         "SurfaceTextureGLToGL_test.cpp",
-        "SurfaceTextureGL_test.cpp",
         "SurfaceTextureMultiContextGL_test.cpp",
-        "Surface_test.cpp",
+        "TestServer_test.cpp",
+        "testserver/TestServer.cpp",
+        "testserver/TestServerClient.cpp",
+        "testserver/TestServerHost.cpp",
         "TextureRenderer.cpp",
         "VsyncEventData_test.cpp",
         "WindowInfo_test.cpp",
@@ -66,10 +98,17 @@ cc_test {
         "android.hardware.configstore-utils",
         "libSurfaceFlingerProp",
         "libGLESv1_CM",
+        "libgui_test_server_aidl-cpp",
         "libinput",
         "libnativedisplay",
     ],
 
+    // This needs to get copied over for the test since it's not part of the
+    // platform.
+    data_libs: [
+        "libgui_test_server_aidl-cpp",
+    ],
+
     static_libs: [
         "libgmock",
     ],
diff --git a/libs/gui/tests/LibGuiMain.cpp b/libs/gui/tests/LibGuiMain.cpp
index 10f7207588..7c7c2cc30f 100644
--- a/libs/gui/tests/LibGuiMain.cpp
+++ b/libs/gui/tests/LibGuiMain.cpp
@@ -14,8 +14,15 @@
  * limitations under the License.
  */
 
-#include "gtest/gtest.h"
-#include "log/log.h"
+#include <android-base/unique_fd.h>
+#include <gtest/gtest.h>
+#include <log/log.h>
+
+#include "testserver/TestServer.h"
+#include "testserver/TestServerClient.h"
+#include "testserver/TestServerHost.h"
+
+using namespace android;
 
 namespace {
 
@@ -32,7 +39,34 @@ class TestCaseLogger : public ::testing::EmptyTestEventListener {
 } // namespace
 
 int main(int argc, char** argv) {
+    // There are three modes that we can run in to support the libgui TestServer:
+    //
+    // - libgui_test : normal mode, runs tests and fork/execs the testserver host process
+    // - libgui_test --test-server-host $recvPipeFd $sendPipeFd : TestServerHost mode, listens on
+    //   $recvPipeFd for commands and sends responses over $sendPipeFd
+    // - libgui_test --test-server $name : TestServer mode, starts a ITestService binder service
+    //   under $name
+    for (int i = 1; i < argc; i++) {
+        std::string arg = argv[i];
+        if (arg == "--test-server-host") {
+            LOG_ALWAYS_FATAL_IF(argc < (i + 2), "--test-server-host requires two pipe fds");
+            // Note that the send/recv are from our perspective.
+            base::unique_fd recvPipeFd = base::unique_fd(atoi(argv[i + 1]));
+            base::unique_fd sendPipeFd = base::unique_fd(atoi(argv[i + 2]));
+            return TestServerHostMain(argv[0], std::move(sendPipeFd), std::move(recvPipeFd));
+        }
+        if (arg == "--test-server") {
+            LOG_ALWAYS_FATAL_IF(argc < (i + 1), "--test-server requires a name");
+            return TestServerMain(argv[i + 1]);
+        }
+    }
     testing::InitGoogleTest(&argc, argv);
     testing::UnitTest::GetInstance()->listeners().Append(new TestCaseLogger());
+
+    // This has to be run *before* any test initialization, because it fork/execs a TestServerHost,
+    // which will later create new binder service. You can't do that in a forked thread after you've
+    // initialized any binder stuff, which some tests do.
+    TestServerClient::InitializeOrDie(argv[0]);
+
     return RUN_ALL_TESTS();
 }
\ No newline at end of file
diff --git a/libs/gui/tests/Surface_test.cpp b/libs/gui/tests/Surface_test.cpp
index 8ab8783c4c..4232443308 100644
--- a/libs/gui/tests/Surface_test.cpp
+++ b/libs/gui/tests/Surface_test.cpp
@@ -14,6 +14,7 @@
  * limitations under the License.
  */
 
+#include "gui/view/Surface.h"
 #include "Constants.h"
 #include "MockConsumer.h"
 
@@ -53,6 +54,8 @@
 #include <limits>
 #include <thread>
 
+#include "testserver/TestServerClient.h"
+
 namespace android {
 
 using namespace std::chrono_literals;
@@ -2363,6 +2366,14 @@ TEST_F(SurfaceTest, QueueAcquireReleaseDequeue_CalledInStack_DoesNotDeadlock) {
 
     EXPECT_EQ(OK, surface->disconnect(NATIVE_WINDOW_API_CPU));
 }
+
+TEST_F(SurfaceTest, ViewSurface_toString) {
+    view::Surface surface{};
+    EXPECT_EQ("", surface.toString());
+
+    surface.name = String16("name");
+    EXPECT_EQ("name", surface.toString());
+}
 #endif // COM_ANDROID_GRAPHICS_LIBGUI_FLAGS(WB_PLATFORM_API_IMPROVEMENTS)
 
 } // namespace android
diff --git a/libs/gui/tests/TestServer_test.cpp b/libs/gui/tests/TestServer_test.cpp
new file mode 100644
index 0000000000..8712988e52
--- /dev/null
+++ b/libs/gui/tests/TestServer_test.cpp
@@ -0,0 +1,99 @@
+/*
+ * 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.
+ */
+
+#include <gtest/gtest.h>
+
+#include <SurfaceFlingerProperties.h>
+#include <android/gui/IDisplayEventConnection.h>
+#include <android/gui/ISurfaceComposer.h>
+#include <android/hardware/configstore/1.0/ISurfaceFlingerConfigs.h>
+#include <android/hardware_buffer.h>
+#include <binder/ProcessState.h>
+#include <com_android_graphics_libgui_flags.h>
+#include <configstore/Utils.h>
+#include <gui/AidlStatusUtil.h>
+#include <gui/BufferItemConsumer.h>
+#include <gui/BufferQueue.h>
+#include <gui/CpuConsumer.h>
+#include <gui/IConsumerListener.h>
+#include <gui/IGraphicBufferConsumer.h>
+#include <gui/IGraphicBufferProducer.h>
+#include <gui/ISurfaceComposer.h>
+#include <gui/Surface.h>
+#include <gui/SurfaceComposerClient.h>
+#include <gui/SyncScreenCaptureListener.h>
+#include <private/gui/ComposerService.h>
+#include <private/gui/ComposerServiceAIDL.h>
+#include <sys/types.h>
+#include <system/window.h>
+#include <ui/BufferQueueDefs.h>
+#include <ui/DisplayMode.h>
+#include <ui/GraphicBuffer.h>
+#include <ui/Rect.h>
+#include <utils/Errors.h>
+#include <utils/String8.h>
+
+#include <cstddef>
+#include <limits>
+#include <thread>
+
+#include "binder/IInterface.h"
+#include "testserver/TestServerClient.h"
+
+namespace android {
+
+namespace {
+
+class TestServerTest : public ::testing::Test {
+protected:
+    TestServerTest() { ProcessState::self()->startThreadPool(); }
+};
+
+} // namespace
+
+TEST_F(TestServerTest, Create) {
+    EXPECT_NE(nullptr, TestServerClient::Create());
+}
+
+TEST_F(TestServerTest, CreateProducer) {
+    sp<TestServerClient> client = TestServerClient::Create();
+    EXPECT_NE(nullptr, client->CreateProducer());
+}
+
+TEST_F(TestServerTest, KillServer) {
+    class DeathWaiter : public IBinder::DeathRecipient {
+    public:
+        virtual void binderDied(const wp<IBinder>&) override { mPromise.set_value(true); }
+        std::future<bool> getFuture() { return mPromise.get_future(); }
+
+        std::promise<bool> mPromise;
+    };
+
+    sp<TestServerClient> client = TestServerClient::Create();
+    sp<IGraphicBufferProducer> producer = client->CreateProducer();
+    EXPECT_NE(nullptr, producer);
+
+    sp<DeathWaiter> deathWaiter = sp<DeathWaiter>::make();
+    EXPECT_EQ(OK, IInterface::asBinder(producer)->linkToDeath(deathWaiter));
+
+    auto deathWaiterFuture = deathWaiter->getFuture();
+    EXPECT_EQ(OK, client->Kill());
+    EXPECT_EQ(nullptr, client->CreateProducer());
+
+    EXPECT_TRUE(deathWaiterFuture.get());
+}
+
+} // namespace android
diff --git a/libs/gui/tests/testserver/TestServer.cpp b/libs/gui/tests/testserver/TestServer.cpp
new file mode 100644
index 0000000000..cd8824e355
--- /dev/null
+++ b/libs/gui/tests/testserver/TestServer.cpp
@@ -0,0 +1,114 @@
+/*
+ * 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.
+ */
+
+#define LOG_TAG "TestServer"
+
+#include <android-base/stringprintf.h>
+#include <binder/IInterface.h>
+#include <binder/IPCThreadState.h>
+#include <binder/IServiceManager.h>
+#include <binder/ProcessState.h>
+#include <binder/Status.h>
+#include <gui/BufferQueue.h>
+#include <gui/IConsumerListener.h>
+#include <gui/IGraphicBufferConsumer.h>
+#include <gui/IGraphicBufferProducer.h>
+#include <gui/view/Surface.h>
+#include <libgui_test_server/BnTestServer.h>
+#include <log/log.h>
+#include <utils/Errors.h>
+
+#include <cstdint>
+#include <cstdlib>
+#include <memory>
+#include <mutex>
+#include <vector>
+
+#include <fcntl.h>
+#include <unistd.h>
+
+#include "TestServer.h"
+
+namespace android {
+
+namespace {
+class TestConsumerListener : public BnConsumerListener {
+    virtual void onFrameAvailable(const BufferItem&) override {}
+    virtual void onBuffersReleased() override {}
+    virtual void onSidebandStreamChanged() override {}
+};
+
+class TestServiceImpl : public libgui_test_server::BnTestServer {
+public:
+    TestServiceImpl(const char* name) : mName(name) {}
+
+    virtual binder::Status createProducer(view::Surface* out) override {
+        std::lock_guard<std::mutex> lock(mMutex);
+
+        BufferQueueHolder bq;
+        BufferQueue::createBufferQueue(&bq.producer, &bq.consumer);
+        sp<TestConsumerListener> listener = sp<TestConsumerListener>::make();
+        bq.consumer->consumerConnect(listener, /*controlledByApp*/ true);
+
+        uint64_t id = 0;
+        bq.producer->getUniqueId(&id);
+        std::string name = base::StringPrintf("%s-%" PRIu64, mName, id);
+
+        out->name = String16(name.c_str());
+        out->graphicBufferProducer = bq.producer;
+        mBqs.push_back(std::move(bq));
+
+        return binder::Status::ok();
+    }
+
+    virtual binder::Status killNow() override {
+        ALOGE("LibGUI Test Service %s dying in response to killNow", mName);
+        _exit(0);
+        // Not reached:
+        return binder::Status::ok();
+    }
+
+private:
+    std::mutex mMutex;
+    const char* mName;
+
+    struct BufferQueueHolder {
+        sp<IGraphicBufferProducer> producer;
+        sp<IGraphicBufferConsumer> consumer;
+    };
+
+    std::vector<BufferQueueHolder> mBqs;
+};
+} // namespace
+
+int TestServerMain(const char* name) {
+    ProcessState::self()->startThreadPool();
+
+    sp<TestServiceImpl> testService = sp<TestServiceImpl>::make(name);
+    ALOGE("service");
+    sp<IServiceManager> serviceManager(defaultServiceManager());
+    LOG_ALWAYS_FATAL_IF(OK != serviceManager->addService(String16(name), testService));
+
+    ALOGD("LibGUI Test Service %s STARTED", name);
+
+    IPCThreadState::self()->joinThreadPool();
+
+    ALOGW("LibGUI Test Service %s DIED", name);
+
+    return 0;
+}
+
+} // namespace android
\ No newline at end of file
diff --git a/libs/gui/tests/testserver/TestServer.h b/libs/gui/tests/testserver/TestServer.h
new file mode 100644
index 0000000000..4226f1bb09
--- /dev/null
+++ b/libs/gui/tests/testserver/TestServer.h
@@ -0,0 +1,31 @@
+/*
+ * 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.
+ */
+
+#pragma once
+
+namespace android {
+
+/*
+ * Main method for a libgui ITestServer server.
+ *
+ * This must be called without any binder setup having been done, because you can't fork and do
+ * binder things once ProcessState is set up.
+ * @param name The service name of the test server to start.
+ * @return retcode
+ */
+int TestServerMain(const char* name);
+
+} // namespace android
diff --git a/libs/gui/tests/testserver/TestServerClient.cpp b/libs/gui/tests/testserver/TestServerClient.cpp
new file mode 100644
index 0000000000..e388074675
--- /dev/null
+++ b/libs/gui/tests/testserver/TestServerClient.cpp
@@ -0,0 +1,199 @@
+/*
+ * 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.
+ */
+
+#include <sys/wait.h>
+#include <cerrno>
+#define LOG_TAG "TestServerClient"
+
+#include <android-base/stringprintf.h>
+#include <binder/IServiceManager.h>
+#include <binder/ProcessState.h>
+#include <libgui_test_server/ITestServer.h>
+#include <log/log.h>
+#include <utils/Errors.h>
+
+#include <errno.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+#include <atomic>
+#include <csignal>
+#include <cstdlib>
+#include <mutex>
+#include <string>
+
+#include "TestServerClient.h"
+#include "TestServerCommon.h"
+
+namespace android {
+
+namespace {
+
+std::string GetUniqueServiceName() {
+    static std::atomic<int> uniqueId = 1;
+
+    pid_t pid = getpid();
+    int id = uniqueId++;
+    return base::StringPrintf("Libgui-TestServer-%d-%d", pid, id);
+}
+
+struct RemoteTestServerHostHolder {
+    RemoteTestServerHostHolder(pid_t pid, int sendFd, int recvFd)
+          : mPid(pid), mSendFd(sendFd), mRecvFd(recvFd) {}
+    ~RemoteTestServerHostHolder() {
+        std::lock_guard lock(mMutex);
+
+        kill(mPid, SIGKILL);
+        close(mSendFd);
+        close(mRecvFd);
+    }
+
+    pid_t CreateTestServerOrDie(std::string name) {
+        std::lock_guard lock(mMutex);
+
+        CreateServerRequest request;
+        strlcpy(request.name, name.c_str(), sizeof(request.name) / sizeof(request.name[0]));
+
+        ssize_t bytes = write(mSendFd, &request, sizeof(request));
+        LOG_ALWAYS_FATAL_IF(bytes != sizeof(request));
+
+        CreateServerResponse response;
+        bytes = read(mRecvFd, &response, sizeof(response));
+        LOG_ALWAYS_FATAL_IF(bytes != sizeof(response));
+
+        return response.pid;
+    }
+
+private:
+    std::mutex mMutex;
+
+    pid_t mPid;
+    int mSendFd;
+    int mRecvFd;
+};
+
+std::unique_ptr<RemoteTestServerHostHolder> g_remoteTestServerHostHolder = nullptr;
+
+} // namespace
+
+void TestServerClient::InitializeOrDie(const char* filename) {
+    int sendPipeFds[2];
+    int ret = pipe(sendPipeFds);
+    LOG_ALWAYS_FATAL_IF(ret, "Unable to create subprocess send pipe");
+
+    int recvPipeFds[2];
+    ret = pipe(recvPipeFds);
+    LOG_ALWAYS_FATAL_IF(ret, "Unable to create subprocess recv pipe");
+
+    pid_t childPid = fork();
+    LOG_ALWAYS_FATAL_IF(childPid < 0, "Unable to fork child process");
+
+    if (childPid == 0) {
+        // We forked!
+        close(sendPipeFds[1]);
+        close(recvPipeFds[0]);
+
+        // We'll be reading from the parent's "send" and writing to the parent's "recv".
+        std::string sendPipe = std::to_string(sendPipeFds[0]);
+        std::string recvPipe = std::to_string(recvPipeFds[1]);
+        char* args[] = {
+                const_cast<char*>(filename),
+                const_cast<char*>("--test-server-host"),
+                const_cast<char*>(sendPipe.c_str()),
+                const_cast<char*>(recvPipe.c_str()),
+                nullptr,
+        };
+
+        ret = execv(filename, args);
+        ALOGE("Failed to exec libguiTestServer. ret=%d errno=%d (%s)", ret, errno, strerror(errno));
+        status_t status = -errno;
+        write(recvPipeFds[1], &status, sizeof(status));
+        _exit(EXIT_FAILURE);
+    }
+
+    close(sendPipeFds[0]);
+    close(recvPipeFds[1]);
+
+    // Check for an OK status that the host started. If so, we're good to go.
+    status_t status;
+    ret = read(recvPipeFds[0], &status, sizeof(status));
+    LOG_ALWAYS_FATAL_IF(ret != sizeof(status), "Unable to read from pipe: %d", ret);
+    LOG_ALWAYS_FATAL_IF(OK != status, "Pipe returned failed status: %d", status);
+
+    g_remoteTestServerHostHolder =
+            std::make_unique<RemoteTestServerHostHolder>(childPid, sendPipeFds[1], recvPipeFds[0]);
+}
+
+sp<TestServerClient> TestServerClient::Create() {
+    std::string serviceName = GetUniqueServiceName();
+
+    pid_t childPid = g_remoteTestServerHostHolder->CreateTestServerOrDie(serviceName);
+    ALOGD("Created child server %s with pid %d", serviceName.c_str(), childPid);
+
+    sp<libgui_test_server::ITestServer> server =
+            waitForService<libgui_test_server::ITestServer>(String16(serviceName.c_str()));
+    LOG_ALWAYS_FATAL_IF(server == nullptr);
+    ALOGD("Created connected to child server %s", serviceName.c_str());
+
+    return sp<TestServerClient>::make(server);
+}
+
+TestServerClient::TestServerClient(const sp<libgui_test_server::ITestServer>& server)
+      : mServer(server) {}
+
+TestServerClient::~TestServerClient() {
+    Kill();
+}
+
+sp<IGraphicBufferProducer> TestServerClient::CreateProducer() {
+    std::lock_guard<std::mutex> lock(mMutex);
+
+    if (!mIsAlive) {
+        return nullptr;
+    }
+
+    view::Surface surface;
+    binder::Status status = mServer->createProducer(&surface);
+
+    if (!status.isOk()) {
+        ALOGE("Failed to create remote producer. Error: %s", status.exceptionMessage().c_str());
+        return nullptr;
+    }
+
+    if (!surface.graphicBufferProducer) {
+        ALOGE("Remote producer returned no IGBP.");
+        return nullptr;
+    }
+
+    return surface.graphicBufferProducer;
+}
+
+status_t TestServerClient::Kill() {
+    std::lock_guard<std::mutex> lock(mMutex);
+    if (!mIsAlive) {
+        return DEAD_OBJECT;
+    }
+
+    mServer->killNow();
+    mServer = nullptr;
+    mIsAlive = false;
+
+    return OK;
+}
+
+} // namespace android
diff --git a/libs/gui/tests/testserver/TestServerClient.h b/libs/gui/tests/testserver/TestServerClient.h
new file mode 100644
index 0000000000..53296344a3
--- /dev/null
+++ b/libs/gui/tests/testserver/TestServerClient.h
@@ -0,0 +1,42 @@
+/*
+ * 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.
+ */
+
+#pragma once
+
+#include <libgui_test_server/ITestServer.h>
+#include <utils/RefBase.h>
+
+namespace android {
+
+class TestServerClient : public RefBase {
+public:
+    static void InitializeOrDie(const char* filename);
+    static sp<TestServerClient> Create();
+
+    TestServerClient(const sp<libgui_test_server::ITestServer>& server);
+    virtual ~TestServerClient() override;
+
+    sp<IGraphicBufferProducer> CreateProducer();
+    status_t Kill();
+
+private:
+    std::mutex mMutex;
+
+    sp<libgui_test_server::ITestServer> mServer;
+    bool mIsAlive = true;
+};
+
+} // namespace android
diff --git a/libs/gui/tests/testserver/TestServerCommon.h b/libs/gui/tests/testserver/TestServerCommon.h
new file mode 100644
index 0000000000..7370f20ef8
--- /dev/null
+++ b/libs/gui/tests/testserver/TestServerCommon.h
@@ -0,0 +1,43 @@
+/*
+ * 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.
+ */
+
+#pragma once
+
+#include <fcntl.h>
+
+namespace android {
+
+/*
+ * Test -> TestServerHost Request to create a new ITestServer fork.
+ */
+struct CreateServerRequest {
+    /*
+     * Service name for new ITestServer.
+     */
+    char name[128];
+};
+
+/*
+ * TestServerHost -> Test Response for creating an ITestServer fork.
+ */
+struct CreateServerResponse {
+    /*
+     * pid of new ITestServer.
+     */
+    pid_t pid;
+};
+
+} // namespace android
\ No newline at end of file
diff --git a/libs/gui/tests/testserver/TestServerHost.cpp b/libs/gui/tests/testserver/TestServerHost.cpp
new file mode 100644
index 0000000000..696c3b9817
--- /dev/null
+++ b/libs/gui/tests/testserver/TestServerHost.cpp
@@ -0,0 +1,95 @@
+/*
+ * 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.
+ */
+
+#define LOG_TAG "TestServerHost"
+
+#include <android-base/unique_fd.h>
+#include <binder/IInterface.h>
+#include <binder/IPCThreadState.h>
+#include <binder/IServiceManager.h>
+#include <binder/ProcessState.h>
+#include <binder/Status.h>
+#include <gui/BufferQueue.h>
+#include <gui/IConsumerListener.h>
+#include <gui/IGraphicBufferConsumer.h>
+#include <gui/IGraphicBufferProducer.h>
+#include <libgui_test_server/BnTestServer.h>
+#include <log/log.h>
+#include <utils/Errors.h>
+
+#include <memory>
+#include <vector>
+
+#include <fcntl.h>
+#include <unistd.h>
+#include <cstddef>
+#include <cstdlib>
+
+#include "TestServerCommon.h"
+#include "TestServerHost.h"
+
+namespace android {
+
+namespace {
+
+pid_t ForkTestServer(const char* filename, char* name) {
+    pid_t childPid = fork();
+    LOG_ALWAYS_FATAL_IF(childPid == -1);
+
+    if (childPid != 0) {
+        return childPid;
+    }
+
+    // We forked!
+    const char* test_server_flag = "--test-server";
+    char* args[] = {
+            const_cast<char*>(filename),
+            const_cast<char*>(test_server_flag),
+            name,
+            nullptr,
+    };
+
+    int ret = execv(filename, args);
+    ALOGE("Failed to exec libgui_test as a TestServer. ret=%d errno=%d (%s)", ret, errno,
+          strerror(errno));
+    _exit(EXIT_FAILURE);
+}
+
+} // namespace
+
+int TestServerHostMain(const char* filename, base::unique_fd sendPipeFd,
+                       base::unique_fd recvPipeFd) {
+    status_t status = OK;
+    LOG_ALWAYS_FATAL_IF(sizeof(status) != write(sendPipeFd.get(), &status, sizeof(status)));
+
+    ALOGE("Launched TestServerHost");
+
+    while (true) {
+        CreateServerRequest request = {};
+        ssize_t bytes = read(recvPipeFd.get(), &request, sizeof(request));
+        LOG_ALWAYS_FATAL_IF(bytes != sizeof(request));
+        pid_t childPid = ForkTestServer(filename, request.name);
+
+        CreateServerResponse response = {};
+        response.pid = childPid;
+        bytes = write(sendPipeFd.get(), &response, sizeof(response));
+        LOG_ALWAYS_FATAL_IF(bytes != sizeof(response));
+    }
+
+    return 0;
+}
+
+} // namespace android
\ No newline at end of file
diff --git a/libs/gui/tests/testserver/TestServerHost.h b/libs/gui/tests/testserver/TestServerHost.h
new file mode 100644
index 0000000000..df22c0c3fe
--- /dev/null
+++ b/libs/gui/tests/testserver/TestServerHost.h
@@ -0,0 +1,38 @@
+/*
+ * 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.
+ */
+
+#pragma once
+
+#include <android-base/unique_fd.h>
+
+#include <string>
+
+namespace android {
+
+/*
+ * Main method for a host process for TestServers.
+ *
+ * This must be called without any binder setup having been done, because you can't fork and do
+ * binder things once ProcessState is set up.
+ * @param filename File name of this binary / the binary to execve into
+ * @param sendPipeFd Pipe FD to send data to.
+ * @param recvPipeFd Pipe FD to receive data from.
+ * @return retcode
+ */
+int TestServerHostMain(const char* filename, base::unique_fd sendPipeFd,
+                       base::unique_fd recvPipeFd);
+
+} // namespace android
diff --git a/libs/gui/tests/testserver/aidl/libgui_test_server/ITestServer.aidl b/libs/gui/tests/testserver/aidl/libgui_test_server/ITestServer.aidl
new file mode 100644
index 0000000000..c939ea00c1
--- /dev/null
+++ b/libs/gui/tests/testserver/aidl/libgui_test_server/ITestServer.aidl
@@ -0,0 +1,12 @@
+package libgui_test_server;
+
+import android.view.Surface;
+
+// Test server for libgui_test
+interface ITestServer {
+    // Create a new producer. The server will have connected to the consumer.
+    Surface createProducer();
+
+    // Kills the server immediately.
+    void killNow();
+}
diff --git a/libs/gui/view/Surface.cpp b/libs/gui/view/Surface.cpp
index 7c15e7cf92..84c2a6ac71 100644
--- a/libs/gui/view/Surface.cpp
+++ b/libs/gui/view/Surface.cpp
@@ -121,5 +121,11 @@ String16 Surface::readMaybeEmptyString16(const Parcel* parcel) {
     return str.value_or(String16());
 }
 
+std::string Surface::toString() const {
+    std::stringstream out;
+    out << name;
+    return out.str();
+}
+
 } // namespace view
 } // namespace android