graphics: add composer 2.2 default impl

This adds

  android.hardware.graphics.composer@2.2-hal
  android.hardware.graphics.composer@2.2-passthrough
  android.hardware.graphics.composer@2.2-service

The -hal module makes it easier to write composer 2.2 HAL and is
reusable by vendors.  The -passthrough module provides a HwcHal
class that implements ComposerHal 2.2 on top of hwcomposer2, and is
also resuable by vendors.  Finally, the -service module provides a
(stub) default implementation.

Test: boots and VTS
Change-Id: I4f940a9dea656abc7d9d485bf48d852c13d2ed56
diff --git a/graphics/composer/2.2/default/service.cpp b/graphics/composer/2.2/default/service.cpp
new file mode 100644
index 0000000..8c5ef18
--- /dev/null
+++ b/graphics/composer/2.2/default/service.cpp
@@ -0,0 +1,55 @@
+/*
+ * Copyright 2018 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 <sched.h>
+
+#include <android/hardware/graphics/composer/2.2/IComposer.h>
+#include <binder/ProcessState.h>
+#include <composer-passthrough/2.2/HwcLoader.h>
+#include <hidl/HidlTransportSupport.h>
+
+using android::hardware::graphics::composer::V2_2::IComposer;
+using android::hardware::graphics::composer::V2_2::passthrough::HwcLoader;
+
+int main() {
+    // the conventional HAL might start binder services
+    android::ProcessState::initWithDriver("/dev/vndbinder");
+    android::ProcessState::self()->setThreadPoolMaxThreadCount(4);
+    android::ProcessState::self()->startThreadPool();
+
+    // same as SF main thread
+    struct sched_param param = {0};
+    param.sched_priority = 2;
+    if (sched_setscheduler(0, SCHED_FIFO | SCHED_RESET_ON_FORK, &param) != 0) {
+        ALOGE("Couldn't set SCHED_FIFO: %d", errno);
+    }
+
+    android::hardware::configureRpcThreadpool(4, true /* will join */);
+
+    android::sp<IComposer> composer = HwcLoader::load();
+    if (composer == nullptr) {
+        return 1;
+    }
+    if (composer->registerAsService() != android::NO_ERROR) {
+        ALOGE("failed to register service");
+        return 1;
+    }
+
+    android::hardware::joinRpcThreadpool();
+
+    ALOGE("service is terminating");
+    return 1;
+}