GraphicsEnv is separated from libui

GraphicsEnv class is separated from libui in order to make libui VNDK.
The class is then built as a standalone library named
'libgraphicsenv.so'. Clients that were using the GraphicsEnv class are
also updated to reference the new library.

Bug: 38097618
Test: sailfish builds and boots

Change-Id: I4c35fdff0e92453b98ea21136ef0f99fab01b6f8
diff --git a/libs/graphicsenv/Android.bp b/libs/graphicsenv/Android.bp
new file mode 100644
index 0000000..f2686d5
--- /dev/null
+++ b/libs/graphicsenv/Android.bp
@@ -0,0 +1,28 @@
+// Copyright (C) 2017 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_library_shared {
+    name: "libgraphicsenv",
+
+    srcs: [
+        "GraphicsEnv.cpp",
+    ],
+
+    shared_libs: [
+        "libnativeloader",
+        "liblog",
+    ],
+
+    export_include_dirs: ["include"],
+}
diff --git a/libs/graphicsenv/GraphicsEnv.cpp b/libs/graphicsenv/GraphicsEnv.cpp
new file mode 100644
index 0000000..0276008
--- /dev/null
+++ b/libs/graphicsenv/GraphicsEnv.cpp
@@ -0,0 +1,81 @@
+/*
+ * Copyright 2017 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_NDEBUG 1
+#define LOG_TAG "GraphicsEnv"
+#include <graphicsenv/GraphicsEnv.h>
+
+#include <mutex>
+
+#include <log/log.h>
+#include <nativeloader/dlext_namespaces.h>
+
+namespace android {
+
+/*static*/ GraphicsEnv& GraphicsEnv::getInstance() {
+    static GraphicsEnv env;
+    return env;
+}
+
+void GraphicsEnv::setDriverPath(const std::string path) {
+    if (!mDriverPath.empty()) {
+        ALOGV("ignoring attempt to change driver path from '%s' to '%s'",
+                mDriverPath.c_str(), path.c_str());
+        return;
+    }
+    ALOGV("setting driver path to '%s'", path.c_str());
+    mDriverPath = path;
+}
+
+android_namespace_t* GraphicsEnv::getDriverNamespace() {
+    static std::once_flag once;
+    std::call_once(once, [this]() {
+        // TODO; In the next version of Android, all graphics drivers will be
+        // loaded into a custom namespace. To minimize risk for this release,
+        // only updated drivers use a custom namespace.
+        //
+        // Additionally, the custom namespace will be
+        // ANDROID_NAMESPACE_TYPE_ISOLATED, and will only have access to a
+        // subset of the system.
+        if (mDriverPath.empty())
+            return;
+
+        char defaultPath[PATH_MAX];
+        android_get_LD_LIBRARY_PATH(defaultPath, sizeof(defaultPath));
+        size_t defaultPathLen = strlen(defaultPath);
+
+        std::string path;
+        path.reserve(mDriverPath.size() + 1 + defaultPathLen);
+        path.append(mDriverPath);
+        path.push_back(':');
+        path.append(defaultPath, defaultPathLen);
+
+        mDriverNamespace = android_create_namespace(
+                "gfx driver",
+                nullptr,                    // ld_library_path
+                path.c_str(),               // default_library_path
+                ANDROID_NAMESPACE_TYPE_SHARED,
+                nullptr,                    // permitted_when_isolated_path
+                nullptr);                   // parent
+    });
+    return mDriverNamespace;
+}
+
+} // namespace android
+
+extern "C" android_namespace_t* android_getDriverNamespace() {
+    return android::GraphicsEnv::getInstance().getDriverNamespace();
+}
diff --git a/libs/graphicsenv/include/graphicsenv/GraphicsEnv.h b/libs/graphicsenv/include/graphicsenv/GraphicsEnv.h
new file mode 100644
index 0000000..7817076
--- /dev/null
+++ b/libs/graphicsenv/include/graphicsenv/GraphicsEnv.h
@@ -0,0 +1,59 @@
+/*
+ * Copyright 2017 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 ANDROID_UI_GRAPHICS_ENV_H
+#define ANDROID_UI_GRAPHICS_ENV_H 1
+
+#include <string>
+
+struct android_namespace_t;
+
+namespace android {
+
+class GraphicsEnv {
+public:
+    static GraphicsEnv& getInstance();
+
+    // Set a search path for loading graphics drivers. The path is a list of
+    // directories separated by ':'. A directory can be contained in a zip file
+    // (drivers must be stored uncompressed and page aligned); such elements
+    // in the search path must have a '!' after the zip filename, e.g.
+    //     /data/app/com.example.driver/base.apk!/lib/arm64-v8a
+    void setDriverPath(const std::string path);
+    android_namespace_t* getDriverNamespace();
+
+private:
+    GraphicsEnv() = default;
+    std::string mDriverPath;
+    android_namespace_t* mDriverNamespace = nullptr;
+};
+
+} // namespace android
+
+/* FIXME
+ * Export an un-mangled function that just does
+ *     return android::GraphicsEnv::getInstance().getDriverNamespace();
+ * This allows libEGL to get the function pointer via dlsym, since it can't
+ * directly link against libgui. In a future release, we'll fix this so that
+ * libgui does not depend on graphics API libraries, and libEGL can link
+ * against it. The current dependencies from libgui -> libEGL are:
+ *  - the GLConsumer class, which should be moved to its own library
+ *  - the EGLsyncKHR synchronization in BufferQueue, which is deprecated and
+ *    will be removed soon.
+ */
+extern "C" android_namespace_t* android_getDriverNamespace();
+
+#endif // ANDROID_UI_GRAPHICS_ENV_H