Merge "Load libRS_internal.so from the rs namespace" into oc-mr1-dev

#include "Context.h"

#include "Device.h"

#include <android/dlext.h>

#include <dlfcn.h>

namespace android {

namespace hardware {

namespace renderscript {

    static_assert(sizeof(size_t) <= sizeof(uint64_t), "RenderScript HIDL Error: sizeof(size_t) > sizeof(uint64_t)");

    const char* filename = "libRS_internal.so";

    void* handle = dlopen(filename, RTLD_LAZY | RTLD_LOCAL);

    // Try to load libRS_internal.so from the "rs" namespace directly.

    typedef struct android_namespace_t* (*GetExportedNamespaceFnPtr)(const char*);

    GetExportedNamespaceFnPtr getExportedNamespace =

        (GetExportedNamespaceFnPtr)dlsym(RTLD_DEFAULT, "android_get_exported_namespace");

    void* handle = nullptr;

    if (getExportedNamespace != nullptr) {

        android_namespace_t* rs_namespace = getExportedNamespace("rs");

        if (rs_namespace != nullptr) {

            const android_dlextinfo dlextinfo = {

                .flags = ANDROID_DLEXT_USE_NAMESPACE, .library_namespace = rs_namespace,

            };

            handle = android_dlopen_ext(filename, RTLD_LAZY | RTLD_LOCAL, &dlextinfo);

        }

    }

    if (handle == nullptr) {

        // if there is no "rs" namespace (in case when this HAL impl is loaded

        // into a vendor process), then use the plain dlopen.

        handle = dlopen(filename, RTLD_LAZY | RTLD_LOCAL);

    }

    dispatchTable dispatchHal = {

        .SetNativeLibDir = (SetNativeLibDirFnPtr) nullptr,