drm/libmediadrm/SharedLibrary.cpp

/*
 * Copyright (C) 2013 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 0
#define LOG_TAG "Drm"

#include <dlfcn.h>
#include <media/stagefright/foundation/ADebug.h>
#include <media/SharedLibrary.h>
#include <utils/Log.h>

namespace android {

    SharedLibrary::SharedLibrary(const String8 &path) {
        mLibHandle = dlopen(path.string(), RTLD_NOW);
    }

    SharedLibrary::~SharedLibrary() {
        if (mLibHandle != NULL) {
            dlclose(mLibHandle);
            mLibHandle = NULL;
        }
    }

    bool SharedLibrary::operator!() const {
        return mLibHandle == NULL;
    }

    void *SharedLibrary::lookup(const char *symbol) const {
        if (!mLibHandle) {
            return NULL;
        }
        // Clear last error before we load the symbol again,
        // in case the caller didn't retrieve it.
        (void)dlerror();
        return dlsym(mLibHandle, symbol);
    }

    const char *SharedLibrary::lastError() const {
        const char *error = dlerror();
        return error ? error : "No errors or unknown error";
    }

};