DynamicLibrary.cpp

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/*
* This file is part of ArmarX.
*
* Copyright (C) 2011-2016, High Performance Humanoid Technologies (H2T), Karlsruhe Institute of Technology (KIT), all rights reserved.
*
* ArmarX is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* ArmarX is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* @package    ArmarX::
* @author     Mirko Waechter ( mirko.waechter at kit dot edu)
* @date       2012
* @copyright  http://www.gnu.org/licenses/gpl-2.0.txt
*             GNU General Public License
*/
 
#include "DynamicLibrary.h"
 
namespace armarx
{
    DynamicLibrary::DynamicLibrary() :
        handle(nullptr)
    {
#ifndef _WIN32
        flags = RTLD_NOW | RTLD_GLOBAL;
#endif
    }
 
    DynamicLibrary::~DynamicLibrary()
    {
        if (!unloadOnDestruct)
        {
            return;
        }
        ARMARX_WARNING << "Unloading " << libPath.string();
        try
        {
            unload();
        }
        catch (exceptions::local::DynamicLibraryException& e)
        {
            ARMARX_ERROR << "Error while unloading dynamic library: " << lastError;
        }
    }
 
    void DynamicLibrary::load(std::filesystem::path libPath)
    {
        if (handle)
        {
            throw exceptions::local::DynamicLibraryException("A library is already loaded. Call unload first and make sure that all references to this library are deleted.");
        }
 
        // if relative and not found, check at ArmarX locations
        if (libPath.is_relative() && !std::filesystem::exists(libPath))
        {
            std::string absolutePath;
 
            if (ArmarXDataPath::getAbsolutePath(libPath.string(), absolutePath))
            {
                libPath = absolutePath;
            }
        }
 
        if (!std::filesystem::exists(libPath))
        {
            throw exceptions::local::DynamicLibraryException("Lib-file not found: " + libPath.string());
        }
 
#ifndef _WIN32
        handle = dlopen(libPath.c_str(), flags);
#endif
 
 
        if (!handle)
        {
#ifndef _WIN32
            const char* error = dlerror();
#endif
 
            if (error)
            {
                lastError = error;
                throw exceptions::local::DynamicLibraryException(lastError);
            }
            else
            {
                throw exceptions::local::DynamicLibraryException("Unknown error");
            }
        }
 
        this->libPath = libPath;
 
    }
 
 
    void DynamicLibrary::unload()
    {
        if (!handle)
        {
            return;
        }
 
        bool result = dlclose(handle) == 0;
 
        if (!result)
        {
            const char* error = dlerror();
 
            if (error)
            {
                lastError = error;
                throw exceptions::local::DynamicLibraryException(lastError);
            }
            else
            {
                throw exceptions::local::DynamicLibraryException("Unknown error");
            }
        }
 
        handle = nullptr;
    }
 
    void DynamicLibrary::reload()
    {
        unload();
        load(libPath);
    }
 
    bool DynamicLibrary::isLibraryLoaded() noexcept
    {
        return handle != nullptr;
    }
 
    void DynamicLibrary::setUnloadOnDestruct(bool unload)
    {
        this->unloadOnDestruct = unload;
    }
 
    void DynamicLibrary::setFlags(int newFlags)
    {
        flags = newFlags;
 
        if (isLibraryLoaded())
        {
            reload();
        }
    }
 
    std::string DynamicLibrary::GetSharedLibraryFileExtension()
    {
#ifdef _WIN32
        return "dll";
#elif __APPLE__
        return "dylib";
#else
        return "so";
#endif
    }
 
    std::filesystem::path DynamicLibrary::getLibraryFilename() noexcept
    {
        return libPath;
    }
 
 
    std::string DynamicLibrary::getErrorMessage() noexcept
    {
        return lastError;
    }
}