khanat-code-old/code/nel/include/nel/misc/dynloadlib.h
2014-09-05 11:07:25 +02:00

263 lines
8.5 KiB
C++

// NeL - MMORPG Framework <http://dev.ryzom.com/projects/nel/>
// Copyright (C) 2010 Winch Gate Property Limited
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as
// published by the Free Software Foundation, either version 3 of the
// License, or (at your option) any later version.
//
// This program 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 Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
#ifndef NL_DYNLIBLOAD_H
#define NL_DYNLIBLOAD_H
#include "types_nl.h"
#include <string>
#include <vector>
#ifdef NL_OS_WINDOWS
struct HINSTANCE__;
typedef struct HINSTANCE__ *HINSTANCE;
typedef HINSTANCE HMODULE; /* HMODULEs can be used in place of HINSTANCEs */
#else
# include <dlfcn.h>
#endif
namespace NLMISC
{
/// Define the os specific type for dynamic library module handler
#if defined (NL_OS_WINDOWS)
typedef HMODULE NL_LIB_HANDLE;
#elif defined (NL_OS_UNIX)
typedef void* NL_LIB_HANDLE;
#else
# error "You must define the module type on this platform"
#endif
#ifdef NL_OS_WINDOWS
// MSCV need explicit tag to export or import symbol for a code module
#define NL_LIB_EXPORT __declspec(dllexport)
#define NL_LIB_IMPORT __declspec(dllimport)
#else
// other systems don't bother with this kind of detail, they export any 'extern' symbol (almost all functions)
#define NL_LIB_EXPORT
#define NL_LIB_IMPORT
#endif
/// Generic dynamic library loading function.
NL_LIB_HANDLE nlLoadLibrary(const std::string &libName);
/// Generic dynamic library unloading function.
bool nlFreeLibrary(NL_LIB_HANDLE libHandle);
/// Generic dynamic library symbol address lookup function.
void *nlGetSymbolAddress(NL_LIB_HANDLE libHandle, const std::string &symbolName);
// Compilation mode specific suffixes
#ifdef NL_OS_WINDOWS
# ifdef NL_DEBUG_INSTRUMENT
const std::string nlLibSuffix("_di");
# elif defined(NL_DEBUG)
const std::string nlLibSuffix("_d");
# elif defined(NL_RELEASE)
const std::string nlLibSuffix("_r");
# else
# error "Unknown compilation mode, can't build suffix"
# endif
#elif defined (NL_OS_UNIX)
const std::string nlLibSuffix; // empty
#else
# error "You must define the lib suffix for your platform"
#endif
// Utility macro to export a module entry point as a C pointer to a C++ class or function
#define NL_LIB_EXPORT_SYMBOL(symbolName, classOrFunctionName, instancePointer) \
extern "C" \
{ \
NL_LIB_EXPORT classOrFunctionName *symbolName = (classOrFunctionName*)instancePointer; \
};
/*
*
* \author Boris Boucher
* \author Nevrax France
* \date 2004
*/
class CLibrary
{
/// Dynamic library handle
NL_LIB_HANDLE _LibHandle;
/// Loaded library name
std::string _LibFileName;
/** When a module handle is assigned to the instance, this
* flag state whether the CLibrary will free the library or not
* when it is deleted.
*/
bool _Ownership;
/** This points to the 'pure' nel library interface.
* This means that the library export an entry point called
* 'NeLLibraryEntry' that points to a INelLibrary interface.
* This interface is used by the CLibrary class to
* manage efficiently the library and to give
* library implementors some hooks on library management.
*/
class INelLibrary *_PureNelLibrary;
/// Lib paths
static std::vector<std::string> _LibPaths;
/// Private copy constructor, not authorized
CLibrary (const CLibrary &other);
// Private assignment operator
CLibrary &operator =(const CLibrary &other);
public:
CLibrary();
/** Assign a existing module handler to a new dynamic library instance
* Note that you cannot use 'pure nel library' this way.
*/
CLibrary(NL_LIB_HANDLE libHandle, bool ownership);
/// Load the specified library and take ownership by default
CLibrary(const std::string &libName, bool addNelDecoration, bool tryLibPath, bool ownership = true);
/// Destructor, free the library if the object have ownership
virtual ~CLibrary();
/** Load the specified library.
* The method assert if a module is already assigned or loaded
* If addNelDecoration is true, the standard Nel suffix and library extention or prefix are
* added to the lib name (with is just a base name).
* If tryLibPath is true, then the method will try to find the required
* library in the added library files (in order of addition).
* Return true if the library load ok.
*/
bool loadLibrary(const std::string &libName, bool addNelDecoration, bool tryLibPath, bool ownership = true);
/** Unload (free) the assigned/loaded library.
* The object must have ownership over the library or the call will assert.
* After this call, you can recall loadLibrary.
*/
void freeLibrary();
/** Get the address a the specified procedure in the library
* Return NULL is the proc is not found,
* Assert if the library is not load or assigned.
*/
void *getSymbolAddress(const std::string &symbolName);
/// Get the name of the loaded library
std::string getLibFileName()
{
return _LibFileName;
}
/// Check whether a library is effectively loaded
bool isLibraryLoaded();
/** Check if the loaded library is a pure library
* Return false if the library is not pure
* or if the library is not loaded.
*/
bool isLibraryPure();
/** Return the pointer on the pure nel library interface.
* Return NULL if isLibraryPure() is false.
*/
class INelLibrary *getNelLibraryInterface();
/** Build a NeL standard library name according to platform and compilation mode setting.
* aka : adding decoration one base lib name.
* e.g : 'mylib' become 'mylib_rd.dll' on Windows ReleaseDebug mode or
* 'libmylib.so' on unix system.
*/
static std::string makeLibName(const std::string &baseName);
/** Remove NeL standard library name decoration according to platform and compilation mode setting.
* e.g : 'mylib_rd.dll' on windows ReleaseDebug mode become 'mylib'
*/
static std::string cleanLibName(const std::string &decoratedName);
/** Add a list of library path
* @see loadLibrary for a discusion about lib path
*/
static void addLibPaths(const std::vector<std::string> &paths);
/** Add a library path
* @see loadLibrary for a discusion about lib path
*/
static void addLibPath(const std::string &path);
};
/** Interface class for 'pure Nel' library module.
* This interface is used to expose a standard
* entry point for dynamically loaded library
* and to add some hooks for library implementor
* over library loading/unloading.
*/
class INelLibrary
{
friend class CLibrary;
/// this counter keep tracks of how many time the library have been loaded in the same process.
uint32 _LoadingCounter;
/// The library context
class CLibraryContext *_LibContext;
/** Called by CLibrary after a successful loadLibrary
* Note : this methods MUST be virtual to ensure
* that the code executed is the one from
* the loaded library.
*/
virtual void _onLibraryLoaded(class INelContext &nelContext);
/** Called by the CLibrary class before unloading the library.
* Note : this methods MUST be virtual to ensure
* that the code executed is the one from
* the loaded library.
*/
virtual void _onLibraryUnloaded();
public:
INelLibrary()
: _LoadingCounter(0),
_LibContext(NULL)
{}
virtual ~INelLibrary();
/// Return the loading counter value
uint32 getLoadingCounter();
/** Called after each loading of the library.
* firstTime is true if this is the first time that
* this library is loaded in the current process.
* If the process load more than once the same
* library, subsequent call to this method will
* have firstTime false.
* Implement this method to initialize think or whatever.
*/
virtual void onLibraryLoaded(bool firstTime) =0;
/** Called after before each unloading of the library.
* lastTime is true if the library will be effectively
* unmapped from the process memory.
* If the library have been loaded more than once,
* then lastTime is false, indicating that the
* library will still be in the process memory
* space after the call.
*/
virtual void onLibraryUnloaded(bool lastTime) =0;
};
#define NLMISC_PURE_LIB_ENTRY_POINT NelLibraryEntry
#define NLMISC_DECL_PURE_LIB(className) \
className _PureLibraryEntryInstance; \
NL_LIB_EXPORT_SYMBOL( NLMISC_PURE_LIB_ENTRY_POINT, NLMISC::INelLibrary, &_PureLibraryEntryInstance)
} // NLMISC
#endif // NL_DYNLIBLOAD_H