This class loads shared libraries and provides function pointers. More...

#include <WSharedLib.h>

Collaboration diagram for WSharedLib:

Classes
struct	data
	Simple class holding an opened library. More...

Public Member Functions
	WSharedLib (boost::filesystem::path lib)
	Constructor. More...

	WSharedLib (const WSharedLib &rhs)
	Copies this instance by increasing the reference counter of the loaded library by 1. More...

virtual	~WSharedLib ()
	Destructor. More...

WSharedLib &	operator= (const WSharedLib &rhs)
	Copy assignment for shared libraries. More...

template<typename FuncType >
void	fetchFunction (const std::string &name, FuncType &func) const
	Search for a function in the shared library. More...

bool	existsFunction (const std::string &name) const
	Check whether the function exists. More...

template<typename PtrType >
void	fetchVariable (const std::string &name, PtrType &variable) const
	Search for an variable in the shared library. More...

std::string	getLibraryName ()
	Returns the filename of the library without path. More...

Static Public Member Functions
static std::string	getSystemPrefix ()
	Returns the prefix used for libraries on the system. More...

static std::string	getSystemSuffix ()
	Returns the suffix for libraries used on the system. More...

static std::string	getSystemLibPath ()
	Returns the default path for libraries on the current system. More...

Private Types
typedef void(*	func_ptr_type) (void)
	neutral function pointer type More...

Private Member Functions
func_ptr_type	findFunction (const std::string &name) const
	Find the specified function pointer in the library. More...

void *	findVariable (const std::string &name) const
	Find the specified symbol in the library. More...

Private Attributes
data *	m_data
	internal data More...

boost::filesystem::path	m_libPath
	path to lib More...

Friends
void	swap (WSharedLib &lhs, WSharedLib &rhs)
	Swap to shared libraries. More...

Detailed Description

This class loads shared libraries and provides function pointers.

This is especially useful for dynamic loading of shared libraries during runtime. This works on Windows, Linux and Mac OS and is based on the openbug shared_lib implementation by Christian Heine heine.nosp@m.@inf.nosp@m.ormat.nosp@m.ik.u.nosp@m.ni-le.nosp@m.ipzi.nosp@m.g.de.

Note: This class performs locking so that under any system variables of shared_lib may be used in multi-threaded environments.

Warning: Because the POSIX standard does not enforce thread safety for the functions dlopen, dlclose, dlerror, and dlsym, these should not be used simultaneously with variables of this class.

Definition at line 44 of file WSharedLib.h.

Member Typedef Documentation

◆ func_ptr_type

typedef void(* WSharedLib::func_ptr_type) (void)

private

neutral function pointer type

Definition at line 155 of file WSharedLib.h.

Constructor & Destructor Documentation

◆ WSharedLib() [1/2]

WSharedLib::WSharedLib ( boost::filesystem::path lib )

explicit

Constructor.

Loads the specified library.

Parameters

lib	the library to load. Can be a DLL,SO or DYLIB (depending on system). This can be an absolut or relative path. Otherwise standard library search directory may be searched.

Note: If the shared library is already loaded, this constructor just increases its reference count. This is detected even if different paths were used (e.g. "./somelib.so", "../libs/somelib.so").

Exceptions

WLibraryLoadFailed if the lib could not be loaded. Maybe because of file not found or link errors.

Definition at line 267 of file WSharedLib.cpp.

◆ WSharedLib() [2/2]

WSharedLib::WSharedLib ( const WSharedLib & rhs )

Copies this instance by increasing the reference counter of the loaded library by 1.

Parameters

rhs	the other Lib.

Definition at line 273 of file WSharedLib.cpp.

◆ ~WSharedLib()

WSharedLib::~WSharedLib ( )

virtual

Destructor.

Decreases the reference counter and unloads the library if the reference count drops to zero.

Definition at line 279 of file WSharedLib.cpp.

References m_data.

Member Function Documentation

◆ existsFunction()

bool WSharedLib::existsFunction ( const std::string & name ) const

Check whether the function exists.

Parameters

name	the name of the function

Returns: true if it exists.

Definition at line 306 of file WSharedLib.cpp.

References WSharedLib::data::existsFunction(), and m_data.

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◆ fetchFunction()

template<typename FuncType >

void WSharedLib::fetchFunction	(	const std::string &	name,
		FuncType &	func
	)		const

Search for a function in the shared library.

Template Parameters

FuncType a function type

Parameters

name	the name of the function
func	will be set to the function pointer

Exceptions

WLibraryFetchFailed if the symbol was not found

Warning: type unsafe, make sure the symbol actually is of the proper type

Definition at line 186 of file WSharedLib.h.

References findFunction().

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◆ fetchVariable()

template<typename PtrType >

void WSharedLib::fetchVariable	(	const std::string &	name,
		PtrType &	variable
	)		const

Search for an variable in the shared library.

Template Parameters

PtrType a pointer type

Parameters

name	the name of the variable
variable	will be set to the variable pointer

Exceptions

WLibraryFetchFailed if the symbol was not found

Warning: type unsafe, make sure the symbol actually is of the proper type

Definition at line 192 of file WSharedLib.h.

References findVariable().

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◆ findFunction()

WSharedLib::func_ptr_type WSharedLib::findFunction ( const std::string & name ) const

private

Find the specified function pointer in the library.

Parameters

name	the symbol to search

Returns: the pointer to the symbol as function pointer

Definition at line 296 of file WSharedLib.cpp.

References WSharedLib::data::findFunction(), and m_data.

Referenced by fetchFunction().

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◆ findVariable()

void * WSharedLib::findVariable ( const std::string & name ) const

private

Find the specified symbol in the library.

Parameters

name	the symbol to search

Returns: the pointer to the symbol as function pointer.

Definition at line 301 of file WSharedLib.cpp.

References WSharedLib::data::findVariable(), and m_data.

Referenced by fetchVariable().

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◆ getLibraryName()

std::string WSharedLib::getLibraryName ( )

Returns the filename of the library without path.

Returns: the filename.

Definition at line 326 of file WSharedLib.cpp.

References m_libPath.

◆ getSystemLibPath()

std::string WSharedLib::getSystemLibPath ( )

static

Returns the default path for libraries on the current system.

This is the directory where to search for .so,.dll or .dylib files. On Unix, this will be "../lib", on Windows ".".

Returns: the path on the system.

Definition at line 321 of file WSharedLib.cpp.

◆ getSystemPrefix()

std::string WSharedLib::getSystemPrefix ( )

static

Returns the prefix used for libraries on the system.

On Unix this mostly is "lib".

Returns: the prefix.

Definition at line 311 of file WSharedLib.cpp.

Referenced by WModuleLoader::getModulePrefix().

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◆ getSystemSuffix()

std::string WSharedLib::getSystemSuffix ( )

static

Returns the suffix for libraries used on the system.

On Unix this mostly is "so", Windows uses "dll" and Mac something like "dylib".

Returns: the suffix.

Definition at line 316 of file WSharedLib.cpp.

Referenced by WModuleLoader::load().

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◆ operator=()

WSharedLib & WSharedLib::operator= ( const WSharedLib & rhs )

Copy assignment for shared libraries.

Parameters

rhs	the one to assign

Returns: this instance copied from the specified one.

Definition at line 284 of file WSharedLib.cpp.

References swap.

Friends And Related Function Documentation

◆ swap

void swap	(	WSharedLib &	lhs,
		WSharedLib &	rhs
	)

friend

Swap to shared libraries.

Parameters

lhs	the one
rhs	the other

Definition at line 291 of file WSharedLib.cpp.

Referenced by operator=().

Member Data Documentation

◆ m_data

data* WSharedLib::m_data

private

internal data

Definition at line 179 of file WSharedLib.h.

Referenced by existsFunction(), findFunction(), findVariable(), and ~WSharedLib().

◆ m_libPath

boost::filesystem::path WSharedLib::m_libPath

private

path to lib

Definition at line 182 of file WSharedLib.h.

Referenced by getLibraryName().

The documentation for this class was generated from the following files:

Classes

Public Member Functions

Static Public Member Functions

Private Types

Private Member Functions

Private Attributes

Friends

Detailed Description

Member Typedef Documentation

◆ func_ptr_type

Constructor & Destructor Documentation

◆ WSharedLib() [1/2]

◆ WSharedLib() [2/2]

◆ ~WSharedLib()

Member Function Documentation

◆ existsFunction()

◆ fetchFunction()

◆ fetchVariable()

◆ findFunction()

◆ findVariable()

◆ getLibraryName()

◆ getSystemLibPath()

◆ getSystemPrefix()

◆ getSystemSuffix()

◆ operator=()

Friends And Related Function Documentation

◆ swap

Member Data Documentation

◆ m_data

◆ m_libPath