SharedLib

SharedLib is an interface to system-specific shared libraries, such as ".dll", ".so" or ".dylib" files. It provides a simple interface to obtain symbol addresses (such as function pointers) from these libraries.

final

class SharedLib {

enum LoadMode;

static SharedLib load(const(char)[] path, LoadMode mode);

static SharedLib loadNoThrow(const(char)[] path, LoadMode mode);

void unload();

void unloadNoThrow();

const(char)[] path [@property getter];

void* getSymbol(const(char)* name);

void* getSymbolNoThrow(const(char)* name);

static uint numLoadedLibs();

}

Members

Enums

LoadMode enum LoadMode: Mapped from RTLD_NOW, RTLD_LAZY, RTLD_GLOBAL and RTLD_LOCAL

Functions

getSymbol void* getSymbol(const(char)* name): Obtains the address of a symbol within the shared library
getSymbolNoThrow void* getSymbolNoThrow(const(char)* name): Obtains the address of a symbol within the shared library
unload void unload(): Unloads the OS-specific shared library associated with this SharedLib instance.
unloadNoThrow void unloadNoThrow(): Unloads the OS-specific shared library associated with this SharedLib instance.

Properties

path const(char)[] path [@property getter]: Returns the path to the OS-specific shared library associated with this object.

Static functions

load SharedLib load(const(char)[] path, LoadMode mode): Loads an OS-specific shared library.
loadNoThrow SharedLib loadNoThrow(const(char)[] path, LoadMode mode): Loads an OS-specific shared library.
numLoadedLibs uint numLoadedLibs(): Returns the total number of libraries currently loaded by SharedLib

Examples

void main() {
    if (auto lib = SharedLib.load(`c:\windows\system32\opengl32.dll`)) {
        Trace.formatln("Library successfully loaded");

        void* ptr = lib.getSymbol("glClear");
        if (ptr) {
            Trace.formatln("Symbol glClear found. Address = 0x{:x}", ptr);
        } else {
            Trace.formatln("Symbol glClear not found");
        }

        lib.unload();
    } else {
        Trace.formatln("Could not load the library");
    }

    assert (0 == SharedLib.numLoadedLibs);
}

This implementation uses reference counting, thus a library is not loaded again if it has been loaded before and not unloaded by the user. Unloading a SharedLib decreases its reference count. When it reaches 0, the shared library associated with it is unloaded and the SharedLib instance is deleted. Please do not delete SharedLib instances manually, unload() will take care of it.

Note: SharedLib is thread-safe.