private CSerialPortLibraryLoader(DirectoryInfo dynamicLinkLibrariesPath)
{
this.dynamicLinkLibrariesPath = dynamicLinkLibrariesPath;
refCount = 1;
var libCSerialPortDllPath = Path.Combine(dynamicLinkLibrariesPath.FullName, "libcserialport.dll");
if (!File.Exists(libCSerialPortDllPath))
{
throw new FileNotFoundException();
}
libCSerialPortDllHandle = Win32Interops.LoadLibrary(libCSerialPortDllPath);
if (libCSerialPortDllHandle == IntPtr.Zero)
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
var libCSerialPortExportDllPath = Path.Combine(dynamicLinkLibrariesPath.FullName, "libcserialportexport.dll");
if (!File.Exists(libCSerialPortExportDllPath))
{
throw new FileNotFoundException();
}
libCSerialPortExportDllHandle = Win32Interops.LoadLibrary(libCSerialPortExportDllPath);
if (libCSerialPortExportDllHandle == IntPtr.Zero)
{
throw new Win32Exception(Marshal.GetLastWin32Error());
}
}
void IDisposable.Dispose()
{
if (libCSerialPortDllHandle != IntPtr.Zero)
{
Win32Interops.FreeLibrary(libCSerialPortDllHandle);
libCSerialPortDllHandle = IntPtr.Zero;
}
if (libCSerialPortExportDllHandle != IntPtr.Zero)
{
Win32Interops.FreeLibrary(libCSerialPortExportDllHandle);
libCSerialPortExportDllHandle = IntPtr.Zero;
}
}
internal T GetInteropDelegate <T>()
{
string functionName = null;
try
{
var attrs = typeof(T).GetCustomAttributes(typeof(LibCSerialPortFunctionAttribute), false);
if (attrs.Length == 0)
{
throw new Exception("Could not find the LibCSerialPortFunctionAttribute.");
}
var attr = (LibCSerialPortFunctionAttribute)attrs[0];
functionName = attr.FunctionName;
lock (this.interopDelegatesLockObject)
{
if (interopDelegates.ContainsKey(functionName))
{
return((T)interopDelegates[attr.FunctionName]);
}
var procAddress = Win32Interops.GetProcAddress(libCSerialPortExportDllHandle, attr.FunctionName);
if (procAddress == IntPtr.Zero)
{
throw new Win32Exception();
}
var delegateForFunctionPointer = MarshalHelper.GetDelegateForFunctionPointer <T>(procAddress);
interopDelegates[attr.FunctionName] = delegateForFunctionPointer;
return(delegateForFunctionPointer);
}
}
catch (Win32Exception e)
{
throw new MissingMethodException(string.Format("The address of the function '{0}' does not exist in library.", functionName), e);
}
}