internal Native(IntPtr target, Selector selector, IntPtr imp, MethodSignature sig)
{
Contract.Requires(selector != null, "selector is null");
Contract.Requires(target == IntPtr.Zero || imp != IntPtr.Zero, "imp is null");
m_target = target;
if (m_target != IntPtr.Zero)
{
if (ms_stackFrames == null)
{
ms_stackFrames = new Dictionary <MethodSignature, StackFrame>(); // note that we have to do this here so each thread gets its own dictionary
}
m_selector = selector;
m_imp = imp;
m_sig = sig ?? new MethodSignature(target, (IntPtr)selector);
if (!ms_stackFrames.TryGetValue(m_sig, out m_stackFrame))
{
m_stackFrame = new StackFrame(m_sig);
ms_stackFrames.Add(m_sig, m_stackFrame);
}
Ffi.FillBuffer(m_stackFrame.ArgBuffers[0], target, "@");
Ffi.FillBuffer(m_stackFrame.ArgBuffers[1], m_selector, ":");
}
}
/// <summary>Calls the native method using the arguments which were set by <c>SetArgs</c>.</summary>
public object Invoke()
{
object result = new NSObject(IntPtr.Zero);
if (m_target != IntPtr.Zero)
{
Ffi.Call(m_stackFrame.Cif, m_imp, m_stackFrame.ResultBuffer, m_stackFrame.ArgBuffers);
result = Ffi.DrainReturnBuffer(m_stackFrame.ResultBuffer, m_stackFrame.ReturnEncoding);
}
return(result);
}
/// <summary>Note that this may be be called once and <c>Invoke</c> many times.</summary>
public void SetArgs(params object[] args)
{
Contract.Requires(args != null, "args is null");
if (m_target != IntPtr.Zero)
{
if (m_sig.GetNumArgs() != 2 + args.Length)
{
throw new InvalidCallException(string.Format("{0} takes {1} arguments but was called with {2} arguments", m_selector, m_sig.GetNumArgs() - 2, args.Length));
}
for (int i = 0; i < args.Length; ++i)
{
string encoding = m_sig.GetArgEncoding(i + 2);
Ffi.FillBuffer(m_stackFrame.ArgBuffers[i + 2], args[i], encoding);
}
}
}
private static IntPtr DoCreateCif(MethodInfo info)
{
IntPtr resultType = Ffi.GetFfiType(info.ReturnType);
ParameterInfo[] parms = info.GetParameters();
int numArgs = parms.Length;
PtrArray argTypes = new PtrArray(numArgs + 3);
argTypes[0] = Ffi.GetFfiType(typeof(NSObject));
argTypes[1] = Ffi.GetFfiType(typeof(Selector));
for (int i = 0; i < numArgs; ++i)
{
Type type = parms[i].ParameterType;
argTypes[i + 2] = Ffi.GetFfiType(type);
}
argTypes[numArgs + 2] = IntPtr.Zero;
return(Ffi.AllocCif(resultType, argTypes)); // note that we don't want to free argTypes
}
public StackFrame(MethodSignature sig)
{
m_returnEncoding = sig.GetReturnEncoding();
IntPtr resultType = Ffi.GetFfiType(m_returnEncoding);
m_resultBuffer = Ffi.CreateBuffer(m_returnEncoding);
int numArgs = sig.GetNumArgs();
m_argBuffers = new PtrArray(numArgs);
m_argTypes = new PtrArray(numArgs + 1);
for (int i = 0; i < numArgs; ++i)
{
string encoding = sig.GetArgEncoding(i);
m_argBuffers[i] = Ffi.CreateBuffer(encoding);
m_argTypes[i] = Ffi.GetFfiType(encoding);
}
m_argTypes[numArgs] = IntPtr.Zero;
m_cif = Ffi.AllocCif(resultType, m_argTypes);
}
internal IntPtr Call(IntPtr dummy, IntPtr resultBuffer, IntPtr argBuffers)
{
Unused.Value = dummy;
IntPtr exception = IntPtr.Zero;
try
{
// Get the this pointer for the method we're calling.
PtrArray argArray = new PtrArray(argBuffers, m_signature.GetNumArgs() + 2);
NSObject instance = (NSObject)Ffi.DrainBuffer(argArray[0], "@");
// Get the selector for the method that was called.
// Get the method arguments.
string encoding;
object[] args = new object[m_signature.GetNumArgs() - 2];
for (int i = 0; i < args.Length; ++i)
{
encoding = m_signature.GetArgEncoding(i + 2);
if (encoding == "@")
{
args[i] = (NSObject)Ffi.DrainBuffer(argArray[i + 2], encoding);
}
else
{
args[i] = Ffi.DrainBuffer(argArray[i + 2], encoding);
}
// Native code doesn't distinguish between unsigned short and unichar
// so we need to fix things up here.
Type ptype = m_info.GetParameters()[i].ParameterType;
if (ptype == typeof(char))
{
args[i] = (char)(UInt16)args[i];
}
else if (ptype != typeof(NSObject) && typeof(NSObject).IsAssignableFrom(ptype))
{
IntPtr ip = (IntPtr)(NSObject)args[i];
args[i] = NSObject.Lookup(ip);
if (args[i] == null && ip != IntPtr.Zero)
{
throw new InvalidCallException(string.Format("Couldn't create a {0} when calling {1}. Is {0} registered or exported?", ptype, m_info.Name));
}
}
// Provide a better error message than the uber lame: "parameters".
if (args[i] != null && !ptype.IsAssignableFrom(args[i].GetType()))
{
throw new InvalidCallException(string.Format("Expected a {0} when calling {1} but have a {2}.", ptype, m_info.Name, args[i].GetType()));
}
}
// Call the method,
object value = m_info.Invoke(instance, args);
// and marshal the result.
encoding = m_signature.GetReturnEncoding();
if (encoding == "c" || encoding == "C" || encoding == "s" || encoding == "S") // per 'man ffi_call' small results must be stuffed into "storage that is sizeof(long) or larger"
{
int r = Convert.ToInt32(value);
Ffi.FillBuffer(resultBuffer, r, "l");
}
else if (encoding != "v" && encoding != "Vv")
{
Ffi.FillBuffer(resultBuffer, value, encoding);
}
}
catch (TargetInvocationException ie)
{
if (LogException != null)
{
LogException(ie);
}
else
{
DoLogException(ie);
}
exception = DoCreateNativeException(ie.InnerException);
}
catch (Exception e)
{
if (LogException != null)
{
LogException(e);
}
else
{
DoLogException(e);
}
exception = DoCreateNativeException(e);
}
return(exception);
}
