private MethodBuilder GetBody(ForkGroup forkGroup)
{
MethodBuilder result = target.DefineMethod(forkGroup.Name, MethodAttributes.Virtual | MethodAttributes.Public,
typeof(void), forkGroup.ParameterTypes);
int parameterCount = forkGroup.Parameters.Length;
ILGenerator generator = result.GetILGenerator();
// IL: Create argument array
generator.DeclareLocal(typeof(object[]));
generator.Emit(OpCodes.Ldc_I4, parameterCount);
generator.Emit(OpCodes.Newarr, typeof(object));
generator.Emit(OpCodes.Stloc_0);
for (int parameterIndex = 0; parameterIndex < parameterCount; parameterIndex++)
{
// Parameters are to be attributed and named nicely
ParameterInfo parameter = forkGroup.Parameters[parameterIndex];
result.DefineParameter(parameterIndex + 1, parameter.Attributes, parameter.Name);
// IL: Wrap up argument array
generator.Emit(OpCodes.Ldloc_0);
generator.Emit(OpCodes.Ldc_I4, parameterIndex);
generator.Emit(OpCodes.Ldarg, parameterIndex + 1);
if (forkGroup.ParameterTypes[parameterIndex].IsValueType)
generator.Emit(OpCodes.Box, forkGroup.ParameterTypes[parameterIndex]);
generator.Emit(OpCodes.Stelem_Ref);
}
// IL: Start caller in new Thread (now using ThreadPool)
generator.Emit(OpCodes.Ldarg_0);
generator.Emit(OpCodes.Ldftn, GetCaller(forkGroup));
generator.Emit(OpCodes.Newobj, typeof(WaitCallback).GetConstructor(new Type[] { typeof(object), typeof(IntPtr) }));
generator.Emit(OpCodes.Ldloc_0);
generator.EmitCall(OpCodes.Call, typeof(ThreadPool).GetMethod("QueueUserWorkItem", new Type[] { typeof(WaitCallback), typeof(object) }), null);
generator.Emit(OpCodes.Pop);
generator.Emit(OpCodes.Ret);
return result;
}
private MethodBuilder GetCaller(ForkGroup forkGroup)
{
MethodBuilder result = target.DefineMethod(string.Format("{0}Caller", forkGroup.Name),
MethodAttributes.Private,
typeof(void), new Type[] { typeof(object) });
result.DefineParameter(1, ParameterAttributes.In, "argumentArray");
int parameterCount = forkGroup.Parameters.Length;
int channelParameterCount = forkGroup.ChannelParameters.Length;
ILGenerator generator = result.GetILGenerator();
generator.Emit(OpCodes.Ldarg_0);
// IL: Unwrap argument array
for (int parameterIndex = 0; parameterIndex < parameterCount; parameterIndex++)
{
generator.Emit(OpCodes.Ldarg_1);
generator.Emit(OpCodes.Ldc_I4, parameterIndex);
generator.Emit(OpCodes.Ldelem_Ref);
if (forkGroup.ParameterTypes[parameterIndex].IsValueType)
generator.Emit(OpCodes.Unbox_Any, forkGroup.ParameterTypes[parameterIndex]);
}
// IL: Prepare channels
for (int channelParameterIndex = 0; channelParameterIndex < channelParameterCount; channelParameterIndex++)
{
generator.DeclareLocal(forkGroup.ChannelParameters[channelParameterIndex].ParameterType.GetElementType());
generator.Emit(OpCodes.Ldloca, channelParameterIndex);
}
// IL: Call parallel method
generator.EmitCall(OpCodes.Call, forkGroup.ParallelMethod, null);
// IL: Handle channel results
for (int channelParameterIndex = 0; channelParameterIndex < channelParameterCount; channelParameterIndex++)
{
Type channelType = forkGroup.ChannelParameters[channelParameterIndex]
.ParameterType.GetElementType();
generator.Emit(OpCodes.Ldarg_0);
generator.Emit(OpCodes.Ldfld, channelImplementer
.GetChannelField(forkGroup.ChannelNames[channelParameterIndex],
channelType));
generator.Emit(OpCodes.Ldloc, channelParameterIndex);
generator.EmitCall(OpCodes.Call, typeof(Channel<>)
.MakeGenericType(new Type[] { channelType })
.GetMethod("Send"), null);
}
generator.Emit(OpCodes.Ret);
return result;
}
public void Implement(ForkGroup forkGroup)
{
target.DefineMethodOverride(GetBody(forkGroup), forkGroup.ForkMethod);
}
