MT4 Child Process

outer.mq4.cpp

// property省略

#import "process.dll"
void OpenChildProcess(string);
void SendToChildProcess(string);
#import

int OnInit() {
  ChartSetInteger(ChartID(), CHART_EVENT_OBJECT_CREATE, true);
  ChartSetInteger(ChartID(), CHART_EVENT_OBJECT_DELETE, true);
  OpenChildProcess("outer.exe");
  SendToChildProcess(StringFormat("{\"type\":\"init\",\"symbol\":\"%s\",\"price\":%s,\"lines\":%s}\n", Symbol(), price(), lines()));
  return INIT_SUCCEEDED;
}
void OnDeinit(const int reason) {
  SendToChildProcess(StringConcatenate("{\"type\":\"close\"}\n"));
}
void OnTick() {
  SendToChildProcess(StringFormat("{\"type\":\"tick\",\"price\":%s}\n", price()));
}
void OnChartEvent(const int id, const long &lparam, const double &dparam, const string &sparam) {
  if (chart_object_changed(id)) {
    SendToChildProcess(StringFormat("{\"type\":\"line\",\"lines\":%s}\n", lines()));
  }
}
string price() {
  return StringFormat("{\"ask\":%s,\"bid\":%s}", DoubleToString(Ask, Digits), DoubleToString(Bid, Digits));
}

bool chart_object_changed(const int id) {
  return id == CHARTEVENT_OBJECT_CREATE
    || id == CHARTEVENT_OBJECT_DELETE
    || id == CHARTEVENT_OBJECT_CHANGE
    || id == CHARTEVENT_OBJECT_DRAG;
}

string lines() {
  string ls = "";
  for (int i = 0; i < ObjectsTotal(ChartID()); i++) {
    string name = ObjectName(i);
    if (ObjectType(name) != OBJ_HLINE) {
      continue;
    }
    double price = ObjectGetDouble(ChartID(), name, OBJPROP_PRICE1);
    long clr = ObjectGetInteger(ChartID(), name, OBJPROP_COLOR);
    string line = StringFormat("{\"name\":\"%s\",\"price\":%s,\"color\":%d},", name, DoubleToString(price, Digits), clr);
    StringAdd(ls, line);
  }
  if (ls != "") {
    ls = StringSubstr(ls, 0, StringLen(ls) - 1);
  }
  return StringConcatenate("[", ls, "]");
}

process.cpp

#include <windows.h>

PROCESS_INFORMATION pi = {};
HANDLE inputPipe = NULL;

extern "C" __declspec(dllexport) void OpenChildProcess(LPTSTR path) {
	SECURITY_ATTRIBUTES sa = {};
	sa.nLength = sizeof(SECURITY_ATTRIBUTES);
	sa.lpSecurityDescriptor = NULL;
	sa.bInheritHandle = TRUE;

	HANDLE inputReadPipe;
	CreatePipe(&inputReadPipe, &inputPipe, &sa, 0);

	STARTUPINFO si = {};
	si.cb = sizeof(STARTUPINFO);
	si.dwFlags = STARTF_USESTDHANDLES;
	si.hStdInput = inputReadPipe;
	si.hStdOutput = GetStdHandle(STD_OUTPUT_HANDLE);
	si.hStdError = GetStdHandle(STD_ERROR_HANDLE);

	PROCESS_INFORMATION pi = {};
	CreateProcess(
		NULL,
		path,
		NULL,
		NULL,
		TRUE,
		0,
		NULL,
		NULL,
		&si,
		&pi);
}

extern "C" __declspec(dllexport) void SendToChildProcess(LPTSTR msg) {
	size_t len = lstrlen(msg) * sizeof(TCHAR);
	WriteFile(inputPipe, msg, len, NULL, NULL);
}

Program.cs

// outer.exe

using System;

namespace ConsoleApplication1
{
    public class Program
    {
        public static void Main(string[] args)
        {
            Console.InputEncoding = System.Text.Encoding.Unicode;
            while (true)
            {
                var x = Console.ReadLine();
                Console.WriteLine(x);
                if (x == "{\"type\":\"close\"}")
                {
                    break;
                }
            }
        }
    }
}