Incrementing a value from a DLL | Forex Factory

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Incrementing a value from a DLL

  • #1
  • First Post: Jul 1, 2019 2:42am Jul 1, 2019 2:42am
Hi,

I am offloading some processes off to a C++ DLL and in this DLL I want to calculate the percentage of how complete the process is.

I am trying to find some way of returning this value back to the EA so that I can display how complete the process is. Any ideas?
All of my attempts so far have resulted in an access violation.

Thanks,

John
  • #2
  • Jul 1, 2019 8:17am Jul 1, 2019 8:17am
Quoting skinner36
Hi, I am offloading some processes off to a C++ DLL and in this DLL I want to calculate the percentage of how complete the process is. I am trying to find some way of returning this value back to the EA so that I can display how complete the process is. Any ideas? All of my attempts so far have resulted in an access violation. Thanks, John
From what you wrote I assume you do the calculations in the DLL in a different thread then the one the EA is running in. In this case notification is easy:
Inserted Code
int progress[1];
 
int OnInit() {
   progress[0] = 0;
   DllStartCalculation(progress);
}
 
int OnTick() {
   int current = progress[0];
   Print("Current progress: "+ current +"%");
}
 
int OnDeinit() {
   DllStopCalculation();
}

Passing the array to the DLL essentially passes a pointer to the array's memory allocated by the terminal. Each time you "made some progress" in the DLL you update the value in the passed array. Then in EA::OnTick() you just read the current value, and do with it whatever you want.

Stopping the DLL from writing to the pointer is required if you remove the EA from the chart, as memory will be freed and you are not allowed to access the pointer passed to the DLL anymore.
It takes blood, sweat and enough tears to wash away the blood.
  • #3
  • Last Post: Aug 22, 2019 4:16am Aug 22, 2019 4:16am
Hi Emmzett,

Would you have any example C++ code utilising threading? I have read various bits of documentation but I can't get anything to work with the above code in the previous post.

Cheers,

John
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