Trouble with Global Variables

I'm having a spot of bother with global variables in this ea.

I want to run more then one instance and becuz the global var name stays the same i end up getting some conflicts in the way it behaves. Or atleast thats what i think is going on.

Would appreciate a nudge in the right direction.

(other stuff on the wish list include option not to restart after next closed sequence and start ea at predefined starting price)

re the globals :

you know your problem is that the ea's are overwriting the same globals and therefore breaking each other, and you want globals that are unique to each instance of the ea running. so, how do you get around this?

you want to have a var called something like Instance at the top of each EA (programmatically global). In your init function do something like

what does this do? well, starting at zero it will check if the global variable exists called MyAwesomeEAInstance (plus the instance number). Once it has found an unused instance number it will set the global var indicating that an instance of your EA now does exist which is using this instance number and if any other charts have the ea attached they will therefore not use this Instance number in their own init setup and will find another free number to use.

now that you have found an available instance number for this ea to use and have staked your claim on this number by setting a gvar indicating this you are good to go.

all you need to do from then onwards with the gvars in the rest of your EA is to have that unique instance number somewhere in the name of the gvars you use.... e.g.


each EA will therefore write it's own unique set of global variables as they will each have the unique Instance number somewhere within the standard string names you are using in the EA. it's now impossible for one EA to interfere with the global var of another instance of the same EA as they are all referring to uniquely named versions of the global variable names you are using.

in the deinit section the ea must give back the instance number so that it is available to any other instances of this ea being run and they can then make use of this number for themselves.


now if you run the ea again this instance number is again available to use.

elegant fix, no?

Very nice!

Thanks for taking a look. I'll play with the code and see what happens.

The ea is only using 1 global variable, so wondering if the gvar name could be set to the magic number to resolve the issue as another solution.

yes indeed, set different MagicNumber for each EA instance and just change line 38 to

gvar_name = "Ref_price_" + Symbol() + MagicNumber + AccountNumber();

including the AccountNumber() is optional, it can be useful if you are testing and switching accounts.

hmm not so fast thar...

that doesn't really make sense. you are saying it's easier to manually specify a different magic number for each instance of the ea instead of letting it automatically configure itself?

seems like you are trying to get around not writing the code to save time and effort when the code will save you so much more time and effort in the long run. it's like running the car with the bonnet up because you can't be bothered putting more water into the radiator which has run dry.

i think magic no is the lazy mans answer (becuz thats me all over). it is user defined when starting the ea anyway so its probably what i'll try first.

nubcake's solution is definately more profound no doubt. if the ea made decent money it would definately be worth the effort, thanks for the help guys. appreciated.

no way i'm saying it's easier, you are spot on with your concept, but it might be easier for pp in this very moment. i just confirmed the magic number 'patch' will probably resolve pp's immediate issue with the ea, as he suggested himself.

thanks for your input too mj.

what you, nubcake, hanover, codemeister and others do here is really great.

fair nuf. i'm just as guilty as anyone of going the cheap route when it suits.