multithreading - Groovy Thread Safety

Question

I am using groovy scripting execution in multi threaded mode. Script themselves are thread safe.

Its like below: //Startup Code. Single threaded

Class<?> scriptClass = getScriptClass(fileName); //utility to get script class from file name
Method method = getMethods(scriptClass); //Utility to get a specific Method
storeMethod(method); //Store method globally.
Object scriptInstance = scriptClass.newInstance();
storeScriptInstance(scriptInstance); //Store script Instance

Multiple threads execute following code: (without any synchronization.)

ScriptInstance scriptInstance = getScriptInstance(); //Utility to get scriptInstance stored in init
Method method = getMethod(); //Utility for getting method stored in init step
Object obj[] = new Object[] { context }; //context variable available per thread.
method.invoke(scriptInstance,obj);

script consists of just one function which is totally thread safe (function is reentrant and modifies context variable.)

This works in my unit testing with multiple threads but couldn't find any material to support this claim. Question => Is it safe under multiple thread execution? More generically, sharing of same script instances across threads to execute scripts functions which themselves are thread safe is safe? Script instances shouldn't have global variables in execution. Context is an argument to script and not global variable.

Please help.

Answer 1

Without the actual function I cannot tell if this is supposed to be threadsafe or not. Since you say that the function modifies the context variable I conclude that you mutate global state. In that case it is not threadsafe without synchronization of some kind. If my assumption is wrong and no global state is mutated, then executing a method by reflection is surely not the problem