A StackOverflowException most often occurs in recursive cases, where code is calling itself in an infinite loop. In this case the stack—a place where memory local to a scope is allocated—grows until there is no more space to contain it.
Fix the recursive loop.
The stack trace should give a very good indicator of the path of the recursive loop. Look for repetition in the trace, and look to remove the cause of the loop.
Recursion is a helpful tool, but as with any loop can easily introduce logic errors, causing it to run infinitely.
Unity, huh, how?
public void DoSomethingRecursively(int iteration)
{
if (iteration > 100) return;
// If this method was called again before the condition was checked,
// or if the iteration parameter was not increased,
// then this loop will run until the stack overflows.
DoSomethingRecursively(iteration + 1);
}In some other cases recursive loops can hit the limit of the stack without the loop being infinite. In these cases you may have to switch the logic to be a more standard loop—like a while loop—so the stack doesn't grow on each loop iteration.
Calling a property inside of itself can cause an infinite recursive loop.
private float _example;
public float Example
{
get
{
// This is a recursive loop.
// Instead of using the backing _example, the property's getter is called again.
if (Example < 10)
return 0;
return _example;
}
}Extracting stack traces can become extremely costly in recursive situations as the size grows. Note that logging with stack traces enabled can become a bottleneck in these situations.