CODEWITHSUNDEEP
java
ripper234
ripper234

Reputation: 230366

What is the maximum depth of the java call stack?

How deep do I need to go into the call stack before I get a StackOverflowError? Is the answer platform dependent?

Upvotes: 122

Views: 83515

Answers (5)

Mukundhan
Mukundhan

Reputation: 3487

While traversing a tree with huge depth, we could face this


/**
 * -Xss10M
 * max call stack count 92766
 * -Xss100M
 * max call stack count 2148286
 */
public class MaxCallStack {
    private Integer stackCount = 0;

    public static void main(String[] args) {
        MaxCallStack maxStack = new MaxCallStack();
        maxStack.evaluate();
    }

    private void evaluate() {
        try {
            Tree tree = new Tree();
            tree.left = tree;
            traverse(tree);
        } catch (StackOverflowError e) {
            System.out.println(String.format("max call stack count %s", stackCount));
        }
    }

    private void traverse(Tree tree) {
        stackCount++;
        if (tree.left != null) {
            traverse(tree.left);
        }
        if (tree.right != null) {
            traverse(tree.right);
        }
    }

    private class Tree {
        Tree left;
        Tree right;
    }
}

Upvotes: 0

troy
troy

Reputation: 714

I tested on my system and didn't find any constant value, sometimes stack overflow occurs after 8900 calls, sometimes only after 7700, random numbers.

public class MainClass {

    private static long depth=0L;

    public static void main(String[] args){
        deep(); 
    }

    private static void deep(){
        System.err.println(++depth);
        deep();
    }

}

Upvotes: 33

sixtytrees
sixtytrees

Reputation: 1233

Compare these two calls:
(1) Static method:

public static void main(String[] args) {
    int i = 14400; 
    while(true){   
        int myResult = testRecursion(i);
        System.out.println(myResult);
        i++;
    }
}

public static int testRecursion(int number) {
    if (number == 1) {
        return 1;
    } else {
        int result = 1 + testRecursion(number - 1);
        return result;
    }    
}
 //Exception in thread "main" java.lang.StackOverflowError after 62844

(2) Non-static method using a different class:

public static void main(String[] args) {
    int i = 14400;
    while(true){       
        TestRecursion tr = new TestRecursion ();
        int myResult = tr.testRecursion(i);
        System.out.println(myResult);
        i++;
    }
} 
//Exception in thread "main" java.lang.StackOverflowError after 14002

Test recursion class has public int testRecursion(int number) { as the only method.

Upvotes: 4

biziclop
biziclop

Reputation: 49804

The stack size can be set with the -Xss command line switch but as a rule of thumb, it is deep enough, hundreds if not thousands of calls deep. (The default is platform dependent, but at least 256k in most platforms.)

If you get a stack overflow, 99% of the time it's caused by an error in the code.

Upvotes: 20

finnw
finnw

Reputation: 48659

It depends on the amount of virtual memory allocated to the stack.

http://www.odi.ch/weblog/posting.php?posting=411

You can tune this with the -Xss VM parameter or with the Thread(ThreadGroup, Runnable, String, long) constructor.

Upvotes: 68

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