Request for review: 7110152 assert(size_in_words <= (julong)max_jint) failed: no overflow

[Bengt Rutisson]

Hi all,

Could I have a couple of reviews for this small change?
http://cr.openjdk.java.net/~brutisso/7110152/webrev.01/

The problem is that CollectedHeap::array_allocate() takes its size as an 
int instead of a size_t. This was exposed by the fix I made to 7102044 
recently.

That change allows arrays to be max_jint long on 64 bit systems. This is 
correct since we can handle this size in a 64 bit size_t even when we 
add the object header. However, it will overflow an int.

Here is a small reproducer that will trigger the assert mentioned in 
7110152 when it is run on a 64 bit VM:

public class MaxJIntArray {
     public static void main(String[] args) {
         final int MAX_JINT = 2147483647;
         double[] a = new double[MAX_JINT];
         System.out.println("Allocated a[" + a.length + "]");
     }
}

The fix is to remove the assert (since it is too strict) and changing 
CollectedHeap::array_allocate() to take a size_t instead of an int.

CR:
7110152 assert(size_in_words <= (julong)max_jint) failed: no overflow
http://monaco.sfbay.sun.com/detail.jsf?cr=7110152

Bengt