RFR: 8185757: QuickSort array size should be size_t

[Kim Barrett]

> On Aug 3, 2017, at 3:05 PM, Thomas Schatzl <thomas.schatzl at oracle.com> wrote:
> 
> Hi,
> 
> On Thu, 2017-08-03 at 14:06 -0400, Kim Barrett wrote:
>>> 
>>> On Aug 3, 2017, at 8:32 AM, Thomas Schatzl <thomas.schatzl at oracle.c
>>> om> wrote:
>>> However, please put the closing brackets of these into extra lines
>>> (quicksort.hpp:76,77) to avoid the casual reader to overlook them.
>> Sorry, but that just looks horrible.  As a casual reader, I wouldn’t
>> even look for them, since if they aren’t there then the code is
>> badly mis-indented.
> 
> Actually I was already at writing about an issue with indentation when
> I noticed the brackets :)
> 
> Not insisting on changing this.

I added a couple of asserts to check for buffer overruns due to a bad comparator:

diff -r 6b62ed03a6a6 -r 7616ceb92653 src/share/vm/utilities/quickSort.hpp
--- a/src/share/vm/utilities/quickSort.hpp	Fri Aug 04 18:02:51 2017 -0400
+++ b/src/share/vm/utilities/quickSort.hpp	Fri Aug 04 19:17:36 2017 -0400
@@ -73,8 +73,12 @@
     T pivot_val = array[pivot];
 
     for ( ; true; ++left_index, --right_index) {
-      for ( ; comparator(array[left_index], pivot_val) < 0; ++left_index) {}
-      for ( ; comparator(array[right_index], pivot_val) > 0; --right_index) {}
+      for ( ; comparator(array[left_index], pivot_val) < 0; ++left_index) {
+        assert(left_index < length, "reached end of partition");
+      }
+      for ( ; comparator(array[right_index], pivot_val) > 0; --right_index) {
+        assert(right_index > 0, "reached start of partition");
+      }
 
       if (left_index < right_index) {
         if (!idempotent || comparator(array[left_index], array[right_index]) != 0) {