A DESCRIPTION OF THE PROBLEM :
In java.base.java.util.PriorityQueue.grow(), to get the new capacity of queue array, there's such code
 "
int newCapacity = ArraysSupport.newLength(oldCapacity,
                minCapacity - oldCapacity, /* minimum growth */
                oldCapacity < 64 ? oldCapacity + 2 : oldCapacity >> 1
                                           /* preferred growth */);
"
, besides a single line comment "// Double size if small; else grow by 50%".

I reckon that when "oldCapacity < 64", the newCapacity should be "oldCapacity * 2" thus double size, other than "oldCapacity + 2". I wonder that if this drag down the performance of array's copy, since "oldCapacity + 2" might cause frequently copying of array when oldCapacity is less than 64.

This issue not only shows up in version 17.0.1, but also JDK14 and JDK8. I don't know if it's intentional or a slip "+" instead of "*". I see that there is a version that "(oldCapacity + 1) * 2" on some blog, but I don't know what version is that.

I wonder why if it's intentional, please. Sorry to interrupt.
Best Regards.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
no need to reproduce, it's in the source code.

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
int newCapacity = ArraysSupport.newLength(oldCapacity,
                minCapacity - oldCapacity, /* minimum growth */
                oldCapacity < 64 ? oldCapacity * 2 : oldCapacity >> 1
                                           /* preferred growth */);
ACTUAL -
int newCapacity = ArraysSupport.newLength(oldCapacity,
                minCapacity - oldCapacity, /* minimum growth */
                oldCapacity < 64 ? oldCapacity + 2 : oldCapacity >> 1
                                           /* preferred growth */);