RFR: 8237521: Memory Access API fixes for 32-bit

[Nick Gasson]

Hi David,

On 01/24/20 14:35 pm, David Holmes wrote:
>>
>> How about we align the size up to ADDRESS_SIZE (== HeapWordSize) in
>> Unsafe.allocateMemory() before the call to allocateMemoryChecks(). Like:
>>
>>    bytes = ((bytes + ADDRESS_SIZE - 1) & ~(ADDRESS_SIZE - 1));
>>
>> Then it will throw an IllegalArgumentException if the result is outside
>> the size_t range. And in the native code we can just assert that the
>> `size' argument is already aligned:
>>
>>    assert(is_aligned(sz, HeapWordSize), "sz not aligned");
>
> That seems quite reasonable.
>

I've done this here:

http://cr.openjdk.java.net/~ngasson/8237521/webrev.02/

Need to check bytes >= 0 before aligning up so that allocateMemory(-1)
still throws an IllegalArgumentException.

Tested with jdk_foreign and runtime/Unsafe/.


Thanks,
Nick