RFR (XS) : 8141641: Runtime: implement range for ErrorLogTimeout

[David Holmes]

On 17/11/2015 8:34 AM, gerard ziemski wrote:
>
>
> On 11/16/2015 03:45 PM, David Holmes wrote:
>>>> I'm making a bit of a hash of this review - sorry.
>>>>
>>>> I agree with Dmitry that the os::sleep call should be changed as above:
>>>>
>>>> os::sleep(this, ErrorLogTimeout * CONST64(1000), false);
>>>>
>>>> but as the sleep arg is a jlong we need to limit ErrorLogTimeout to
>>>> (MAX_JLONG/1000) _but_ that's too big for uintx on
>>>> 32-bit. Which means the true range is different on 32-bit versus
>>>> 64-bit. So if I finally get this right we should have
>>>> the range as:
>>>>
>>>> range(0, LP64_ONLY(MAX_JLONG/1000) NOT_LP64(UINTX_MAX))
>>>>
>>>> Not sure we have MAX_JLONG defined as a constant. I don't agree with
>>>> just selecting the 32-bit range as that again
>>>> becomes an arbitrary constraint on 64-bit.
>>>
>>> Since os:sleep() takes jlong (8 bytes long on both 32 and 64 bit), them
>>> it would appear that the most straightforward solution is to change
>>> ErrorLogTimeout type from "uintx" to "uint64_t" (also 8 bytes on both 32
>>> and 64 bit) and then we can have the range simply defined as:
>>>
>>> range(0, max_jlong/1000)
>>>
>>> And then we can have:
>>>
>>> os::sleep(this, ErrorLogTimeout * CONST64(1000), false); // in seconds
>>>
>>> Do we agree?
>>
>> Not quite. First if ErrorLogTimeout is 64-bit then we don't need to
>> apply CONST64 to 1000 as integer promotion will take
>> care of it. But we then pass an unsigned 64-bit value where a signed
>> 64-bit value is expected and that will need a cast
>> to avoid a conversion warning.
>>
>> So perhaps ErrorLogTimeout should be int64_t instead - even though
>> only positive values are valid?
>
> There is no int64_t allowed in the globals's macro definition - uint64_t
> seems like the best type we have available here for jlong.
>
> So perhaps:
>
> os::sleep(this, (jlong)ErrorLogTimeout * 1000, false); // in seconds
>
> is the closest/best we can do?

So be it.

Thanks,
David

>
> cheers