RFR: 8000617: It should be possible to allocate memory without the VM dying.

[Vitaly Davidovich]

Yeah, I figured it was done this way to save on code, it just doesn't look
typical/idiomatic I think and hence requires the "dothrow" discriminator;
dothrow = nothrow_t looks odd as well.

Instead of bool true/false, could use an enum to make it more readable.

Cheers guys

Sent from my phone
On Oct 10, 2012 4:41 PM, "Keith McGuigan" <keith.mcguigan at oracle.com> wrote:

>
>
> On 10/10/2012 4:29 PM, Vitaly Davidovich wrote:
>
>> Hi Nils,
>>
>> In thread.cpp, line 1614 - what's its purpose? Some leftover code?
>>
>> In allocation.cpp, "dothrow" constant is assigned std::nothrow_t but isn't
>> nothrow_t for *not* throwing? This constant is then used to actually
>> signal
>> oom in one of the methods - seems odd.
>>
>> Also, in ResourceObject::operator new() there's an assertion that
>> nothrow_t
>> == std::nothrow - what's the purpose? Why would someone use this overload
>> if they're not looking to skip bad_alloc? What sort of error are you
>> thinking of here?
>>
>> Finally, I think the idiomatic way to do this type of stuff is to have a
>> separate overload of the alloc function that accepts nothrow_t whereas you
>> seem to have functions that take nothrow_t as a parameter, but then you
>> check if its the "dothrow" constant inside to see if oom should be
>> reported.  It seems cleaner to have overloads where the one taking
>> nothrow_t automatically means don't throw?
>>
>
> The problem with doing it that way is that it's harder to share code in
> the implementation of the allocation routines.  Either all of the routines
> (all the way down) need to be overloaded (and duplicated), or you need to
> both the overloads to call into a common subroutine which takes some
> parameter which indicates the throw mode.  It could be a 'bool', but why
> not just use a std::nothrow_t instead?  It's much more descriptive at the
> callsite for what is actually going on, rather than a naked 'true' or
> 'false' which requires one to check the declaration to see the purpose.
>
> That's essentially what this code is doing:  for the parts that are
> common, the nothrow/dothrow values are used as the discriminator.
>
> (Oh and I give this a thumbs-up, Nils, once you get rid of that leftover
> line in thread.cpp).
>
> --
> - Keith
>