[ros-dev] Re: [ros-diffs] [hbirr] 16714: - Removed R_EXTRA_STACK because R_EXTRA_STACK and R_STACK must have the same size.

[Hartmut Birr]

Royce Mitchell III wrote:

> hbirr at svn.reactos.com wrote:
>
>> - Initialized an allocated block completely before release the lock.
>>
>> @@ -719,9 +725,9 @@
>>  
>>
>>     {
>>         if ( (NewBlock = RQueRemove ( &pool->Que[que][align] )) )
>>         {
>>  
>>
>> -            R_RELEASE_MUTEX(pool);
>>  
>>
>>             RiUsedInit ( NewBlock, Tag );
>>             RiUsedInitRedZone ( NewBlock, NumberOfBytes );
>>  
>>
>> +            R_RELEASE_MUTEX(pool);
>>  
>>
>>             return RHdrToBody(NewBlock);
>>         }
>>         queBytes = 16 << que;
>> @@ -865,11 +871,10 @@
>>  
>>
>>     NewBlock = (PR_USED)BestBlock;
>>     RiUsedInit ( NewBlock, Tag );
>>
>>  
>>
>> -    R_RELEASE_MUTEX(pool);
>> -
>>  
>>
>>     /*  RtlZeroMemory(RHdrToBody(NewBlock), NumberOfBytes);*/
>>
>>     RiUsedInitRedZone ( NewBlock, NumberOfBytes );
>>  
>>
>> +    R_RELEASE_MUTEX(pool);
>>  
>>
>>
>>     return RHdrToBody(NewBlock);
>> }
>>  
>>
> Hartmut,
>
> If you don't mind, I'm curious how this was causing a problem, the
> stuff that was being initialized outside of the lock shouldn't (in my
> feeble mind) have been "visible" upon reentry until this block is
> freed again.
>
I've add a 'paged pool check thread' which is activated each 10 minutes.
The thread allocates a zero size block, which triggers the checking. If
the thread does check a new allocated block between releasing the lock
and intializing the red zone, I get a wrong hit.

- Hartmut