(offtopic: Purify and Valgrind) Re: [Coin-discuss] Purify UMR CoinFactorization::pivotOneOtherRow

[Matthew Galati]

>In short, Valgrind can detect many errors that Purify can't detect, 
>



I was unaware of this - and am surprised.



> 
>I regularly use valgrind to test new versions of CSDP, but it slows
>computations down by several orders of magnitude, so I can only run
>the code on small test problems.  Purify and other malloc debugging
>libraries are much faster.
>


Purify is very slow too - they all will be. But the time it saves in 
debugging is well worth it.

You can customize Purify to what level of "protection" you want - e.g., 
"Red Zone Length". The more protection, the slower it runs.

"
This option specifies the number of stack frames to be recorded and

       printed in the function call chain of a Purify  message.   This  option
       also  affects the extent of the red zone area around memory blocks used
       by Purify to detect array bound errors.  Since Purify stores  the  call
       chain  of the function allocating the memory in the red zone at the end
       of the block, set this to a larger value to increase this red zone  and
       increase the extent of the area where incorrect array boundary accesses
       will be detected.  This will also change the memory and swap space used
       by the program.
"