Re: many exceptions cause memory leak?

[Christopher Broeg <broeg@astro.uni-jena.de>]

Christopher Broeg wrote:
> Simon Wright wrote:
>> Christopher Broeg <broeg@astro.uni-jena.de> writes:
>>
>>> I am by no means an expert in programming but I figured that all
>>> memory assigned by pointers is returned. I do not use my own storage
>>> pool but allocate just by
>>> is new...
>>> so it is all on the heap, I guess.
>>
>> GNAT doesn't automatically free this memory until the end of the
>> program. You need to free it yourself.
> 
> I do use unchecked deallocation on all pointers. I now have used gnatmem 
> and found one memory leak that was my fault. There are still a few 
> thousand "leaks" due to ada exception handling, though. Gnatmem output 
> follows:
> 
> Global information
> ------------------
>    Total number of allocations        :109993
>    Total number of deallocations      :97243
>    Final Water Mark (non freed mem)   :  29.85 Megabytes
>    High Water Mark                    :  29.90 Megabytes
> 
> Allocation Root # 1
> -------------------
>  Number of non freed allocations    :12702
>  Final Water Mark (non freed mem)   :  80.87 Kilobytes
>  High Water Mark                    :  80.87 Kilobytes
>  Backtrace                          :
>    a-except.adb:1396 <ada__exceptions___elabb>
> 
> I do think that the program now stays constnat in size, or at least 
> asymtotically approaches a relatively small constant size in memory. 
> running the code over night, the high water mark of the entire program 
> was small, so I hope the problem is solved. But since the program had 
> already finished by this morning, I couldn't check independently using 
> top, also I could not check whether this means reserved memory only and 
> what happens with the virtual memory. It used to be twice as large as 
> the reserved. I'll know in another 10 hours if everything is fine now.
> 
> Still, I am wondering if the above begaviour is normal. It is only 60kB, 
> so no big deal, but 12702 non freed allocations? Is this normal? They 
> always stem from line 1396 in a-except.adb. It is the place where a 
> dummy procecdure called ZZZ is called. It appears to me that this should 
> be a one-time per program lifetime event. Does this mean that there are 
> 12702 somehow independent exception occurences in my program?
> 
> thanks for all your help,
> 
> Chris
Addition:
Could compiling with debug information be the reason for the above 
behaviour?

Chris