Re: Memory leaks in 2.01

Halfdan Ingvarsson <[email protected]>
Newsgroups gmane.comp.video.openexr.devel
Message-ID <[email protected]>
Ideally the two calls should eventually be wrapped inside of a DllMain 
(Windows), or marked with __attribute__((constructor/destructor)) 
(Linux/OSX), making it all nice, tidy and automatic.

  - ½


On 13-11-05 05:31 AM, Michael Reinhardt wrote:
> Hi,
>
> if it is convenient for you to call a single method upon unloading, my 
> patch might help you. You have to call 
> "OPENEXR_IMF_NAMESPACE::staticUninitialize();" (I know, this is not 
> the best name for it.) when you want to unload the library. It will 
> delete the typemap and kill the memory leak. It works flawless in my 
> application, but I can't guarantee that it will work in every 
> situation. ;-) What I want to say: This is a quick hack. There might 
> be bugs inside.
>
> Michael
>
> P.s.: I had to adjust the file structure of the IlmImf library, so the 
> file paths in the patch file won't fit.
>
> Am 04.11.2013 16:17, schrieb Juri Abramov:
>>
>> *Note that if someone builds a plugin around OpenEXR library and 
>> unloads it, the memory leak is there. It is small, and mostly just 
>> annoying as one needs to add exceptions for memory leak hunting 
>> tools. It would be great to have some clean function/method.*
>>
>> **
>>
>> *Juri*
>>
>> **
>>
>> *From:*[email protected] 
>> [mailto:[email protected]] *On 
>> Behalf Of *Michael Reinhardt
>> *Sent:* 04 November, 2013 15:58
>> *To:* OpenEXR Devel List
>> *Subject:* Re: [Openexr-devel] Memory leaks in 2.01
>>
>> Hi Gerhard,
>>
>> I don't think you encountered a real memory leak. It just looks like 
>> one. (I stumbled upon this "leak" some time ago ;-) ). Upon creating 
>> a file - or something else that can handle Header object - a function 
>> named staticInitialize() (ImfHeader.h) is called. This function 
>> registers the basic attributes (e.g. Double, String, ...). These 
>> basic attributes are stored inside a static variable of the type 
>> LockedTypeMap (ImfAttribute.c). Afterwards, they are not touched 
>> again. The registration remains until the process ends. This is 
>> expected behaviour in my opinion. (Initialization is done once.)
>> Since the container for the basic attributes is a "function static  
>> variable", it will be deleted upon exit of the calling process. (As 
>> all remaining memory allocations will do.)
>>
>> This memory is allocated once. There is no growing runtime leak. Your 
>> memory leak detector is getting angry, because it checks the memory 
>> map too early. This "lazy static initialization" isn't recognized by 
>> the mem checker.
>>
>> IMHO, there is no way to circumvent this behaviour without having to 
>> initialize the typemap with every creation of an FileObject. And 
>> that's not very performant.
>>
>> I hope, I could allay your concerns.
>>
>> Michael
>>
>> Am 04.11.2013 08:04, schrieb Gerhard Huber:
>>
>>     Hi,
>>
>>     when I just create in InputFile
>>                     EXRReadFile    exrFile(file);
>>                     InputFile    inFile(exrFile);
>>     I get some memory leaks. I think the problem are some unreleased
>>     Attributes. The size of the memory leaks is almost 48 Bytes and
>>     one with 104 Bytes.
>>
>>     Gerhard
>>
>>
>>
>>
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