Flann Index release memory unexpectedly. (Bug #2536)

Added by Lichao Chen over 12 years ago. Updated over 12 years ago.

Status:Cancelled Start date:2012-11-14
Priority:Normal Due date:
Assignee:Lichao Chen % Done:

0%
Category:flann
Target version:2.4.4
Affected version: Operating System:
Difficulty: HW Platform:
Pull request:

Description

class AClass {
public:
AClass(){
}
private:
Index ind;
}

AClass::AClass(){
code to load feavec from text files....

ind = Index(feavec, parms);
}

ind cannot be used any more, since after the assignment, the local copy's ~Index will be called, and member index won't be retained. As a result, the member var ind will have an invalid pointer void index.

Associated revisions

Revision 6ef94b52
Added by Andrey Pavlenko almost 11 years ago

Merge pull request #2536 from ilya-lavrenov:tapi_resize_linear

History

#1
Updated by Stefan R over 12 years ago

Disclaimer: I have not used that FLANN part of OpenCV but the separate library.

This is most likely not a bug. You must hold the vectors that are being indexed by FLANN in memory.
As long as `ind` is valid, `feavec` must contain the vectors and must not be released.

#2
Updated by Lichao Chen over 12 years ago

Yes, you are right, and I did keep feavec unreleased, the problem is that, besides the data vector(which is feavec here), the flann also generates some index info, which is stored in void* index, and it will be released once the local copy is not accessible. I resolved this problem by using
+ Index *ind;
- Index *ind;

+ ind = new Index(feavec, parms);
- ind = Index(feavec, parms);

So instead of doing a Index object copy, I just assign the pointer here, and it works now.

Stefan R wrote:

Disclaimer: I have not used that FLANN part of OpenCV but the separate library.

This is most likely not a bug. You must hold the vectors that are being indexed by FLANN in memory.
As long as `ind` is valid, `feavec` must contain the vectors and must not be released.

#3
Updated by Andrey Kamaev over 12 years ago

Close as not a bug.

  • Target version set to 2.4.4
  • Status changed from Open to Cancelled

#5
Updated by Lichao Chen over 12 years ago

http://code.opencv.org/issues/2050
Then you should also close this one. they are identical
Andrey Kamaev wrote:

Close as not a bug.

#6
Updated by Andrey Kamaev over 12 years ago

That issue has a good point about documentation update. So lets keep it open.
I've marked this as a duplicate of #2050

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