Ask Your Question

Invalid pointer, double free or corruption

asked 2013-05-25 01:54:15 -0600

ben2316 gravatar image

I'm reading in many images to do feature extraction and training for an SVM, and I keep getting seemingly random segmentation faults when the code reads in over X images and tries to release a Mat object from a function:

*** glibc detected *** /home/.../build/test: free(): invalid pointer: 0x0000000001bd3100 ***
======= Backtrace: =========


(gdb) bt
0  0x00007ffff6586425 in __GI_raise (sig=<optimized out>) at ../nptl/sysdeps/unix/sysv/linux/raise.c:64
#1  0x00007ffff6589b8b in __GI_abort () at abort.c:91
#2  0x00007ffff65c439e in __libc_message (do_abort=2, fmt=0x7ffff66ce008 "*** glibc detected *** %s: %s: 0x%s ***\n")
at ../sysdeps/unix/sysv/linux/libc_fatal.c:201
#3  0x00007ffff65ceb96 in malloc_printerr (action=3, str=0x7ffff66ca913 "free(): invalid pointer", ptr=<optimized out>)
at malloc.c:5018
#4  0x000000000040de29 in cv::Mat::release (this=0x7fffffffd420) at /usr/local/include/opencv2/core/mat.hpp:367
#5  0x000000000040dae2 in cv::Mat::~Mat (this=0x7fffffffd420, __in_chrg=<optimized out>)
at /usr/local/include/opencv2/core/mat.hpp:276
#6  0x000000000040c568 in getMask (input=...) at /home/.../test.cpp:109
#7  0x000000000040d0bd in main (argc=2, argv=0x7fffffffe258) at /home/.../test.cpp:195

test.cpp:109 is the last line of this code block (return finalMask):

Mat getMask(Mat input)
  Mat finalMask;
  const Size ksize(14,14);
  morphologyEx(realMask, finalMask, MORPH_CLOSE, getStructuringElement(MORPH_ELLIPSE, ksize));
  const double thresh = 255.0 / 2.0;
  const double maxval = 255.0;
  threshold(finalMask, finalMask, thresh, maxval, THRESH_BINARY);
  return finalMask;

I've been trying to narrow down the problem, but I can't seem to figure it out. In some examples, it fails on consistently on the 423rd image read in. Other times when I changed the code, it failed consistently on the 547th image. Can anyone point me in the right direction to debug this problem?

edit retag flag offensive close merge delete


forgot to mention that in some instances the error was "double free or corruption"

ben2316 gravatar imageben2316 ( 2013-05-25 01:55:58 -0600 )edit

1 answer

Sort by ยป oldest newest most voted

answered 2013-05-28 19:21:01 -0600

ben2316 gravatar image

updated 2013-05-28 19:21:48 -0600

I think I solved my problem. In the code below, I kept reassigning the Mat variable image while looping through sub-directories of images.

Mat image;
for(directory_iterator di(dirPath); di != directory_iterator(); di++)
  // read in file
    for(directory_iterator j(di->path()); j != directory_iterator(); j++)
      image = imread(j->path().c_str(), CV_LOAD_IMAGE_COLOR);
      Mat maskImage = getMask(image);

When I declared image in the innermost for-loop, I stopped having problems. Can anyone explain why reassigning image multiple times would eventually cause memory problems?

edit flag offensive delete link more

Question Tools


Asked: 2013-05-25 01:54:15 -0600

Seen: 2,939 times

Last updated: May 28 '13