错误？使用findContours（）时增加每次迭代的内存使用量

时间：2013-08-21 00:14:48

标签： c++ opencv

我一直试图调试一个月，确定这是我糟糕的编程习惯，但我认为这可能是一个错误，所以在我报告之前我先问这里。

请考虑以下代码：

#include <sys/resource.h> // memory management.
#include <stdio.h>
#include <iostream>
#include <iomanip>

#include "opencv2/highgui/highgui.hpp"
#include "opencv2/core/core.hpp"
#include "opencv2/imgproc/imgproc.hpp"
#include "opencv2/video/background_segm.hpp"

using namespace std;
using namespace cv;

// Load frame from disk.
void readFrame(int frameNum, Mat &frame) {
    // Construct filenames
    Mat image;
    stringstream number, filename;

    number << setw(7) << setfill('0') << frameNum; // expecting over 1e10 images over the installation period.
    filename << "../images/store-" << number.str() << ".jpg"; // assumes jpegs!//
    cout << "Loading filename: " << filename.str() << endl;

    image = imread( filename.str() );

    if (image.empty() or !image.data) {
        cout << "Input image empty:\n";
    }

    frame = image.clone();
}

// Class to hold the perceptual chunks.
class percepUnit {

    public:
        cv::Mat image; // percept itself
        cv::Mat mask; // alpha channel

        // constructor method
        percepUnit(cv::Mat &ROI, cv::Mat &alpha, int ix, int iy, int iw, int ih, int area)  {
            image = ROI.clone();
            mask = alpha.clone();
        }
};

// Segment foreground from background
void segmentForeground(list<percepUnit*> &percepUnitsForeground, Mat &foreground, Mat &frame) {
    Mat contourImage = Mat(foreground.rows, foreground.cols, CV_8UC1, Scalar::all(0));
    vector<vector<Point>> contours;
    int area;

    // The following causes strange spikes in memory usage:
    // find contours
    findContours(foreground, contours, CV_RETR_EXTERNAL, CV_CHAIN_APPROX_SIMPLE);

    for (int idx = 0; idx < contours.size(); idx++) {

        area = contourArea(contours[idx]);

        if (area > 100) {

            percepUnit *thisUnit = new percepUnit(frame, contourImage, 0, 0, 100,100, area);
            percepUnitsForeground.push_back(thisUnit); // Append to percepUnits
        }
    }

    /* The following does not:
    findContours(foreground, contours, CV_RETR_EXTERNAL, CV_CHAIN_APPROX_SIMPLE);

    for (int idx = 0; idx < contours.size(); idx++) {
        area = contourArea(contours[idx]);
    }*/

    /* Neither does this:
    for (int idx = 0; idx < 10; idx++) {
        percepUnit *thisUnit = new percepUnit(frame, contourImage, 0, 0, 100,100, area);
        percepUnitsForeground.push_back(thisUnit); // Append to percepUnits
    }*/
}

int main(int argc, const char** argv)
{
    int frameCount = 78298; 
    Mat frame, foreground;
    BackgroundSubtractorMOG2 MOG2model;
    list<percepUnit*> scratchPercepUnitsForeground;

    // add rusage stuff
    struct rusage usage; // memory usage.

    for(int i=0; i<= 75; i++)
    {
        // run full segmenter here.  (background disabled)

        readFrame(frameCount, frame); // was frame = readFrame();

        // Only process if this frame actually loaded (non empty)
        if ( not frame.empty() ) {

            MOG2model(frame,foreground); // Update MOG2 model, downscale?

            // before we segment again clear scratch
            // TODO how to delete the actual memory allocated? Run delete on everything?
            for (list<percepUnit*>::iterator percepIter = scratchPercepUnitsForeground.begin(); 
                 percepIter != scratchPercepUnitsForeground.end();
                 percepIter++) {

                delete *percepIter; // delete what we point to.
                //percepIter = scratchPercepUnitsForeground.erase(percepIter); // remove the pointer itself, and update the iterator.
            }
            // Added with EDIT1
            scratchPercepUnitsForeground.clear();

            // Segment the foreground regions and generate boolImage to extract from background.
            segmentForeground(scratchPercepUnitsForeground, foreground, frame);

        }

        frameCount++;

        getrusage(RUSAGE_SELF, &usage);
        cout << "DEBUG leakTest_bug_report " << i << " " << usage.ru_maxrss/1024.0 << endl;
    }

    return 0;
}

如果您使用此处提供的图像（http://www.ekran.org/tmp/images.tar.gz），您会发现程序的内存使用量增加，并且它似乎随着前景轮廓的数量而增加。由于我正在清除每个帧的存储空间（scratchPercepUnitsForeground），我不明白为什么应该增加内存使用量。 segmentForeground（）函数应退出，为每个帧释放所有已用内存。由于我们仅在函数退出后检查内存使用情况，因此内存使用量应该随时间保持不变。似乎有些东西遗留下来，我无法弄明白。

如果我在没有percepUnit（）构造函数的情况下运行findContours（）部分，则内存使用量是不变的，正如我所期望的那样。如果我只运行不带findContours（）的percepUnit（）构造函数，则内存使用量是不变的。只有当我同时使用时才会增加内存使用量请参阅上面的segmentForeground（）中的注释代码。

我已经在我的两台机器（AMD64，linux）和运行opencv 2.4.6.1和2.4.5上确认了这个问题。

EDIT1

上面的代码已更改为包含以下建议，但问题仍然存在。

这是内存增加的样子：

Memory Usage http://www.ekran.org/tmp/memory.png

红线是在调用findContours（）和构造函数时看到的内存增加（ 与上面链接的测试图像相关）。下面的稳定行是我们运行findContours（）或构造函数的两种情况。

Valgrind输出

==2055== Memcheck, a memory error detector
==2055== Copyright (C) 2002-2011, and GNU GPL'd, by Julian Seward et al.
==2055== Using Valgrind-3.7.0 and LibVEX; rerun with -h for copyright info
==2055== Command: ./leakTest
==2055== 
==2055== 
==2055== HEAP SUMMARY:
==2055==     in use at exit: 217,751,704 bytes in 112 blocks
==2055==   total heap usage: 800,066 allocs, 799,954 frees, 29,269,767,865 bytes allocated
==2055== 
==2055== 568 bytes in 1 blocks are still reachable in loss record 1 of 12
==2055==    at 0x4C2B6CD: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==2055==    by 0x63A720A: __fopen_internal (iofopen.c:76)
==2055==    by 0xA8BC050: libjpeg_general_init (in /usr/lib/x86_64-linux-gnu/libjpeg.so.8.0.2)
==2055==    by 0x400F305: call_init.part.0 (dl-init.c:85)
==2055==    by 0x400F3DE: _dl_init (dl-init.c:52)
==2055==    by 0x40016E9: ??? (in /lib/x86_64-linux-gnu/ld-2.15.so)
==2055== 
==2055== 2,072 bytes in 1 blocks are still reachable in loss record 2 of 12
==2055==    at 0x4C2B6CD: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==2055==    by 0x1495F675: ??? (in /usr/lib/x86_64-linux-gnu/libpixman-1.so.0.24.4)
==2055==    by 0x1495E4AE: ??? (in /usr/lib/x86_64-linux-gnu/libpixman-1.so.0.24.4)
==2055==    by 0x14950888: ??? (in /usr/lib/x86_64-linux-gnu/libpixman-1.so.0.24.4)
==2055==    by 0x149253B8: ??? (in /usr/lib/x86_64-linux-gnu/libpixman-1.so.0.24.4)
==2055==    by 0x400F305: call_init.part.0 (dl-init.c:85)
==2055==    by 0x400F3DE: _dl_init (dl-init.c:52)
==2055==    by 0x40016E9: ??? (in /lib/x86_64-linux-gnu/ld-2.15.so)
==2055== 
==2055== 2,072 bytes in 1 blocks are still reachable in loss record 3 of 12
==2055==    at 0x4C2B6CD: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==2055==    by 0x1495F675: ??? (in /usr/lib/x86_64-linux-gnu/libpixman-1.so.0.24.4)
==2055==    by 0x1495E0EF: ??? (in /usr/lib/x86_64-linux-gnu/libpixman-1.so.0.24.4)
==2055==    by 0x14950890: ??? (in /usr/lib/x86_64-linux-gnu/libpixman-1.so.0.24.4)
==2055==    by 0x149253B8: ??? (in /usr/lib/x86_64-linux-gnu/libpixman-1.so.0.24.4)
==2055==    by 0x400F305: call_init.part.0 (dl-init.c:85)
==2055==    by 0x400F3DE: _dl_init (dl-init.c:52)
==2055==    by 0x40016E9: ??? (in /lib/x86_64-linux-gnu/ld-2.15.so)
==2055== 
==2055== 2,072 bytes in 1 blocks are still reachable in loss record 4 of 12
==2055==    at 0x4C2B6CD: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==2055==    by 0x1495F675: ??? (in /usr/lib/x86_64-linux-gnu/libpixman-1.so.0.24.4)
==2055==    by 0x14971A6F: ??? (in /usr/lib/x86_64-linux-gnu/libpixman-1.so.0.24.4)
==2055==    by 0x14950898: ??? (in /usr/lib/x86_64-linux-gnu/libpixman-1.so.0.24.4)
==2055==    by 0x149253B8: ??? (in /usr/lib/x86_64-linux-gnu/libpixman-1.so.0.24.4)
==2055==    by 0x400F305: call_init.part.0 (dl-init.c:85)
==2055==    by 0x400F3DE: _dl_init (dl-init.c:52)
==2055==    by 0x40016E9: ??? (in /lib/x86_64-linux-gnu/ld-2.15.so)
==2055== 
==2055== 2,072 bytes in 1 blocks are still reachable in loss record 5 of 12
==2055==    at 0x4C2B6CD: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==2055==    by 0x1495F675: ??? (in /usr/lib/x86_64-linux-gnu/libpixman-1.so.0.24.4)
==2055==    by 0x1499024F: ??? (in /usr/lib/x86_64-linux-gnu/libpixman-1.so.0.24.4)
==2055==    by 0x149508A0: ??? (in /usr/lib/x86_64-linux-gnu/libpixman-1.so.0.24.4)
==2055==    by 0x149253B8: ??? (in /usr/lib/x86_64-linux-gnu/libpixman-1.so.0.24.4)
==2055==    by 0x400F305: call_init.part.0 (dl-init.c:85)
==2055==    by 0x400F3DE: _dl_init (dl-init.c:52)
==2055==    by 0x40016E9: ??? (in /lib/x86_64-linux-gnu/ld-2.15.so)
==2055== 
==2055== 2,072 bytes in 1 blocks are still reachable in loss record 6 of 12
==2055==    at 0x4C2B6CD: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==2055==    by 0x1495F675: ??? (in /usr/lib/x86_64-linux-gnu/libpixman-1.so.0.24.4)
==2055==    by 0x149610EF: ??? (in /usr/lib/x86_64-linux-gnu/libpixman-1.so.0.24.4)
==2055==    by 0x149253B8: ??? (in /usr/lib/x86_64-linux-gnu/libpixman-1.so.0.24.4)
==2055==    by 0x400F305: call_init.part.0 (dl-init.c:85)
==2055==    by 0x400F3DE: _dl_init (dl-init.c:52)
==2055==    by 0x40016E9: ??? (in /lib/x86_64-linux-gnu/ld-2.15.so)
==2055== 
==2055== 4,096 bytes in 1 blocks are still reachable in loss record 7 of 12
==2055==    at 0x4C2B6CD: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==2055==    by 0xA8BC067: libjpeg_general_init (in /usr/lib/x86_64-linux-gnu/libjpeg.so.8.0.2)
==2055==    by 0x400F305: call_init.part.0 (dl-init.c:85)
==2055==    by 0x400F3DE: _dl_init (dl-init.c:52)
==2055==    by 0x40016E9: ??? (in /lib/x86_64-linux-gnu/ld-2.15.so)
==2055== 
==2055== 1,555,228 bytes in 1 blocks are possibly lost in loss record 8 of 12
==2055==    at 0x4C2B6CD: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==2055==    by 0x4E87A90: cv::fastMalloc(unsigned long) (in /usr/local/lib/libopencv_core.so.2.4.5)
==2055==    by 0x4ECDBF1: cv::Mat::create(int, int const*, int) (in /usr/local/lib/libopencv_core.so.2.4.5)
==2055==    by 0x4ECE378: cv::_OutputArray::create(int, int, int, int, bool, int) const (in /usr/local/lib/libopencv_core.so.2.4.5)
==2055==    by 0x4F52F7D: cv::Mat::copyTo(cv::_OutputArray const&) const (in /usr/local/lib/libopencv_core.so.2.4.5)
==2055==    by 0x40253C: cv::Mat::clone() const (mat.hpp:335)
==2055==    by 0x4028D5: percepUnit::percepUnit(cv::Mat&, cv::Mat&, int, int, int, int, int) (leakTest.cpp:43)
==2055==    by 0x401E0E: segmentForeground(std::list<percepUnit*, std::allocator<percepUnit*> >&, cv::Mat&, cv::Mat&) (leakTest.cpp:63)
==2055==    by 0x40202D: main (leakTest.cpp:114)
==2055== 
==2055== 37,325,024 bytes in 8 blocks are possibly lost in loss record 9 of 12
==2055==    at 0x4C2B6CD: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==2055==    by 0x4E87A90: cv::fastMalloc(unsigned long) (in /usr/local/lib/libopencv_core.so.2.4.5)
==2055==    by 0x4ECDBF1: cv::Mat::create(int, int const*, int) (in /usr/local/lib/libopencv_core.so.2.4.5)
==2055==    by 0x4ECE378: cv::_OutputArray::create(int, int, int, int, bool, int) const (in /usr/local/lib/libopencv_core.so.2.4.5)
==2055==    by 0x4F52F7D: cv::Mat::copyTo(cv::_OutputArray const&) const (in /usr/local/lib/libopencv_core.so.2.4.5)
==2055==    by 0x40253C: cv::Mat::clone() const (mat.hpp:335)
==2055==    by 0x402897: percepUnit::percepUnit(cv::Mat&, cv::Mat&, int, int, int, int, int) (leakTest.cpp:42)
==2055==    by 0x401E0E: segmentForeground(std::list<percepUnit*, std::allocator<percepUnit*> >&, cv::Mat&, cv::Mat&) (leakTest.cpp:63)
==2055==    by 0x40202D: main (leakTest.cpp:114)
==2055== 
==2055== 52,877,752 bytes in 34 blocks are indirectly lost in loss record 10 of 12
==2055==    at 0x4C2B6CD: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==2055==    by 0x4E87A90: cv::fastMalloc(unsigned long) (in /usr/local/lib/libopencv_core.so.2.4.5)
==2055==    by 0x4ECDBF1: cv::Mat::create(int, int const*, int) (in /usr/local/lib/libopencv_core.so.2.4.5)
==2055==    by 0x4ECE378: cv::_OutputArray::create(int, int, int, int, bool, int) const (in /usr/local/lib/libopencv_core.so.2.4.5)
==2055==    by 0x4F52F7D: cv::Mat::copyTo(cv::_OutputArray const&) const (in /usr/local/lib/libopencv_core.so.2.4.5)
==2055==    by 0x40253C: cv::Mat::clone() const (mat.hpp:335)
==2055==    by 0x4028D5: percepUnit::percepUnit(cv::Mat&, cv::Mat&, int, int, int, int, int) (leakTest.cpp:43)
==2055==    by 0x401E0E: segmentForeground(std::list<percepUnit*, std::allocator<percepUnit*> >&, cv::Mat&, cv::Mat&) (leakTest.cpp:63)
==2055==    by 0x40202D: main (leakTest.cpp:114)
==2055== 
==2055== 125,971,956 bytes in 27 blocks are indirectly lost in loss record 11 of 12
==2055==    at 0x4C2B6CD: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==2055==    by 0x4E87A90: cv::fastMalloc(unsigned long) (in /usr/local/lib/libopencv_core.so.2.4.5)
==2055==    by 0x4ECDBF1: cv::Mat::create(int, int const*, int) (in /usr/local/lib/libopencv_core.so.2.4.5)
==2055==    by 0x4ECE378: cv::_OutputArray::create(int, int, int, int, bool, int) const (in /usr/local/lib/libopencv_core.so.2.4.5)
==2055==    by 0x4F52F7D: cv::Mat::copyTo(cv::_OutputArray const&) const (in /usr/local/lib/libopencv_core.so.2.4.5)
==2055==    by 0x40253C: cv::Mat::clone() const (mat.hpp:335)
==2055==    by 0x402897: percepUnit::percepUnit(cv::Mat&, cv::Mat&, int, int, int, int, int) (leakTest.cpp:42)
==2055==    by 0x401E0E: segmentForeground(std::list<percepUnit*, std::allocator<percepUnit*> >&, cv::Mat&, cv::Mat&) (leakTest.cpp:63)
==2055==    by 0x40202D: main (leakTest.cpp:114)
==2055== 
==2055== 178,856,428 (6,720 direct, 178,849,708 indirect) bytes in 35 blocks are definitely lost in loss record 12 of 12
==2055==    at 0x4C2B1C7: operator new(unsigned long) (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==2055==    by 0x401DD3: segmentForeground(std::list<percepUnit*, std::allocator<percepUnit*> >&, cv::Mat&, cv::Mat&) (leakTest.cpp:63)
==2055==    by 0x40202D: main (leakTest.cpp:114)
==2055== 
==2055== LEAK SUMMARY:
==2055==    definitely lost: 6,720 bytes in 35 blocks
==2055==    indirectly lost: 178,849,708 bytes in 61 blocks
==2055==      possibly lost: 38,880,252 bytes in 9 blocks
==2055==    still reachable: 15,024 bytes in 7 blocks
==2055==         suppressed: 0 bytes in 0 blocks
==2055== 
==2055== For counts of detected and suppressed errors, rerun with: -v
==2055== ERROR SUMMARY: 3 errors from 3 contexts (suppressed: 2 from 2)

所以基本上这似乎告诉我们，percepUnit构造函数中可能存在clone（）的问题。在没有findContours（）的情况下运行构造函数显示没有内存增加（如上所述），其中包括使用“new”。 jpeg阅读器也经过了单元测试，没有内存增加。因此，valgrind输出似乎没有任何帮助。

这应该是可重复的！在提供答案之前，请确保您可以重现它。

EDIT2（修订代码和valgrind输出，删除指针方法）

这里我已经从指向实例列表的指针列表中更改了列表。内存增加得到确认。

#include <sys/resource.h> // memory management.
#include <stdio.h>
#include <iostream>
#include <iomanip>

#include "opencv2/highgui/highgui.hpp"
#include "opencv2/core/core.hpp"
#include "opencv2/imgproc/imgproc.hpp"
#include "opencv2/video/background_segm.hpp"

using namespace std;
using namespace cv;

// Load frame from disk.
void readFrame(int frameNum, Mat &frame) {
    // Construct filenames
    Mat image;
    stringstream number, filename;

    number << setw(7) << setfill('0') << frameNum; // expecting over 1e10 images over the installation period.
    filename << "../images/store-" << number.str() << ".jpg"; // assumes jpegs!//
    cout << "Loading filename: " << filename.str() << endl;

    image = imread( filename.str() );

    if (image.empty() or !image.data) {
        cout << "Input image empty:\n";
    }

    frame = image.clone();
}

// Class to hold the perceptual chunks.
class percepUnit {

    public:
        cv::Mat image; // percept itself
        cv::Mat mask; // alpha channel

        // constructor method
        percepUnit(cv::Mat &ROI, cv::Mat &alpha, int ix, int iy, int iw, int ih, int area)  {
            image = ROI.clone();
            mask = alpha.clone();
        }
};

// Segment foreground from background
void segmentForeground(list<percepUnit> &percepUnitsForeground, Mat &foreground, Mat &frame) {
    Mat contourImage = Mat(foreground.rows, foreground.cols, CV_8UC1, Scalar::all(0));
    vector<vector<Point>> contours;
    int area;

    // The following causes strange spikes in memory usage:
    // find contours
    findContours(foreground, contours, CV_RETR_EXTERNAL, CV_CHAIN_APPROX_SIMPLE);

    for (int idx = 0; idx < contours.size(); idx++) {

        area = contourArea(contours[idx]);

        if (area > 100) {

            percepUnit thisUnit = percepUnit(frame, contourImage, 0, 0, 100,100, area);
            percepUnitsForeground.push_back(thisUnit); // Append to percepUnits
        }
    }

    /* The following does not:
    findContours(foreground, contours, CV_RETR_EXTERNAL, CV_CHAIN_APPROX_SIMPLE);

    for (int idx = 0; idx < contours.size(); idx++) {
        area = contourArea(contours[idx]);
    }*/

    /* Neither does this:
    for (int idx = 0; idx < 10; idx++) {
        percepUnit thisUnit = percepUnit(frame, contourImage, 0, 0, 100,100, area);
        percepUnitsForeground.push_back(thisUnit); // Append to percepUnits
    }*/
}

int main(int argc, const char** argv)
{
    int frameCount = 78298; 
    Mat frame, foreground;
    BackgroundSubtractorMOG2 MOG2model;
    list<percepUnit> scratchPercepUnitsForeground;

    // add rusage stuff
    struct rusage usage; // memory usage.

    for(int i=0; i<= 75; i++)
    {
        // run full segmenter here.  (background disabled)

        readFrame(frameCount, frame); // was frame = readFrame();

        // Only process if this frame actually loaded (non empty)
        if ( not frame.empty() ) {

            MOG2model(frame,foreground); // Update MOG2 model, downscale?

            // before we segment again clear scratch
            scratchPercepUnitsForeground.clear();

            // Segment the foreground regions and generate boolImage to extract from background.
            segmentForeground(scratchPercepUnitsForeground, foreground, frame);

        }

        frameCount++;

        getrusage(RUSAGE_SELF, &usage);
        cout << "DEBUG leakTest_bug_report " << i << " " << usage.ru_maxrss/1024.0 << endl;
    }

    return 0;
}

这是相应的valgrind输出：

==3562== Memcheck, a memory error detector
==3562== Copyright (C) 2002-2011, and GNU GPL'd, by Julian Seward et al.
==3562== Using Valgrind-3.7.0 and LibVEX; rerun with -h for copyright info
==3562== Command: ./leakTest
==3562== 
==3562== 
==3562== HEAP SUMMARY:
==3562==     in use at exit: 15,024 bytes in 7 blocks
==3562==   total heap usage: 795,556 allocs, 795,549 frees, 29,269,731,785 bytes allocated
==3562== 
==3562== 568 bytes in 1 blocks are still reachable in loss record 1 of 7
==3562==    at 0x4C2B6CD: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==3562==    by 0x63A720A: __fopen_internal (iofopen.c:76)
==3562==    by 0xA8BC050: libjpeg_general_init (in /usr/lib/x86_64-linux-gnu/libjpeg.so.8.0.2)
==3562==    by 0x400F305: call_init.part.0 (dl-init.c:85)
==3562==    by 0x400F3DE: _dl_init (dl-init.c:52)
==3562==    by 0x40016E9: ??? (in /lib/x86_64-linux-gnu/ld-2.15.so)
==3562== 
==3562== 2,072 bytes in 1 blocks are still reachable in loss record 2 of 7
==3562==    at 0x4C2B6CD: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==3562==    by 0x1495F675: ??? (in /usr/lib/x86_64-linux-gnu/libpixman-1.so.0.24.4)
==3562==    by 0x1495E4AE: ??? (in /usr/lib/x86_64-linux-gnu/libpixman-1.so.0.24.4)
==3562==    by 0x14950888: ??? (in /usr/lib/x86_64-linux-gnu/libpixman-1.so.0.24.4)
==3562==    by 0x149253B8: ??? (in /usr/lib/x86_64-linux-gnu/libpixman-1.so.0.24.4)
==3562==    by 0x400F305: call_init.part.0 (dl-init.c:85)
==3562==    by 0x400F3DE: _dl_init (dl-init.c:52)
==3562==    by 0x40016E9: ??? (in /lib/x86_64-linux-gnu/ld-2.15.so)
==3562== 
==3562== 2,072 bytes in 1 blocks are still reachable in loss record 3 of 7
==3562==    at 0x4C2B6CD: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==3562==    by 0x1495F675: ??? (in /usr/lib/x86_64-linux-gnu/libpixman-1.so.0.24.4)
==3562==    by 0x1495E0EF: ??? (in /usr/lib/x86_64-linux-gnu/libpixman-1.so.0.24.4)
==3562==    by 0x14950890: ??? (in /usr/lib/x86_64-linux-gnu/libpixman-1.so.0.24.4)
==3562==    by 0x149253B8: ??? (in /usr/lib/x86_64-linux-gnu/libpixman-1.so.0.24.4)
==3562==    by 0x400F305: call_init.part.0 (dl-init.c:85)
==3562==    by 0x400F3DE: _dl_init (dl-init.c:52)
==3562==    by 0x40016E9: ??? (in /lib/x86_64-linux-gnu/ld-2.15.so)
==3562== 
==3562== 2,072 bytes in 1 blocks are still reachable in loss record 4 of 7
==3562==    at 0x4C2B6CD: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==3562==    by 0x1495F675: ??? (in /usr/lib/x86_64-linux-gnu/libpixman-1.so.0.24.4)
==3562==    by 0x14971A6F: ??? (in /usr/lib/x86_64-linux-gnu/libpixman-1.so.0.24.4)
==3562==    by 0x14950898: ??? (in /usr/lib/x86_64-linux-gnu/libpixman-1.so.0.24.4)
==3562==    by 0x149253B8: ??? (in /usr/lib/x86_64-linux-gnu/libpixman-1.so.0.24.4)
==3562==    by 0x400F305: call_init.part.0 (dl-init.c:85)
==3562==    by 0x400F3DE: _dl_init (dl-init.c:52)
==3562==    by 0x40016E9: ??? (in /lib/x86_64-linux-gnu/ld-2.15.so)
==3562== 
==3562== 2,072 bytes in 1 blocks are still reachable in loss record 5 of 7
==3562==    at 0x4C2B6CD: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==3562==    by 0x1495F675: ??? (in /usr/lib/x86_64-linux-gnu/libpixman-1.so.0.24.4)
==3562==    by 0x1499024F: ??? (in /usr/lib/x86_64-linux-gnu/libpixman-1.so.0.24.4)
==3562==    by 0x149508A0: ??? (in /usr/lib/x86_64-linux-gnu/libpixman-1.so.0.24.4)
==3562==    by 0x149253B8: ??? (in /usr/lib/x86_64-linux-gnu/libpixman-1.so.0.24.4)
==3562==    by 0x400F305: call_init.part.0 (dl-init.c:85)
==3562==    by 0x400F3DE: _dl_init (dl-init.c:52)
==3562==    by 0x40016E9: ??? (in /lib/x86_64-linux-gnu/ld-2.15.so)
==3562== 
==3562== 2,072 bytes in 1 blocks are still reachable in loss record 6 of 7
==3562==    at 0x4C2B6CD: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==3562==    by 0x1495F675: ??? (in /usr/lib/x86_64-linux-gnu/libpixman-1.so.0.24.4)
==3562==    by 0x149610EF: ??? (in /usr/lib/x86_64-linux-gnu/libpixman-1.so.0.24.4)
==3562==    by 0x149253B8: ??? (in /usr/lib/x86_64-linux-gnu/libpixman-1.so.0.24.4)
==3562==    by 0x400F305: call_init.part.0 (dl-init.c:85)
==3562==    by 0x400F3DE: _dl_init (dl-init.c:52)
==3562==    by 0x40016E9: ??? (in /lib/x86_64-linux-gnu/ld-2.15.so)
==3562== 
==3562== 4,096 bytes in 1 blocks are still reachable in loss record 7 of 7
==3562==    at 0x4C2B6CD: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==3562==    by 0xA8BC067: libjpeg_general_init (in /usr/lib/x86_64-linux-gnu/libjpeg.so.8.0.2)
==3562==    by 0x400F305: call_init.part.0 (dl-init.c:85)
==3562==    by 0x400F3DE: _dl_init (dl-init.c:52)
==3562==    by 0x40016E9: ??? (in /lib/x86_64-linux-gnu/ld-2.15.so)
==3562== 
==3562== LEAK SUMMARY:
==3562==    definitely lost: 0 bytes in 0 blocks
==3562==    indirectly lost: 0 bytes in 0 blocks
==3562==      possibly lost: 0 bytes in 0 blocks
==3562==    still reachable: 15,024 bytes in 7 blocks
==3562==         suppressed: 0 bytes in 0 blocks
==3562== 
==3562== For counts of detected and suppressed errors, rerun with: -v
==3562== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 2 from 2)

然而，记忆仍然无法解释地增加:(从之前的情节总体增加是由于在valgrind中运行此测试。）

memory usage http://www.ekran.org/tmp/memory2.png

对于相同的代码，这里是massif输出：http://www.ekran.org/tmp/massif.print.leak 没有调用findContours（）的非泄漏情况的massif输出，只有percepUnit构造函数：http://www.ekran.org/tmp/massif.print.noLeak

EDIT3

在跨线程（http://answers.opencv.org/question/19172/bug-increasing-memory-usage-per-iteration-when/）中建议我读取proc而不是使用rusage方法，看看这个，内存不会稳定增加：（！）

memory usage http://www.ekran.org/tmp/memory_proc.png

这看起来与地块输出相似!!所以我想我需要重做所有的单元测试。任何人都有理由我不应该放弃这个问题来考虑问题吗？

4 个答案:

答案 0 :(得分：4)

ptr-list清理的for循环正在跳过项目，因为在循环体本身中同时包含increment子句（percepIter++）和迭代器重新分配（来自{{1}的返回值）呼叫）。

换句话说，你是对迭代器进行双倍递增，跳过每个偶数时段的项目。

我在下面标记了它：

erase()

您可以通过多种方式解决此问题。例如，通过从for循环中删除增量表达式：

        for (list<percepUnit*>::iterator percepIter = scratchPercepUnitsForeground.begin(); 
             percepIter != scratchPercepUnitsForeground.end();
             percepIter++) { // ADVANCES ITERATOR

            delete *percepIter; // delete what we point to.
            percepIter = scratchPercepUnitsForeground.erase(percepIter); // ADVANCES ITERATOR
        }

同样，您可以简单地枚举列表，然后在释放所有指向对象后调用列表 for (list<percepUnit*>::iterator percepIter = scratchPercepUnitsForeground.begin(); percepIter != scratchPercepUnitsForeground.end();) { delete *percepIter; // delete what we point to. percepIter = scratchPercepUnitsForeground.erase(percepIter); } 方法。

clear()

就个人而言，如果我不得不选择其中一个，我更喜欢后者。除其他外，它更快，更易读。

但是如果我编码这个我会使用智能指针，这会使这完全无关紧要，因为你可以简单地解雇 for (list<percepUnit*>::iterator percepIter = scratchPercepUnitsForeground.begin(); percepIter != scratchPercepUnitsForeground.end(); ++percepIter) { delete *percepIter; } scratchPercepUnitsForeground.clear(); 并完成它。清除列表内容后，所有智能指针析构函数都将触发，然后它们将为您删除其对象。这个概念被称为资源获取初始化（简称RAII），它简单地表示包括动态分配在内的所有事物都具有基于范围的生命周期，并在范围退出时自动回收资源。 You can read more about it here

无论如何，那些肯定泄漏的地方，以及根据事物的外观判断的重要事件。

答案 1 :(得分：2)

对我来说，使用rusage进行图表分析会单调增加这一事实是值得怀疑的。

rusage州的文件：

  

使用的最大驻留集大小，以千字节为单位。也就是说，同时处理的物理内存的最大千字节数。

由于您可能只针对多个图像收集同一过程的统计信息，因此rusage报告所有图像中的最大内存使用量的结论是有意义的。

实际上，使用不同的分析工具（OS X上的Instruments）会生成显示当前内存使用情况的图表：

Memory allocations

这与使用proc的结果非常相似。我的结论是rusage不是你想要的分析工具。

答案 2 :(得分：1)

我在谷歌搜索后发现了这个问题似乎是同样的问题（valgrind使用包含_dl_init和libpixman-1的回溯报告“仍然可以访问”内存）。我正在使用64位的Fedora 18。我设法用绝对最小的C可执行文件和.so库重现问题... C程序只有一个返回0的主函数，而.so只有一个函数（从未实际调用过），它也会立即退出然而，valgrind仍然报告了5个不同的块，共计10,360个字节。我决定发布这个以防其他一些可怜的灵魂用了一个月调试同样的问题！无论是什么错误，它似乎不太可能是由可执行文件和库引起的，两者都不起作用。

答案 3 :(得分：0)

在进一步研究中，当我在Ubuntu 13.04（GCC 4.7.3，与Fedora 18的GCC 4.7.2相比）上重新编译可执行文件和.so文件时，内存泄漏消失了。我没有做任何其他更改所以问题肯定不是我的代码。即使在我将它转移回Fedora机器之后，固定的.so仍然是完美的。我建议使用较新版本的gcc重新编译您正在使用的任何/所有共享对象。至于内存使用量随时间增加的问题，我不知道，因为我的项目非常小，分配的内存很少，并且很快就会退出。

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