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6
7             How To Track Down Suspected Memory Leaks in libcurl
8             ===================================================
9
10Single-threaded
11
12  Please note that this memory leak system is not adjusted to work in more
13  than one thread. If you want/need to use it in a multi-threaded app. Please
14  adjust accordingly.
15
16
17Build
18
19  Rebuild libcurl with -DCURLDEBUG (usually, rerunning configure with
20  --enable-debug fixes this). 'make clean' first, then 'make' so that all
21  files actually are rebuilt properly. It will also make sense to build
22  libcurl with the debug option (usually -g to the compiler) so that debugging
23  it will be easier if you actually do find a leak in the library.
24
25  This will create a library that has memory debugging enabled.
26
27Modify Your Application
28
29  Add a line in your application code:
30
31       curl_memdebug("dump");
32
33  This will make the malloc debug system output a full trace of all resource
34  using functions to the given file name. Make sure you rebuild your program
35  and that you link with the same libcurl you built for this purpose as
36  described above.
37
38Run Your Application
39
40  Run your program as usual. Watch the specified memory trace file grow.
41
42  Make your program exit and use the proper libcurl cleanup functions etc. So
43  that all non-leaks are returned/freed properly.
44
45Analyze the Flow
46
47  Use the tests/memanalyze.pl perl script to analyze the dump file:
48
49    tests/memanalyze.pl dump
50
51  This now outputs a report on what resources that were allocated but never
52  freed etc. This report is very fine for posting to the list!
53
54  If this doesn't produce any output, no leak was detected in libcurl. Then
55  the leak is mostly likely to be in your code.
56