2

次のコードは正しくコンパイルされ、valgrindはリークを報告しません。

# include <libxml/encoding.h>
# include <libxml/xmlwriter.h>

int main(void) {
  xmlTextWriterPtr XMLWriter = xmlNewTextWriterFilename("example.xml", 0);
  xmlTextWriterStartDocument(XMLWriter, NULL, NULL, NULL);
  xmlTextWriterEndDocument(XMLWriter);
  xmlFreeTextWriter(XMLWriter);
  xmlCleanupParser();
  return 0;
}

-----------------------------------------

==26059== HEAP SUMMARY:
==26059==     in use at exit: 0 bytes in 0 blocks
==26059==   total heap usage: 16 allocs, 16 frees, 4,774 bytes allocated
==26059== 
==26059== All heap blocks were freed -- no leaks are possible

ただし、xmlNewTextWriterFilename呼び出しでエンコーディングが指定されると、次のようになります。

# include <libxml/encoding.h>
# include <libxml/xmlwriter.h>

int main(void) {
  xmlTextWriterPtr XMLWriter = xmlNewTextWriterFilename("example.xml", 0);
  xmlTextWriterStartDocument(XMLWriter, NULL, "UTF-8", NULL);
  xmlTextWriterEndDocument(XMLWriter);
  xmlFreeTextWriter(XMLWriter);
  xmlCleanupParser();
  return 0;
}

-----------------------------------------

==26082== HEAP SUMMARY:
==26082==     in use at exit: 422 bytes in 17 blocks
==26082==   total heap usage: 36 allocs, 19 frees, 9,224 bytes allocated
==26082== 
==26082== 5 bytes in 1 blocks are still reachable in loss record 1 of 17
==26082==    at 0x402BE68: malloc (in /usr/lib/valgrind/vgpreload_memcheck-x86-linux.so)
==26082==    by 0x40EC23B: xmlStrndup (in /usr/lib/i386-linux-gnu/libxml2.so.2.7.8)
==26082==    by 0x494942FF: ???
==26082== 
==26082== 6 bytes in 1 blocks are still reachable in loss record 2 of 17
==26082==    at 0x402BE68: malloc (in /usr/lib/valgrind/vgpreload_memcheck-x86-linux.so)
==26082==    by 0x40EC23B: xmlStrndup (in /usr/lib/i386-linux-gnu/libxml2.so.2.7.8)
==26082==    by 0x37: ???
==26082== 
==26082== 6 bytes in 1 blocks are still reachable in loss record 3 of 17
==26082==    at 0x402BE68: malloc (in /usr/lib/valgrind/vgpreload_memcheck-x86-linux.so)
==26082==    by 0x40EC23B: xmlStrndup (in /usr/lib/i386-linux-gnu/libxml2.so.2.7.8)
==26082==    by 0x39350048: ???
==26082== 
==26082== 7 bytes in 1 blocks are still reachable in loss record 4 of 17
==26082==    at 0x402BE68: malloc (in /usr/lib/valgrind/vgpreload_memcheck-x86-linux.so)
==26082==    by 0x40EC23B: xmlStrndup (in /usr/lib/i386-linux-gnu/libxml2.so.2.7.8)
==26082==    by 0x45003630: ???
==26082== 
==26082== 9 bytes in 1 blocks are still reachable in loss record 5 of 17
==26082==    at 0x402BE68: malloc (in /usr/lib/valgrind/vgpreload_memcheck-x86-linux.so)
==26082==    by 0x40EC23B: xmlStrndup (in /usr/lib/i386-linux-gnu/libxml2.so.2.7.8)
==26082==    by 0x454C3630: ???
==26082== 
==26082== 9 bytes in 1 blocks are still reachable in loss record 6 of 17
==26082==    at 0x402BE68: malloc (in /usr/lib/valgrind/vgpreload_memcheck-x86-linux.so)
==26082==    by 0x40EC23B: xmlStrndup (in /usr/lib/i386-linux-gnu/libxml2.so.2.7.8)
==26082==    by 0x45423630: ???
==26082== 
==26082== 9 bytes in 1 blocks are still reachable in loss record 7 of 17
==26082==    at 0x402BE68: malloc (in /usr/lib/valgrind/vgpreload_memcheck-x86-linux.so)
==26082==    by 0x40EC23B: xmlStrndup (in /usr/lib/i386-linux-gnu/libxml2.so.2.7.8)
==26082==    by 0x49494352: ???
==26082== 
==26082== 11 bytes in 1 blocks are still reachable in loss record 8 of 17
==26082==    at 0x402BE68: malloc (in /usr/lib/valgrind/vgpreload_memcheck-x86-linux.so)
==26082==    by 0x40EC23B: xmlStrndup (in /usr/lib/i386-linux-gnu/libxml2.so.2.7.8)
==26082==    by 0x39353837: ???
==26082== 
==26082== 20 bytes in 1 blocks are still reachable in loss record 9 of 17
==26082==    at 0x402BE68: malloc (in /usr/lib/valgrind/vgpreload_memcheck-x86-linux.so)
==26082==    by 0x406E9D1: xmlNewCharEncodingHandler (in /usr/lib/i386-linux-gnu/libxml2.so.2.7.8)
==26082==    by 0x406EB28: xmlInitCharEncodingHandlers (in /usr/lib/i386-linux-gnu/libxml2.so.2.7.8)
==26082==    by 0x41B54D2: (below main) (libc-start.c:226)
==26082== 
==26082== 20 bytes in 1 blocks are still reachable in loss record 10 of 17
==26082==    at 0x402BE68: malloc (in /usr/lib/valgrind/vgpreload_memcheck-x86-linux.so)
==26082==    by 0x406E9D1: xmlNewCharEncodingHandler (in /usr/lib/i386-linux-gnu/libxml2.so.2.7.8)
==26082==    by 0x406EB44: xmlInitCharEncodingHandlers (in /usr/lib/i386-linux-gnu/libxml2.so.2.7.8)
==26082==    by 0x41B54D2: (below main) (libc-start.c:226)
==26082== 
==26082== 20 bytes in 1 blocks are still reachable in loss record 11 of 17
==26082==    at 0x402BE68: malloc (in /usr/lib/valgrind/vgpreload_memcheck-x86-linux.so)
==26082==    by 0x406E9D1: xmlNewCharEncodingHandler (in /usr/lib/i386-linux-gnu/libxml2.so.2.7.8)
==26082==    by 0x406EB6C: xmlInitCharEncodingHandlers (in /usr/lib/i386-linux-gnu/libxml2.so.2.7.8)
==26082==    by 0x41B54D2: (below main) (libc-start.c:226)
==26082== 
==26082== 20 bytes in 1 blocks are still reachable in loss record 12 of 17
==26082==    at 0x402BE68: malloc (in /usr/lib/valgrind/vgpreload_memcheck-x86-linux.so)
==26082==    by 0x406E9D1: xmlNewCharEncodingHandler (in /usr/lib/i386-linux-gnu/libxml2.so.2.7.8)
==26082==    by 0x406EB94: xmlInitCharEncodingHandlers (in /usr/lib/i386-linux-gnu/libxml2.so.2.7.8)
==26082==    by 0x41B54D2: (below main) (libc-start.c:226)
==26082== 
==26082== 20 bytes in 1 blocks are still reachable in loss record 13 of 17
==26082==    at 0x402BE68: malloc (in /usr/lib/valgrind/vgpreload_memcheck-x86-linux.so)
==26082==    by 0x406E9D1: xmlNewCharEncodingHandler (in /usr/lib/i386-linux-gnu/libxml2.so.2.7.8)
==26082==    by 0x406EBB6: xmlInitCharEncodingHandlers (in /usr/lib/i386-linux-gnu/libxml2.so.2.7.8)
==26082==    by 0x41B54D2: (below main) (libc-start.c:226)
==26082== 
==26082== 20 bytes in 1 blocks are still reachable in loss record 14 of 17
==26082==    at 0x402BE68: malloc (in /usr/lib/valgrind/vgpreload_memcheck-x86-linux.so)
==26082==    by 0x406E9D1: xmlNewCharEncodingHandler (in /usr/lib/i386-linux-gnu/libxml2.so.2.7.8)
==26082==    by 0x406EBCC: xmlInitCharEncodingHandlers (in /usr/lib/i386-linux-gnu/libxml2.so.2.7.8)
==26082==    by 0x41B54D2: (below main) (libc-start.c:226)
==26082== 
==26082== 20 bytes in 1 blocks are still reachable in loss record 15 of 17
==26082==    at 0x402BE68: malloc (in /usr/lib/valgrind/vgpreload_memcheck-x86-linux.so)
==26082==    by 0x406E9D1: xmlNewCharEncodingHandler (in /usr/lib/i386-linux-gnu/libxml2.so.2.7.8)
==26082==    by 0x406EBE2: xmlInitCharEncodingHandlers (in /usr/lib/i386-linux-gnu/libxml2.so.2.7.8)
==26082==    by 0x41B54D2: (below main) (libc-start.c:226)
==26082== 
==26082== 20 bytes in 1 blocks are still reachable in loss record 16 of 17
==26082==    at 0x402BE68: malloc (in /usr/lib/valgrind/vgpreload_memcheck-x86-linux.so)
==26082==    by 0x406E9D1: xmlNewCharEncodingHandler (in /usr/lib/i386-linux-gnu/libxml2.so.2.7.8)
==26082==    by 0x406EC02: xmlInitCharEncodingHandlers (in /usr/lib/i386-linux-gnu/libxml2.so.2.7.8)
==26082==    by 0x41B54D2: (below main) (libc-start.c:226)
==26082== 
==26082== 200 bytes in 1 blocks are still reachable in loss record 17 of 17
==26082==    at 0x402BE68: malloc (in /usr/lib/valgrind/vgpreload_memcheck-x86-linux.so)
==26082==    by 0x406EABE: xmlInitCharEncodingHandlers (in /usr/lib/i386-linux-gnu/libxml2.so.2.7.8)
==26082==    by 0x41B54D2: (below main) (libc-start.c:226)
==26082== 
==26082== LEAK SUMMARY:
==26082==    definitely lost: 0 bytes in 0 blocks
==26082==    indirectly lost: 0 bytes in 0 blocks
==26082==      possibly lost: 0 bytes in 0 blocks
==26082==    still reachable: 422 bytes in 17 blocks
==26082==         suppressed: 0 bytes in 0 blocks

何をしますか？これは宿題です-valgrindの結果を無視することはできません。

4

1 に答える 1

5

xmlCleanupParser（）を呼び出す直前に、xmlCleanupCharEncodingHandlers（）への呼び出しを追加します。

私のMacOS10.7.5開発マシン（libxml 20703）では、これにより、libxml2で報告された「まだ到達可能な」リークが修正されます。

ところで、 ？？？オブジェクトファイルのデバッグシンボルが使用できないことを意味します。この情報があると、メモリリークを追跡するときに非常に役立ちます。デバッグ情報をインストールする手順は、Linuxディストリビューションによって異なります。たとえば、Ubuntuでは、。を使用してlibxml2デバッグ情報をインストールできますsudo apt-get install libxml2-dbg。https://live.gnome.org/GettingTraces/DistroSpecificInstructionsを参照してください

于 2012-12-16T18:20:49.590 に答える