标题: Valgrind 检测linux上c++内存泄露 [打印本页] 作者: liangjz 时间: 2008-7-15 21:23 标题: Valgrind 检测linux上c++内存泄露 Linux c++上常用内存泄露检测工具有valgrind, Rational purify。Valgrind免费。Valgrind 可以在 32 位或 64 位 PowerPC/Linux 内核上工作。
Valgrind工具包包含多个工具，如Memcheck,Cachegrind,Helgrind, Callgrind，Massif。下面分别介绍个工具的作用：
Memcheck 工具主要检查下面的程序错误：
• 使用未初始化的内存 (Use of uninitialised memory)
• 使用已经释放了的内存 (Reading/writing memory after it has been free’d)
• 使用超过 malloc分配的内存空间(Reading/writing off the end of malloc’d blocks)
• 对堆栈的非法访问 (Reading/writing inappropriate areas on the stack)
• 申请的空间是否有释放 (Memory leaks – where pointers to malloc’d blocks are lost forever)
• malloc/free/new/delete申请和释放内存的匹配(Mismatched use of malloc/new/new [] vs free/delete/delete [])
• src和dst的重叠(Overlapping src and dst pointers in memcpy() and related functions)
Valgrind不检查静态分配数组的使用情况。
Valgrind占用了更多的内存--可达两倍于你程序的正常使用量。如果你用Valgrind来检测使用大量内存的程序就会遇到问题，它可能会用很长的时间来运行测试
2.1. 下载安装 http://www.valgrind.org
安装
./configure;make;make install
2.2. 编译程序
被检测程序加入 –g -fno-inline 编译选项保留调试信息。
==4591==
==4591== Thread 1:
==4591== Conditional jump or move depends on uninitialised value(s)
==4591== at 0x805687B: main (TestQuery.cpp:478)
==4591==
==4591== Conditional jump or move depends on uninitialised value(s)
==4591== at 0x8056894: main (TestQuery.cpp:478)
==4591==
==4591== Conditional jump or move depends on uninitialised value(s)
==4591== at 0x80568AD: main (TestQuery.cpp:478)
==4591== Warning: set address range perms: large range 215212032 (noaccess)
==4591== Warning: set address range perms: large range 125145088 (noaccess)
==4591==
==4591== ERROR SUMMARY: 6 errors from 4 contexts (suppressed: 18 from 1)
==4591== malloc/free: in use at exit: 496 bytes in 2 blocks.
==4591== malloc/free: 928,605 allocs, 928,603 frees, 2,514,165,074 bytes allocated.
==4591== For counts of detected errors, rerun with: -v
==4591== searching for pointers to 2 not-freed blocks.
==4591== checked 10,260,564 bytes.
==4591==
==4591==
==4591== 144 bytes in 1 blocks are possibly lost in loss record 1 of 2
==4591== at 0x4005906: calloc (vg_replace_malloc.c:279)
==4591== by 0xB3671A: _dl_allocate_tls (in /lib/ld-2.3.4.so)
==4591== by 0xD9491E: pthread_create@@GLIBC_2.1 (in /lib/tls/libpthread-2.3.4.so)
==4591== by 0x8200C66: public_unit::CThread::start(void*) (Thread.cpp:25)
==4591== by 0x80567C3: main (TestQuery.cpp:473)
==4591==
==4591==
==4591== 352 bytes in 1 blocks are still reachable in loss record 2 of 2
==4591== at 0x40044F6: malloc (vg_replace_malloc.c:149)
==4591== by 0xB9905E: __fopen_internal (in /lib/tls/libc-2.3.4.so)
==4591== by 0xB9911C: fopen@@GLIBC_2.1 (in /lib/tls/libc-2.3.4.so)
==4591== by 0x805940C: CSearchThread::run(void*) (TestQuery.cpp:363)
==4591== by 0x8200D09: public_unit::CThread::thread_func(void*) (Thread.cpp:44)
==4591== by 0xD94370: start_thread (in /lib/tls/libpthread-2.3.4.so)
==4591== by 0xC0DFFD: clone (in /lib/tls/libc-2.3.4.so)
==4591==
==4591== LEAK SUMMARY:
==4591== definitely lost: 0 bytes in 0 blocks.
==4591== possibly lost: 144 bytes in 1 blocks.
==4591== still reachable: 352 bytes in 1 blocks.
==4591== suppressed: 0 bytes in 0 blocks.
关键字在：ERROR SUMMARY, LEAK SUMMARY
"definitely lost" means your program is leaking memory -- fix it!
"possibly lost" means your program is probably leaking memory, unless you're doing funny things with pointers.
"still reachable" means your program is probably ok -- it didn't free some memory it could have. This is quite common and often reasonable. Don't use --show-reachable=yes if you don't want to see these reports.
"suppressed" means that a leak error has been suppressed. There are some suppressions in the default suppression files. You can ignore suppressed errors
另外一种方式，激活加载调试器
gcc -Wall -g -pg -o get_XMLDOC get_XMLDOC.c
$ valgrind --db-attach=yes --leak-check=full ./get_XMLDOC ~/eragon/data/offer_gb.xml 1.xml 10
==8956== Memcheck, a memory error detector.
==8956== Copyright (C) 2002-2006, and GNU GPL'd, by Julian Seward et al.
==8956== Using LibVEX rev 1606, a library for dynamic binary translation.
==8956== Copyright (C) 2004-2006, and GNU GPL'd, by OpenWorks LLP.
==8956== Using valgrind-3.2.0, a dynamic binary instrumentation framework.
==8956== Copyright (C) 2000-2006, and GNU GPL'd, by Julian Seward et al.
==8956== For more details, rerun with: -v
==8956==
==8956==
==8956== ---- Attach to debugger ? --- [Return/N/n/Y/y/C/c] ----
==8956==
==8956== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 12 from 1)
==8956== malloc/free: in use at exit: 1,953 bytes in 2 blocks.
==8956== malloc/free: 4 allocs, 2 frees, 2,657 bytes allocated.
==8956== For counts of detected errors, rerun with: -v
==8956== searching for pointers to 2 not-freed blocks.
==8956== checked 52,840 bytes.
==8956==
==8956== 1 bytes in 1 blocks are definitely lost in loss record 1 of 2
==8956== at 0x40044F6: malloc (vg_replace_malloc.c:149)
==8956== by 0x80488C0: main (get_XMLDOC.c:38)
==8956==
==8956== LEAK SUMMARY:
==8956== definitely lost: 1 bytes in 1 blocks.
==8956== possibly lost: 0 bytes in 0 blocks.
==8956== still reachable: 1,952 bytes in 1 blocks.
==8956== suppressed: 0 bytes in 0 blocks.
==8956== Reachable blocks (those to which a pointer was found) are not shown.
==8956== To see them, rerun with: --show-reachable=yes
Profiling timer expired
4607为进程号。
$ ll
-rw------- 1 search search 712159 7月 9 22:31 callgrind.out.4607
$ callgrind_annotate --auto=yes callgrind.out.4607
WARNING: header line 2 malformed, ignoring
line: 'creator: callgrind-3.2.0'
--------------------------------------------------------------------------------
I1 cache:
D1 cache:
L2 cache:
Timerange: Basic block 0 - 46942078
Trigger: Program termination
Profiled target: ./iquery -f ../conf/se.conf_forum -s forum_thread?q=mp4 (PID 4607, part 1)
Events recorded: Ir
Events shown: Ir
Event sort order: Ir
Thresholds: 99
Include dirs:
User annotated:
Auto-annotation: on
--------------------------------------------------------------------------------
Ir
--------------------------------------------------------------------------------
251,772,397 PROGRAM TOTALS