Valgrind 中被抑制的泄漏意味着什么？

Question

我在文件fifo.h 和fifo.c 中开发了FIFO 列表（队列）的纯C 实现，并编写了一个测试程序testfifo.c，我将其编译为./bin/testfifo。节点结构在list.h中定义。

我像这样在 OS X 10.6 上通过 Valgrind 运行我的程序

valgrind --tool=memcheck --leak-check=full --show-reachable=yes ./bin/testfifo

并得到以下输出

==54688== Memcheck, a memory error detector
==54688== Copyright (C) 2002-2011, and GNU GPL'd, by Julian Seward et al.
==54688== Using Valgrind-3.7.0 and LibVEX; rerun with -h for copyright info
==54688== Command: bin/testfifo
==54688== 
--54688-- bin/testfifo:
--54688-- dSYM directory is missing; consider using --dsymutil=yes
==54688== 
==54688== HEAP SUMMARY:
==54688==     in use at exit: 88 bytes in 1 blocks
==54688==   total heap usage: 11 allocs, 10 frees, 248 bytes allocated
==54688== 
==54688== LEAK SUMMARY:
==54688==    definitely lost: 0 bytes in 0 blocks
==54688==    indirectly lost: 0 bytes in 0 blocks
==54688==      possibly lost: 0 bytes in 0 blocks
==54688==    still reachable: 0 bytes in 0 blocks
==54688==         suppressed: 88 bytes in 1 blocks
==54688== 
==54688== For counts of detected and suppressed errors, rerun with: -v
==54688== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)

根据泄漏摘要，没有泄漏，但我仍然想知道“抑制”泄漏是什么。另外，alloc 和 free 的数量不匹配，所以我不确定是否有泄漏。

----编辑----

跑步

valgrind --tool=memcheck --leak-check=full --show-reachable=yes -v ./bin/testfifo

在 OS X 10.6 上会产生相当长且令人困惑的输出，但我已经运行了

valgrind --tool=memcheck --leak-check=full --show-reachable=yes ./bin/testfifo

在 Linux 机器上得到以下输出：

==32688== Memcheck, a memory error detector
==32688== Copyright (C) 2002-2010, and GNU GPL'd, by Julian Seward et al.
==32688== Using Valgrind-3.6.1 and LibVEX; rerun with -h for copyright info
==32688== Command: bin/testfifo
==32688== 
==32688== 
==32688== HEAP SUMMARY:
==32688==     in use at exit: 0 bytes in 0 blocks
==32688==   total heap usage: 10 allocs, 10 frees, 160 bytes allocated
==32688== 
==32688== All heap blocks were freed -- no leaks are possible
==32688== 
==32688== For counts of detected and suppressed errors, rerun with: -v
==32688== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 4 from 4)

alloc's 和 free's 现在匹配，因此 OS X 上的额外分配似乎是由于某些系统库造成的，正如已建议的那样。

我已经使用-v 选项运行了相同的命令，以显示 4 个被抑制的错误，但我没有得到任何易于理解的新信息。

Answer 1

这些是代码之外的泄漏、（可能是共享的）库中的泄漏或已知的误报。使用-v 运行 valgrind 应该会告知您使用的抑制。