glib2 是否真的会使用 ALWAYS-MALLOC 泄漏内存？

这个问题是not许多其他人的重复，因为我do use G_DEBUG=gc-friendly and G_SLICE=always-malloc这是源代码：

#include <glib.h>

int main (int argc, char *argv[])
{
    GHashTable *ht;
    ht=g_hash_table_new(g_str_hash,g_str_equal);
    g_hash_table_insert(ht,"foo","bar");
    g_hash_table_destroy(ht);
    return 0;
}

这是 Valgrind 在这段代码上的输出：

# G_DEBUG=gc-friendly G_SLICE=always-malloc valgrind --leak-check=full --show-reachable=yes ./test_vg
==1880== Memcheck, a memory error detector
==1880== Copyright (C) 2002-2010, and GNU GPL'd, by Julian Seward et al.
==1880== Using Valgrind-3.6.0 and LibVEX; rerun with -h for copyright info
==1880== Command: ./test_vg
==1880==
==1880==
==1880== HEAP SUMMARY:
==1880==     in use at exit: 1,260 bytes in 3 blocks
==1880==   total heap usage: 5 allocs, 2 frees, 1,524 bytes allocated
==1880==
==1880== 252 bytes in 1 blocks are still reachable in loss record 1 of 3
==1880==    at 0x4A04A28: calloc (vg_replace_malloc.c:467)
==1880==    by 0x35C8241707: g_malloc0 (in /lib64/libglib-2.0.so.0.2200.5)
==1880==    by 0x35C8255742: ??? (in /lib64/libglib-2.0.so.0.2200.5)
==1880==    by 0x35C825669D: g_slice_alloc (in /lib64/libglib-2.0.so.0.2200.5)
==1880==    by 0x35C822B1D2: g_hash_table_new_full (in /lib64/libglib-2.0.so.0.2200.5)
==1880==    by 0x400671: main (in /home/data/test_vg)
==1880==
==1880== 504 bytes in 1 blocks are still reachable in loss record 2 of 3
==1880==    at 0x4A04A28: calloc (vg_replace_malloc.c:467)
==1880==    by 0x35C8241707: g_malloc0 (in /lib64/libglib-2.0.so.0.2200.5)
==1880==    by 0x35C8255722: ??? (in /lib64/libglib-2.0.so.0.2200.5)
==1880==    by 0x35C825669D: g_slice_alloc (in /lib64/libglib-2.0.so.0.2200.5)
==1880==    by 0x35C822B1D2: g_hash_table_new_full (in /lib64/libglib-2.0.so.0.2200.5)
==1880==    by 0x400671: main (in /home/data/test_vg)
==1880==
==1880== 504 bytes in 1 blocks are still reachable in loss record 3 of 3
==1880==    at 0x4A04A28: calloc (vg_replace_malloc.c:467)
==1880==    by 0x35C8241707: g_malloc0 (in /lib64/libglib-2.0.so.0.2200.5)
==1880==    by 0x35C825578B: ??? (in /lib64/libglib-2.0.so.0.2200.5)
==1880==    by 0x35C825669D: g_slice_alloc (in /lib64/libglib-2.0.so.0.2200.5)
==1880==    by 0x35C822B1D2: g_hash_table_new_full (in /lib64/libglib-2.0.so.0.2200.5)
==1880==    by 0x400671: main (in /home/data/test_vg)
==1880==
==1880== LEAK SUMMARY:
==1880==    definitely lost: 0 bytes in 0 blocks
==1880==    indirectly lost: 0 bytes in 0 blocks
==1880==      possibly lost: 0 bytes in 0 blocks
==1880==    still reachable: 1,260 bytes in 3 blocks
==1880==         suppressed: 0 bytes in 0 blocks
==1880==
==1880== For counts of detected and suppressed errors, rerun with: -v
==1880== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 6 from 6)

是内存泄漏吗？

回答你的问题：不，这不是传统意义上的内存泄漏。你的代码没问题。

即使你使用G_DEBUG=gc-friendly and G_SLICE=always-malloc，GLib 在退出时总是留下“仍然可访问”的内存。不要使用--show-reachable=yes选项，否则在使用 GLib 时，您将始终得到受污染的 Valgrind 输出。但是，如果您分配在静态变量或全局变量中保留指针的内存（“仍然可访问”内存），请务必小心。在这种情况下，您最终可能会忽略自己的“真实”泄漏。