CODEWITHSUNDEEP
mysqlcgccmemory-leaks
opc0de
opc0de

Reputation: 11768

Memoryleak in mysql using different thread

I am writing a simple C program to request some data from a mysql db the function does not report a memory leak when used in a single thread application, but while in a thread it does.

The function is this I have stripped the unnecesary code

BOOL getip(char * ip,int * port,BOOL serie)
{
    MYSQL * conn,mysql;
    MYSQL_RES * res;
    MYSQL_ROW row;



   char * server = "someip";
    char * user = "root";
    char * pass = "root";
    char * db = "testdb";
    char * query = NULL;

mysql_init(&mysql);

mysql_close(&mysql);

}

> ==30295== HEAP SUMMARY:
> ==30295==     in use at exit: 73,872 bytes in 21 blocks
> ==30295==   total heap usage: 85 allocs, 64 frees, 119,908 bytes allocated
> ==30295== 
> ==30295== 128 bytes in 1 blocks are definitely lost in loss record 2 of 5
> ==30295==    at 0x402A629: calloc (in /usr/lib/valgrind/vgpreload_memcheck-x86-linux.so)
> ==30295==    by 0x408FB63: my_thread_init (in /usr/lib/i386-linux-gnu/libmysqlclient.so.18.0.0)
> ==30295==    by 0x408FE43: my_thread_global_init (in /usr/lib/i386-linux-gnu/libmysqlclient.so.18.0.0)
> ==30295==    by 0x408E2D7: my_init (in /usr/lib/i386-linux-gnu/libmysqlclient.so.18.0.0)
> ==30295==    by 0x406B3FA: mysql_server_init (in /usr/lib/i386-linux-gnu/libmysqlclient.so.18.0.0)
> ==30295==    by 0x406CB28: mysql_init (in /usr/lib/i386-linux-gnu/libmysqlclient.so.18.0.0)
> ==30295==    by 0x8048DD1: getip (database.c:22)
> ==30295==    by 0x80492DD: sockit (listener.c:50)
> ==30295==    by 0x4378D4B: start_thread (pthread_create.c:308)
> ==30295==    by 0x447BD3D: clone (clone.S:130)
> ==30295== 
> ==30295== LEAK SUMMARY:
> ==30295==    definitely lost: 128 bytes in 1 blocks
> ==30295==    indirectly lost: 0 bytes in 0 blocks
> ==30295==      possibly lost: 0 bytes in 0 blocks
> ==30295==    still reachable: 73,744 bytes in 20 blocks
> ==30295==         suppressed: 0 bytes in 0 blocks
> ==30295== Reachable blocks (those to which a pointer was found) are not shown.
> ==30295== To see them, rerun with: --leak-check=full --show-reachable=yes

every time the function executes the leak increases so it got to be an error

What am I doing wrong ?

Upvotes: 3

Views: 673

Answers (2)

Binu Babu
Binu Babu

Reputation: 127

Try mysql_thread_end() instead of mysql_library_end()

Upvotes: 2

David Ranieri
David Ranieri

Reputation: 41017

Does mysql_library_end();at the very end helps?

Test this:

int main(void)
{
    MYSQL *mysql;

    mysql_init(mysql);
    mysql_close(mysql);
    mysql_library_end();

    return 0;
}

Upvotes: 3

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