Re: [Libdbi-drivers-devel] mysql driver memory leak in threaded application

[Markus H. <mar...@mh...>]

 

Am 2013-10-08 06:54, schrieb Ethan Funk: 

> I would like to recommend the following code change to the 0.9 mysql driver code to prevent a memory leak when the driver is linked against the thread-safe mysqlclient_r library. The if(mysql_thread_safe()) statement should ensure that the mysql cleanup function I added for threads is not invoked if the driver is linked against the non-reentrant mysqlclient library. The MySQL documentation indicates that "mysql_thread_init() is automatically called by my_init(), which itself is automatically called by mysql_init(), mysql_library_init(),mysql_server_init(), and mysql_connect(). If you invoke any of those functions,mysql_thread_init() will be called for you." So all that is missing is the mysql_thread_end call. 
> 
> If each thread has it's own connection, and libdbi instance, as recommended by the libdbi documentation, this should work transparently.
> 
> [...]

> int dbd_disconnect(dbi_conn_t *conn) { 
> if (conn->connection) { 
> mysql_close((MYSQL *)conn->connection); 
> // added to resolve memory leak in threadsafe mysqlclient library: assume each thread has it's own connection 
> if(mysql_thread_safe()) 
> mysql_thread_end(); 
> } 
> return 0; 
> }

Hi, 

this sounds reasonable as long as everyone sticks to the
recommendations. I'll ask the other way round: is there anyone out there
who insists on sharing connections between threads? 

regards, 

Markus 

-- 
Markus Hoenicka
http://www.mhoenicka.de
AQ score 38