Re: bzr commit into mysql-5.1-bugteam branch (Alexey.Kopytov:2812) Bug#40552

[Sergei Golubchik]

Hi, Alexey!

On Feb 27, Alexey Kopytov wrote:
>  2812 Alexey Kopytov	2009-02-27
>       Fix for bug #40552: Race condition around default_directories  
>                           in load_defaults() 
>       
>       load_defaults(), my_search_option_files() and 
>       my_print_default_files()  utilized a global variable 
>       containing  a pointer to thread local memory. This could lead 
>       to race conditions when those functions were called with high 
>       concurrency. 
>       
> === modified file 'sql-common/client.c'
> --- a/sql-common/client.c	2008-03-29 08:02:54 +0000
> +++ b/sql-common/client.c	2009-02-27 09:26:06 +0000
> @@ -1021,7 +1021,7 @@ void mysql_read_default_options(struct s
>    argc=1; argv=argv_buff; argv_buff[0]= (char*) "client";
>    groups[0]= (char*) "client"; groups[1]= (char*) group; groups[2]=0;
>  
> -  load_defaults(filename, groups, &argc, &argv);
> +  my_load_defaults(filename, groups, &argc, &argv, NULL);

Hm. I expected you'll pass a local buffer here. Why NULL ? How you're
going to free the memorz allocated in my_load_defaults() ?

Note when merging into 5.1 - Gluh has added load_defaults() call to
sql_plugin.cc, you'll need to change that to a thread-safe version too,
as that place may be run concurrently by many threads.

Regards / Mit vielen Grüßen,
Sergei

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