Hi,

I'm writing mariadb daemon type plugin. 

I hava a question. 

In a daemon thread, I want to use THD instance. for example,

-----------------------------------------------------------------------------------

class THD;

static int plugin_init() {

...

pthread_create(&id,&attr,my_func,...);

}

void my_func(void* p) 

{

THD* thd = new THD;

thd->thread_stack= (char*) &thd;

thd->store_globals();

tables.init_one_table("performance_schema", 18, "events_statements_current", 25, "events_statements_current", TL_READ);

open_and_lock_tables(thd, &tables, FALSE, MYSQL_LOCK_IGNORE_TIMEOUT);

...

}

--------------------------------------------------------------------------------------------

but In my_func(), new THD cause error. I guess thread problem. 

So I moved that code to plugin_init() for test as below

--------------------------------------------------------------

class THD;

static int plugin_init() {

...

pthread_create(&id,&attr,my_func,...);

THD* thd = new THD;

thd->thread_stack= (char*) &thd;

thd->store_globals();

tables.init_one_table("performance_schema", 18, "events_statements_current", 25, "events_statements_current", TL_READ);

open_and_lock_tables(thd, &tables, FALSE, MYSQL_LOCK_IGNORE_TIMEOUT);

...

}

-----------------------------------------------------------------------------

and then there is no problem. but I need a daemon thread. 

I think that the reason of this error is assertion of thread. So I changed my code as below. 

---------------------------------------------------------------------------------

class THD;

THD* thd;

static int plugin_init() {

...

pthread_create(&id,&attr,my_func,...);

THD* thd = new THD;  // moved here from my_func() for avoiding error.

}

void my_func(void* p) 

{

thd->thread_stack= (char*) &thd;

thd->store_globals();

tables.init_one_table("performance_schema", 18, "events_statements_current", 25, "events_statements_current", TL_READ);

open_and_lock_tables(thd, &tables, FALSE, MYSQL_LOCK_IGNORE_TIMEOUT);

...

}

-----------------------------------------------------------------------------------------

At this time, thd->store_globals() cause error. 

In sql_class.cc , mysys_var->id= thread_id    cause error because  mysys_var is null.

Let me know how to use THD instance in daemon thread. 

Regards,

Kyungnam