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Threadpool -address review comments

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This commit is contained in:
Vladislav Vaintroub 2012-01-15 11:17:45 +01:00
commit 18c9b345b4
3 changed files with 454 additions and 320 deletions
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79
sql/threadpool_common.cc
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@ -7,15 +7,9 @@
#include <sql_connect.h>
#include <sql_audit.h>
#include <debug_sync.h>
#include <threadpool.h>
extern bool login_connection(THD *thd);
extern bool do_command(THD *thd);
extern void prepare_new_connection_state(THD* thd);
extern void end_connection(THD *thd);
extern void thd_cleanup(THD *thd);
extern void delete_thd(THD *thd);
/* Threadpool parameters */
uint threadpool_min_threads;
@ -27,14 +21,15 @@ uint threadpool_oversubscribe;
extern "C" pthread_key(struct st_my_thread_var*, THR_KEY_mysys);
extern bool do_command(THD*);
/*
Worker threads contexts, and THD contexts.
=====================================
=========================================
Both worker threads and connections have their sets of thread local variables
At the moment it is mysys_var (which has e.g dbug my_error and similar
goodies inside), and PSI per-client structure.
At the moment it is mysys_var (this has specific data for dbug, my_error and
similar goodies), and PSI per-client structure.
Whenever query is executed following needs to be done:
@ -77,7 +72,7 @@ struct Worker_thread_context
/*
Attach/associate the connection with the OS thread,
*/
static inline bool thread_attach(THD* thd)
static bool thread_attach(THD* thd)
{
pthread_setspecific(THR_KEY_mysys,thd->mysys_var);
thd->thread_stack=(char*)&thd;
@ -95,11 +90,10 @@ int threadpool_add_connection(THD *thd)
worker_context.save();
/*
Create a new connection context: mysys_thread_var and PSI thread
Store them in thd->mysys_var and thd->scheduler.m_psi.
Create a new connection context: mysys_thread_var and PSI thread
Store them in THD.
*/
/* Use my_thread_init() to create new mysys_thread_var. */
pthread_setspecific(THR_KEY_mysys, 0);
my_thread_init();
thd->mysys_var= (st_my_thread_var *)pthread_getspecific(THR_KEY_mysys);
@ -125,21 +119,29 @@ int threadpool_add_connection(THD *thd)
thd->start_utime= now;
thd->thr_create_utime= now;
if (setup_connection_thread_globals(thd) == 0)
if (!setup_connection_thread_globals(thd))
{
if (login_connection(thd) == 0)
if (!login_connection(thd))
{
prepare_new_connection_state(thd);
retval = thd_is_connection_alive(thd)?0:-1;
thd->net.reading_or_writing= 1;
prepare_new_connection_state(thd);
/*
Check if THD is ok, as prepare_new_connection_state()
can fail, for example if init command failed.
*/
if (thd_is_connection_alive(thd))
{
retval= 0;
thd->net.reading_or_writing= 1;
thd->skip_wait_timeout= true;
}
}
}
thd->skip_wait_timeout= true;
worker_context.restore();
return retval;
}
void threadpool_remove_connection(THD *thd)
{
@ -147,9 +149,7 @@ void threadpool_remove_connection(THD *thd)
worker_context.save();
thread_attach(thd);
thd->killed= KILL_CONNECTION;
thd->net.reading_or_writing= 0;
end_connection(thd);
@ -163,11 +163,13 @@ void threadpool_remove_connection(THD *thd)
mysql_mutex_unlock(&LOCK_thread_count);
mysql_cond_broadcast(&COND_thread_count);
/* Free resources (thread_var and PSI connection specific struct)*/
/*
Free resources associated with this connection:
mysys thread_var and PSI thread.
*/
my_thread_end();
worker_context.restore();
}
int threadpool_process_request(THD *thd)
@ -181,8 +183,8 @@ int threadpool_process_request(THD *thd)
if (thd->killed >= KILL_CONNECTION)
{
/*
kill flag can be set have been killed by
timeout handler or by a KILL command
killed flag was set by timeout handler
or KILL command. Return error.
*/
worker_context.restore();
return 1;
@ -206,33 +208,18 @@ int threadpool_process_request(THD *thd)
vio= thd->net.vio;
if (!vio->has_data(vio))
{
/*
More info on this debug sync is in sql_parse.cc
*/
/* More info on this debug sync is in sql_parse.cc*/
DEBUG_SYNC(thd, "before_do_command_net_read");
thd->net.reading_or_writing= 1;
break;
}
}
if (!retval)
thd->net.reading_or_writing= 1;
}
worker_context.restore();
return retval;
}
/*
Scheduler struct, individual functions are implemented
in threadpool_unix.cc or threadpool_win.cc
*/
extern bool tp_init();
extern void tp_add_connection(THD*);
extern void tp_wait_begin(THD *, int);
extern void tp_wait_end(THD*);
extern void tp_post_kill_notification(THD *thd);
extern void tp_end(void);
static scheduler_functions tp_scheduler_functions=
{
0, // max_threads
@ -255,7 +242,7 @@ void pool_of_threads_scheduler(struct scheduler_functions *func,
uint *arg_connection_count)
{
*func = tp_scheduler_functions;
func->max_threads= *arg_max_connections + 1;
func->max_threads= threadpool_max_threads;
func->max_connections= arg_max_connections;
func->connection_count= arg_connection_count;
scheduler_init();