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/* Copyright (C) 2006 MySQL AB
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
#include <drizzled/server_includes.h>
#include <drizzled/atomics.h>
#include <drizzled/gettext.h>
#include <drizzled/error.h>
#include <drizzled/plugin/scheduler.h>
#include <drizzled/connect.h>
#include <drizzled/sql_parse.h>
#include <drizzled/session.h>
#include <drizzled/connect.h>
#include <string>
using namespace std;
static uint32_t max_threads;
class Multi_thread_scheduler: public Scheduler
{
drizzled::atomic<uint32_t> thread_count;
pthread_attr_t multi_thread_attrib;
public:
Multi_thread_scheduler(uint32_t threads): Scheduler(threads)
{
thread_count= 0;
/* Parameter for threads created for connections */
(void) pthread_attr_init(&multi_thread_attrib);
(void) pthread_attr_setdetachstate(&multi_thread_attrib,
PTHREAD_CREATE_DETACHED);
pthread_attr_setscope(&multi_thread_attrib, PTHREAD_SCOPE_SYSTEM);
{
struct sched_param tmp_sched_param;
memset(&tmp_sched_param, 0, sizeof(tmp_sched_param));
tmp_sched_param.sched_priority= WAIT_PRIOR;
(void)pthread_attr_setschedparam(&multi_thread_attrib, &tmp_sched_param);
}
}
~Multi_thread_scheduler()
{
(void) pthread_mutex_lock(&LOCK_thread_count);
while (thread_count)
{
pthread_cond_wait(&COND_thread_count, &LOCK_thread_count);
}
(void) pthread_mutex_unlock(&LOCK_thread_count);
pthread_attr_destroy(&multi_thread_attrib);
}
virtual bool add_connection(Session *session)
{
int error;
thread_count++;
if ((error= pthread_create(&session->real_id, &multi_thread_attrib, handle_one_connection, static_cast<void*>(session))))
return true;
return false;
}
/*
End connection, in case when we are using 'no-threads'
*/
virtual bool end_thread(Session *session, bool)
{
unlink_session(session); /* locks LOCK_thread_count and deletes session */
thread_count--;
my_thread_end();
pthread_exit(0);
return true; // We should never reach this point
}
virtual uint32_t count(void)
{
return thread_count;
}
};
class MultiThreadFactory : public SchedulerFactory
{
public:
MultiThreadFactory() : SchedulerFactory("multi_thread")
{
addAlias("multi-thread");
}
~MultiThreadFactory() { if (scheduler != NULL) delete scheduler; }
Scheduler *operator() ()
{
if (scheduler == NULL)
scheduler= new Multi_thread_scheduler(max_threads);
return scheduler;
}
};
static MultiThreadFactory *factory= NULL;
static int init(PluginRegistry ®istry)
{
factory= new MultiThreadFactory();
registry.add(factory);
return 0;
}
static int deinit(PluginRegistry ®istry)
{
if (factory)
{
registry.remove(factory);
delete factory;
}
return 0;
}
static DRIZZLE_SYSVAR_UINT(max_threads, max_threads,
PLUGIN_VAR_RQCMDARG,
N_("Maximum number of user threads available."),
NULL, NULL, 2048, 1, 4048, 0);
static struct st_mysql_sys_var* system_variables[]= {
DRIZZLE_SYSVAR(max_threads),
NULL
};
drizzle_declare_plugin(multi_thread)
{
"multi_thread",
"0.1",
"Brian Aker",
"One Thread Per Session Scheduler",
PLUGIN_LICENSE_GPL,
init, /* Plugin Init */
deinit, /* Plugin Deinit */
NULL, /* status variables */
system_variables, /* system variables */
NULL /* config options */
}
drizzle_declare_plugin_end;
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