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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 <plugin/multi_thread/multi_thread.h>
using namespace std;
using namespace drizzled;
/* Configuration variables. */
static uint32_t max_threads;
/* Global's (TBR) */
static MultiThreadScheduler *scheduler= NULL;
/**
* Function to be run as a thread for each session.
*/
namespace
{
extern "C" pthread_handler_t session_thread(void *arg);
}
namespace
{
extern "C" pthread_handler_t session_thread(void *arg)
{
Session *session= static_cast<Session*>(arg);
MultiThreadScheduler *sched= static_cast<MultiThreadScheduler*>(session->scheduler);
sched->runSession(session);
return NULL;
}
}
bool MultiThreadScheduler::addSession(Session *session)
{
if (thread_count >= max_threads)
return true;
thread_count++;
if (pthread_create(&session->real_id, &attr, session_thread,
static_cast<void*>(session)))
{
thread_count--;
return true;
}
return false;
}
void MultiThreadScheduler::killSessionNow(Session *session)
{
/* Locks LOCK_thread_count and deletes session */
unlink_session(session);
thread_count--;
my_thread_end();
pthread_exit(0);
/* We should never reach this point. */
}
MultiThreadScheduler::~MultiThreadScheduler()
{
(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);
(void) pthread_attr_destroy(&attr);
}
static int init(drizzled::plugin::Registry ®istry)
{
scheduler= new MultiThreadScheduler("multi_thread");
registry.add(scheduler);
return 0;
}
static int deinit(drizzled::plugin::Registry ®istry)
{
registry.remove(scheduler);
delete scheduler;
return 0;
}
static DRIZZLE_SYSVAR_UINT(max_threads, max_threads,
PLUGIN_VAR_RQCMDARG,
N_("Maximum number of user threads available."),
NULL, NULL, 2048, 1, 4096, 0);
static drizzle_sys_var* system_variables[]= {
DRIZZLE_SYSVAR(max_threads),
NULL
};
DRIZZLE_DECLARE_PLUGIN
{
"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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