~drizzle-trunk/drizzle/development

/* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-

 *  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:

 *

 * Copyright 2009 Sun Microsystems

 *

 * Authors:

 *

 * Patrick Galbraith <pat@patg.net>

 *

 *

 *  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 <unistd.h>

#include <time.h>

#include <drizzled/server_includes.h>

#include <drizzled/session.h>

#include <drizzled/item/func.h>

#include <mysys/my_pthread.h>

#include <drizzled/function/str/strfunc.h>

#include <string>

using namespace std;

using namespace drizzled;

class Item_func_sleep : public Item_int_func

{

  /* for thread-safe sleep() */

  pthread_mutex_t LOCK_sleep;

public:

  int64_t val_int();

  Item_func_sleep() : Item_int_func()

  {

    unsigned_flag= true;

  }

  const char *func_name() const

  {

    return "sleep";

  }

  void fix_length_and_dec()

  {

    max_length= 1;

  }

  bool check_argument_count(int n)

  {

    return (n == 1);

  }

};

int64_t Item_func_sleep::val_int()

{

  int error= 0;

  /* int time in seconds, decimal allowed */

  double dtime;

  struct timespec abstime;

  pthread_cond_t cond;

  Session *session= current_session;

  if ((arg_count != 1) || ! (dtime= args[0]->val_real()))

  {

    null_value= true;

    return 0;

  }

  /*

    On 64-bit OSX pthread_cond_timedwait() waits forever

    if passed abstime time has already been exceeded by 

    the system time.

    When given a very short timeout (< 10 mcs) just return 

    immediately.

    We assume that the lines between this test and the call 

    to pthread_cond_timedwait() will be executed in less than 0.00001 sec.

  */

  if (dtime < 0.00001)

    return 0;

  /* need to obtain time value for passing to cond_timedwait */

  set_timespec_nsec(abstime, (uint64_t)(dtime * 1000000000ULL));

  pthread_mutex_init(&LOCK_sleep, MY_MUTEX_INIT_FAST);

  pthread_cond_init(&cond, NULL);

  /* don't run if not killed */

  pthread_mutex_lock(&LOCK_sleep);

  while (! session->killed)

  {

    error= pthread_cond_timedwait(&cond, &LOCK_sleep, &abstime);

    if (error == ETIMEDOUT || error == ETIME)

    {

      break;

    }

    error= 0;

  }

  pthread_mutex_unlock(&LOCK_sleep);

  /* relenquish pthread cond */

  pthread_cond_destroy(&cond);

  pthread_mutex_destroy(&LOCK_sleep);

  null_value= false;

  return (int64_t) 0;

}

plugin::Create_function<Item_func_sleep> *sleep_udf= NULL;

static int sleep_plugin_init(drizzled::plugin::Registry &registry)

{

  sleep_udf= new plugin::Create_function<Item_func_sleep>("sleep");

  registry.add(sleep_udf);

  return 0;

}

static int sleep_plugin_deinit(drizzled::plugin::Registry &registry)

{

  registry.remove(sleep_udf);

  delete sleep_udf;

  return 0;

}

drizzle_declare_plugin(sleep)

{

  "sleep",

  "1.0",

  "Patrick Galbraith",

  "sleep()",

  PLUGIN_LICENSE_GPL,

  sleep_plugin_init, /* Plugin Init */

  sleep_plugin_deinit, /* Plugin Deinit */

  NULL,   /* status variables */

  NULL,   /* system variables */

  NULL    /* config options */

}

drizzle_declare_plugin_end;