/* Copyright (c) 2006, 2012, Oracle and/or its affiliates. All rights reserved.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License, version 2.0,
   as published by the Free Software Foundation.

   This program is also distributed with certain software (including
   but not limited to OpenSSL) that is licensed under separate terms,
   as designated in a particular file or component or in included license
   documentation.  The authors of MySQL hereby grant you an additional
   permission to link the program and your derivative works with the
   separately licensed software that they have included with MySQL.

   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, version 2.0, 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 */

// First include (the generated) my_config.h, to get correct platform defines.
#include "my_config.h"
#include <gtest/gtest.h>

#include <my_global.h>
#include <my_sys.h>
#include <my_atomic.h>


namespace mysys_my_atomic_unittest {

#include "thr_template.cc"

volatile int32 b32;
volatile int32  c32;
my_atomic_rwlock_t rwl;

/* add and sub a random number in a loop. Must get 0 at the end */
pthread_handler_t test_atomic_add(void *arg)
{
  int m= (*(int *)arg)/2;
  int32 x;
  for (x= ((int)(intptr)(&m)); m ; m--)
  {
    x= (x*m+0x87654321) & INT_MAX32;
    my_atomic_rwlock_wrlock(&rwl);
    my_atomic_add32(&bad, x);
    my_atomic_rwlock_wrunlock(&rwl);

    my_atomic_rwlock_wrlock(&rwl);
    my_atomic_add32(&bad, -x);
    my_atomic_rwlock_wrunlock(&rwl);
  }
  mysql_mutex_lock(&mutex);
  if (!--running_threads) mysql_cond_signal(&cond);
  mysql_mutex_unlock(&mutex);
  return 0;
}

volatile int64 a64;
/* add and sub a random number in a loop. Must get 0 at the end */
pthread_handler_t test_atomic_add64(void *arg)
{
  int m= (*(int *)arg)/2;
  int64 x;
  for (x= ((int64)(intptr)(&m)); m ; m--)
  {
    x= (x*m+0xfdecba987654321LL) & INT_MAX64;
    my_atomic_rwlock_wrlock(&rwl);
    my_atomic_add64(&a64, x);
    my_atomic_rwlock_wrunlock(&rwl);

    my_atomic_rwlock_wrlock(&rwl);
    my_atomic_add64(&a64, -x);
    my_atomic_rwlock_wrunlock(&rwl);
  }
  mysql_mutex_lock(&mutex);
  if (!--running_threads)
  {
    bad= (a64 != 0);
    mysql_cond_signal(&cond);
  }
  mysql_mutex_unlock(&mutex);
  return 0;
}


/*
  1. generate thread number 0..N-1 from b32
  2. add it to bad
  3. swap thread numbers in c32
  4. (optionally) one more swap to avoid 0 as a result
  5. subtract result from bad
  must get 0 in bad at the end
*/
pthread_handler_t test_atomic_fas(void *arg)
{
  int    m= *(int *)arg;
  int32  x;

  my_atomic_rwlock_wrlock(&rwl);
  x= my_atomic_add32(&b32, 1);
  my_atomic_rwlock_wrunlock(&rwl);

  my_atomic_rwlock_wrlock(&rwl);
  my_atomic_add32(&bad, x);
  my_atomic_rwlock_wrunlock(&rwl);

  for (; m ; m--)
  {
    my_atomic_rwlock_wrlock(&rwl);
    x= my_atomic_fas32(&c32, x);
    my_atomic_rwlock_wrunlock(&rwl);
  }

  if (!x)
  {
    my_atomic_rwlock_wrlock(&rwl);
    x= my_atomic_fas32(&c32, x);
    my_atomic_rwlock_wrunlock(&rwl);
  }

  my_atomic_rwlock_wrlock(&rwl);
  my_atomic_add32(&bad, -x);
  my_atomic_rwlock_wrunlock(&rwl);

  mysql_mutex_lock(&mutex);
  if (!--running_threads) mysql_cond_signal(&cond);
  mysql_mutex_unlock(&mutex);
  return 0;
}

/*
  same as test_atomic_add, but my_atomic_add32 is emulated with
  my_atomic_cas32 - notice that the slowdown is proportional to the
  number of CPUs
*/
pthread_handler_t test_atomic_cas(void *arg)
{
  int m= (*(int *)arg)/2, ok= 0;
  int32 x, y;
  for (x= ((int)(intptr)(&m)); m ; m--)
  {
    my_atomic_rwlock_wrlock(&rwl);
    y= my_atomic_load32(&bad);
    my_atomic_rwlock_wrunlock(&rwl);
    x= (x*m+0x87654321) & INT_MAX32;
    do {
      my_atomic_rwlock_wrlock(&rwl);
      ok= my_atomic_cas32(&bad, &y, (uint32)y+x);
      my_atomic_rwlock_wrunlock(&rwl);
    } while (!ok) ;
    do {
      my_atomic_rwlock_wrlock(&rwl);
      ok= my_atomic_cas32(&bad, &y, y-x);
      my_atomic_rwlock_wrunlock(&rwl);
    } while (!ok) ;
  }
  mysql_mutex_lock(&mutex);
  if (!--running_threads) mysql_cond_signal(&cond);
  mysql_mutex_unlock(&mutex);
  return 0;
}


void do_tests()
{
  bad= my_atomic_initialize();
  EXPECT_FALSE(bad) << "my_atomic_initialize() returned";

  my_atomic_rwlock_init(&rwl);

  b32= c32= 0;
  test_concurrently("my_atomic_add32", test_atomic_add, THREADS, CYCLES);
  b32= c32= 0;
  test_concurrently("my_atomic_fas32", test_atomic_fas, THREADS, CYCLES);
  b32= c32= 0;
  test_concurrently("my_atomic_cas32", test_atomic_cas, THREADS, CYCLES);

  {
    /*
      If b is not volatile, the wrong assembly code is generated on OSX Lion
      as the variable is optimized away as a constant.
      See Bug#62533 / Bug#13030056.
      Another workaround is to specify architecture explicitly using e.g.
      CFLAGS/CXXFLAGS= "-m64".
    */
    volatile int64 b=0x1000200030004000LL;
    a64=0;
    my_atomic_add64(&a64, b);
    EXPECT_EQ(a64, b) << "add64";
  }
  a64=0;
  test_concurrently("my_atomic_add64", test_atomic_add64, THREADS, CYCLES);

  my_atomic_rwlock_destroy(&rwl);
}


TEST(Mysys, Atomic)
{
  mysql_mutex_init(0, &mutex, 0);
  mysql_cond_init(0, &cond, NULL);
  pthread_attr_init(&thr_attr);
  pthread_attr_setdetachstate(&thr_attr, PTHREAD_CREATE_DETACHED);
 
  do_tests();

  mysql_mutex_destroy(&mutex);
  mysql_cond_destroy(&cond);
  pthread_attr_destroy(&thr_attr);
}

}
