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/*
* The MIT License
*
* Copyright (C) 2016 Alexander Saprykin <saprykin.spb@gmail.com>
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* 'Software'), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#include "pmem.h"
#include "pspinlock.h"
#ifdef P_CC_SUN
# define PSPINLOCK_INT_CAST(x) (pint *) (x)
#else
# define PSPINLOCK_INT_CAST(x) x
#endif
struct PSpinLock_ {
volatile pint spin;
};
P_LIB_API PSpinLock *
p_spinlock_new (void)
{
PSpinLock *ret;
if (P_UNLIKELY ((ret = p_malloc0 (sizeof (PSpinLock))) == NULL)) {
P_ERROR ("PSpinLock::p_spinlock_new: failed to allocate memory");
return NULL;
}
return ret;
}
P_LIB_API pboolean
p_spinlock_lock (PSpinLock *spinlock)
{
pint tmp_int;
if (P_UNLIKELY (spinlock == NULL))
return FALSE;
do {
tmp_int = 0;
} while ((pboolean) __atomic_compare_exchange_n (PSPINLOCK_INT_CAST (&(spinlock->spin)),
&tmp_int,
1,
0,
__ATOMIC_ACQUIRE,
__ATOMIC_RELAXED) == FALSE);
return TRUE;
}
P_LIB_API pboolean
p_spinlock_trylock (PSpinLock *spinlock)
{
pint tmp_int = 0;
if (P_UNLIKELY (spinlock == NULL))
return FALSE;
return (pboolean) __atomic_compare_exchange_n (PSPINLOCK_INT_CAST (&(spinlock->spin)),
&tmp_int,
1,
0,
__ATOMIC_ACQUIRE,
__ATOMIC_RELAXED);
}
P_LIB_API pboolean
p_spinlock_unlock (PSpinLock *spinlock)
{
if (P_UNLIKELY (spinlock == NULL))
return FALSE;
__atomic_store_4 (PSPINLOCK_INT_CAST (&(spinlock->spin)), 0, __ATOMIC_RELEASE);
return TRUE;
}
P_LIB_API void
p_spinlock_free (PSpinLock *spinlock)
{
p_free (spinlock);
}
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