mirror of
https://github.com/apache/nuttx.git
synced 2026-08-06 21:19:03 +00:00
111 lines
4.3 KiB
C
111 lines
4.3 KiB
C
/****************************************************************************
|
|
* arch/sim/src/up_testset.c
|
|
*
|
|
* Copyright (C) 2016 Gregory Nutt. All rights reserved.
|
|
* Author: Gregory Nutt <gnutt@nuttx.org>
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
*
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in
|
|
* the documentation and/or other materials provided with the
|
|
* distribution.
|
|
* 3. Neither the name NuttX nor the names of its contributors may be
|
|
* used to endorse or promote products derived from this software
|
|
* without specific prior written permission.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
|
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
|
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
|
|
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
|
|
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
|
|
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
|
|
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
|
|
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
|
|
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
|
|
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
|
|
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
|
* POSSIBILITY OF SUCH DAMAGE.
|
|
*
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Included Files
|
|
****************************************************************************/
|
|
|
|
#include <stdint.h>
|
|
#include <pthread.h>
|
|
|
|
/****************************************************************************
|
|
* Pre-processor Definitions
|
|
****************************************************************************/
|
|
/* Must match definitions in arch/sim/include/spinlock.h */
|
|
|
|
#define SP_UNLOCKED 0 /* The Un-locked state */
|
|
#define SP_LOCKED 1 /* The Locked state */
|
|
|
|
/****************************************************************************
|
|
* Public Types
|
|
****************************************************************************/
|
|
/* Must match definitions in arch/sim/include/spinlock.h */
|
|
|
|
typedef uint8_t spinlock_t;
|
|
|
|
/****************************************************************************
|
|
* Private Data
|
|
****************************************************************************/
|
|
|
|
#ifdef CONFIG_SMP
|
|
static pthread_mutex_t g_tsmutex = PTHREAD_MUTEX_INITIALIZER;
|
|
#endif
|
|
|
|
/****************************************************************************
|
|
* Public Functions
|
|
****************************************************************************/
|
|
|
|
/****************************************************************************
|
|
* Name: up_testset
|
|
*
|
|
* Description:
|
|
* Perform an atomic test and set operation on the provided spinlock.
|
|
*
|
|
* This function must be provided via the architecture-specific logic.
|
|
*
|
|
* Input Parameters:
|
|
* lock - The address of spinlock object.
|
|
*
|
|
* Returned Value:
|
|
* The spinlock is always locked upon return. The value of previous value
|
|
* of the spinlock variable is returned, either SP_LOCKED if the spinlock
|
|
* as previously locked (meaning that the test-and-set operation failed to
|
|
* obtain the lock) or SP_UNLOCKED if the spinlock was previously unlocked
|
|
* (meaning that we successfully obtained the lock)
|
|
*
|
|
****************************************************************************/
|
|
|
|
spinlock_t up_testset(volatile spinlock_t *lock)
|
|
{
|
|
#ifdef CONFIG_SMP
|
|
/* In the multi-CPU SMP case, we use a mutex to assure that the following
|
|
* test and set is atomic.
|
|
*/
|
|
|
|
(void)pthread_mutex_lock(&g_tsmutex);
|
|
#endif
|
|
|
|
/* In the non-SMP case, the simulation is implemented with a single thread
|
|
* the test-and-set operation is inherently atomic.
|
|
*/
|
|
|
|
spinlock_t ret = *lock;
|
|
*lock = SP_LOCKED;
|
|
|
|
#ifdef CONFIG_SMP
|
|
(void)pthread_mutex_unlock(&g_tsmutex);
|
|
#endif
|
|
return ret;
|
|
}
|