Contiki-NG
atomic.c
1 /*
2  * Copyright (c) 2019, Toshiba Corporation
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
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8  *
9  * 1. Redistributions of source code must retain the above copyright
10  * notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  * notice, this list of conditions and the following disclaimer in the
13  * documentation and/or other materials provided with the distribution.
14  * 3. Neither the name of the copyright holder nor the names of its
15  * contributors may be used to endorse or promote products derived
16  * from this software without specific prior written permission.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
21  * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
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29  * OF THE POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 /**
33  * \addtogroup atomic
34  * @{
35  */
36 
37 #include "atomic.h"
38 #include <sys/critical.h>
39 
40 /*---------------------------------------------------------------------------*/
41 bool
42 atomic_generic_cas_uint8(uint8_t *target, uint8_t old_val, uint8_t new_val)
43 {
44  bool ret = false;
46  if(*target == old_val) {
47  *target = new_val;
48  ret = true;
49  }
50  critical_exit(status);
51  return ret;
52 }
53 /** @} */
static void critical_exit(int_master_status_t status)
Exit a critical section and restore the master interrupt.
Definition: critical.h:81
static int_master_status_t critical_enter()
Enter a critical section.
Definition: critical.h:65
INT_MASTER_STATUS_DATATYPE int_master_status_t
Master interrupt state representation data type.
Definition: int-master.h:62
bool atomic_generic_cas_uint8(uint8_t *target, uint8_t old_val, uint8_t new_val)
Atomic compare-and-swap (CAS) on a byte (generic impl.)
Definition: atomic.c:42