1 /*
2  * Copyright (C) 2021 Huawei Device Co., Ltd.
3  * Licensed under the Apache License, Version 2.0 (the "License");
4  * you may not use this file except in compliance with the License.
5  * You may obtain a copy of the License at
6  *
7  *     http://www.apache.org/licenses/LICENSE-2.0
8  *
9  * Unless required by applicable law or agreed to in writing, software
10  * distributed under the License is distributed on an "AS IS" BASIS,
11  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12  * See the License for the specific language governing permissions and
13  * limitations under the License.
14  */
15 
16 #ifndef SPINLOCK_H
17 #define SPINLOCK_H
18 
19 typedef struct {
20     volatile int lock;
21 } Spinlock;
22 
23 
24 #if defined(__x86_64__)
25 #include <emmintrin.h>
26 
Pause(void)27 inline static void Pause(void)
28 {
29     _mm_pause();
30 }
31 #elif defined(RTP_ARCH_ARM)
Pause(void)32 static inline void Pause(void)
33 {
34     asm volatile("yield" ::: "memory");
35 }
36 #else
Pause(void)37 static inline void Pause(void)
38 {
39 }
40 #endif
41 
SpinLockInit(Spinlock * spinlock)42 static inline void SpinLockInit(Spinlock *spinlock)
43 {
44     spinlock->lock = 0;
45 }
46 
SpinLockTryLock(Spinlock * spinlock)47 static inline int SpinLockTryLock(Spinlock *spinlock)
48 {
49     if (__sync_bool_compare_and_swap(&spinlock->lock, 0, 1) == 0) {
50         return 0;
51     }
52 
53     return 1;
54 }
55 
SpinLock(Spinlock * spinlock)56 static inline void SpinLock(Spinlock *spinlock)
57 {
58     while (!SpinLockTryLock(spinlock)) {
59         do {
60             Pause();
61         } while (!!spinlock->lock);
62     }
63 }
64 
SpinUnlock(Spinlock * spinlock)65 static inline void SpinUnlock(Spinlock *spinlock)
66 {
67     __sync_lock_release(&spinlock->lock);
68 }
69 
70 #endif /* SPINLOCK_H */
71 
72