DPDK: Data Plane Development Kit

18.08.0-rc0
rte_rwlock.h
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1 /* SPDX-License-Identifier: BSD-3-Clause
2  * Copyright(c) 2010-2014 Intel Corporation
3  */
4 
5 #ifndef _RTE_RWLOCK_H_
6 #define _RTE_RWLOCK_H_
7 
20 #ifdef __cplusplus
21 extern "C" {
22 #endif
23 
24 #include <rte_common.h>
25 #include <rte_atomic.h>
26 #include <rte_pause.h>
27 
33 typedef struct {
34  volatile int32_t cnt;
35 } rte_rwlock_t;
36 
40 #define RTE_RWLOCK_INITIALIZER { 0 }
41 
48 static inline void
50 {
51  rwl->cnt = 0;
52 }
53 
60 static inline void
62 {
63  int32_t x;
64  int success = 0;
65 
66  while (success == 0) {
67  x = rwl->cnt;
68  /* write lock is held */
69  if (x < 0) {
70  rte_pause();
71  continue;
72  }
73  success = rte_atomic32_cmpset((volatile uint32_t *)&rwl->cnt,
74  (uint32_t)x, (uint32_t)(x + 1));
75  }
76 }
77 
84 static inline void
86 {
87  rte_atomic32_dec((rte_atomic32_t *)(intptr_t)&rwl->cnt);
88 }
89 
96 static inline void
98 {
99  int32_t x;
100  int success = 0;
101 
102  while (success == 0) {
103  x = rwl->cnt;
104  /* a lock is held */
105  if (x != 0) {
106  rte_pause();
107  continue;
108  }
109  success = rte_atomic32_cmpset((volatile uint32_t *)&rwl->cnt,
110  0, (uint32_t)-1);
111  }
112 }
113 
120 static inline void
122 {
123  rte_atomic32_inc((rte_atomic32_t *)(intptr_t)&rwl->cnt);
124 }
125 
139 static inline void
141 
148 static inline void
150 
164 static inline void
166 
173 static inline void
175 
176 #ifdef __cplusplus
177 }
178 #endif
179 
180 #endif /* _RTE_RWLOCK_H_ */