Marco Zecchini / Mbed OS Example_RTOS

Rtos API example

mbed-os/platform/mbed_critical.h@0:9fca2b23d0ba, 2019-02-23 (annotated)

Committer:
marcozecchini
Date:
Sat Feb 23 12:13:36 2019 +0000
Revision:
0:9fca2b23d0ba
final commit

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marcozecchini 0:9fca2b23d0ba 1
marcozecchini 0:9fca2b23d0ba 2 /*
marcozecchini 0:9fca2b23d0ba 3 * Copyright (c) 2015-2016, ARM Limited, All Rights Reserved
marcozecchini 0:9fca2b23d0ba 4 * SPDX-License-Identifier: Apache-2.0
marcozecchini 0:9fca2b23d0ba 5 *
marcozecchini 0:9fca2b23d0ba 6 * Licensed under the Apache License, Version 2.0 (the "License"); you may
marcozecchini 0:9fca2b23d0ba 7 * not use this file except in compliance with the License.
marcozecchini 0:9fca2b23d0ba 8 * You may obtain a copy of the License at
marcozecchini 0:9fca2b23d0ba 9 *
marcozecchini 0:9fca2b23d0ba 10 * http://www.apache.org/licenses/LICENSE-2.0
marcozecchini 0:9fca2b23d0ba 11 *
marcozecchini 0:9fca2b23d0ba 12 * Unless required by applicable law or agreed to in writing, software
marcozecchini 0:9fca2b23d0ba 13 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
marcozecchini 0:9fca2b23d0ba 14 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
marcozecchini 0:9fca2b23d0ba 15 * See the License for the specific language governing permissions and
marcozecchini 0:9fca2b23d0ba 16 * limitations under the License.
marcozecchini 0:9fca2b23d0ba 17 */
marcozecchini 0:9fca2b23d0ba 18
marcozecchini 0:9fca2b23d0ba 19 #ifndef __MBED_UTIL_CRITICAL_H__
marcozecchini 0:9fca2b23d0ba 20 #define __MBED_UTIL_CRITICAL_H__
marcozecchini 0:9fca2b23d0ba 21
marcozecchini 0:9fca2b23d0ba 22 #include <stdbool.h>
marcozecchini 0:9fca2b23d0ba 23 #include <stdint.h>
marcozecchini 0:9fca2b23d0ba 24 #include <stddef.h>
marcozecchini 0:9fca2b23d0ba 25
marcozecchini 0:9fca2b23d0ba 26 #ifdef __cplusplus
marcozecchini 0:9fca2b23d0ba 27 extern "C" {
marcozecchini 0:9fca2b23d0ba 28 #endif
marcozecchini 0:9fca2b23d0ba 29
marcozecchini 0:9fca2b23d0ba 30 /** \addtogroup platform */
marcozecchini 0:9fca2b23d0ba 31 /** @{*/
marcozecchini 0:9fca2b23d0ba 32 /**
marcozecchini 0:9fca2b23d0ba 33 * \defgroup platform_critical critical section function
marcozecchini 0:9fca2b23d0ba 34 * @{
marcozecchini 0:9fca2b23d0ba 35 */
marcozecchini 0:9fca2b23d0ba 36
marcozecchini 0:9fca2b23d0ba 37 /** Determine the current interrupts enabled state
marcozecchini 0:9fca2b23d0ba 38 *
marcozecchini 0:9fca2b23d0ba 39 * This function can be called to determine whether or not interrupts are currently enabled.
marcozecchini 0:9fca2b23d0ba 40 * @note
marcozecchini 0:9fca2b23d0ba 41 * NOTE:
marcozecchini 0:9fca2b23d0ba 42 * This function works for both cortex-A and cortex-M, although the underlyng implementation
marcozecchini 0:9fca2b23d0ba 43 * differs.
marcozecchini 0:9fca2b23d0ba 44 * @return true if interrupts are enabled, false otherwise
marcozecchini 0:9fca2b23d0ba 45 */
marcozecchini 0:9fca2b23d0ba 46 bool core_util_are_interrupts_enabled(void);
marcozecchini 0:9fca2b23d0ba 47
marcozecchini 0:9fca2b23d0ba 48 /** Determine if this code is executing from an interrupt
marcozecchini 0:9fca2b23d0ba 49 *
marcozecchini 0:9fca2b23d0ba 50 * This function can be called to determine if the code is running on interrupt context.
marcozecchini 0:9fca2b23d0ba 51 * @note
marcozecchini 0:9fca2b23d0ba 52 * NOTE:
marcozecchini 0:9fca2b23d0ba 53 * This function works for both cortex-A and cortex-M, although the underlyng implementation
marcozecchini 0:9fca2b23d0ba 54 * differs.
marcozecchini 0:9fca2b23d0ba 55 * @return true if in an isr, false otherwise
marcozecchini 0:9fca2b23d0ba 56 */
marcozecchini 0:9fca2b23d0ba 57 bool core_util_is_isr_active(void);
marcozecchini 0:9fca2b23d0ba 58
marcozecchini 0:9fca2b23d0ba 59 /** Mark the start of a critical section
marcozecchini 0:9fca2b23d0ba 60 *
marcozecchini 0:9fca2b23d0ba 61 * This function should be called to mark the start of a critical section of code.
marcozecchini 0:9fca2b23d0ba 62 * @note
marcozecchini 0:9fca2b23d0ba 63 * NOTES:
marcozecchini 0:9fca2b23d0ba 64 * 1) The use of this style of critical section is targetted at C based implementations.
marcozecchini 0:9fca2b23d0ba 65 * 2) These critical sections can be nested.
marcozecchini 0:9fca2b23d0ba 66 * 3) The interrupt enable state on entry to the first critical section (of a nested set, or single
marcozecchini 0:9fca2b23d0ba 67 * section) will be preserved on exit from the section.
marcozecchini 0:9fca2b23d0ba 68 * 4) This implementation will currently only work on code running in privileged mode.
marcozecchini 0:9fca2b23d0ba 69 */
marcozecchini 0:9fca2b23d0ba 70 void core_util_critical_section_enter(void);
marcozecchini 0:9fca2b23d0ba 71
marcozecchini 0:9fca2b23d0ba 72 /** Mark the end of a critical section
marcozecchini 0:9fca2b23d0ba 73 *
marcozecchini 0:9fca2b23d0ba 74 * This function should be called to mark the end of a critical section of code.
marcozecchini 0:9fca2b23d0ba 75 * @note
marcozecchini 0:9fca2b23d0ba 76 * NOTES:
marcozecchini 0:9fca2b23d0ba 77 * 1) The use of this style of critical section is targetted at C based implementations.
marcozecchini 0:9fca2b23d0ba 78 * 2) These critical sections can be nested.
marcozecchini 0:9fca2b23d0ba 79 * 3) The interrupt enable state on entry to the first critical section (of a nested set, or single
marcozecchini 0:9fca2b23d0ba 80 * section) will be preserved on exit from the section.
marcozecchini 0:9fca2b23d0ba 81 * 4) This implementation will currently only work on code running in privileged mode.
marcozecchini 0:9fca2b23d0ba 82 */
marcozecchini 0:9fca2b23d0ba 83 void core_util_critical_section_exit(void);
marcozecchini 0:9fca2b23d0ba 84
marcozecchini 0:9fca2b23d0ba 85 /**
marcozecchini 0:9fca2b23d0ba 86 * Atomic compare and set. It compares the contents of a memory location to a
marcozecchini 0:9fca2b23d0ba 87 * given value and, only if they are the same, modifies the contents of that
marcozecchini 0:9fca2b23d0ba 88 * memory location to a given new value. This is done as a single atomic
marcozecchini 0:9fca2b23d0ba 89 * operation. The atomicity guarantees that the new value is calculated based on
marcozecchini 0:9fca2b23d0ba 90 * up-to-date information; if the value had been updated by another thread in
marcozecchini 0:9fca2b23d0ba 91 * the meantime, the write would fail due to a mismatched expectedCurrentValue.
marcozecchini 0:9fca2b23d0ba 92 *
marcozecchini 0:9fca2b23d0ba 93 * Refer to https://en.wikipedia.org/wiki/Compare-and-set [which may redirect
marcozecchini 0:9fca2b23d0ba 94 * you to the article on compare-and swap].
marcozecchini 0:9fca2b23d0ba 95 *
marcozecchini 0:9fca2b23d0ba 96 * @param ptr The target memory location.
marcozecchini 0:9fca2b23d0ba 97 * @param[in,out] expectedCurrentValue A pointer to some location holding the
marcozecchini 0:9fca2b23d0ba 98 * expected current value of the data being set atomically.
marcozecchini 0:9fca2b23d0ba 99 * The computed 'desiredValue' should be a function of this current value.
marcozecchini 0:9fca2b23d0ba 100 * @note: This is an in-out parameter. In the
marcozecchini 0:9fca2b23d0ba 101 * failure case of atomic_cas (where the
marcozecchini 0:9fca2b23d0ba 102 * destination isn't set), the pointee of expectedCurrentValue is
marcozecchini 0:9fca2b23d0ba 103 * updated with the current value.
marcozecchini 0:9fca2b23d0ba 104 * @param[in] desiredValue The new value computed based on '*expectedCurrentValue'.
marcozecchini 0:9fca2b23d0ba 105 *
marcozecchini 0:9fca2b23d0ba 106 * @return true if the memory location was atomically
marcozecchini 0:9fca2b23d0ba 107 * updated with the desired value (after verifying
marcozecchini 0:9fca2b23d0ba 108 * that it contained the expectedCurrentValue),
marcozecchini 0:9fca2b23d0ba 109 * false otherwise. In the failure case,
marcozecchini 0:9fca2b23d0ba 110 * exepctedCurrentValue is updated with the new
marcozecchini 0:9fca2b23d0ba 111 * value of the target memory location.
marcozecchini 0:9fca2b23d0ba 112 *
marcozecchini 0:9fca2b23d0ba 113 * pseudocode:
marcozecchini 0:9fca2b23d0ba 114 * function cas(p : pointer to int, old : pointer to int, new : int) returns bool {
marcozecchini 0:9fca2b23d0ba 115 * if *p != *old {
marcozecchini 0:9fca2b23d0ba 116 * *old = *p
marcozecchini 0:9fca2b23d0ba 117 * return false
marcozecchini 0:9fca2b23d0ba 118 * }
marcozecchini 0:9fca2b23d0ba 119 * *p = new
marcozecchini 0:9fca2b23d0ba 120 * return true
marcozecchini 0:9fca2b23d0ba 121 * }
marcozecchini 0:9fca2b23d0ba 122 *
marcozecchini 0:9fca2b23d0ba 123 * @note: In the failure case (where the destination isn't set), the value
marcozecchini 0:9fca2b23d0ba 124 * pointed to by expectedCurrentValue is still updated with the current value.
marcozecchini 0:9fca2b23d0ba 125 * This property helps writing concise code for the following incr:
marcozecchini 0:9fca2b23d0ba 126 *
marcozecchini 0:9fca2b23d0ba 127 * function incr(p : pointer to int, a : int) returns int {
marcozecchini 0:9fca2b23d0ba 128 * done = false
marcozecchini 0:9fca2b23d0ba 129 * value = *p // This fetch operation need not be atomic.
marcozecchini 0:9fca2b23d0ba 130 * while not done {
marcozecchini 0:9fca2b23d0ba 131 * done = atomic_cas(p, &value, value + a) // *value gets updated automatically until success
marcozecchini 0:9fca2b23d0ba 132 * }
marcozecchini 0:9fca2b23d0ba 133 * return value + a
marcozecchini 0:9fca2b23d0ba 134 * }
marcozecchini 0:9fca2b23d0ba 135 */
marcozecchini 0:9fca2b23d0ba 136 bool core_util_atomic_cas_u8(uint8_t *ptr, uint8_t *expectedCurrentValue, uint8_t desiredValue);
marcozecchini 0:9fca2b23d0ba 137
marcozecchini 0:9fca2b23d0ba 138 /**
marcozecchini 0:9fca2b23d0ba 139 * Atomic compare and set. It compares the contents of a memory location to a
marcozecchini 0:9fca2b23d0ba 140 * given value and, only if they are the same, modifies the contents of that
marcozecchini 0:9fca2b23d0ba 141 * memory location to a given new value. This is done as a single atomic
marcozecchini 0:9fca2b23d0ba 142 * operation. The atomicity guarantees that the new value is calculated based on
marcozecchini 0:9fca2b23d0ba 143 * up-to-date information; if the value had been updated by another thread in
marcozecchini 0:9fca2b23d0ba 144 * the meantime, the write would fail due to a mismatched expectedCurrentValue.
marcozecchini 0:9fca2b23d0ba 145 *
marcozecchini 0:9fca2b23d0ba 146 * Refer to https://en.wikipedia.org/wiki/Compare-and-set [which may redirect
marcozecchini 0:9fca2b23d0ba 147 * you to the article on compare-and swap].
marcozecchini 0:9fca2b23d0ba 148 *
marcozecchini 0:9fca2b23d0ba 149 * @param ptr The target memory location.
marcozecchini 0:9fca2b23d0ba 150 * @param[in,out] expectedCurrentValue A pointer to some location holding the
marcozecchini 0:9fca2b23d0ba 151 * expected current value of the data being set atomically.
marcozecchini 0:9fca2b23d0ba 152 * The computed 'desiredValue' should be a function of this current value.
marcozecchini 0:9fca2b23d0ba 153 * @note: This is an in-out parameter. In the
marcozecchini 0:9fca2b23d0ba 154 * failure case of atomic_cas (where the
marcozecchini 0:9fca2b23d0ba 155 * destination isn't set), the pointee of expectedCurrentValue is
marcozecchini 0:9fca2b23d0ba 156 * updated with the current value.
marcozecchini 0:9fca2b23d0ba 157 * @param[in] desiredValue The new value computed based on '*expectedCurrentValue'.
marcozecchini 0:9fca2b23d0ba 158 *
marcozecchini 0:9fca2b23d0ba 159 * @return true if the memory location was atomically
marcozecchini 0:9fca2b23d0ba 160 * updated with the desired value (after verifying
marcozecchini 0:9fca2b23d0ba 161 * that it contained the expectedCurrentValue),
marcozecchini 0:9fca2b23d0ba 162 * false otherwise. In the failure case,
marcozecchini 0:9fca2b23d0ba 163 * exepctedCurrentValue is updated with the new
marcozecchini 0:9fca2b23d0ba 164 * value of the target memory location.
marcozecchini 0:9fca2b23d0ba 165 *
marcozecchini 0:9fca2b23d0ba 166 * pseudocode:
marcozecchini 0:9fca2b23d0ba 167 * function cas(p : pointer to int, old : pointer to int, new : int) returns bool {
marcozecchini 0:9fca2b23d0ba 168 * if *p != *old {
marcozecchini 0:9fca2b23d0ba 169 * *old = *p
marcozecchini 0:9fca2b23d0ba 170 * return false
marcozecchini 0:9fca2b23d0ba 171 * }
marcozecchini 0:9fca2b23d0ba 172 * *p = new
marcozecchini 0:9fca2b23d0ba 173 * return true
marcozecchini 0:9fca2b23d0ba 174 * }
marcozecchini 0:9fca2b23d0ba 175 *
marcozecchini 0:9fca2b23d0ba 176 * @note: In the failure case (where the destination isn't set), the value
marcozecchini 0:9fca2b23d0ba 177 * pointed to by expectedCurrentValue is still updated with the current value.
marcozecchini 0:9fca2b23d0ba 178 * This property helps writing concise code for the following incr:
marcozecchini 0:9fca2b23d0ba 179 *
marcozecchini 0:9fca2b23d0ba 180 * function incr(p : pointer to int, a : int) returns int {
marcozecchini 0:9fca2b23d0ba 181 * done = false
marcozecchini 0:9fca2b23d0ba 182 * value = *p // This fetch operation need not be atomic.
marcozecchini 0:9fca2b23d0ba 183 * while not done {
marcozecchini 0:9fca2b23d0ba 184 * done = atomic_cas(p, &value, value + a) // *value gets updated automatically until success
marcozecchini 0:9fca2b23d0ba 185 * }
marcozecchini 0:9fca2b23d0ba 186 * return value + a
marcozecchini 0:9fca2b23d0ba 187 * }
marcozecchini 0:9fca2b23d0ba 188 */
marcozecchini 0:9fca2b23d0ba 189 bool core_util_atomic_cas_u16(uint16_t *ptr, uint16_t *expectedCurrentValue, uint16_t desiredValue);
marcozecchini 0:9fca2b23d0ba 190
marcozecchini 0:9fca2b23d0ba 191 /**
marcozecchini 0:9fca2b23d0ba 192 * Atomic compare and set. It compares the contents of a memory location to a
marcozecchini 0:9fca2b23d0ba 193 * given value and, only if they are the same, modifies the contents of that
marcozecchini 0:9fca2b23d0ba 194 * memory location to a given new value. This is done as a single atomic
marcozecchini 0:9fca2b23d0ba 195 * operation. The atomicity guarantees that the new value is calculated based on
marcozecchini 0:9fca2b23d0ba 196 * up-to-date information; if the value had been updated by another thread in
marcozecchini 0:9fca2b23d0ba 197 * the meantime, the write would fail due to a mismatched expectedCurrentValue.
marcozecchini 0:9fca2b23d0ba 198 *
marcozecchini 0:9fca2b23d0ba 199 * Refer to https://en.wikipedia.org/wiki/Compare-and-set [which may redirect
marcozecchini 0:9fca2b23d0ba 200 * you to the article on compare-and swap].
marcozecchini 0:9fca2b23d0ba 201 *
marcozecchini 0:9fca2b23d0ba 202 * @param ptr The target memory location.
marcozecchini 0:9fca2b23d0ba 203 * @param[in,out] expectedCurrentValue A pointer to some location holding the
marcozecchini 0:9fca2b23d0ba 204 * expected current value of the data being set atomically.
marcozecchini 0:9fca2b23d0ba 205 * The computed 'desiredValue' should be a function of this current value.
marcozecchini 0:9fca2b23d0ba 206 * @note: This is an in-out parameter. In the
marcozecchini 0:9fca2b23d0ba 207 * failure case of atomic_cas (where the
marcozecchini 0:9fca2b23d0ba 208 * destination isn't set), the pointee of expectedCurrentValue is
marcozecchini 0:9fca2b23d0ba 209 * updated with the current value.
marcozecchini 0:9fca2b23d0ba 210 * @param[in] desiredValue The new value computed based on '*expectedCurrentValue'.
marcozecchini 0:9fca2b23d0ba 211 *
marcozecchini 0:9fca2b23d0ba 212 * @return true if the memory location was atomically
marcozecchini 0:9fca2b23d0ba 213 * updated with the desired value (after verifying
marcozecchini 0:9fca2b23d0ba 214 * that it contained the expectedCurrentValue),
marcozecchini 0:9fca2b23d0ba 215 * false otherwise. In the failure case,
marcozecchini 0:9fca2b23d0ba 216 * exepctedCurrentValue is updated with the new
marcozecchini 0:9fca2b23d0ba 217 * value of the target memory location.
marcozecchini 0:9fca2b23d0ba 218 *
marcozecchini 0:9fca2b23d0ba 219 * pseudocode:
marcozecchini 0:9fca2b23d0ba 220 * function cas(p : pointer to int, old : pointer to int, new : int) returns bool {
marcozecchini 0:9fca2b23d0ba 221 * if *p != *old {
marcozecchini 0:9fca2b23d0ba 222 * *old = *p
marcozecchini 0:9fca2b23d0ba 223 * return false
marcozecchini 0:9fca2b23d0ba 224 * }
marcozecchini 0:9fca2b23d0ba 225 * *p = new
marcozecchini 0:9fca2b23d0ba 226 * return true
marcozecchini 0:9fca2b23d0ba 227 * }
marcozecchini 0:9fca2b23d0ba 228 *
marcozecchini 0:9fca2b23d0ba 229 * @note: In the failure case (where the destination isn't set), the value
marcozecchini 0:9fca2b23d0ba 230 * pointed to by expectedCurrentValue is still updated with the current value.
marcozecchini 0:9fca2b23d0ba 231 * This property helps writing concise code for the following incr:
marcozecchini 0:9fca2b23d0ba 232 *
marcozecchini 0:9fca2b23d0ba 233 * function incr(p : pointer to int, a : int) returns int {
marcozecchini 0:9fca2b23d0ba 234 * done = false
marcozecchini 0:9fca2b23d0ba 235 * value = *p // This fetch operation need not be atomic.
marcozecchini 0:9fca2b23d0ba 236 * while not done {
marcozecchini 0:9fca2b23d0ba 237 * done = atomic_cas(p, &value, value + a) // *value gets updated automatically until success
marcozecchini 0:9fca2b23d0ba 238 * }
marcozecchini 0:9fca2b23d0ba 239 * return value + a
marcozecchini 0:9fca2b23d0ba 240 * }
marcozecchini 0:9fca2b23d0ba 241 */
marcozecchini 0:9fca2b23d0ba 242 bool core_util_atomic_cas_u32(uint32_t *ptr, uint32_t *expectedCurrentValue, uint32_t desiredValue);
marcozecchini 0:9fca2b23d0ba 243
marcozecchini 0:9fca2b23d0ba 244 /**
marcozecchini 0:9fca2b23d0ba 245 * Atomic compare and set. It compares the contents of a memory location to a
marcozecchini 0:9fca2b23d0ba 246 * given value and, only if they are the same, modifies the contents of that
marcozecchini 0:9fca2b23d0ba 247 * memory location to a given new value. This is done as a single atomic
marcozecchini 0:9fca2b23d0ba 248 * operation. The atomicity guarantees that the new value is calculated based on
marcozecchini 0:9fca2b23d0ba 249 * up-to-date information; if the value had been updated by another thread in
marcozecchini 0:9fca2b23d0ba 250 * the meantime, the write would fail due to a mismatched expectedCurrentValue.
marcozecchini 0:9fca2b23d0ba 251 *
marcozecchini 0:9fca2b23d0ba 252 * Refer to https://en.wikipedia.org/wiki/Compare-and-set [which may redirect
marcozecchini 0:9fca2b23d0ba 253 * you to the article on compare-and swap].
marcozecchini 0:9fca2b23d0ba 254 *
marcozecchini 0:9fca2b23d0ba 255 * @param ptr The target memory location.
marcozecchini 0:9fca2b23d0ba 256 * @param[in,out] expectedCurrentValue A pointer to some location holding the
marcozecchini 0:9fca2b23d0ba 257 * expected current value of the data being set atomically.
marcozecchini 0:9fca2b23d0ba 258 * The computed 'desiredValue' should be a function of this current value.
marcozecchini 0:9fca2b23d0ba 259 * @note: This is an in-out parameter. In the
marcozecchini 0:9fca2b23d0ba 260 * failure case of atomic_cas (where the
marcozecchini 0:9fca2b23d0ba 261 * destination isn't set), the pointee of expectedCurrentValue is
marcozecchini 0:9fca2b23d0ba 262 * updated with the current value.
marcozecchini 0:9fca2b23d0ba 263 * @param[in] desiredValue The new value computed based on '*expectedCurrentValue'.
marcozecchini 0:9fca2b23d0ba 264 *
marcozecchini 0:9fca2b23d0ba 265 * @return true if the memory location was atomically
marcozecchini 0:9fca2b23d0ba 266 * updated with the desired value (after verifying
marcozecchini 0:9fca2b23d0ba 267 * that it contained the expectedCurrentValue),
marcozecchini 0:9fca2b23d0ba 268 * false otherwise. In the failure case,
marcozecchini 0:9fca2b23d0ba 269 * exepctedCurrentValue is updated with the new
marcozecchini 0:9fca2b23d0ba 270 * value of the target memory location.
marcozecchini 0:9fca2b23d0ba 271 *
marcozecchini 0:9fca2b23d0ba 272 * pseudocode:
marcozecchini 0:9fca2b23d0ba 273 * function cas(p : pointer to int, old : pointer to int, new : int) returns bool {
marcozecchini 0:9fca2b23d0ba 274 * if *p != *old {
marcozecchini 0:9fca2b23d0ba 275 * *old = *p
marcozecchini 0:9fca2b23d0ba 276 * return false
marcozecchini 0:9fca2b23d0ba 277 * }
marcozecchini 0:9fca2b23d0ba 278 * *p = new
marcozecchini 0:9fca2b23d0ba 279 * return true
marcozecchini 0:9fca2b23d0ba 280 * }
marcozecchini 0:9fca2b23d0ba 281 *
marcozecchini 0:9fca2b23d0ba 282 * @note: In the failure case (where the destination isn't set), the value
marcozecchini 0:9fca2b23d0ba 283 * pointed to by expectedCurrentValue is still updated with the current value.
marcozecchini 0:9fca2b23d0ba 284 * This property helps writing concise code for the following incr:
marcozecchini 0:9fca2b23d0ba 285 *
marcozecchini 0:9fca2b23d0ba 286 * function incr(p : pointer to int, a : int) returns int {
marcozecchini 0:9fca2b23d0ba 287 * done = false
marcozecchini 0:9fca2b23d0ba 288 * value = *p // This fetch operation need not be atomic.
marcozecchini 0:9fca2b23d0ba 289 * while not done {
marcozecchini 0:9fca2b23d0ba 290 * done = atomic_cas(p, &value, value + a) // *value gets updated automatically until success
marcozecchini 0:9fca2b23d0ba 291 * }
marcozecchini 0:9fca2b23d0ba 292 * return value + a
marcozecchini 0:9fca2b23d0ba 293 * }
marcozecchini 0:9fca2b23d0ba 294 */
marcozecchini 0:9fca2b23d0ba 295 bool core_util_atomic_cas_ptr(void **ptr, void **expectedCurrentValue, void *desiredValue);
marcozecchini 0:9fca2b23d0ba 296
marcozecchini 0:9fca2b23d0ba 297 /**
marcozecchini 0:9fca2b23d0ba 298 * Atomic increment.
marcozecchini 0:9fca2b23d0ba 299 * @param valuePtr Target memory location being incremented.
marcozecchini 0:9fca2b23d0ba 300 * @param delta The amount being incremented.
marcozecchini 0:9fca2b23d0ba 301 * @return The new incremented value.
marcozecchini 0:9fca2b23d0ba 302 */
marcozecchini 0:9fca2b23d0ba 303 uint8_t core_util_atomic_incr_u8(uint8_t *valuePtr, uint8_t delta);
marcozecchini 0:9fca2b23d0ba 304
marcozecchini 0:9fca2b23d0ba 305 /**
marcozecchini 0:9fca2b23d0ba 306 * Atomic increment.
marcozecchini 0:9fca2b23d0ba 307 * @param valuePtr Target memory location being incremented.
marcozecchini 0:9fca2b23d0ba 308 * @param delta The amount being incremented.
marcozecchini 0:9fca2b23d0ba 309 * @return The new incremented value.
marcozecchini 0:9fca2b23d0ba 310 */
marcozecchini 0:9fca2b23d0ba 311 uint16_t core_util_atomic_incr_u16(uint16_t *valuePtr, uint16_t delta);
marcozecchini 0:9fca2b23d0ba 312
marcozecchini 0:9fca2b23d0ba 313 /**
marcozecchini 0:9fca2b23d0ba 314 * Atomic increment.
marcozecchini 0:9fca2b23d0ba 315 * @param valuePtr Target memory location being incremented.
marcozecchini 0:9fca2b23d0ba 316 * @param delta The amount being incremented.
marcozecchini 0:9fca2b23d0ba 317 * @return The new incremented value.
marcozecchini 0:9fca2b23d0ba 318 */
marcozecchini 0:9fca2b23d0ba 319 uint32_t core_util_atomic_incr_u32(uint32_t *valuePtr, uint32_t delta);
marcozecchini 0:9fca2b23d0ba 320
marcozecchini 0:9fca2b23d0ba 321 /**
marcozecchini 0:9fca2b23d0ba 322 * Atomic increment.
marcozecchini 0:9fca2b23d0ba 323 * @param valuePtr Target memory location being incremented.
marcozecchini 0:9fca2b23d0ba 324 * @param delta The amount being incremented in bytes.
marcozecchini 0:9fca2b23d0ba 325 * @return The new incremented value.
marcozecchini 0:9fca2b23d0ba 326 *
marcozecchini 0:9fca2b23d0ba 327 * @note The type of the pointer argument is not taken into account
marcozecchini 0:9fca2b23d0ba 328 * and the pointer is incremented by bytes.
marcozecchini 0:9fca2b23d0ba 329 */
marcozecchini 0:9fca2b23d0ba 330 void *core_util_atomic_incr_ptr(void **valuePtr, ptrdiff_t delta);
marcozecchini 0:9fca2b23d0ba 331
marcozecchini 0:9fca2b23d0ba 332 /**
marcozecchini 0:9fca2b23d0ba 333 * Atomic decrement.
marcozecchini 0:9fca2b23d0ba 334 * @param valuePtr Target memory location being decremented.
marcozecchini 0:9fca2b23d0ba 335 * @param delta The amount being decremented.
marcozecchini 0:9fca2b23d0ba 336 * @return The new decremented value.
marcozecchini 0:9fca2b23d0ba 337 */
marcozecchini 0:9fca2b23d0ba 338 uint8_t core_util_atomic_decr_u8(uint8_t *valuePtr, uint8_t delta);
marcozecchini 0:9fca2b23d0ba 339
marcozecchini 0:9fca2b23d0ba 340 /**
marcozecchini 0:9fca2b23d0ba 341 * Atomic decrement.
marcozecchini 0:9fca2b23d0ba 342 * @param valuePtr Target memory location being decremented.
marcozecchini 0:9fca2b23d0ba 343 * @param delta The amount being decremented.
marcozecchini 0:9fca2b23d0ba 344 * @return The new decremented value.
marcozecchini 0:9fca2b23d0ba 345 */
marcozecchini 0:9fca2b23d0ba 346 uint16_t core_util_atomic_decr_u16(uint16_t *valuePtr, uint16_t delta);
marcozecchini 0:9fca2b23d0ba 347
marcozecchini 0:9fca2b23d0ba 348 /**
marcozecchini 0:9fca2b23d0ba 349 * Atomic decrement.
marcozecchini 0:9fca2b23d0ba 350 * @param valuePtr Target memory location being decremented.
marcozecchini 0:9fca2b23d0ba 351 * @param delta The amount being decremented.
marcozecchini 0:9fca2b23d0ba 352 * @return The new decremented value.
marcozecchini 0:9fca2b23d0ba 353 */
marcozecchini 0:9fca2b23d0ba 354 uint32_t core_util_atomic_decr_u32(uint32_t *valuePtr, uint32_t delta);
marcozecchini 0:9fca2b23d0ba 355
marcozecchini 0:9fca2b23d0ba 356 /**
marcozecchini 0:9fca2b23d0ba 357 * Atomic decrement.
marcozecchini 0:9fca2b23d0ba 358 * @param valuePtr Target memory location being decremented.
marcozecchini 0:9fca2b23d0ba 359 * @param delta The amount being decremented in bytes.
marcozecchini 0:9fca2b23d0ba 360 * @return The new decremented value.
marcozecchini 0:9fca2b23d0ba 361 *
marcozecchini 0:9fca2b23d0ba 362 * @note The type of the pointer argument is not taken into account
marcozecchini 0:9fca2b23d0ba 363 * and the pointer is decremented by bytes
marcozecchini 0:9fca2b23d0ba 364 */
marcozecchini 0:9fca2b23d0ba 365 void *core_util_atomic_decr_ptr(void **valuePtr, ptrdiff_t delta);
marcozecchini 0:9fca2b23d0ba 366
marcozecchini 0:9fca2b23d0ba 367 #ifdef __cplusplus
marcozecchini 0:9fca2b23d0ba 368 } // extern "C"
marcozecchini 0:9fca2b23d0ba 369 #endif
marcozecchini 0:9fca2b23d0ba 370 /**@}*/
marcozecchini 0:9fca2b23d0ba 371
marcozecchini 0:9fca2b23d0ba 372 /**@}*/
marcozecchini 0:9fca2b23d0ba 373
marcozecchini 0:9fca2b23d0ba 374 #endif // __MBED_UTIL_CRITICAL_H__
marcozecchini 0:9fca2b23d0ba 375
marcozecchini 0:9fca2b23d0ba 376
marcozecchini 0:9fca2b23d0ba 377