Nicolas Borla / Mbed OS BBR_1Ebene

BBR 1 Ebene

mbed-os/platform/mbed_critical.h@0:fbdae7e6d805, 2018-05-14 (annotated)

Committer:
borlanic
Date:
Mon May 14 11:29:06 2018 +0000
Revision:
0:fbdae7e6d805
BBR

Who changed what in which revision?

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borlanic 0:fbdae7e6d805 1
borlanic 0:fbdae7e6d805 2 /*
borlanic 0:fbdae7e6d805 3 * Copyright (c) 2015-2016, ARM Limited, All Rights Reserved
borlanic 0:fbdae7e6d805 4 * SPDX-License-Identifier: Apache-2.0
borlanic 0:fbdae7e6d805 5 *
borlanic 0:fbdae7e6d805 6 * Licensed under the Apache License, Version 2.0 (the "License"); you may
borlanic 0:fbdae7e6d805 7 * not use this file except in compliance with the License.
borlanic 0:fbdae7e6d805 8 * You may obtain a copy of the License at
borlanic 0:fbdae7e6d805 9 *
borlanic 0:fbdae7e6d805 10 * http://www.apache.org/licenses/LICENSE-2.0
borlanic 0:fbdae7e6d805 11 *
borlanic 0:fbdae7e6d805 12 * Unless required by applicable law or agreed to in writing, software
borlanic 0:fbdae7e6d805 13 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
borlanic 0:fbdae7e6d805 14 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
borlanic 0:fbdae7e6d805 15 * See the License for the specific language governing permissions and
borlanic 0:fbdae7e6d805 16 * limitations under the License.
borlanic 0:fbdae7e6d805 17 */
borlanic 0:fbdae7e6d805 18
borlanic 0:fbdae7e6d805 19 #ifndef __MBED_UTIL_CRITICAL_H__
borlanic 0:fbdae7e6d805 20 #define __MBED_UTIL_CRITICAL_H__
borlanic 0:fbdae7e6d805 21
borlanic 0:fbdae7e6d805 22 #include <stdbool.h>
borlanic 0:fbdae7e6d805 23 #include <stdint.h>
borlanic 0:fbdae7e6d805 24 #include <stddef.h>
borlanic 0:fbdae7e6d805 25
borlanic 0:fbdae7e6d805 26 #ifdef __cplusplus
borlanic 0:fbdae7e6d805 27 extern "C" {
borlanic 0:fbdae7e6d805 28 #endif
borlanic 0:fbdae7e6d805 29
borlanic 0:fbdae7e6d805 30 /** \addtogroup platform */
borlanic 0:fbdae7e6d805 31 /** @{*/
borlanic 0:fbdae7e6d805 32 /**
borlanic 0:fbdae7e6d805 33 * \defgroup platform_critical critical section function
borlanic 0:fbdae7e6d805 34 * @{
borlanic 0:fbdae7e6d805 35 */
borlanic 0:fbdae7e6d805 36
borlanic 0:fbdae7e6d805 37 /** Determine the current interrupts enabled state
borlanic 0:fbdae7e6d805 38 *
borlanic 0:fbdae7e6d805 39 * This function can be called to determine whether or not interrupts are currently enabled.
borlanic 0:fbdae7e6d805 40 * @note
borlanic 0:fbdae7e6d805 41 * NOTE:
borlanic 0:fbdae7e6d805 42 * This function works for both cortex-A and cortex-M, although the underlyng implementation
borlanic 0:fbdae7e6d805 43 * differs.
borlanic 0:fbdae7e6d805 44 * @return true if interrupts are enabled, false otherwise
borlanic 0:fbdae7e6d805 45 */
borlanic 0:fbdae7e6d805 46 bool core_util_are_interrupts_enabled(void);
borlanic 0:fbdae7e6d805 47
borlanic 0:fbdae7e6d805 48 /** Determine if this code is executing from an interrupt
borlanic 0:fbdae7e6d805 49 *
borlanic 0:fbdae7e6d805 50 * This function can be called to determine if the code is running on interrupt context.
borlanic 0:fbdae7e6d805 51 * @note
borlanic 0:fbdae7e6d805 52 * NOTE:
borlanic 0:fbdae7e6d805 53 * This function works for both cortex-A and cortex-M, although the underlyng implementation
borlanic 0:fbdae7e6d805 54 * differs.
borlanic 0:fbdae7e6d805 55 * @return true if in an isr, false otherwise
borlanic 0:fbdae7e6d805 56 */
borlanic 0:fbdae7e6d805 57 bool core_util_is_isr_active(void);
borlanic 0:fbdae7e6d805 58
borlanic 0:fbdae7e6d805 59 /** Mark the start of a critical section
borlanic 0:fbdae7e6d805 60 *
borlanic 0:fbdae7e6d805 61 * This function should be called to mark the start of a critical section of code.
borlanic 0:fbdae7e6d805 62 * @note
borlanic 0:fbdae7e6d805 63 * NOTES:
borlanic 0:fbdae7e6d805 64 * 1) The use of this style of critical section is targetted at C based implementations.
borlanic 0:fbdae7e6d805 65 * 2) These critical sections can be nested.
borlanic 0:fbdae7e6d805 66 * 3) The interrupt enable state on entry to the first critical section (of a nested set, or single
borlanic 0:fbdae7e6d805 67 * section) will be preserved on exit from the section.
borlanic 0:fbdae7e6d805 68 * 4) This implementation will currently only work on code running in privileged mode.
borlanic 0:fbdae7e6d805 69 */
borlanic 0:fbdae7e6d805 70 void core_util_critical_section_enter(void);
borlanic 0:fbdae7e6d805 71
borlanic 0:fbdae7e6d805 72 /** Mark the end of a critical section
borlanic 0:fbdae7e6d805 73 *
borlanic 0:fbdae7e6d805 74 * This function should be called to mark the end of a critical section of code.
borlanic 0:fbdae7e6d805 75 * @note
borlanic 0:fbdae7e6d805 76 * NOTES:
borlanic 0:fbdae7e6d805 77 * 1) The use of this style of critical section is targetted at C based implementations.
borlanic 0:fbdae7e6d805 78 * 2) These critical sections can be nested.
borlanic 0:fbdae7e6d805 79 * 3) The interrupt enable state on entry to the first critical section (of a nested set, or single
borlanic 0:fbdae7e6d805 80 * section) will be preserved on exit from the section.
borlanic 0:fbdae7e6d805 81 * 4) This implementation will currently only work on code running in privileged mode.
borlanic 0:fbdae7e6d805 82 */
borlanic 0:fbdae7e6d805 83 void core_util_critical_section_exit(void);
borlanic 0:fbdae7e6d805 84
borlanic 0:fbdae7e6d805 85 /**
borlanic 0:fbdae7e6d805 86 * Determine if we are currently in a critical section
borlanic 0:fbdae7e6d805 87 *
borlanic 0:fbdae7e6d805 88 * @return true if in a critical section, false otherwise.
borlanic 0:fbdae7e6d805 89 */
borlanic 0:fbdae7e6d805 90 bool core_util_in_critical_section(void);
borlanic 0:fbdae7e6d805 91
borlanic 0:fbdae7e6d805 92 /**
borlanic 0:fbdae7e6d805 93 * Atomic compare and set. It compares the contents of a memory location to a
borlanic 0:fbdae7e6d805 94 * given value and, only if they are the same, modifies the contents of that
borlanic 0:fbdae7e6d805 95 * memory location to a given new value. This is done as a single atomic
borlanic 0:fbdae7e6d805 96 * operation. The atomicity guarantees that the new value is calculated based on
borlanic 0:fbdae7e6d805 97 * up-to-date information; if the value had been updated by another thread in
borlanic 0:fbdae7e6d805 98 * the meantime, the write would fail due to a mismatched expectedCurrentValue.
borlanic 0:fbdae7e6d805 99 *
borlanic 0:fbdae7e6d805 100 * Refer to https://en.wikipedia.org/wiki/Compare-and-set [which may redirect
borlanic 0:fbdae7e6d805 101 * you to the article on compare-and swap].
borlanic 0:fbdae7e6d805 102 *
borlanic 0:fbdae7e6d805 103 * @param ptr The target memory location.
borlanic 0:fbdae7e6d805 104 * @param[in,out] expectedCurrentValue A pointer to some location holding the
borlanic 0:fbdae7e6d805 105 * expected current value of the data being set atomically.
borlanic 0:fbdae7e6d805 106 * The computed 'desiredValue' should be a function of this current value.
borlanic 0:fbdae7e6d805 107 * @note: This is an in-out parameter. In the
borlanic 0:fbdae7e6d805 108 * failure case of atomic_cas (where the
borlanic 0:fbdae7e6d805 109 * destination isn't set), the pointee of expectedCurrentValue is
borlanic 0:fbdae7e6d805 110 * updated with the current value.
borlanic 0:fbdae7e6d805 111 * @param[in] desiredValue The new value computed based on '*expectedCurrentValue'.
borlanic 0:fbdae7e6d805 112 *
borlanic 0:fbdae7e6d805 113 * @return true if the memory location was atomically
borlanic 0:fbdae7e6d805 114 * updated with the desired value (after verifying
borlanic 0:fbdae7e6d805 115 * that it contained the expectedCurrentValue),
borlanic 0:fbdae7e6d805 116 * false otherwise. In the failure case,
borlanic 0:fbdae7e6d805 117 * exepctedCurrentValue is updated with the new
borlanic 0:fbdae7e6d805 118 * value of the target memory location.
borlanic 0:fbdae7e6d805 119 *
borlanic 0:fbdae7e6d805 120 * pseudocode:
borlanic 0:fbdae7e6d805 121 * function cas(p : pointer to int, old : pointer to int, new : int) returns bool {
borlanic 0:fbdae7e6d805 122 * if *p != *old {
borlanic 0:fbdae7e6d805 123 * *old = *p
borlanic 0:fbdae7e6d805 124 * return false
borlanic 0:fbdae7e6d805 125 * }
borlanic 0:fbdae7e6d805 126 * *p = new
borlanic 0:fbdae7e6d805 127 * return true
borlanic 0:fbdae7e6d805 128 * }
borlanic 0:fbdae7e6d805 129 *
borlanic 0:fbdae7e6d805 130 * @note: In the failure case (where the destination isn't set), the value
borlanic 0:fbdae7e6d805 131 * pointed to by expectedCurrentValue is instead updated with the current value.
borlanic 0:fbdae7e6d805 132 * This property helps writing concise code for the following incr:
borlanic 0:fbdae7e6d805 133 *
borlanic 0:fbdae7e6d805 134 * function incr(p : pointer to int, a : int) returns int {
borlanic 0:fbdae7e6d805 135 * done = false
borlanic 0:fbdae7e6d805 136 * value = *p // This fetch operation need not be atomic.
borlanic 0:fbdae7e6d805 137 * while not done {
borlanic 0:fbdae7e6d805 138 * done = atomic_cas(p, &value, value + a) // *value gets updated automatically until success
borlanic 0:fbdae7e6d805 139 * }
borlanic 0:fbdae7e6d805 140 * return value + a
borlanic 0:fbdae7e6d805 141 * }
borlanic 0:fbdae7e6d805 142 *
borlanic 0:fbdae7e6d805 143 * @note: This corresponds to the C11 "atomic_compare_exchange_strong" - it
borlanic 0:fbdae7e6d805 144 * always succeeds if the current value is expected, as per the pseudocode
borlanic 0:fbdae7e6d805 145 * above; it will not spuriously fail as "atomic_compare_exchange_weak" may.
borlanic 0:fbdae7e6d805 146 */
borlanic 0:fbdae7e6d805 147 bool core_util_atomic_cas_u8(volatile uint8_t *ptr, uint8_t *expectedCurrentValue, uint8_t desiredValue);
borlanic 0:fbdae7e6d805 148
borlanic 0:fbdae7e6d805 149 /**
borlanic 0:fbdae7e6d805 150 * Atomic compare and set. It compares the contents of a memory location to a
borlanic 0:fbdae7e6d805 151 * given value and, only if they are the same, modifies the contents of that
borlanic 0:fbdae7e6d805 152 * memory location to a given new value. This is done as a single atomic
borlanic 0:fbdae7e6d805 153 * operation. The atomicity guarantees that the new value is calculated based on
borlanic 0:fbdae7e6d805 154 * up-to-date information; if the value had been updated by another thread in
borlanic 0:fbdae7e6d805 155 * the meantime, the write would fail due to a mismatched expectedCurrentValue.
borlanic 0:fbdae7e6d805 156 *
borlanic 0:fbdae7e6d805 157 * Refer to https://en.wikipedia.org/wiki/Compare-and-set [which may redirect
borlanic 0:fbdae7e6d805 158 * you to the article on compare-and swap].
borlanic 0:fbdae7e6d805 159 *
borlanic 0:fbdae7e6d805 160 * @param ptr The target memory location.
borlanic 0:fbdae7e6d805 161 * @param[in,out] expectedCurrentValue A pointer to some location holding the
borlanic 0:fbdae7e6d805 162 * expected current value of the data being set atomically.
borlanic 0:fbdae7e6d805 163 * The computed 'desiredValue' should be a function of this current value.
borlanic 0:fbdae7e6d805 164 * @note: This is an in-out parameter. In the
borlanic 0:fbdae7e6d805 165 * failure case of atomic_cas (where the
borlanic 0:fbdae7e6d805 166 * destination isn't set), the pointee of expectedCurrentValue is
borlanic 0:fbdae7e6d805 167 * updated with the current value.
borlanic 0:fbdae7e6d805 168 * @param[in] desiredValue The new value computed based on '*expectedCurrentValue'.
borlanic 0:fbdae7e6d805 169 *
borlanic 0:fbdae7e6d805 170 * @return true if the memory location was atomically
borlanic 0:fbdae7e6d805 171 * updated with the desired value (after verifying
borlanic 0:fbdae7e6d805 172 * that it contained the expectedCurrentValue),
borlanic 0:fbdae7e6d805 173 * false otherwise. In the failure case,
borlanic 0:fbdae7e6d805 174 * exepctedCurrentValue is updated with the new
borlanic 0:fbdae7e6d805 175 * value of the target memory location.
borlanic 0:fbdae7e6d805 176 *
borlanic 0:fbdae7e6d805 177 * pseudocode:
borlanic 0:fbdae7e6d805 178 * function cas(p : pointer to int, old : pointer to int, new : int) returns bool {
borlanic 0:fbdae7e6d805 179 * if *p != *old {
borlanic 0:fbdae7e6d805 180 * *old = *p
borlanic 0:fbdae7e6d805 181 * return false
borlanic 0:fbdae7e6d805 182 * }
borlanic 0:fbdae7e6d805 183 * *p = new
borlanic 0:fbdae7e6d805 184 * return true
borlanic 0:fbdae7e6d805 185 * }
borlanic 0:fbdae7e6d805 186 *
borlanic 0:fbdae7e6d805 187 * @note: In the failure case (where the destination isn't set), the value
borlanic 0:fbdae7e6d805 188 * pointed to by expectedCurrentValue is instead updated with the current value.
borlanic 0:fbdae7e6d805 189 * This property helps writing concise code for the following incr:
borlanic 0:fbdae7e6d805 190 *
borlanic 0:fbdae7e6d805 191 * function incr(p : pointer to int, a : int) returns int {
borlanic 0:fbdae7e6d805 192 * done = false
borlanic 0:fbdae7e6d805 193 * value = *p // This fetch operation need not be atomic.
borlanic 0:fbdae7e6d805 194 * while not done {
borlanic 0:fbdae7e6d805 195 * done = atomic_cas(p, &value, value + a) // *value gets updated automatically until success
borlanic 0:fbdae7e6d805 196 * }
borlanic 0:fbdae7e6d805 197 * return value + a
borlanic 0:fbdae7e6d805 198 * }
borlanic 0:fbdae7e6d805 199 *
borlanic 0:fbdae7e6d805 200 * @note: This corresponds to the C11 "atomic_compare_exchange_strong" - it
borlanic 0:fbdae7e6d805 201 * always succeeds if the current value is expected, as per the pseudocode
borlanic 0:fbdae7e6d805 202 * above; it will not spuriously fail as "atomic_compare_exchange_weak" may.
borlanic 0:fbdae7e6d805 203 */
borlanic 0:fbdae7e6d805 204 bool core_util_atomic_cas_u16(volatile uint16_t *ptr, uint16_t *expectedCurrentValue, uint16_t desiredValue);
borlanic 0:fbdae7e6d805 205
borlanic 0:fbdae7e6d805 206 /**
borlanic 0:fbdae7e6d805 207 * Atomic compare and set. It compares the contents of a memory location to a
borlanic 0:fbdae7e6d805 208 * given value and, only if they are the same, modifies the contents of that
borlanic 0:fbdae7e6d805 209 * memory location to a given new value. This is done as a single atomic
borlanic 0:fbdae7e6d805 210 * operation. The atomicity guarantees that the new value is calculated based on
borlanic 0:fbdae7e6d805 211 * up-to-date information; if the value had been updated by another thread in
borlanic 0:fbdae7e6d805 212 * the meantime, the write would fail due to a mismatched expectedCurrentValue.
borlanic 0:fbdae7e6d805 213 *
borlanic 0:fbdae7e6d805 214 * Refer to https://en.wikipedia.org/wiki/Compare-and-set [which may redirect
borlanic 0:fbdae7e6d805 215 * you to the article on compare-and swap].
borlanic 0:fbdae7e6d805 216 *
borlanic 0:fbdae7e6d805 217 * @param ptr The target memory location.
borlanic 0:fbdae7e6d805 218 * @param[in,out] expectedCurrentValue A pointer to some location holding the
borlanic 0:fbdae7e6d805 219 * expected current value of the data being set atomically.
borlanic 0:fbdae7e6d805 220 * The computed 'desiredValue' should be a function of this current value.
borlanic 0:fbdae7e6d805 221 * @note: This is an in-out parameter. In the
borlanic 0:fbdae7e6d805 222 * failure case of atomic_cas (where the
borlanic 0:fbdae7e6d805 223 * destination isn't set), the pointee of expectedCurrentValue is
borlanic 0:fbdae7e6d805 224 * updated with the current value.
borlanic 0:fbdae7e6d805 225 * @param[in] desiredValue The new value computed based on '*expectedCurrentValue'.
borlanic 0:fbdae7e6d805 226 *
borlanic 0:fbdae7e6d805 227 * @return true if the memory location was atomically
borlanic 0:fbdae7e6d805 228 * updated with the desired value (after verifying
borlanic 0:fbdae7e6d805 229 * that it contained the expectedCurrentValue),
borlanic 0:fbdae7e6d805 230 * false otherwise. In the failure case,
borlanic 0:fbdae7e6d805 231 * exepctedCurrentValue is updated with the new
borlanic 0:fbdae7e6d805 232 * value of the target memory location.
borlanic 0:fbdae7e6d805 233 *
borlanic 0:fbdae7e6d805 234 * pseudocode:
borlanic 0:fbdae7e6d805 235 * function cas(p : pointer to int, old : pointer to int, new : int) returns bool {
borlanic 0:fbdae7e6d805 236 * if *p != *old {
borlanic 0:fbdae7e6d805 237 * *old = *p
borlanic 0:fbdae7e6d805 238 * return false
borlanic 0:fbdae7e6d805 239 * }
borlanic 0:fbdae7e6d805 240 * *p = new
borlanic 0:fbdae7e6d805 241 * return true
borlanic 0:fbdae7e6d805 242 * }
borlanic 0:fbdae7e6d805 243 *
borlanic 0:fbdae7e6d805 244 * @note: In the failure case (where the destination isn't set), the value
borlanic 0:fbdae7e6d805 245 * pointed to by expectedCurrentValue is instead updated with the current value.
borlanic 0:fbdae7e6d805 246 * This property helps writing concise code for the following incr:
borlanic 0:fbdae7e6d805 247 *
borlanic 0:fbdae7e6d805 248 * function incr(p : pointer to int, a : int) returns int {
borlanic 0:fbdae7e6d805 249 * done = false
borlanic 0:fbdae7e6d805 250 * value = *p // This fetch operation need not be atomic.
borlanic 0:fbdae7e6d805 251 * while not done {
borlanic 0:fbdae7e6d805 252 * done = atomic_cas(p, &value, value + a) // *value gets updated automatically until success
borlanic 0:fbdae7e6d805 253 * }
borlanic 0:fbdae7e6d805 254 * return value + a
borlanic 0:fbdae7e6d805 255 *
borlanic 0:fbdae7e6d805 256 * @note: This corresponds to the C11 "atomic_compare_exchange_strong" - it
borlanic 0:fbdae7e6d805 257 * always succeeds if the current value is expected, as per the pseudocode
borlanic 0:fbdae7e6d805 258 * above; it will not spuriously fail as "atomic_compare_exchange_weak" may.
borlanic 0:fbdae7e6d805 259 * }
borlanic 0:fbdae7e6d805 260 */
borlanic 0:fbdae7e6d805 261 bool core_util_atomic_cas_u32(volatile uint32_t *ptr, uint32_t *expectedCurrentValue, uint32_t desiredValue);
borlanic 0:fbdae7e6d805 262
borlanic 0:fbdae7e6d805 263 /**
borlanic 0:fbdae7e6d805 264 * Atomic compare and set. It compares the contents of a memory location to a
borlanic 0:fbdae7e6d805 265 * given value and, only if they are the same, modifies the contents of that
borlanic 0:fbdae7e6d805 266 * memory location to a given new value. This is done as a single atomic
borlanic 0:fbdae7e6d805 267 * operation. The atomicity guarantees that the new value is calculated based on
borlanic 0:fbdae7e6d805 268 * up-to-date information; if the value had been updated by another thread in
borlanic 0:fbdae7e6d805 269 * the meantime, the write would fail due to a mismatched expectedCurrentValue.
borlanic 0:fbdae7e6d805 270 *
borlanic 0:fbdae7e6d805 271 * Refer to https://en.wikipedia.org/wiki/Compare-and-set [which may redirect
borlanic 0:fbdae7e6d805 272 * you to the article on compare-and swap].
borlanic 0:fbdae7e6d805 273 *
borlanic 0:fbdae7e6d805 274 * @param ptr The target memory location.
borlanic 0:fbdae7e6d805 275 * @param[in,out] expectedCurrentValue A pointer to some location holding the
borlanic 0:fbdae7e6d805 276 * expected current value of the data being set atomically.
borlanic 0:fbdae7e6d805 277 * The computed 'desiredValue' should be a function of this current value.
borlanic 0:fbdae7e6d805 278 * @note: This is an in-out parameter. In the
borlanic 0:fbdae7e6d805 279 * failure case of atomic_cas (where the
borlanic 0:fbdae7e6d805 280 * destination isn't set), the pointee of expectedCurrentValue is
borlanic 0:fbdae7e6d805 281 * updated with the current value.
borlanic 0:fbdae7e6d805 282 * @param[in] desiredValue The new value computed based on '*expectedCurrentValue'.
borlanic 0:fbdae7e6d805 283 *
borlanic 0:fbdae7e6d805 284 * @return true if the memory location was atomically
borlanic 0:fbdae7e6d805 285 * updated with the desired value (after verifying
borlanic 0:fbdae7e6d805 286 * that it contained the expectedCurrentValue),
borlanic 0:fbdae7e6d805 287 * false otherwise. In the failure case,
borlanic 0:fbdae7e6d805 288 * exepctedCurrentValue is updated with the new
borlanic 0:fbdae7e6d805 289 * value of the target memory location.
borlanic 0:fbdae7e6d805 290 *
borlanic 0:fbdae7e6d805 291 * pseudocode:
borlanic 0:fbdae7e6d805 292 * function cas(p : pointer to int, old : pointer to int, new : int) returns bool {
borlanic 0:fbdae7e6d805 293 * if *p != *old {
borlanic 0:fbdae7e6d805 294 * *old = *p
borlanic 0:fbdae7e6d805 295 * return false
borlanic 0:fbdae7e6d805 296 * }
borlanic 0:fbdae7e6d805 297 * *p = new
borlanic 0:fbdae7e6d805 298 * return true
borlanic 0:fbdae7e6d805 299 * }
borlanic 0:fbdae7e6d805 300 *
borlanic 0:fbdae7e6d805 301 * @note: In the failure case (where the destination isn't set), the value
borlanic 0:fbdae7e6d805 302 * pointed to by expectedCurrentValue is instead updated with the current value.
borlanic 0:fbdae7e6d805 303 * This property helps writing concise code for the following incr:
borlanic 0:fbdae7e6d805 304 *
borlanic 0:fbdae7e6d805 305 * function incr(p : pointer to int, a : int) returns int {
borlanic 0:fbdae7e6d805 306 * done = false
borlanic 0:fbdae7e6d805 307 * value = *p // This fetch operation need not be atomic.
borlanic 0:fbdae7e6d805 308 * while not done {
borlanic 0:fbdae7e6d805 309 * done = atomic_cas(p, &value, value + a) // *value gets updated automatically until success
borlanic 0:fbdae7e6d805 310 * }
borlanic 0:fbdae7e6d805 311 * return value + a
borlanic 0:fbdae7e6d805 312 * }
borlanic 0:fbdae7e6d805 313 *
borlanic 0:fbdae7e6d805 314 * @note: This corresponds to the C11 "atomic_compare_exchange_strong" - it
borlanic 0:fbdae7e6d805 315 * always succeeds if the current value is expected, as per the pseudocode
borlanic 0:fbdae7e6d805 316 * above; it will not spuriously fail as "atomic_compare_exchange_weak" may.
borlanic 0:fbdae7e6d805 317 */
borlanic 0:fbdae7e6d805 318 bool core_util_atomic_cas_ptr(void * volatile *ptr, void **expectedCurrentValue, void *desiredValue);
borlanic 0:fbdae7e6d805 319
borlanic 0:fbdae7e6d805 320 /**
borlanic 0:fbdae7e6d805 321 * Atomic increment.
borlanic 0:fbdae7e6d805 322 * @param valuePtr Target memory location being incremented.
borlanic 0:fbdae7e6d805 323 * @param delta The amount being incremented.
borlanic 0:fbdae7e6d805 324 * @return The new incremented value.
borlanic 0:fbdae7e6d805 325 */
borlanic 0:fbdae7e6d805 326 uint8_t core_util_atomic_incr_u8(volatile uint8_t *valuePtr, uint8_t delta);
borlanic 0:fbdae7e6d805 327
borlanic 0:fbdae7e6d805 328 /**
borlanic 0:fbdae7e6d805 329 * Atomic increment.
borlanic 0:fbdae7e6d805 330 * @param valuePtr Target memory location being incremented.
borlanic 0:fbdae7e6d805 331 * @param delta The amount being incremented.
borlanic 0:fbdae7e6d805 332 * @return The new incremented value.
borlanic 0:fbdae7e6d805 333 */
borlanic 0:fbdae7e6d805 334 uint16_t core_util_atomic_incr_u16(volatile uint16_t *valuePtr, uint16_t delta);
borlanic 0:fbdae7e6d805 335
borlanic 0:fbdae7e6d805 336 /**
borlanic 0:fbdae7e6d805 337 * Atomic increment.
borlanic 0:fbdae7e6d805 338 * @param valuePtr Target memory location being incremented.
borlanic 0:fbdae7e6d805 339 * @param delta The amount being incremented.
borlanic 0:fbdae7e6d805 340 * @return The new incremented value.
borlanic 0:fbdae7e6d805 341 */
borlanic 0:fbdae7e6d805 342 uint32_t core_util_atomic_incr_u32(volatile uint32_t *valuePtr, uint32_t delta);
borlanic 0:fbdae7e6d805 343
borlanic 0:fbdae7e6d805 344 /**
borlanic 0:fbdae7e6d805 345 * Atomic increment.
borlanic 0:fbdae7e6d805 346 * @param valuePtr Target memory location being incremented.
borlanic 0:fbdae7e6d805 347 * @param delta The amount being incremented in bytes.
borlanic 0:fbdae7e6d805 348 * @return The new incremented value.
borlanic 0:fbdae7e6d805 349 *
borlanic 0:fbdae7e6d805 350 * @note The type of the pointer argument is not taken into account
borlanic 0:fbdae7e6d805 351 * and the pointer is incremented by bytes.
borlanic 0:fbdae7e6d805 352 */
borlanic 0:fbdae7e6d805 353 void *core_util_atomic_incr_ptr(void * volatile *valuePtr, ptrdiff_t delta);
borlanic 0:fbdae7e6d805 354
borlanic 0:fbdae7e6d805 355 /**
borlanic 0:fbdae7e6d805 356 * Atomic decrement.
borlanic 0:fbdae7e6d805 357 * @param valuePtr Target memory location being decremented.
borlanic 0:fbdae7e6d805 358 * @param delta The amount being decremented.
borlanic 0:fbdae7e6d805 359 * @return The new decremented value.
borlanic 0:fbdae7e6d805 360 */
borlanic 0:fbdae7e6d805 361 uint8_t core_util_atomic_decr_u8(volatile uint8_t *valuePtr, uint8_t delta);
borlanic 0:fbdae7e6d805 362
borlanic 0:fbdae7e6d805 363 /**
borlanic 0:fbdae7e6d805 364 * Atomic decrement.
borlanic 0:fbdae7e6d805 365 * @param valuePtr Target memory location being decremented.
borlanic 0:fbdae7e6d805 366 * @param delta The amount being decremented.
borlanic 0:fbdae7e6d805 367 * @return The new decremented value.
borlanic 0:fbdae7e6d805 368 */
borlanic 0:fbdae7e6d805 369 uint16_t core_util_atomic_decr_u16(volatile uint16_t *valuePtr, uint16_t delta);
borlanic 0:fbdae7e6d805 370
borlanic 0:fbdae7e6d805 371 /**
borlanic 0:fbdae7e6d805 372 * Atomic decrement.
borlanic 0:fbdae7e6d805 373 * @param valuePtr Target memory location being decremented.
borlanic 0:fbdae7e6d805 374 * @param delta The amount being decremented.
borlanic 0:fbdae7e6d805 375 * @return The new decremented value.
borlanic 0:fbdae7e6d805 376 */
borlanic 0:fbdae7e6d805 377 uint32_t core_util_atomic_decr_u32(volatile uint32_t *valuePtr, uint32_t delta);
borlanic 0:fbdae7e6d805 378
borlanic 0:fbdae7e6d805 379 /**
borlanic 0:fbdae7e6d805 380 * Atomic decrement.
borlanic 0:fbdae7e6d805 381 * @param valuePtr Target memory location being decremented.
borlanic 0:fbdae7e6d805 382 * @param delta The amount being decremented in bytes.
borlanic 0:fbdae7e6d805 383 * @return The new decremented value.
borlanic 0:fbdae7e6d805 384 *
borlanic 0:fbdae7e6d805 385 * @note The type of the pointer argument is not taken into account
borlanic 0:fbdae7e6d805 386 * and the pointer is decremented by bytes
borlanic 0:fbdae7e6d805 387 */
borlanic 0:fbdae7e6d805 388 void *core_util_atomic_decr_ptr(void * volatile *valuePtr, ptrdiff_t delta);
borlanic 0:fbdae7e6d805 389
borlanic 0:fbdae7e6d805 390 #ifdef __cplusplus
borlanic 0:fbdae7e6d805 391 } // extern "C"
borlanic 0:fbdae7e6d805 392 #endif
borlanic 0:fbdae7e6d805 393 /**@}*/
borlanic 0:fbdae7e6d805 394
borlanic 0:fbdae7e6d805 395 /**@}*/
borlanic 0:fbdae7e6d805 396
borlanic 0:fbdae7e6d805 397 #endif // __MBED_UTIL_CRITICAL_H__
borlanic 0:fbdae7e6d805 398
borlanic 0:fbdae7e6d805 399
borlanic 0:fbdae7e6d805 400