Jim Carver / Mbed OS mbed-cloud-workshop-connect-PIR

Important changes to repositories hosted on mbed.com

Mbed hosted mercurial repositories are deprecated and are due to be permanently deleted in July 2026.

To keep a copy of this software download the repository Zip archive or clone locally using Mercurial.

It is also possible to export all your personal repositories from the account settings page.

Dependencies:   HTS221

Fork of mbed-cloud-workshop-connect-HTS221 by Jim Carver

simple-mbed-cloud-client/mbed-cloud-client/update-client-hub/modules/atomic-queue/source/atomic.h@0:6b753f761943, 2018-10-12 (annotated)

Committer:
JimCarver
Date:
Fri Oct 12 21:22:49 2018 +0000
Revision:
0:6b753f761943
Initial commit

Who changed what in which revision?

UserRevisionLine numberNew contents of line
JimCarver 0:6b753f761943 1 // ----------------------------------------------------------------------------
JimCarver 0:6b753f761943 2 // Copyright 2015-2017 ARM Ltd.
JimCarver 0:6b753f761943 3 //
JimCarver 0:6b753f761943 4 // SPDX-License-Identifier: Apache-2.0
JimCarver 0:6b753f761943 5 //
JimCarver 0:6b753f761943 6 // Licensed under the Apache License, Version 2.0 (the "License");
JimCarver 0:6b753f761943 7 // you may not use this file except in compliance with the License.
JimCarver 0:6b753f761943 8 // You may obtain a copy of the License at
JimCarver 0:6b753f761943 9 //
JimCarver 0:6b753f761943 10 // http://www.apache.org/licenses/LICENSE-2.0
JimCarver 0:6b753f761943 11 //
JimCarver 0:6b753f761943 12 // Unless required by applicable law or agreed to in writing, software
JimCarver 0:6b753f761943 13 // distributed under the License is distributed on an "AS IS" BASIS,
JimCarver 0:6b753f761943 14 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
JimCarver 0:6b753f761943 15 // See the License for the specific language governing permissions and
JimCarver 0:6b753f761943 16 // limitations under the License.
JimCarver 0:6b753f761943 17 // ----------------------------------------------------------------------------
JimCarver 0:6b753f761943 18
JimCarver 0:6b753f761943 19 #ifndef ATOMIC_QUEUE_ATOMIC_H
JimCarver 0:6b753f761943 20 #define ATOMIC_QUEUE_ATOMIC_H
JimCarver 0:6b753f761943 21 #include <stdint.h>
JimCarver 0:6b753f761943 22
JimCarver 0:6b753f761943 23
JimCarver 0:6b753f761943 24
JimCarver 0:6b753f761943 25 #ifdef __cplusplus
JimCarver 0:6b753f761943 26 extern "C" {
JimCarver 0:6b753f761943 27 #endif
JimCarver 0:6b753f761943 28
JimCarver 0:6b753f761943 29 enum {
JimCarver 0:6b753f761943 30 AQ_ATOMIC_CAS_DEREF_SUCCESS = 0,
JimCarver 0:6b753f761943 31 AQ_ATOMIC_CAS_DEREF_NULLPTR,
JimCarver 0:6b753f761943 32 AQ_ATOMIC_CAS_DEREF_VALUE,
JimCarver 0:6b753f761943 33 AQ_ATOMIC_CAS_DEREF_INTERUPTED,
JimCarver 0:6b753f761943 34 };
JimCarver 0:6b753f761943 35
JimCarver 0:6b753f761943 36 /**
JimCarver 0:6b753f761943 37 * @brief Atomically compares the value of a dereferenced pointer, replacing the pointer on success.
JimCarver 0:6b753f761943 38 * @detail aq_atomic_cas_deref_uintptr provides a mechanism to atomically change a pointer based on a value contained
JimCarver 0:6b753f761943 39 * in the structure referenced by the pointer. This is done in the following sequence of operations:
JimCarver 0:6b753f761943 40 *
JimCarver 0:6b753f761943 41 * 1. Load the value of `*ptrAddr`
JimCarver 0:6b753f761943 42 * 2. Optionally store the current value of `*ptrAddr`
JimCarver 0:6b753f761943 43 * 3. Check that the pointer is valid: `*ptrAddr != NULL`
JimCarver 0:6b753f761943 44 * 4. Check the value of the referenced location: `*(*ptrAddr + valueOffset) == expectedDerefValue` (casts omitted)
JimCarver 0:6b753f761943 45 * 5. If 3 and 4 succeeded, store newPtrValue: `*ptrAddr = newPtrValue` (NOTE: in non-blocking implementations, this step can fail)
JimCarver 0:6b753f761943 46 * 6. Return a status code based on the results of 3, 4, 5.
JimCarver 0:6b753f761943 47 *
JimCarver 0:6b753f761943 48 * @param[in,out] ptrAddr The address of the pointer to manipulate
JimCarver 0:6b753f761943 49 * @param[out] currentPtrValue A pointer to a container for the current value of *ptrAddr
JimCarver 0:6b753f761943 50 * @param[in] expectedDerefValue This is the value that is expected at *(uintptr_t *)((uintptr_t)*ptrAddr + valueOffset)
JimCarver 0:6b753f761943 51 * @param[in] newPtrValue The value to store to *ptrAddr if the comparison is successful
JimCarver 0:6b753f761943 52 * @param[in] valueOffset The offset of the target value from *ptrAddr
JimCarver 0:6b753f761943 53 *
JimCarver 0:6b753f761943 54 * @retval AQ_ATOMIC_CAS_DEREF_SUCCESS The compare and set has succeeded
JimCarver 0:6b753f761943 55 * @retval AQ_ATOMIC_CAS_DEREF_NULLPTR `*ptrAddr` was `NULL`
JimCarver 0:6b753f761943 56 * @retval AQ_ATOMIC_CAS_DEREF_VALUE The value test failed (*(*ptrAddr + valueOffset) != expectedDerefValue`)
JimCarver 0:6b753f761943 57 * @retval AQ_ATOMIC_CAS_DEREF_INTERUPTED Another context modified `*ptrAddr`
JimCarver 0:6b753f761943 58 */
JimCarver 0:6b753f761943 59 int aq_atomic_cas_deref_uintptr(uintptr_t* volatile * ptrAddr,
JimCarver 0:6b753f761943 60 uintptr_t** currentPtrValue,
JimCarver 0:6b753f761943 61 uintptr_t expectedDerefValue,
JimCarver 0:6b753f761943 62 uintptr_t* newPtrValue,
JimCarver 0:6b753f761943 63 uintptr_t valueOffset);
JimCarver 0:6b753f761943 64
JimCarver 0:6b753f761943 65 #ifdef __cplusplus
JimCarver 0:6b753f761943 66 } // extern "C"
JimCarver 0:6b753f761943 67 #endif
JimCarver 0:6b753f761943 68 #endif // ATOMIC_QUEUE_ATOMIC_H