Marco Zecchini / Mbed OS Example_RTOS

Rtos API example

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

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

Who changed what in which revision?

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marcozecchini 0:9fca2b23d0ba 1
marcozecchini 0:9fca2b23d0ba 2 /** \addtogroup platform */
marcozecchini 0:9fca2b23d0ba 3 /** @{*/
marcozecchini 0:9fca2b23d0ba 4 /**
marcozecchini 0:9fca2b23d0ba 5 * \defgroup platform_SingletonPtr SingletonPtr class
marcozecchini 0:9fca2b23d0ba 6 * @{
marcozecchini 0:9fca2b23d0ba 7 */
marcozecchini 0:9fca2b23d0ba 8 /* mbed Microcontroller Library
marcozecchini 0:9fca2b23d0ba 9 * Copyright (c) 2006-2013 ARM Limited
marcozecchini 0:9fca2b23d0ba 10 *
marcozecchini 0:9fca2b23d0ba 11 * Licensed under the Apache License, Version 2.0 (the "License");
marcozecchini 0:9fca2b23d0ba 12 * you may not use this file except in compliance with the License.
marcozecchini 0:9fca2b23d0ba 13 * You may obtain a copy of the License at
marcozecchini 0:9fca2b23d0ba 14 *
marcozecchini 0:9fca2b23d0ba 15 * http://www.apache.org/licenses/LICENSE-2.0
marcozecchini 0:9fca2b23d0ba 16 *
marcozecchini 0:9fca2b23d0ba 17 * Unless required by applicable law or agreed to in writing, software
marcozecchini 0:9fca2b23d0ba 18 * distributed under the License is distributed on an "AS IS" BASIS,
marcozecchini 0:9fca2b23d0ba 19 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
marcozecchini 0:9fca2b23d0ba 20 * See the License for the specific language governing permissions and
marcozecchini 0:9fca2b23d0ba 21 * limitations under the License.
marcozecchini 0:9fca2b23d0ba 22 */
marcozecchini 0:9fca2b23d0ba 23 #ifndef SINGLETONPTR_H
marcozecchini 0:9fca2b23d0ba 24 #define SINGLETONPTR_H
marcozecchini 0:9fca2b23d0ba 25
marcozecchini 0:9fca2b23d0ba 26 #include <stdint.h>
marcozecchini 0:9fca2b23d0ba 27 #include <new>
marcozecchini 0:9fca2b23d0ba 28 #include "platform/mbed_assert.h"
marcozecchini 0:9fca2b23d0ba 29 #ifdef MBED_CONF_RTOS_PRESENT
marcozecchini 0:9fca2b23d0ba 30 #include "cmsis_os2.h"
marcozecchini 0:9fca2b23d0ba 31 #endif
marcozecchini 0:9fca2b23d0ba 32
marcozecchini 0:9fca2b23d0ba 33 #ifdef MBED_CONF_RTOS_PRESENT
marcozecchini 0:9fca2b23d0ba 34 extern osMutexId_t singleton_mutex_id;
marcozecchini 0:9fca2b23d0ba 35 #endif
marcozecchini 0:9fca2b23d0ba 36
marcozecchini 0:9fca2b23d0ba 37 /** Lock the singleton mutex
marcozecchini 0:9fca2b23d0ba 38 *
marcozecchini 0:9fca2b23d0ba 39 * This function is typically used to provide
marcozecchini 0:9fca2b23d0ba 40 * exclusive access when initializing a
marcozecchini 0:9fca2b23d0ba 41 * global object.
marcozecchini 0:9fca2b23d0ba 42 */
marcozecchini 0:9fca2b23d0ba 43 inline static void singleton_lock(void)
marcozecchini 0:9fca2b23d0ba 44 {
marcozecchini 0:9fca2b23d0ba 45 #ifdef MBED_CONF_RTOS_PRESENT
marcozecchini 0:9fca2b23d0ba 46 osMutexAcquire(singleton_mutex_id, osWaitForever);
marcozecchini 0:9fca2b23d0ba 47 #endif
marcozecchini 0:9fca2b23d0ba 48 }
marcozecchini 0:9fca2b23d0ba 49
marcozecchini 0:9fca2b23d0ba 50 /** Unlock the singleton mutex
marcozecchini 0:9fca2b23d0ba 51 *
marcozecchini 0:9fca2b23d0ba 52 * This function is typically used to provide
marcozecchini 0:9fca2b23d0ba 53 * exclusive access when initializing a
marcozecchini 0:9fca2b23d0ba 54 * global object.
marcozecchini 0:9fca2b23d0ba 55 */
marcozecchini 0:9fca2b23d0ba 56 inline static void singleton_unlock(void)
marcozecchini 0:9fca2b23d0ba 57 {
marcozecchini 0:9fca2b23d0ba 58 #ifdef MBED_CONF_RTOS_PRESENT
marcozecchini 0:9fca2b23d0ba 59 osMutexRelease (singleton_mutex_id);
marcozecchini 0:9fca2b23d0ba 60 #endif
marcozecchini 0:9fca2b23d0ba 61 }
marcozecchini 0:9fca2b23d0ba 62
marcozecchini 0:9fca2b23d0ba 63 /** Utility class for creating an using a singleton
marcozecchini 0:9fca2b23d0ba 64 *
marcozecchini 0:9fca2b23d0ba 65 * @note Synchronization level: Thread safe
marcozecchini 0:9fca2b23d0ba 66 *
marcozecchini 0:9fca2b23d0ba 67 * @note: This class must only be used in a static context -
marcozecchini 0:9fca2b23d0ba 68 * this class must never be allocated or created on the
marcozecchini 0:9fca2b23d0ba 69 * stack.
marcozecchini 0:9fca2b23d0ba 70 *
marcozecchini 0:9fca2b23d0ba 71 * @note: This class is lazily initialized on first use.
marcozecchini 0:9fca2b23d0ba 72 * This class is a POD type so if it is not used it will
marcozecchini 0:9fca2b23d0ba 73 * be garbage collected.
marcozecchini 0:9fca2b23d0ba 74 */
marcozecchini 0:9fca2b23d0ba 75 template <class T>
marcozecchini 0:9fca2b23d0ba 76 struct SingletonPtr {
marcozecchini 0:9fca2b23d0ba 77
marcozecchini 0:9fca2b23d0ba 78 /** Get a pointer to the underlying singleton
marcozecchini 0:9fca2b23d0ba 79 *
marcozecchini 0:9fca2b23d0ba 80 * @returns
marcozecchini 0:9fca2b23d0ba 81 * A pointer to the singleton
marcozecchini 0:9fca2b23d0ba 82 */
marcozecchini 0:9fca2b23d0ba 83 T* get() {
marcozecchini 0:9fca2b23d0ba 84 if (NULL == _ptr) {
marcozecchini 0:9fca2b23d0ba 85 singleton_lock();
marcozecchini 0:9fca2b23d0ba 86 if (NULL == _ptr) {
marcozecchini 0:9fca2b23d0ba 87 _ptr = new (_data) T();
marcozecchini 0:9fca2b23d0ba 88 }
marcozecchini 0:9fca2b23d0ba 89 singleton_unlock();
marcozecchini 0:9fca2b23d0ba 90 }
marcozecchini 0:9fca2b23d0ba 91 // _ptr was not zero initialized or was
marcozecchini 0:9fca2b23d0ba 92 // corrupted if this assert is hit
marcozecchini 0:9fca2b23d0ba 93 MBED_ASSERT(_ptr == (T *)&_data);
marcozecchini 0:9fca2b23d0ba 94 return _ptr;
marcozecchini 0:9fca2b23d0ba 95 }
marcozecchini 0:9fca2b23d0ba 96
marcozecchini 0:9fca2b23d0ba 97 /** Get a pointer to the underlying singleton
marcozecchini 0:9fca2b23d0ba 98 *
marcozecchini 0:9fca2b23d0ba 99 * @returns
marcozecchini 0:9fca2b23d0ba 100 * A pointer to the singleton
marcozecchini 0:9fca2b23d0ba 101 */
marcozecchini 0:9fca2b23d0ba 102 T* operator->() {
marcozecchini 0:9fca2b23d0ba 103 return get();
marcozecchini 0:9fca2b23d0ba 104 }
marcozecchini 0:9fca2b23d0ba 105
marcozecchini 0:9fca2b23d0ba 106 // This is zero initialized when in global scope
marcozecchini 0:9fca2b23d0ba 107 T *_ptr;
marcozecchini 0:9fca2b23d0ba 108 // Force data to be 4 byte aligned
marcozecchini 0:9fca2b23d0ba 109 uint32_t _data[(sizeof(T) + sizeof(uint32_t) - 1) / sizeof(uint32_t)];
marcozecchini 0:9fca2b23d0ba 110 };
marcozecchini 0:9fca2b23d0ba 111
marcozecchini 0:9fca2b23d0ba 112 #endif
marcozecchini 0:9fca2b23d0ba 113 /**@}*/
marcozecchini 0:9fca2b23d0ba 114
marcozecchini 0:9fca2b23d0ba 115 /**@}*/