Kev Mann / mbed-dev-OS5_10_4

RTC auf true

platform/SingletonPtr.h@2:7aab896b1a3b, 2019-03-13 (annotated)

Committer:
kevman
Date:
Wed Mar 13 11:03:24 2019 +0000
Revision:
2:7aab896b1a3b
Parent:
0:38ceb79fef03 
2019-03-13

Who changed what in which revision?

UserRevisionLine numberNew contents of line
kevman 0:38ceb79fef03 1
kevman 0:38ceb79fef03 2 /** \addtogroup platform */
kevman 0:38ceb79fef03 3 /** @{*/
kevman 0:38ceb79fef03 4 /**
kevman 0:38ceb79fef03 5 * \defgroup platform_SingletonPtr SingletonPtr class
kevman 0:38ceb79fef03 6 * @{
kevman 0:38ceb79fef03 7 */
kevman 0:38ceb79fef03 8 /* mbed Microcontroller Library
kevman 0:38ceb79fef03 9 * Copyright (c) 2006-2013 ARM Limited
kevman 0:38ceb79fef03 10 *
kevman 0:38ceb79fef03 11 * Licensed under the Apache License, Version 2.0 (the "License");
kevman 0:38ceb79fef03 12 * you may not use this file except in compliance with the License.
kevman 0:38ceb79fef03 13 * You may obtain a copy of the License at
kevman 0:38ceb79fef03 14 *
kevman 0:38ceb79fef03 15 * http://www.apache.org/licenses/LICENSE-2.0
kevman 0:38ceb79fef03 16 *
kevman 0:38ceb79fef03 17 * Unless required by applicable law or agreed to in writing, software
kevman 0:38ceb79fef03 18 * distributed under the License is distributed on an "AS IS" BASIS,
kevman 0:38ceb79fef03 19 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
kevman 0:38ceb79fef03 20 * See the License for the specific language governing permissions and
kevman 0:38ceb79fef03 21 * limitations under the License.
kevman 0:38ceb79fef03 22 */
kevman 0:38ceb79fef03 23 #ifndef SINGLETONPTR_H
kevman 0:38ceb79fef03 24 #define SINGLETONPTR_H
kevman 0:38ceb79fef03 25
kevman 0:38ceb79fef03 26 #include <stdint.h>
kevman 0:38ceb79fef03 27 #include <new>
kevman 0:38ceb79fef03 28 #include "platform/mbed_assert.h"
kevman 0:38ceb79fef03 29 #ifdef MBED_CONF_RTOS_PRESENT
kevman 0:38ceb79fef03 30 #include "cmsis_os2.h"
kevman 0:38ceb79fef03 31 #endif
kevman 0:38ceb79fef03 32
kevman 0:38ceb79fef03 33 #ifdef MBED_CONF_RTOS_PRESENT
kevman 0:38ceb79fef03 34 extern osMutexId_t singleton_mutex_id;
kevman 0:38ceb79fef03 35 #endif
kevman 0:38ceb79fef03 36
kevman 0:38ceb79fef03 37 /** Lock the singleton mutex
kevman 0:38ceb79fef03 38 *
kevman 0:38ceb79fef03 39 * This function is typically used to provide
kevman 0:38ceb79fef03 40 * exclusive access when initializing a
kevman 0:38ceb79fef03 41 * global object.
kevman 0:38ceb79fef03 42 */
kevman 0:38ceb79fef03 43 inline static void singleton_lock(void)
kevman 0:38ceb79fef03 44 {
kevman 0:38ceb79fef03 45 #ifdef MBED_CONF_RTOS_PRESENT
kevman 0:38ceb79fef03 46 if (!singleton_mutex_id) {
kevman 0:38ceb79fef03 47 // RTOS has not booted yet so no mutex is needed
kevman 0:38ceb79fef03 48 return;
kevman 0:38ceb79fef03 49 }
kevman 0:38ceb79fef03 50 osMutexAcquire(singleton_mutex_id, osWaitForever);
kevman 0:38ceb79fef03 51 #endif
kevman 0:38ceb79fef03 52 }
kevman 0:38ceb79fef03 53
kevman 0:38ceb79fef03 54 /** Unlock the singleton mutex
kevman 0:38ceb79fef03 55 *
kevman 0:38ceb79fef03 56 * This function is typically used to provide
kevman 0:38ceb79fef03 57 * exclusive access when initializing a
kevman 0:38ceb79fef03 58 * global object.
kevman 0:38ceb79fef03 59 */
kevman 0:38ceb79fef03 60 inline static void singleton_unlock(void)
kevman 0:38ceb79fef03 61 {
kevman 0:38ceb79fef03 62 #ifdef MBED_CONF_RTOS_PRESENT
kevman 0:38ceb79fef03 63 if (!singleton_mutex_id) {
kevman 0:38ceb79fef03 64 // RTOS has not booted yet so no mutex is needed
kevman 0:38ceb79fef03 65 return;
kevman 0:38ceb79fef03 66 }
kevman 0:38ceb79fef03 67 osMutexRelease(singleton_mutex_id);
kevman 0:38ceb79fef03 68 #endif
kevman 0:38ceb79fef03 69 }
kevman 0:38ceb79fef03 70
kevman 0:38ceb79fef03 71 /** Utility class for creating an using a singleton
kevman 0:38ceb79fef03 72 *
kevman 0:38ceb79fef03 73 * @note Synchronization level: Thread safe
kevman 0:38ceb79fef03 74 *
kevman 0:38ceb79fef03 75 * @note: This class must only be used in a static context -
kevman 0:38ceb79fef03 76 * this class must never be allocated or created on the
kevman 0:38ceb79fef03 77 * stack.
kevman 0:38ceb79fef03 78 *
kevman 0:38ceb79fef03 79 * @note: This class is lazily initialized on first use.
kevman 0:38ceb79fef03 80 * This class is a POD type so if it is not used it will
kevman 0:38ceb79fef03 81 * be garbage collected.
kevman 0:38ceb79fef03 82 */
kevman 0:38ceb79fef03 83 template <class T>
kevman 0:38ceb79fef03 84 struct SingletonPtr {
kevman 0:38ceb79fef03 85
kevman 0:38ceb79fef03 86 /** Get a pointer to the underlying singleton
kevman 0:38ceb79fef03 87 *
kevman 0:38ceb79fef03 88 * @returns
kevman 0:38ceb79fef03 89 * A pointer to the singleton
kevman 0:38ceb79fef03 90 */
kevman 0:38ceb79fef03 91 T *get()
kevman 0:38ceb79fef03 92 {
kevman 0:38ceb79fef03 93 if (NULL == _ptr) {
kevman 0:38ceb79fef03 94 singleton_lock();
kevman 0:38ceb79fef03 95 if (NULL == _ptr) {
kevman 0:38ceb79fef03 96 _ptr = new (_data) T();
kevman 0:38ceb79fef03 97 }
kevman 0:38ceb79fef03 98 singleton_unlock();
kevman 0:38ceb79fef03 99 }
kevman 0:38ceb79fef03 100 // _ptr was not zero initialized or was
kevman 0:38ceb79fef03 101 // corrupted if this assert is hit
kevman 0:38ceb79fef03 102 MBED_ASSERT(_ptr == (T *)&_data);
kevman 0:38ceb79fef03 103 return _ptr;
kevman 0:38ceb79fef03 104 }
kevman 0:38ceb79fef03 105
kevman 0:38ceb79fef03 106 /** Get a pointer to the underlying singleton
kevman 0:38ceb79fef03 107 *
kevman 0:38ceb79fef03 108 * @returns
kevman 0:38ceb79fef03 109 * A pointer to the singleton
kevman 0:38ceb79fef03 110 */
kevman 0:38ceb79fef03 111 T *operator->()
kevman 0:38ceb79fef03 112 {
kevman 0:38ceb79fef03 113 return get();
kevman 0:38ceb79fef03 114 }
kevman 0:38ceb79fef03 115
kevman 0:38ceb79fef03 116 // This is zero initialized when in global scope
kevman 0:38ceb79fef03 117 T *_ptr;
kevman 0:38ceb79fef03 118 // Force data to be 4 byte aligned
kevman 0:38ceb79fef03 119 uint32_t _data[(sizeof(T) + sizeof(uint32_t) - 1) / sizeof(uint32_t)];
kevman 0:38ceb79fef03 120 };
kevman 0:38ceb79fef03 121
kevman 0:38ceb79fef03 122 #endif
kevman 0:38ceb79fef03 123 /**@}*/
kevman 0:38ceb79fef03 124
kevman 0:38ceb79fef03 125 /**@}*/