Mark Turner / mbed

mbed library for slider v2

Dependents:   kl46z_slider_v2

SingletonPtr.h@0:b7116bd48af6, 2016-09-14 (annotated)

Committer:
mturner5
Date:
Wed Sep 14 07:04:27 2016 +0000
Revision:
0:b7116bd48af6
Tried to use the timer.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
mturner5 0:b7116bd48af6 1 /* mbed Microcontroller Library
mturner5 0:b7116bd48af6 2 * Copyright (c) 2006-2013 ARM Limited
mturner5 0:b7116bd48af6 3 *
mturner5 0:b7116bd48af6 4 * Licensed under the Apache License, Version 2.0 (the "License");
mturner5 0:b7116bd48af6 5 * you may not use this file except in compliance with the License.
mturner5 0:b7116bd48af6 6 * You may obtain a copy of the License at
mturner5 0:b7116bd48af6 7 *
mturner5 0:b7116bd48af6 8 * http://www.apache.org/licenses/LICENSE-2.0
mturner5 0:b7116bd48af6 9 *
mturner5 0:b7116bd48af6 10 * Unless required by applicable law or agreed to in writing, software
mturner5 0:b7116bd48af6 11 * distributed under the License is distributed on an "AS IS" BASIS,
mturner5 0:b7116bd48af6 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
mturner5 0:b7116bd48af6 13 * See the License for the specific language governing permissions and
mturner5 0:b7116bd48af6 14 * limitations under the License.
mturner5 0:b7116bd48af6 15 */
mturner5 0:b7116bd48af6 16 #ifndef SINGLETONPTR_H
mturner5 0:b7116bd48af6 17 #define SINGLETONPTR_H
mturner5 0:b7116bd48af6 18
mturner5 0:b7116bd48af6 19 #include <stdint.h>
mturner5 0:b7116bd48af6 20 #include <new>
mturner5 0:b7116bd48af6 21 #include "mbed_assert.h"
mturner5 0:b7116bd48af6 22 #ifdef MBED_CONF_RTOS_PRESENT
mturner5 0:b7116bd48af6 23 #include "cmsis_os.h"
mturner5 0:b7116bd48af6 24 #endif
mturner5 0:b7116bd48af6 25
mturner5 0:b7116bd48af6 26 #ifdef MBED_CONF_RTOS_PRESENT
mturner5 0:b7116bd48af6 27 extern osMutexId singleton_mutex_id;
mturner5 0:b7116bd48af6 28 #endif
mturner5 0:b7116bd48af6 29
mturner5 0:b7116bd48af6 30 /** Lock the singleton mutex
mturner5 0:b7116bd48af6 31 *
mturner5 0:b7116bd48af6 32 * This function is typically used to provide
mturner5 0:b7116bd48af6 33 * exclusive access when initializing a
mturner5 0:b7116bd48af6 34 * global object.
mturner5 0:b7116bd48af6 35 */
mturner5 0:b7116bd48af6 36 inline static void singleton_lock(void)
mturner5 0:b7116bd48af6 37 {
mturner5 0:b7116bd48af6 38 #ifdef MBED_CONF_RTOS_PRESENT
mturner5 0:b7116bd48af6 39 osMutexWait(singleton_mutex_id, osWaitForever);
mturner5 0:b7116bd48af6 40 #endif
mturner5 0:b7116bd48af6 41 }
mturner5 0:b7116bd48af6 42
mturner5 0:b7116bd48af6 43 /** Unlock the singleton mutex
mturner5 0:b7116bd48af6 44 *
mturner5 0:b7116bd48af6 45 * This function is typically used to provide
mturner5 0:b7116bd48af6 46 * exclusive access when initializing a
mturner5 0:b7116bd48af6 47 * global object.
mturner5 0:b7116bd48af6 48 */
mturner5 0:b7116bd48af6 49 inline static void singleton_unlock(void)
mturner5 0:b7116bd48af6 50 {
mturner5 0:b7116bd48af6 51 #ifdef MBED_CONF_RTOS_PRESENT
mturner5 0:b7116bd48af6 52 osMutexRelease (singleton_mutex_id);
mturner5 0:b7116bd48af6 53 #endif
mturner5 0:b7116bd48af6 54 }
mturner5 0:b7116bd48af6 55
mturner5 0:b7116bd48af6 56 /** Utility class for creating an using a singleton
mturner5 0:b7116bd48af6 57 *
mturner5 0:b7116bd48af6 58 * @Note Synchronization level: Thread safe
mturner5 0:b7116bd48af6 59 *
mturner5 0:b7116bd48af6 60 * @Note: This class must only be used in a static context -
mturner5 0:b7116bd48af6 61 * this class must never be allocated or created on the
mturner5 0:b7116bd48af6 62 * stack.
mturner5 0:b7116bd48af6 63 *
mturner5 0:b7116bd48af6 64 * @Note: This class is lazily initialized on first use.
mturner5 0:b7116bd48af6 65 * This class is a POD type so if it is not used it will
mturner5 0:b7116bd48af6 66 * be garbage collected.
mturner5 0:b7116bd48af6 67 */
mturner5 0:b7116bd48af6 68 template <class T>
mturner5 0:b7116bd48af6 69 struct SingletonPtr {
mturner5 0:b7116bd48af6 70
mturner5 0:b7116bd48af6 71 /** Get a pointer to the underlying singleton
mturner5 0:b7116bd48af6 72 *
mturner5 0:b7116bd48af6 73 * @returns
mturner5 0:b7116bd48af6 74 * A pointer to the singleton
mturner5 0:b7116bd48af6 75 */
mturner5 0:b7116bd48af6 76 T* get() {
mturner5 0:b7116bd48af6 77 if (NULL == _ptr) {
mturner5 0:b7116bd48af6 78 singleton_lock();
mturner5 0:b7116bd48af6 79 if (NULL == _ptr) {
mturner5 0:b7116bd48af6 80 _ptr = new (_data) T();
mturner5 0:b7116bd48af6 81 }
mturner5 0:b7116bd48af6 82 singleton_unlock();
mturner5 0:b7116bd48af6 83 }
mturner5 0:b7116bd48af6 84 // _ptr was not zero initialized or was
mturner5 0:b7116bd48af6 85 // corrupted if this assert is hit
mturner5 0:b7116bd48af6 86 MBED_ASSERT(_ptr == (T *)&_data);
mturner5 0:b7116bd48af6 87 return _ptr;
mturner5 0:b7116bd48af6 88 }
mturner5 0:b7116bd48af6 89
mturner5 0:b7116bd48af6 90 /** Get a pointer to the underlying singleton
mturner5 0:b7116bd48af6 91 *
mturner5 0:b7116bd48af6 92 * @returns
mturner5 0:b7116bd48af6 93 * A pointer to the singleton
mturner5 0:b7116bd48af6 94 */
mturner5 0:b7116bd48af6 95 T* operator->() {
mturner5 0:b7116bd48af6 96 return get();
mturner5 0:b7116bd48af6 97 }
mturner5 0:b7116bd48af6 98
mturner5 0:b7116bd48af6 99 // This is zero initialized when in global scope
mturner5 0:b7116bd48af6 100 T *_ptr;
mturner5 0:b7116bd48af6 101 // Force data to be 4 byte aligned
mturner5 0:b7116bd48af6 102 uint32_t _data[(sizeof(T) + sizeof(uint32_t) - 1) / sizeof(uint32_t)];
mturner5 0:b7116bd48af6 103 };
mturner5 0:b7116bd48af6 104
mturner5 0:b7116bd48af6 105 #endif