PES4 / Mbed OS Queue_02

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mbed-os/rtos/ConditionVariable.cpp@0:6bf0743ece18, 2020-03-28 (annotated)

Committer:
demayer
Date:
Sat Mar 28 15:28:19 2020 +0000
Revision:
0:6bf0743ece18
IMU Thread with an event-queue running parallel to handle tasks like a 5 times blinking LED. Button with interrupt detected.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
demayer 0:6bf0743ece18 1 /* mbed Microcontroller Library
demayer 0:6bf0743ece18 2 * Copyright (c) 2017-2017 ARM Limited
demayer 0:6bf0743ece18 3 *
demayer 0:6bf0743ece18 4 * Permission is hereby granted, free of charge, to any person obtaining a copy
demayer 0:6bf0743ece18 5 * of this software and associated documentation files (the "Software"), to deal
demayer 0:6bf0743ece18 6 * in the Software without restriction, including without limitation the rights
demayer 0:6bf0743ece18 7 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
demayer 0:6bf0743ece18 8 * copies of the Software, and to permit persons to whom the Software is
demayer 0:6bf0743ece18 9 * furnished to do so, subject to the following conditions:
demayer 0:6bf0743ece18 10 *
demayer 0:6bf0743ece18 11 * The above copyright notice and this permission notice shall be included in
demayer 0:6bf0743ece18 12 * all copies or substantial portions of the Software.
demayer 0:6bf0743ece18 13 *
demayer 0:6bf0743ece18 14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
demayer 0:6bf0743ece18 15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
demayer 0:6bf0743ece18 16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
demayer 0:6bf0743ece18 17 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
demayer 0:6bf0743ece18 18 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
demayer 0:6bf0743ece18 19 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
demayer 0:6bf0743ece18 20 * SOFTWARE.
demayer 0:6bf0743ece18 21 */
demayer 0:6bf0743ece18 22 #include "rtos/ConditionVariable.h"
demayer 0:6bf0743ece18 23 #include "rtos/Thread.h"
demayer 0:6bf0743ece18 24
demayer 0:6bf0743ece18 25 #include "mbed_error.h"
demayer 0:6bf0743ece18 26 #include "mbed_assert.h"
demayer 0:6bf0743ece18 27
demayer 0:6bf0743ece18 28 namespace rtos {
demayer 0:6bf0743ece18 29
demayer 0:6bf0743ece18 30
demayer 0:6bf0743ece18 31 ConditionVariable::Waiter::Waiter(): sem(0), prev(NULL), next(NULL), in_list(false)
demayer 0:6bf0743ece18 32 {
demayer 0:6bf0743ece18 33 // No initialization to do
demayer 0:6bf0743ece18 34 }
demayer 0:6bf0743ece18 35
demayer 0:6bf0743ece18 36 ConditionVariable::ConditionVariable(Mutex &mutex): _mutex(mutex), _wait_list(NULL)
demayer 0:6bf0743ece18 37 {
demayer 0:6bf0743ece18 38 // No initialization to do
demayer 0:6bf0743ece18 39 }
demayer 0:6bf0743ece18 40
demayer 0:6bf0743ece18 41 void ConditionVariable::wait()
demayer 0:6bf0743ece18 42 {
demayer 0:6bf0743ece18 43 wait_for(osWaitForever);
demayer 0:6bf0743ece18 44 }
demayer 0:6bf0743ece18 45
demayer 0:6bf0743ece18 46 bool ConditionVariable::wait_for(uint32_t millisec)
demayer 0:6bf0743ece18 47 {
demayer 0:6bf0743ece18 48 Waiter current_thread;
demayer 0:6bf0743ece18 49 MBED_ASSERT(_mutex.get_owner() == Thread::gettid());
demayer 0:6bf0743ece18 50 MBED_ASSERT(_mutex._count == 1);
demayer 0:6bf0743ece18 51 _add_wait_list(&_wait_list, &current_thread);
demayer 0:6bf0743ece18 52
demayer 0:6bf0743ece18 53 _mutex.unlock();
demayer 0:6bf0743ece18 54
demayer 0:6bf0743ece18 55 int32_t sem_count = current_thread.sem.wait(millisec);
demayer 0:6bf0743ece18 56 bool timeout = (sem_count > 0) ? false : true;
demayer 0:6bf0743ece18 57
demayer 0:6bf0743ece18 58 _mutex.lock();
demayer 0:6bf0743ece18 59
demayer 0:6bf0743ece18 60 if (current_thread.in_list) {
demayer 0:6bf0743ece18 61 _remove_wait_list(&_wait_list, &current_thread);
demayer 0:6bf0743ece18 62 }
demayer 0:6bf0743ece18 63
demayer 0:6bf0743ece18 64 return timeout;
demayer 0:6bf0743ece18 65 }
demayer 0:6bf0743ece18 66
demayer 0:6bf0743ece18 67 void ConditionVariable::notify_one()
demayer 0:6bf0743ece18 68 {
demayer 0:6bf0743ece18 69 MBED_ASSERT(_mutex.get_owner() == Thread::gettid());
demayer 0:6bf0743ece18 70 if (_wait_list != NULL) {
demayer 0:6bf0743ece18 71 _wait_list->sem.release();
demayer 0:6bf0743ece18 72 _remove_wait_list(&_wait_list, _wait_list);
demayer 0:6bf0743ece18 73 }
demayer 0:6bf0743ece18 74 }
demayer 0:6bf0743ece18 75
demayer 0:6bf0743ece18 76 void ConditionVariable::notify_all()
demayer 0:6bf0743ece18 77 {
demayer 0:6bf0743ece18 78 MBED_ASSERT(_mutex.get_owner() == Thread::gettid());
demayer 0:6bf0743ece18 79 while (_wait_list != NULL) {
demayer 0:6bf0743ece18 80 _wait_list->sem.release();
demayer 0:6bf0743ece18 81 _remove_wait_list(&_wait_list, _wait_list);
demayer 0:6bf0743ece18 82 }
demayer 0:6bf0743ece18 83 }
demayer 0:6bf0743ece18 84
demayer 0:6bf0743ece18 85 void ConditionVariable::_add_wait_list(Waiter **wait_list, Waiter *waiter)
demayer 0:6bf0743ece18 86 {
demayer 0:6bf0743ece18 87 if (NULL == *wait_list) {
demayer 0:6bf0743ece18 88 // Nothing in the list so add it directly.
demayer 0:6bf0743ece18 89 // Update prev and next pointer to reference self
demayer 0:6bf0743ece18 90 *wait_list = waiter;
demayer 0:6bf0743ece18 91 waiter->next = waiter;
demayer 0:6bf0743ece18 92 waiter->prev = waiter;
demayer 0:6bf0743ece18 93 } else {
demayer 0:6bf0743ece18 94 // Add after the last element
demayer 0:6bf0743ece18 95 Waiter *first = *wait_list;
demayer 0:6bf0743ece18 96 Waiter *last = (*wait_list)->prev;
demayer 0:6bf0743ece18 97
demayer 0:6bf0743ece18 98 // Update new entry
demayer 0:6bf0743ece18 99 waiter->next = first;
demayer 0:6bf0743ece18 100 waiter->prev = last;
demayer 0:6bf0743ece18 101
demayer 0:6bf0743ece18 102 // Insert into the list
demayer 0:6bf0743ece18 103 first->prev = waiter;
demayer 0:6bf0743ece18 104 last->next = waiter;
demayer 0:6bf0743ece18 105 }
demayer 0:6bf0743ece18 106 waiter->in_list = true;
demayer 0:6bf0743ece18 107 }
demayer 0:6bf0743ece18 108
demayer 0:6bf0743ece18 109 void ConditionVariable::_remove_wait_list(Waiter **wait_list, Waiter *waiter)
demayer 0:6bf0743ece18 110 {
demayer 0:6bf0743ece18 111 Waiter *prev = waiter->prev;
demayer 0:6bf0743ece18 112 Waiter *next = waiter->next;
demayer 0:6bf0743ece18 113
demayer 0:6bf0743ece18 114 // Remove from list
demayer 0:6bf0743ece18 115 prev->next = waiter->next;
demayer 0:6bf0743ece18 116 next->prev = waiter->prev;
demayer 0:6bf0743ece18 117 *wait_list = waiter->next;
demayer 0:6bf0743ece18 118
demayer 0:6bf0743ece18 119 if (*wait_list == waiter) {
demayer 0:6bf0743ece18 120 // This was the last element in the list
demayer 0:6bf0743ece18 121 *wait_list = NULL;
demayer 0:6bf0743ece18 122 }
demayer 0:6bf0743ece18 123
demayer 0:6bf0743ece18 124 // Invalidate pointers
demayer 0:6bf0743ece18 125 waiter->next = NULL;
demayer 0:6bf0743ece18 126 waiter->prev = NULL;
demayer 0:6bf0743ece18 127 waiter->in_list = false;
demayer 0:6bf0743ece18 128 }
demayer 0:6bf0743ece18 129
demayer 0:6bf0743ece18 130 ConditionVariable::~ConditionVariable()
demayer 0:6bf0743ece18 131 {
demayer 0:6bf0743ece18 132 MBED_ASSERT(NULL == _wait_list);
demayer 0:6bf0743ece18 133 }
demayer 0:6bf0743ece18 134
demayer 0:6bf0743ece18 135 }