Kev Mann / mbed-dev-OS5_10_4

RTC auf true

rtos/ConditionVariable.cpp@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 /* mbed Microcontroller Library
kevman 0:38ceb79fef03 2 * Copyright (c) 2017-2017 ARM Limited
kevman 0:38ceb79fef03 3 *
kevman 0:38ceb79fef03 4 * Permission is hereby granted, free of charge, to any person obtaining a copy
kevman 0:38ceb79fef03 5 * of this software and associated documentation files (the "Software"), to deal
kevman 0:38ceb79fef03 6 * in the Software without restriction, including without limitation the rights
kevman 0:38ceb79fef03 7 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
kevman 0:38ceb79fef03 8 * copies of the Software, and to permit persons to whom the Software is
kevman 0:38ceb79fef03 9 * furnished to do so, subject to the following conditions:
kevman 0:38ceb79fef03 10 *
kevman 0:38ceb79fef03 11 * The above copyright notice and this permission notice shall be included in
kevman 0:38ceb79fef03 12 * all copies or substantial portions of the Software.
kevman 0:38ceb79fef03 13 *
kevman 0:38ceb79fef03 14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
kevman 0:38ceb79fef03 15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
kevman 0:38ceb79fef03 16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
kevman 0:38ceb79fef03 17 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
kevman 0:38ceb79fef03 18 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
kevman 0:38ceb79fef03 19 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
kevman 0:38ceb79fef03 20 * SOFTWARE.
kevman 0:38ceb79fef03 21 */
kevman 0:38ceb79fef03 22 #include "rtos/ConditionVariable.h"
kevman 0:38ceb79fef03 23 #include "rtos/Kernel.h"
kevman 0:38ceb79fef03 24 #include "rtos/Thread.h"
kevman 0:38ceb79fef03 25
kevman 0:38ceb79fef03 26 #include "mbed_error.h"
kevman 0:38ceb79fef03 27 #include "mbed_assert.h"
kevman 0:38ceb79fef03 28
kevman 0:38ceb79fef03 29 namespace rtos {
kevman 0:38ceb79fef03 30
kevman 0:38ceb79fef03 31 ConditionVariable::Waiter::Waiter(): sem(0), prev(NULL), next(NULL), in_list(false)
kevman 0:38ceb79fef03 32 {
kevman 0:38ceb79fef03 33 // No initialization to do
kevman 0:38ceb79fef03 34 }
kevman 0:38ceb79fef03 35
kevman 0:38ceb79fef03 36 ConditionVariable::ConditionVariable(Mutex &mutex): _mutex(mutex), _wait_list(NULL)
kevman 0:38ceb79fef03 37 {
kevman 0:38ceb79fef03 38 // No initialization to do
kevman 0:38ceb79fef03 39 }
kevman 0:38ceb79fef03 40
kevman 0:38ceb79fef03 41 void ConditionVariable::wait()
kevman 0:38ceb79fef03 42 {
kevman 0:38ceb79fef03 43 wait_for(osWaitForever);
kevman 0:38ceb79fef03 44 }
kevman 0:38ceb79fef03 45
kevman 0:38ceb79fef03 46 bool ConditionVariable::wait_for(uint32_t millisec)
kevman 0:38ceb79fef03 47 {
kevman 0:38ceb79fef03 48 Waiter current_thread;
kevman 0:38ceb79fef03 49 MBED_ASSERT(_mutex.get_owner() == Thread::gettid());
kevman 0:38ceb79fef03 50 MBED_ASSERT(_mutex._count == 1);
kevman 0:38ceb79fef03 51 _add_wait_list(&_wait_list, &current_thread);
kevman 0:38ceb79fef03 52
kevman 0:38ceb79fef03 53 _mutex.unlock();
kevman 0:38ceb79fef03 54
kevman 0:38ceb79fef03 55 int32_t sem_count = current_thread.sem.wait(millisec);
kevman 0:38ceb79fef03 56 bool timeout = (sem_count > 0) ? false : true;
kevman 0:38ceb79fef03 57
kevman 0:38ceb79fef03 58 _mutex.lock();
kevman 0:38ceb79fef03 59
kevman 0:38ceb79fef03 60 if (current_thread.in_list) {
kevman 0:38ceb79fef03 61 _remove_wait_list(&_wait_list, &current_thread);
kevman 0:38ceb79fef03 62 }
kevman 0:38ceb79fef03 63
kevman 0:38ceb79fef03 64 return timeout;
kevman 0:38ceb79fef03 65 }
kevman 0:38ceb79fef03 66
kevman 0:38ceb79fef03 67 bool ConditionVariable::wait_until(uint64_t millisec)
kevman 0:38ceb79fef03 68 {
kevman 0:38ceb79fef03 69 uint64_t now = Kernel::get_ms_count();
kevman 0:38ceb79fef03 70
kevman 0:38ceb79fef03 71 if (now >= millisec) {
kevman 0:38ceb79fef03 72 // Time has already passed - standard behaviour is to
kevman 0:38ceb79fef03 73 // treat as a "try".
kevman 0:38ceb79fef03 74 return wait_for(0);
kevman 0:38ceb79fef03 75 } else if (millisec - now >= osWaitForever) {
kevman 0:38ceb79fef03 76 // Exceeds maximum delay of underlying wait_for -
kevman 0:38ceb79fef03 77 // spuriously wake after 49 days, indicating no timeout.
kevman 0:38ceb79fef03 78 wait_for(osWaitForever - 1);
kevman 0:38ceb79fef03 79 return false;
kevman 0:38ceb79fef03 80 } else {
kevman 0:38ceb79fef03 81 return wait_for(millisec - now);
kevman 0:38ceb79fef03 82 }
kevman 0:38ceb79fef03 83 }
kevman 0:38ceb79fef03 84
kevman 0:38ceb79fef03 85 void ConditionVariable::notify_one()
kevman 0:38ceb79fef03 86 {
kevman 0:38ceb79fef03 87 MBED_ASSERT(_mutex.get_owner() == Thread::gettid());
kevman 0:38ceb79fef03 88 if (_wait_list != NULL) {
kevman 0:38ceb79fef03 89 _wait_list->sem.release();
kevman 0:38ceb79fef03 90 _remove_wait_list(&_wait_list, _wait_list);
kevman 0:38ceb79fef03 91 }
kevman 0:38ceb79fef03 92 }
kevman 0:38ceb79fef03 93
kevman 0:38ceb79fef03 94 void ConditionVariable::notify_all()
kevman 0:38ceb79fef03 95 {
kevman 0:38ceb79fef03 96 MBED_ASSERT(_mutex.get_owner() == Thread::gettid());
kevman 0:38ceb79fef03 97 while (_wait_list != NULL) {
kevman 0:38ceb79fef03 98 _wait_list->sem.release();
kevman 0:38ceb79fef03 99 _remove_wait_list(&_wait_list, _wait_list);
kevman 0:38ceb79fef03 100 }
kevman 0:38ceb79fef03 101 }
kevman 0:38ceb79fef03 102
kevman 0:38ceb79fef03 103 void ConditionVariable::_add_wait_list(Waiter **wait_list, Waiter *waiter)
kevman 0:38ceb79fef03 104 {
kevman 0:38ceb79fef03 105 if (NULL == *wait_list) {
kevman 0:38ceb79fef03 106 // Nothing in the list so add it directly.
kevman 0:38ceb79fef03 107 // Update prev and next pointer to reference self
kevman 0:38ceb79fef03 108 *wait_list = waiter;
kevman 0:38ceb79fef03 109 waiter->next = waiter;
kevman 0:38ceb79fef03 110 waiter->prev = waiter;
kevman 0:38ceb79fef03 111 } else {
kevman 0:38ceb79fef03 112 // Add after the last element
kevman 0:38ceb79fef03 113 Waiter *first = *wait_list;
kevman 0:38ceb79fef03 114 Waiter *last = (*wait_list)->prev;
kevman 0:38ceb79fef03 115
kevman 0:38ceb79fef03 116 // Update new entry
kevman 0:38ceb79fef03 117 waiter->next = first;
kevman 0:38ceb79fef03 118 waiter->prev = last;
kevman 0:38ceb79fef03 119
kevman 0:38ceb79fef03 120 // Insert into the list
kevman 0:38ceb79fef03 121 first->prev = waiter;
kevman 0:38ceb79fef03 122 last->next = waiter;
kevman 0:38ceb79fef03 123 }
kevman 0:38ceb79fef03 124 waiter->in_list = true;
kevman 0:38ceb79fef03 125 }
kevman 0:38ceb79fef03 126
kevman 0:38ceb79fef03 127 void ConditionVariable::_remove_wait_list(Waiter **wait_list, Waiter *waiter)
kevman 0:38ceb79fef03 128 {
kevman 0:38ceb79fef03 129 Waiter *prev = waiter->prev;
kevman 0:38ceb79fef03 130 Waiter *next = waiter->next;
kevman 0:38ceb79fef03 131
kevman 0:38ceb79fef03 132 // Remove from list
kevman 0:38ceb79fef03 133 prev->next = waiter->next;
kevman 0:38ceb79fef03 134 next->prev = waiter->prev;
kevman 0:38ceb79fef03 135 *wait_list = waiter->next;
kevman 0:38ceb79fef03 136
kevman 0:38ceb79fef03 137 if (*wait_list == waiter) {
kevman 0:38ceb79fef03 138 // This was the last element in the list
kevman 0:38ceb79fef03 139 *wait_list = NULL;
kevman 0:38ceb79fef03 140 }
kevman 0:38ceb79fef03 141
kevman 0:38ceb79fef03 142 // Invalidate pointers
kevman 0:38ceb79fef03 143 waiter->next = NULL;
kevman 0:38ceb79fef03 144 waiter->prev = NULL;
kevman 0:38ceb79fef03 145 waiter->in_list = false;
kevman 0:38ceb79fef03 146 }
kevman 0:38ceb79fef03 147
kevman 0:38ceb79fef03 148 ConditionVariable::~ConditionVariable()
kevman 0:38ceb79fef03 149 {
kevman 0:38ceb79fef03 150 MBED_ASSERT(NULL == _wait_list);
kevman 0:38ceb79fef03 151 }
kevman 0:38ceb79fef03 152
kevman 0:38ceb79fef03 153 }