Andrew Boie | 489d747 | 2017-06-06 13:51:55 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2015-2016 Wind River Systems, Inc. |
| 3 | * |
| 4 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 5 | * you may not use this file except in compliance with the License. |
| 6 | * You may obtain a copy of the License at |
| 7 | * |
| 8 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 9 | * |
| 10 | * Unless required by applicable law or agreed to in writing, software |
| 11 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 13 | * See the License for the specific language governing permissions and |
| 14 | * limitations under the License. |
| 15 | */ |
| 16 | |
| 17 | /** |
| 18 | * @file C++ Synchronization demo. Uses basic C++ functionality. |
| 19 | */ |
| 20 | |
| 21 | #include <stdio.h> |
| 22 | #include <zephyr.h> |
| 23 | #include <arch/cpu.h> |
| 24 | #include <misc/printk.h> |
| 25 | |
| 26 | /** |
| 27 | * @class semaphore the basic pure virtual semaphore class |
| 28 | */ |
| 29 | class semaphore { |
| 30 | public: |
| 31 | virtual int wait(void) = 0; |
| 32 | virtual int wait(int timeout) = 0; |
| 33 | virtual void give(void) = 0; |
| 34 | }; |
| 35 | |
| 36 | /* specify delay between greetings (in ms); compute equivalent in ticks */ |
| 37 | #define SLEEPTIME 500 |
| 38 | #define STACKSIZE 2000 |
| 39 | |
| 40 | struct k_thread coop_thread; |
Andrew Boie | e87eaca | 2017-06-02 14:08:58 -0700 | [diff] [blame] | 41 | K_THREAD_STACK_DEFINE(coop_stack, STACKSIZE); |
Andrew Boie | 489d747 | 2017-06-06 13:51:55 -0700 | [diff] [blame] | 42 | |
| 43 | /* |
| 44 | * @class cpp_semaphore |
Anas Nashif | abbaac9 | 2017-12-05 09:43:43 -0500 | [diff] [blame] | 45 | * @brief Semaphore |
Andrew Boie | 489d747 | 2017-06-06 13:51:55 -0700 | [diff] [blame] | 46 | * |
| 47 | * Class derives from the pure virtual semaphore class and |
Anas Nashif | abbaac9 | 2017-12-05 09:43:43 -0500 | [diff] [blame] | 48 | * implements it's methods for the semaphore |
Andrew Boie | 489d747 | 2017-06-06 13:51:55 -0700 | [diff] [blame] | 49 | */ |
| 50 | class cpp_semaphore: public semaphore { |
| 51 | protected: |
| 52 | struct k_sem _sema_internal; |
| 53 | public: |
| 54 | cpp_semaphore(); |
| 55 | virtual ~cpp_semaphore() {} |
| 56 | virtual int wait(void); |
| 57 | virtual int wait(int timeout); |
| 58 | virtual void give(void); |
| 59 | }; |
| 60 | |
| 61 | /* |
| 62 | * @brief cpp_semaphore basic constructor |
| 63 | */ |
| 64 | cpp_semaphore::cpp_semaphore() |
| 65 | { |
| 66 | printk("Create semaphore %p\n", this); |
| 67 | k_sem_init(&_sema_internal, 0, UINT_MAX); |
| 68 | } |
| 69 | |
| 70 | /* |
| 71 | * @brief wait for a semaphore |
| 72 | * |
| 73 | * Test a semaphore to see if it has been signaled. If the signal |
| 74 | * count is greater than zero, it is decremented. |
| 75 | * |
| 76 | * @return 1 when semaphore is available |
| 77 | */ |
| 78 | int cpp_semaphore::wait(void) |
| 79 | { |
| 80 | k_sem_take(&_sema_internal, K_FOREVER); |
| 81 | return 1; |
| 82 | } |
| 83 | |
| 84 | /* |
| 85 | * @brief wait for a semaphore within a specified timeout |
| 86 | * |
| 87 | * Test a semaphore to see if it has been signaled. If the signal |
| 88 | * count is greater than zero, it is decremented. The function |
| 89 | * waits for timeout specified |
| 90 | * |
| 91 | * @param timeout the specified timeout in ticks |
| 92 | * |
| 93 | * @return 1 if semaphore is available, 0 if timed out |
| 94 | */ |
| 95 | int cpp_semaphore::wait(int timeout) |
| 96 | { |
| 97 | return k_sem_take(&_sema_internal, timeout); |
| 98 | } |
| 99 | |
| 100 | /** |
| 101 | * |
| 102 | * @brief Signal a semaphore |
| 103 | * |
| 104 | * This routine signals the specified semaphore. |
| 105 | * |
| 106 | * @return N/A |
| 107 | */ |
| 108 | void cpp_semaphore::give(void) |
| 109 | { |
| 110 | k_sem_give(&_sema_internal); |
| 111 | } |
| 112 | |
| 113 | cpp_semaphore sem_main; |
| 114 | cpp_semaphore sem_coop; |
| 115 | |
| 116 | void coop_thread_entry(void) |
| 117 | { |
| 118 | struct k_timer timer; |
| 119 | |
| 120 | k_timer_init(&timer, NULL, NULL); |
| 121 | |
| 122 | while (1) { |
| 123 | /* wait for main thread to let us have a turn */ |
| 124 | sem_coop.wait(); |
| 125 | |
| 126 | /* say "hello" */ |
| 127 | printk("%s: Hello World!\n", __FUNCTION__); |
| 128 | |
| 129 | /* wait a while, then let main thread have a turn */ |
| 130 | k_timer_start(&timer, SLEEPTIME, 0); |
| 131 | k_timer_status_sync(&timer); |
| 132 | sem_main.give(); |
| 133 | } |
| 134 | } |
| 135 | |
Andrew Boie | ba95aa0 | 2017-08-14 14:32:39 -0700 | [diff] [blame] | 136 | int main(void) |
Andrew Boie | 489d747 | 2017-06-06 13:51:55 -0700 | [diff] [blame] | 137 | { |
| 138 | struct k_timer timer; |
| 139 | |
| 140 | k_thread_create(&coop_thread, coop_stack, STACKSIZE, |
| 141 | (k_thread_entry_t) coop_thread_entry, |
| 142 | NULL, NULL, NULL, K_PRIO_COOP(7), 0, 0); |
| 143 | k_timer_init(&timer, NULL, NULL); |
| 144 | |
| 145 | while (1) { |
| 146 | /* say "hello" */ |
| 147 | printk("%s: Hello World!\n", __FUNCTION__); |
| 148 | |
| 149 | /* wait a while, then let coop thread have a turn */ |
| 150 | k_timer_start(&timer, SLEEPTIME, 0); |
| 151 | k_timer_status_sync(&timer); |
| 152 | sem_coop.give(); |
| 153 | |
| 154 | /* Wait for coop thread to let us have a turn */ |
| 155 | sem_main.wait(); |
| 156 | } |
Andrew Boie | ba95aa0 | 2017-08-14 14:32:39 -0700 | [diff] [blame] | 157 | |
| 158 | return 0; |
Andrew Boie | 489d747 | 2017-06-06 13:51:55 -0700 | [diff] [blame] | 159 | } |