BearPi-HM_Nano开发板HarmonyOS内核编程开发——事件标志

本示例将演示如何在BearPi-HM_Nano开发板上使用cmsis 2.0 接口使用事件标志同步线程

EventFlags API分析

osEventFlagsNew()

osEventFlagsId_t osEventFlagsNew(const osEventFlagsAttr_t *attr)

描述：

osEventFlagsNew函数创建了一个新的事件标志对象，用于跨线程发送事件，并返回事件标志对象标识符的指针，或者在出现错误时返回NULL。可以在RTOS启动(调用 osKernelStart)之前安全地调用该函数，但不能在内核初始化 (调用 osKernelInitialize)之前调用该函数。

注意 :不能在中断服务调用该函数

参数：

osEventFlagsSet()

uint32_t osEventFlagsSet(osEventFlagsId_t ef_id,uint32_t flags)

描述： osEventFlagsSet函数在一个由参数ef_id指定的事件标记对象中设置由参数flags指定的事件标记。

注意 :不能在中断服务调用该函数

参数：

osEventFlagsWait()

uint32_t osEventFlagsWait(osEventFlagsId_t ef_id,uint32_t flags,uint32_t options,uint32_t timeout)

描述： osEventFlagsWait函数挂起当前运行线程，直到设置了由参数ef_id指定的事件对象中的任何或所有由参数flags指定的事件标志。当这些事件标志被设置，函数立即返回。否则，线程将被置于阻塞状态。

注意 :如果参数timeout设置为0，可以从中断服务例程调用

参数：

软件设计

软件设计

主要代码分析

在Event_example函数中，通过osEventFlagsNew()函数创建了事件标记ID，Thread_EventReceiver()函数中通过osEventFlagsWait()函数一直将线程置于阻塞状态，等待事件标记。在Thread_EventSender()函数中通过osEventFlagsSet()函数每隔1S设置的标志，实现任务间的同步。

event_yuchuan_example.c

#include <stdio.h>
#include "ohos_init.h"
#include "cmsis_os2.h"
#include "iot_gpio.h"
#include "iot_gpio_ex.h"

#define FLAGS_MSK1 0x00000001U
#define FLAGS_MSK2 0x00000002U
#define FLAGS_MSK3 0x00000003U

#define GPIO_LED 2

osEventFlagsId_t evnetId;

void yuchuanSenderEvent(void *argument)
{
    (void)argument;
    while (1)
    {
        //osEventFlagsSet(evnetId,FLAGS_MSK1);
        osEventFlagsSet(evnetId,FLAGS_MSK2);
        osEventFlagsSet(evnetId,FLAGS_MSK3);
        osThreadYield();
        //设置高电平点亮LED灯
        IoTGpioSetOutputVal(GPIO_LED,IOT_GPIO_VALUE1);

        //printf("Yuchuan Thread Sender!!!\n");
        osDelay(100);
    }
    
}

void huayingReceiveEvent(void *argument)
{
    (void)argument;
    uint32_t flag;
    while (1)
    {
        //设置GPIO输出低电平熄灭LED灯
        IoTGpioSetOutputVal(GPIO_LED,IOT_GPIO_VALUE0);
        flag = osEventFlagsWait(evnetId,FLAGS_MSK1|FLAGS_MSK2|FLAGS_MSK3,osFlagsWaitAny,osWaitForever);
        //flag = osEventFlagsWait(evnetId,FLAGS_MSK1|FLAGS_MSK2|FLAGS_MSK3,osFlagsWaitAll,osWaitForever);
    
        printf("Receive Flags is %d\n",flag);
        osDelay(100);
    }
    
}

static void yuchuanEventExample(void)
{
    //初始化GPIO
    IoTGpioInit(GPIO_LED);
    //设置GPIO为输出方向
    IoTGpioSetDir(GPIO_LED,IOT_GPIO_DIR_OUT);

    evnetId = osEventFlagsNew(NULL);

    osThreadAttr_t attr;
    attr.attr_bits = 0U;
    attr.cb_mem = NULL;
    attr.cb_size = 0U;
    attr.stack_mem = NULL;
    attr.stack_size = 1024 * 4;
    attr.priority = 25;

    attr.name = "YuchuanSenderThread";
    if (osThreadNew((osThreadFunc_t)yuchuanSenderEvent,NULL,&attr) == NULL)
    {
        /* code */
        printf("Falied to Create Sender Event!!!\n");
    }

    attr.name = "HuayingSenderThread";
    if (osThreadNew((osThreadFunc_t)huayingReceiveEvent,NULL,&attr) == NULL)
    {
        /* code */
        printf("Falied to Create Receive Evnet!!!\n");
    }
}

APP_FEATURE_INIT(yuchuanEventExample);

编译调试

applications/sample/BearPi/BearPi-HM_Nano/sample/A3_YuchuanEvent/BUILD.gn

static_library("yuchuanEvent"){
    sources = [
        "event_yuchuan_example.c",
    ]

    include_dirs = [
        "//utils/native/lite/include",
        "//kernel/liteos_m/kal/cmsis",
        "//base/iot_hardware/peripheral/interfaces/kits",
    ]
}

修改 BUILD.gn 文件

修改 applications\BearPi\BearPi-HM_Nano\sample路径下 BUILD.gn 文件，指定yuchuanEvent参与编译。

# Copyright (c) 2020 Nanjing Xiaoxiongpai Intelligent Technology Co., Ltd.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import("//build/lite/config/component/lite_component.gni")

lite_component("sample") {
    features = [
        #"A1_kernal_thread:thread_example",
        #"A2_kernel_timer:timer_example",
        #"A3_kernel_event:event_example",
        #"A4_kernel_mutex:mutex_example",
        #"A5_kernel_semaphore:semaphore_example",
        #"A6_kernel_message:message_example",

        #"B1_basic_led_blink:led_example",
        #"B2_basic_button:button_example",
        #"B3_basic_pwm_led:pwm_example",
        #"B4_basic_adc:adc_example", 
        #"B5_basic_i2c_nfc:i2c_example",
        #"B6_basic_uart:uart_example",
        
        #"C1_e53_sf1_mq2:e53_sf1_example",
        #"C2_e53_ia1_temp_humi_pls:e53_ia1_example",
        #"C3_e53_sc1_pls:e53_sc1_example",
        #"C4_e53_sc2_axis:e53_sc2_example",
        #"C5_e53_is1_infrared:e53_is1_example",

        #"D1_iot_wifi_ap:wifi_ap",
        #"D2_iot_wifi_sta_connect:wifi_sta_connect",        
        #"D3_iot_udp_client:udp_client",
        #"D4_iot_tcp_server:tcp_server",
        #"D5_iot_mqtt:iot_mqtt",        
        #"D6_iot_cloud_oc:oc_mqtt",
        #"D7_iot_cloud_onenet:onenet_mqtt",
        #"D8_iot_cloud_oc_smoke:cloud_oc_smoke",
        #"D9_iot_cloud_oc_light:cloud_oc_light",
        #"D10_iot_cloud_oc_manhole_cover:cloud_oc_manhole_cover",
        #"D11_iot_cloud_oc_infrared:cloud_oc_infrared",
        #"D12_iot_cloud_oc_agriculture:cloud_oc_agriculture",
        #"D13_iot_cloud_oc_gps:cloud_oc_gps",
        #"A1_YuchuanThread:yuchuanThread",
        #"A2_YuchuanTimer:yuchuanTimer",
        #"A4_YuchuanMutex:yuchuanMutex",
        #"A5_YuchuanSemaphore:yuchuanSemaphore",
        "A3_YuchuanEvent:yuchuanEvent",
    ]
}

运行结果

示例代码编译烧录代码后，按下开发板的RESET按键，通过串口助手查看日志，会每隔1S输出一次日志。

ready to OS start
sdk ver:Hi3861V100R001C00SPC025 2020-09-03 18:10:00
FileSystem mount ok.
wifi init success!

hiview init success.Receive Flags is 3
00 00:00:00 0 132 D 0/HIVIEW: log limit init success.
00 00:00:00 0 132 I 1/SAMGR: Bootstrap core services(count:3).
00 00:00:00 0 132 I 1/SAMGR: Init service:0x4b0308 TaskPool:0xe4b3c
00 00:00:00 0 132 I 1/SAMGR: Init service:0x4b0314 TaskPool:0xe4b5c
00 00:00:00 0 132 I 1/SAMGR: Init service:0x4b07e0 TaskPool:0xe4b7c
00 00:00:00 0 164 I 1/SAMGR: Init service 0x4b0314 <time: 0ms> success!
00 00:00:00 0 64 I 1/SAMGR: Init service 0x4b0308 <time: 0ms> success!
00 00:00:00 0 8 I 1/SAMGR: Init service 0x4b07e0 <time: 10ms> success!
00 00:00:00 0 8 I 1/SAMGR: Initialized all core system services!
00 00:00:00 0 64 I 1/SAMGR: Bootstrap system and application services(count:0).
00 00:00:00 0 64 I 1/SAMGR: Initialized all system and application services!
00 00:00:00 0 64 I 1/SAMGR: Bootstrap dynamic registered services(count:0).
Receive Flags is 3
Receive Flags is 3
Receive Flags is 3
Receive Flags is 3
Receive Flags is 3
Receive Flags is 3
Receive Flags is 3
Receive Flags is 3
Receive Flags is 3
Receive Flags is 3
Receive Flags is 3
Receive Flags is 3
Receive Flags is 3