OpenHarmony设备开发 轻量系统内核（LiteOS-M）内核通信机制

typedef struct tagEvent {
    UINT32 uwEventID;        /* 事件集合，表示已经处理（写入和清零）的事件集合 */
    LOS_DL_LIST stEventList; /* 等待特定事件的任务链表 */
} EVENT_CB_S, *PEVENT_CB_S;

#include "los_event.h"
#include "los_task.h"

/* 事件控制结构体 */
EVENT_CB_S g_exampleEvent;

/* 等待的事件类型 */
#define EVENT_WAIT 0x00000001

/* 等待超时时间 */
#define EVENT_TIMEOUT 100

/* 用例任务入口函数 */
VOID EventReadTask(VOID)
{
    UINT32 ret;
    UINT32 event;

    /* 超时等待方式读事件,超时时间为100 ticks, 若100 ticks后未读取到指定事件，读事件超时，任务直接唤醒 */
    printf("Example_Event wait event 0x%x \n", EVENT_WAIT);

    event = LOS_EventRead(&g_exampleEvent, EVENT_WAIT, LOS_WAITMODE_AND, EVENT_TIMEOUT);
    if (event == EVENT_WAIT) {
        printf("Example_Event, read event :0x%x\n", event);
    } else {
        printf("Example_Event, read event timeout\n");
    }
}

UINT32 ExampleEvent(VOID)
{
    UINT32 ret;
    UINT32 taskId;
    TSK_INIT_PARAM_S taskParam = { 0 };

    /* 事件初始化 */
    ret = LOS_EventInit(&g_exampleEvent);
    if (ret != LOS_OK) {
        printf("init event failed .\n");
        return LOS_NOK;
    }

    /* 创建任务 */
    taskParam.pfnTaskEntry = (TSK_ENTRY_FUNC)EventReadTask;
    taskParam.pcName       = "EventReadTask";
    taskParam.uwStackSize  = LOSCFG_BASE_CORE_TSK_DEFAULT_STACK_SIZE;
    taskParam.usTaskPrio   = 3;
    ret = LOS_TaskCreate(&taskId, &taskParam);
    if (ret != LOS_OK) {
        printf("task create failed.\n");
        return LOS_NOK;
    }

    /* 写事件 */
    printf("Example_TaskEntry write event.\n");

    ret = LOS_EventWrite(&g_exampleEvent, EVENT_WAIT);
    if (ret != LOS_OK) {
        printf("event write failed.\n");
        return LOS_NOK;
    }

    /* 清标志位 */
    printf("EventMask:%d\n", g_exampleEvent.uwEventID);
    LOS_EventClear(&g_exampleEvent, ~g_exampleEvent.uwEventID);
    printf("EventMask:%d\n", g_exampleEvent.uwEventID);

    /* 删除事件 */
    ret = LOS_EventDestroy(&g_exampleEvent);
    if (ret != LOS_OK) {
        printf("destory event failed .\n");
        return LOS_NOK;
    }

    return LOS_OK;
}

Example_Event wait event 0x1
Example_TaskEntry write event.
Example_Event, read event :0x1
EventMask:1
EventMask:0

#include "los_mux.h"

/* 互斥锁句柄 */
UINT32 g_testMux;

VOID ExampleMutexTask1(VOID)
{
    UINT32 ret;

    printf("task1 try to get  mutex, wait 10 ticks.\n");
    /* 申请互斥锁 */
    ret = LOS_MuxPend(g_testMux, 10);
    if (ret == LOS_OK) {
        printf("task1 get mutex g_testMux.\n");
        /* 释放互斥锁，这个分支正常不应该进来 */
        LOS_MuxPost(g_testMux);
        LOS_MuxDelete(g_testMux);
        return;
    }
    
    if (ret == LOS_ERRNO_MUX_TIMEOUT ) {
        printf("task1 timeout and try to get mutex, wait forever.\n");
        /* 申请互斥锁 */
        ret = LOS_MuxPend(g_testMux, LOS_WAIT_FOREVER);
        if (ret == LOS_OK) {
            printf("task1 wait forever, get mutex g_testMux.\n");
            /* 释放互斥锁 */
            LOS_MuxPost(g_testMux);
            /* 删除互斥锁 */
            LOS_MuxDelete(g_testMux);
            printf("task1 post and delete mutex g_testMux.\n");
            return;
        }
    }
    
    return;
}

VOID ExampleMutexTask2(VOID)
{
    printf("task2 try to get  mutex, wait forever.\n");
    /* 申请互斥锁 */
    (VOID)LOS_MuxPend(g_testMux, LOS_WAIT_FOREVER);
    printf("task2 get mutex g_testMux and suspend 100 ticks.\n");

    /* 任务休眠100Ticks */
    LOS_TaskDelay(100);

    printf("task2 resumed and post the g_testMux\n");
    /* 释放互斥锁 */
    LOS_MuxPost(g_testMux);
    return;
}

UINT32 ExampleMutex(VOID)
{
    UINT32 ret;
    TSK_INIT_PARAM_S task1 = { 0 };
    TSK_INIT_PARAM_S task2 = { 0 };
    UINT32 taskId01;
    UINT32 taskId02;

    /* 创建互斥锁 */
    LOS_MuxCreate(&g_testMux);

    /* 锁任务调度 */
    LOS_TaskLock();

    /* 创建任务1 */
    task1.pfnTaskEntry = (TSK_ENTRY_FUNC)ExampleMutexTask1;
    task1.pcName       = "MutexTsk1";
    task1.uwStackSize  = LOSCFG_BASE_CORE_TSK_DEFAULT_STACK_SIZE;
    task1.usTaskPrio   = 5;
    ret = LOS_TaskCreate(&taskId01, &task1);
    if (ret != LOS_OK) {
        printf("task1 create failed.\n");
        return LOS_NOK;
    }

    /* 创建任务2 */
    task2.pfnTaskEntry = (TSK_ENTRY_FUNC)ExampleMutexTask2;
    task2.pcName       = "MutexTsk2";
    task2.uwStackSize  = LOSCFG_BASE_CORE_TSK_DEFAULT_STACK_SIZE;
    task2.usTaskPrio   = 4;
    ret = LOS_TaskCreate(&taskId02, &task2);
    if (ret != LOS_OK) {
        printf("task2 create failed.\n");
        return LOS_NOK;
    }

    /* 解锁任务调度 */
    LOS_TaskUnlock();

    return LOS_OK;
}

task2 try to get  mutex, wait forever.
task2 get mutex g_testMux and suspend 100 ticks.
task1 try to get  mutex, wait 10 ticks.
task1 timeout and try to get mutex, wait forever.
task2 resumed and post the g_testMux
task1 wait forever, get mutex g_testMux.
task1 post and delete mutex g_testMux.

typedef struct 
{
    UINT8       *queue;                          		/* 队列消息内存空间的指针 */
    UINT8 		*queueName								/* 队列名称 */
    UINT16      queueState;                      		/* 队列状态 */
    UINT16      queueLen;                        		/* 队列中消息节点个数，即队列长度 */
    UINT16      queueSize;                       		/* 消息节点大小 */
    UINT16      queueID;                         		/* 队列ID */
    UINT16      queueHead;                       		/* 消息头节点位置（数组下标）*/
    UINT16      queueTail;                       		/* 消息尾节点位置（数组下标）*/
    UINT16      readWriteableCnt[OS_READWRITE_LEN]; 	/* 数组下标0的元素表示队列中可读消息数，                              
                                                    		数组下标1的元素表示队列中可写消息数 */
    LOS_DL_LIST readWriteList[OS_READWRITE_LEN];    	/* 读取或写入消息的任务等待链表， 
                                                       		下标0：读取链表，下标1：写入链表 */
    LOS_DL_LIST memList;                         		/* 内存块链表 */
} LosQueueCB;

#include "los_task.h"
#include "los_queue.h"

STATIC UINT32 g_queue;
#define BUFFER_LEN 50

VOID SendEntry(VOID)
{
    UINT32 ret = 0;
    CHAR abuf[] = "test message";
    UINT32 len = sizeof(abuf);

    ret = LOS_QueueWriteCopy(g_queue, abuf, len, 0);
    if (ret != LOS_OK) {
        printf("send message failure, error: %x\n", ret);
    }
}

VOID RecvEntry(VOID)
{
    UINT32 ret = 0;
    CHAR readBuf[BUFFER_LEN] = {0};
    UINT32 readLen = BUFFER_LEN;

    /* 休眠1s */
    usleep(1000000);
    ret = LOS_QueueReadCopy(g_queue, readBuf, &readLen, 0);
    if (ret != LOS_OK) {
        printf("recv message failure, error: %x\n", ret);
    }

    printf("recv message: %s.\n", readBuf);

    ret = LOS_QueueDelete(g_queue);
    if (ret != LOS_OK) {
        printf("delete the queue failure, error: %x\n", ret);
    }

    printf("delete the queue success.\n");
}

UINT32 ExampleQueue(VOID)
{
    printf("start queue example.\n");
    UINT32 ret = 0;
    UINT32 task1;
    UINT32 task2;
    TSK_INIT_PARAM_S taskParam1 = { 0 };
    TSK_INIT_PARAM_S taskParam2 = { 0 };

    LOS_TaskLock();

    taskParam1.pfnTaskEntry = (TSK_ENTRY_FUNC)SendEntry;
    taskParam1.usTaskPrio = 9;
    taskParam1.uwStackSize = LOSCFG_BASE_CORE_TSK_DEFAULT_STACK_SIZE;
    taskParam1.pcName = "SendQueue";
    ret = LOS_TaskCreate(&task1, &taskParam1);
    if(ret != LOS_OK) {
        printf("create task1 failed, error: %x\n", ret);
        return ret;
    }

    taskParam2.pfnTaskEntry = (TSK_ENTRY_FUNC)RecvEntry;
    taskParam2.usTaskPrio = 10;
    taskParam2.uwStackSize = LOSCFG_BASE_CORE_TSK_DEFAULT_STACK_SIZE;
    taskParam2.pcName = "RecvQueue";
    ret = LOS_TaskCreate(&task2, &taskParam2);
    if(ret != LOS_OK) {
        printf("create task2 failed, error: %x\n", ret);
        return ret;
    }

    ret = LOS_QueueCreate("queue", 5, &g_queue, 0, 50);
    if(ret != LOS_OK) {
        printf("create queue failure, error: %x\n", ret);
    }

    printf("create the queue success.\n");
    LOS_TaskUnlock();
    return ret;
}

start queue example.
create the queue success.
recv message: test message.
delete the queue success.

/**
 * 信号量控制块数据结构
 */
typedef struct {
    UINT16            semStat;          /* 信号量状态 */
    UINT16            semType;          /* 信号量类型 */
    UINT16            semCount;         /* 信号量计数 */
    UINT16            semId;            /* 信号量索引号 */
    LOS_DL_LIST       semList;          /* 用于插入阻塞于信号量的任务 */
} LosSemCB;

#include "los_sem.h"

/* 信号量结构体id */
static UINT32 g_semId;

VOID ExampleSemTask1(VOID)
{
    UINT32 ret;

    printf("ExampleSemTask1 try get sem g_semId, timeout 10 ticks.\n");
    /* 定时阻塞模式申请信号量，定时时间为10ticks */
    ret = LOS_SemPend(g_semId, 10);
    /* 申请到信号量 */
    if (ret == LOS_OK) {
         LOS_SemPost(g_semId);
         return;
    }
    
    /* 定时时间到，未申请到信号量 */
    if (ret == LOS_ERRNO_SEM_TIMEOUT) {
        printf("ExampleSemTask1 timeout and try get sem g_semId wait forever.\n");
        /*永久阻塞模式申请信号量*/
        ret = LOS_SemPend(g_semId, LOS_WAIT_FOREVER);
        printf("ExampleSemTask1 wait_forever and get sem g_semId.\n");
        if (ret == LOS_OK) {
            LOS_SemPost(g_semId);
            return;
        }
    }
}

VOID ExampleSemTask2(VOID)
{
    UINT32 ret;
    printf("ExampleSemTask2 try get sem g_semId wait forever.\n");

    /* 永久阻塞模式申请信号量 */
    ret = LOS_SemPend(g_semId, LOS_WAIT_FOREVER);
    if (ret == LOS_OK) {
        printf("ExampleSemTask2 get sem g_semId and then delay 20 ticks.\n");
    }

    /* 任务休眠20 ticks */
    LOS_TaskDelay(20);
    printf("ExampleSemTask2 post sem g_semId.\n");

    /* 释放信号量 */
    LOS_SemPost(g_semId);
    return;
}

UINT32 ExampleSem(VOID)
{
    UINT32 ret;
    TSK_INIT_PARAM_S task1 = { 0 };
    TSK_INIT_PARAM_S task2 = { 0 };
    UINT32 taskId1;
    UINT32 taskId2;

   /* 创建信号量 */
    LOS_SemCreate(0, &g_semId);

    /* 锁任务调度 */
    LOS_TaskLock();

    /* 创建任务1 */
    task1.pfnTaskEntry = (TSK_ENTRY_FUNC)ExampleSemTask1;
    task1.pcName       = "TestTask1";
    task1.uwStackSize  = LOSCFG_BASE_CORE_TSK_DEFAULT_STACK_SIZE;
    task1.usTaskPrio   = 5;
    ret = LOS_TaskCreate(&taskId1, &task1);
    if (ret != LOS_OK) {
        printf("task1 create failed.\n");
        return LOS_NOK;
    }

    /* 创建任务2 */
    task2.pfnTaskEntry = (TSK_ENTRY_FUNC)ExampleSemTask2;
    task2.pcName       = "TestTask2";
    task2.uwStackSize  = LOSCFG_BASE_CORE_TSK_DEFAULT_STACK_SIZE;
    task2.usTaskPrio   = 4;
    ret = LOS_TaskCreate(&taskId2, &task2);
    if (ret != LOS_OK) {
        printf("task2 create failed.\n");
        return LOS_NOK;
    }

    /* 解锁任务调度 */
    LOS_TaskUnlock();

    ret = LOS_SemPost(g_semId);

    /* 任务休眠400 ticks */
    LOS_TaskDelay(400);

    /* 删除信号量 */
    LOS_SemDelete(g_semId);
    return LOS_OK;
}

ExampleSemTask2 try get sem g_semId wait forever.
ExampleSemTask1 try get sem g_semId, timeout 10 ticks.
ExampleSemTask2 get sem g_semId and then delay 20 ticks.
ExampleSemTask1 timeout and try get sem g_semId wait forever.
ExampleSemTask2 post sem g_semId.
ExampleSemTask1 wait_forever and get sem g_semId.