编程实例 (SMP)

实例描述

本实例介绍基本的任务操作方法，包含任务创建、任务延时、任务锁与解锁调度、挂起和恢复等操作，阐述任务优先级调度的机制以及各接口的应用。

编程示例

前提条件：在menuconfig菜单中完成任务模块的配置和SMP模式使能。

UINT32 g_taskLoId;
UINT32 g_taskHiId;
#define TSK_PRIOR_HI 4
#define TSK_PRIOR_LO 5

UINT32 Example_TaskHi(VOID)
{
    UINT32 ret;

    printf("[cpu%d] Enter TaskHi Handler.\r\n", ArchCurrCpuid());

    /* 延时2个Tick，延时后该任务会挂起，执行剩余任务中最高优先级的任务(g_taskLoId任务) */
    ret = LOS_TaskDelay(2);
    if (ret != LOS_OK) {
        printf("Delay Task Failed.\r\n");
        return LOS_NOK;
    }

    /* 2个Tick后，该任务恢复，继续执行 */
    printf("TaskHi LOS_TaskDelay Done.\r\n");

    /* 挂起自身任务 */
    ret = LOS_TaskSuspend(g_taskHiId);
    if (ret != LOS_OK) {
        printf("Suspend TaskHi Failed.\r\n");
        return LOS_NOK;
    }
    printf("TaskHi LOS_TaskResume Success.\r\n");
    return ret;
}

/* 低优先级任务入口函数 */
UINT32 Example_TaskLo(VOID)
{
    UINT32 ret;

    printf("[cpu%d] Enter TaskLo Handler.\r\n", ArchCurrCpuid());

    /* 延时2个Tick，延时后该任务会挂起，执行剩余任务中就高优先级的任务(背景任务) */
    ret = LOS_TaskDelay(2);
    if (ret != LOS_OK) {
        printf("Delay TaskLo Failed.\r\n");
        return LOS_NOK;
    }

    printf("TaskHi LOS_TaskDelete Success.\r\n");
    return ret;
}

/* 任务测试入口函数，创建两个不同优先级的任务 */
UINT32 Example_TskCaseEntry(VOID)
{
    UINT32 ret;
    TSK_INIT_PARAM_S initParam = {0};

    /* 锁任务调度 */
    LOS_TaskLock();

    printf("LOS_TaskLock() Success on cpu%d!\r\n", ArchCurrCpuid());

    initParam.pfnTaskEntry = (TSK_ENTRY_FUNC)Example_TaskHi;
    initParam.usTaskPrio = TSK_PRIOR_HI;
    initParam.pcName = "TaskHi";
    initParam.uwStackSize = LOSCFG_TASK_MIN_STACK_SIZE;
    initParam.uwResved   = LOS_TASK_STATUS_DETACHED;
#ifdef LOSCFG_KERNEL_SMP
    /* 绑定高优先级任务到CPU1运行 */
    initParam.usCpuAffiMask = CPUID_TO_AFFI_MASK(ArchCurrCpuid());
#endif
    /* 创建高优先级任务，由于CPU1的调度器被锁，任务创建成功后不会马上执行 */
    ret = LOS_TaskCreate(&g_taskHiId, &initParam);
    if (ret != LOS_OK) {
        LOS_TaskUnlock();

        printf("Example_TaskHi create Failed!\r\n");
        return LOS_NOK;
    }

    printf("Example_TaskHi create Success!\r\n");

    initParam.pfnTaskEntry = (TSK_ENTRY_FUNC)Example_TaskLo;
    initParam.usTaskPrio = TSK_PRIOR_LO;
    initParam.pcName = "TaskLo";
    initParam.uwStackSize = LOSCFG_TASK_MIN_STACK_SIZE;
    initParam.uwResved   = LOS_TASK_STATUS_DETACHED;
#ifdef LOSCFG_KERNEL_SMP
    /* 低优先级任务不设置CPU亲和性 */
    initParam.usCpuAffiMask = 0;
#endif
    /* 创建低优先级任务，尽管锁任务调度，但是由于该任务没有绑定该处理器，任务创建成功后可以马上在其他CPU执行 */
    ret = LOS_TaskCreate(&g_taskLoId, &initParam);
    if (ret != LOS_OK) {
        LOS_TaskUnlock();

        printf("Example_TaskLo create Failed!\r\n");
        return LOS_NOK;
    }

    printf("Example_TaskLo create Success!\r\n");

    /* 解锁任务调度，此时会发生任务调度，执行就绪列表中最高优先级任务 */
    LOS_TaskUnlock();

    return LOS_OK;
}

结果验证

编译运行得到的结果为：

LOS_TaskLock() success on cpu1!
Example_TaskHi create Success!
Example_TaskLo create Success!
[cpu2] Enter TaskLo Handler.
[cpu1] Enter TaskHi Handler.
TaskHi LOS_TaskDelete Success.
TaskHi LOS_TaskDelay Done.

完整实例代码

sample_task_smp.c