os_flag.c

avr ucos 代码 测试环境：source insight WINAVR 4个进程

/*
*********************************************************************************************************
*                                                uC/OS-II
*                                          The Real-Time Kernel
*                                         EVENT FLAG  MANAGEMENT
*
*                          (c) Copyright 2001-2002, Jean J. Labrosse, Weston, FL
*                                           All Rights Reserved
*
* File : OS_FLAG.C
* By   : Jean J. Labrosse
*********************************************************************************************************
*/

#ifndef  OS_MASTER_FILE
#include "INCLUDES.H"
#endif

#if (OS_VERSION >= 251) && (OS_FLAG_EN > 0) && (OS_MAX_FLAGS > 0)
/*
*********************************************************************************************************
*                                            LOCAL PROTOTYPES
                                                    局部定义
*********************************************************************************************************
*/

static  void     OS_FlagBlock(OS_FLAG_GRP *pgrp, OS_FLAG_NODE *pnode, OS_FLAGS flags, INT8U wait_type, INT16U timeout);
static  BOOLEAN  OS_FlagTaskRdy(OS_FLAG_NODE *pnode, OS_FLAGS flags_rdy);

/*$PAGE*/
/*
*********************************************************************************************************
*                              CHECK THE STATUS OF FLAGS IN AN EVENT FLAG GROUP
*
* Description: This function is called to check the status of a combination of bits to be set or cleared
*              in an event flag group.  Your application can check for ANY bit to be set/cleared or ALL
*              bits to be set/cleared.
*
*              This call does not block if the desired flags are not present.
*
* Arguments  : pgrp          is a pointer to the desired event flag group.
*
*              flags         Is a bit pattern indicating which bit(s) (i.e. flags) you wish to check.
*                            The bits you want are specified by setting the corresponding bits in
*                            'flags'.  e.g. if your application wants to wait for bits 0 and 1 then
*                            'flags' would contain 0x03.
*
*              wait_type     specifies whether you want ALL bits to be set/cleared or ANY of the bits
*                            to be set/cleared.
*                            You can specify the following argument:
*
*                            OS_FLAG_WAIT_CLR_ALL   You will check ALL bits in 'flags' to be clear (0)
*                            OS_FLAG_WAIT_CLR_ANY   You will check ANY bit  in 'flags' to be clear (0)
*                            OS_FLAG_WAIT_SET_ALL   You will check ALL bits in 'flags' to be set   (1)
*                            OS_FLAG_WAIT_SET_ANY   You will check ANY bit  in 'flags' to be set   (1)
*
*                            NOTE: Add OS_FLAG_CONSUME if you want the event flag to be 'consumed' by
*                                  the call.  Example, to wait for any flag in a group AND then clear
*                                  the flags that are present, set 'wait_type' to:
*
*                                  OS_FLAG_WAIT_SET_ANY + OS_FLAG_CONSUME
*
*              err           is a pointer to an error code and can be:
*                            OS_NO_ERR              No error
*                            OS_ERR_EVENT_TYPE      You are not pointing to an event flag group
*                            OS_FLAG_ERR_WAIT_TYPE  You didn't specify a proper 'wait_type' argument.
*                            OS_FLAG_INVALID_PGRP   You passed a NULL pointer instead of the event flag
*                                                   group handle.
*                            OS_FLAG_ERR_NOT_RDY    The desired flags you are waiting for are not
*                                                   available.
*
* Returns    : The state of the flags in the event flag group.
*
* Called from: Task or ISR
                                    无等待地获得事件标志组中的事件标志
描述：去检查事件标志组中结合位的状态是置位还是被清除，你能
                检查任何将被置位或者清除的位或者全部位
                如果等待事件不发生，调用事件并不挂起。与OSFlagPend()唯一不同点
参数：pgrp：指向目标事件标志组的指针
                flags：是一个位的模式显示要检查的位，比如：你要检测0位和1位，那么你将它
                           设置为0x03
                wait_type ：标记你想全部检测还是只想检测其实一部分。你能标记如下参数：
*                            OS_FLAG_WAIT_CLR_ALL   你将检测flags中全部的清零位
*                            OS_FLAG_WAIT_CLR_ANY   你将检测flags中任何清零位
*                            OS_FLAG_WAIT_SET_ALL   你将检测flags中全部的置一位
*                            OS_FLAG_WAIT_SET_ANY   你将检测flags中任何置一位
               如果想事件标志被调用函数清除的话，要加上OS_FLAG_CONSUME，比如：如果
               想要组与后清除，那么将wait_type设置成OS_FLAG_WAIT_SET_ANY + OS_FLAG_CONSUME
               err 指向错误代码的指针，可以为：
*                            OS_NO_ERR             无误
*                            OS_ERR_EVENT_TYPE      没有指向任务事件标志组
*                            OS_FLAG_ERR_WAIT_TYPE  你没有设置正确的 'wait_type' 参数
*                            OS_FLAG_INVALID_PGRP   你传送了零指针而不是事件标志组操作
*                            OS_FLAG_ERR_NOT_RDY    你等待的目标标志不合理
返回：事件标志组的标志状态
从任务和ISR中调用
*********************************************************************************************************
*/

#if OS_FLAG_ACCEPT_EN > 0
OS_FLAGS  OSFlagAccept (OS_FLAG_GRP *pgrp, OS_FLAGS flags, INT8U wait_type, INT8U *err)
{
#if OS_CRITICAL_METHOD == 3                                /* Allocate storage for CPU status register */
    OS_CPU_SR     cpu_sr;
#endif
    OS_FLAGS      flags_cur;
    OS_FLAGS      flags_rdy;
    BOOLEAN       consume;


#if OS_ARG_CHK_EN > 0
    if (pgrp == (OS_FLAG_GRP *)0) {                        /* Validate 'pgrp'                          */
        *err = OS_FLAG_INVALID_PGRP;
        return ((OS_FLAGS)0);//非空的pgrp'
    }
    if (pgrp->OSFlagType != OS_EVENT_TYPE_FLAG) {          /* Validate event block type                */
        *err = OS_ERR_EVENT_TYPE;
        return ((OS_FLAGS)0);//合理的事件控制块类型
    }
#endif
    if (wait_type & OS_FLAG_CONSUME) {                     /* See if we need to consume the flags      */
        wait_type &= ~OS_FLAG_CONSUME;
        consume    = TRUE;
    } else {
        consume    = FALSE;
    }//是否需要清除位
/*$PAGE*/
    *err = OS_NO_ERR;                                      /* Assume NO error until proven otherwise.  */
//初始化无错
    OS_ENTER_CRITICAL();
    switch (wait_type) {
        case OS_FLAG_WAIT_SET_ALL:                         /* See if all required flags are set        */
             flags_rdy = pgrp->OSFlagFlags & flags;        /* Extract only the bits we want            */
             if (flags_rdy == flags) {                     /* Must match ALL the bits that we want     */
                 //如果刚好是我们要的
                 if (consume == TRUE) {                    /* See if we need to consume the flags      */
                     pgrp->OSFlagFlags &= ~flags_rdy;      /* Clear ONLY the flags that we wanted      */
                 }//是否要清除
             } else {
                 *err  = OS_FLAG_ERR_NOT_RDY;//没有我们想要的，返回不合理
             }
             flags_cur = pgrp->OSFlagFlags;                /* Will return the state of the group       */
			 //返回标志
             OS_EXIT_CRITICAL();
             break;

        case OS_FLAG_WAIT_SET_ANY:
             flags_rdy = pgrp->OSFlagFlags & flags;        /* Extract only the bits we want            */
             if (flags_rdy != (OS_FLAGS)0) {               /* See if any flag set                      */
			 	//是否有标志置位
                 if (consume == TRUE) {                    /* See if we need to consume the flags      */
                     pgrp->OSFlagFlags &= ~flags_rdy;      /* Clear ONLY the flags that we got         */
                 }//是否需要清除位
             } else {//没有标志置位
                 *err  = OS_FLAG_ERR_NOT_RDY;
             }
             flags_cur = pgrp->OSFlagFlags;                /* Will return the state of the group       */
			 //返回组状态，
             OS_EXIT_CRITICAL();
             break;

#if OS_FLAG_WAIT_CLR_EN > 0
        case OS_FLAG_WAIT_CLR_ALL:                         /* See if all required flags are cleared    */
             flags_rdy = ~pgrp->OSFlagFlags & flags;       /* Extract only the bits we want            */
			 //设置位
             if (flags_rdy == flags) {                     /* Must match ALL the bits that we want     */
			 	//必须所有的位都匹配
                 if (consume == TRUE) {                    /* See if we need to consume the flags      */
                     pgrp->OSFlagFlags |= flags_rdy;       /* Set ONLY the flags that we wanted        */
                 }//是否要设置位
             } else {
                 *err  = OS_FLAG_ERR_NOT_RDY;//不是所有位都匹配
             }
             flags_cur = pgrp->OSFlagFlags;                /* Will return the state of the group       */
			 //返回标志组状态
             OS_EXIT_CRITICAL();
             break;

        case OS_FLAG_WAIT_CLR_ANY:
             flags_rdy = ~pgrp->OSFlagFlags & flags;       /* Extract only the bits we want            */
             if (flags_rdy != (OS_FLAGS)0) {               /* See if any flag cleared                  */
                 if (consume == TRUE) {                    /* See if we need to consume the flags      */
                     pgrp->OSFlagFlags |= flags_rdy;       /* Set ONLY the flags that we got           */
                 }
             } else {
                 *err  = OS_FLAG_ERR_NOT_RDY;
             }
             flags_cur = pgrp->OSFlagFlags;                /* Will return the state of the group       */
             OS_EXIT_CRITICAL();
             break;
#endif

        default://其它异常情况
             OS_EXIT_CRITICAL();
             flags_cur = (OS_FLAGS)0;
             *err      = OS_FLAG_ERR_WAIT_TYPE;
             break;
    }
    return (flags_cur);//返回状态
}
#endif

/*$PAGE*/
/*
*********************************************************************************************************
*                                           CREATE AN EVENT FLAG
*
* Description: This function is called to create an event flag group.
*
* Arguments  : flags         Contains the initial value to store in the event flag group.
*
*              err           is a pointer to an error code which will be returned to your application:
*                               OS_NO_ERR                if the call was successful.
*                               OS_ERR_CREATE_ISR        if you attempted to create an Event Flag from an
*                                                        ISR.
*                               OS_FLAG_GRP_DEPLETED     if there are no more event flag groups
*
* Returns    : A pointer to an event flag group or a NULL pointer if no more groups are available.
*
* Called from: Task ONLY
                                                     建立一个事件标志组
描述：建立一个事件标志组