μCOS-II中OS_SEM.C源码中文注释版

《μCOS-II中OS_SEM.C源码中文注释版》由会员上传分享，免费在线阅读，更多相关内容在行业资料-天天文库。

1、xilentz的网络文摘博客园   首页   新随笔   联系   订阅   管理随笔-204 文章-0 评论-10 trackbacks-0OS_SEM.C/***********************************************************************************************************                                               uC/OS-II*                                         TheRe

2、al-TimeKernel*                                         SEMAPHOREMANAGEMENT**                         (c)Copyright1992-2002,JeanJ.Labrosse,Weston,FL*                                          AllRightsReserved**File:OS_SEM.C*By  :JeanJ.Labrosse***********************************************

3、***********************************************************/#ifndef OS_MASTER_FILE#include"includes.h"#endif#ifOS_SEM_EN>0/***********************************************************************************************************                                          ACCEPTSEMAPHORE接受

4、信号量**Description:Thisfunctionchecksthesemaphoretoseeifaresourceisavailableor,ifanevent*             occurred. UnlikeOSSemPend(),OSSemAccept()doesnotsuspendthecallingtaskifthe*             resourceisnotavailableortheeventdidnotoccur.**Arguments :pevent    isapointertotheeventcontrolblock**

5、Returns   :> 0      iftheresourceisavailableortheeventdidnotoccurthesemaphoreis*                        decrementedtoobtaintheresource.*             ==0      iftheresourceisnotavailableortheeventdidnotoccuror,*                        if'pevent'isaNULLpointeror,*                        ify

6、oudidn'tpassapointertoasemaphore**********************************************************************************************************/#ifOS_SEM_ACCEPT_EN>0INT16U OSSemAccept(OS_EVENT*pevent){#ifOS_CRITICAL_METHOD==3                          /*AllocatestorageforCPUstatusregister     *

7、/   OS_CPU_SR cpu_sr;#endif      INT16U    cnt;#ifOS_ARG_CHK_EN>0   if(pevent==(OS_EVENT*)0){                   /*Validate'pevent'                            */       return(0);   }   if(pevent->OSEventType!=OS_EVENT_TYPE_SEM){  /*Validateeventblocktype