selectdemo.c

2410/vxworks/tornado下的基本实验包括 serial,ramdrv,interrupt,multi-tasking,FTP,TCP,UDP

/* selectDemo.c - 使用select 的例子*/
 
 
 #include "vxWorks.h"
 #include "taskLib.h"
 #include "selectLib.h"
 #include <string.h> 
 #include <ioLib.h>  
 #include <stdio.h>  
 #include <fioLib.h>
 #include <pipeDrv.h> 
 #include <sysLib.h> 
 
 #define BUFFERSIZE     25                               /* 缓冲区大小 */
 #define NUM_FDS     2                                /* 监听的设备个数   */
 #define ONE_SEC     1
 #define STRING1 "SelectDemo: Message #1" 
 #define STRING2 "SelectDemo: Message #2"
 #define STRING3 "Quitting SelectDemo"
 #define MAX_NUM_MSG 2                  /* 管道中最多的消息个数*/
 #define MSG_SIZE    100                           /* 消息的最大值*/
 LOCAL int inFd1;                   /*/pipe/1  文件描述符*/  
 LOCAL int inFd2;                   /* /pipe/2 文件描述符*/
 
 
 /*******************************************************************************
 * selectOnReadFds - selectOnReadFds 任务函数
 * 这个任务调用select 监听两个管道,直到其中一个变为可读,
 * 然后从中读取信息.
 *
 * RETURNS: OK or ERROR
 */
 
 STATUS selectOnReadFds ()
     {
     char receiveString [BUFFERSIZE];      /* 接收消息缓冲区 */
     struct fd_set readFds;
     struct fd_set saveFds;
     int width;
     int bytesRead;
     int numFds;                                         
     int notFinished = TRUE;
 
     width = 0;
     FD_ZERO (&saveFds);    /* 初始化,清空文件描述字集合*/
 
     /* width 变量是被测试的最大文件描述符的位数,
     		这里是inFd1和inFd2中的大者+1
      */
     FD_SET (inFd1, &saveFds); /* 设置 inFd1 对应位*/
     FD_SET (inFd2, &saveFds); /* 设置 inFd2 对应位*/     
     width = (inFd1 > inFd2) ? inFd1 : inFd2;
     width++; 
 
     while (notFinished)
         {
         readFds = saveFds;
         printf ("selectOnReadFds: Number of bits (in fd_set struct) to be tested = %d\n", width);
 
         /* 任务因等待多文件描述符而阻塞,通过使用select()函数直到
             一个或多个文件描述符变为有效
          */
 
         if ((numFds = select (width, &readFds, NULL, NULL, NULL)) == ERROR)
             {
             perror (" ERROR in select");   
             return (ERROR);
             }
         else 
             printf ("selectOnReadFds: Number of file descriptors ready for reading = %d\n", numFds);
 
         if (FD_ISSET (inFd1, &readFds))
             {
             /* /pipe/1 处于可读状态 */
             bzero (receiveString, BUFFERSIZE);
             if ((bytesRead = read (inFd1, receiveString, BUFFERSIZE)) > OK)
                 printf ("selectOnReadFds: Message read from /pipe/1 device - \"%s\"\n",(char *) receiveString);
             if (strcmp (receiveString, STRING3) == 0)
                 notFinished = FALSE;
             }    
         else 
             printf ("selectOnReadFds: The fd inFd1 of /pipe/1 dev. is not READY for reading\n");
 
         if (FD_ISSET (inFd2, &readFds))
             {
             /* /pipe/2  处于可读状态*/
             bzero (receiveString, BUFFERSIZE);
             if ((bytesRead = read (inFd2, receiveString, BUFFERSIZE)) > OK)
                 printf ("selectOnReadFds: Message read from /pipe/2 device - \"%s\"\n", (char *) receiveString);
             }    
         else 
             printf ("selectOnReadFds: The fd inFd2 of /pipe/2 dev. is not READY for reading\n");
         printf ("\n");
         }
 
         return (OK);
     }
 
 /******************************************************************************
  *
  * selectDemoInit - 初始化管道设备函数 
  *
  * 这个程序初始化管道设备,使之可进行读/写操作	
  *
  */
 
 void selectDemoInit ()
     {
 
     if (pipeDevCreate ("/pipe/1",MAX_NUM_MSG, MSG_SIZE) == ERROR)
         perror ("selectDemoInit: error in creating\"/pipe/1\"");
     else 
         printf ("\"/pipe/1\" pipe device created\n");
 
     if (pipeDevCreate ("/pipe/2", MAX_NUM_MSG, MSG_SIZE) == ERROR)
         perror ("selectDemoInit: error in creating \"/pipe/2\"");
      else 
         printf ("\"/pipe/2\" pipe device created\n\n");
 
      if ((inFd1 = open ("/pipe/1", UPDATE, 0644)) == ERROR) 
         perror (" Error opening file \"/pipe/1\"") ;
      else 
         printf ("Value of the fd for /pipe/1 = %d \n", inFd1);
 
      if ((inFd2 = open ("/pipe/2", UPDATE, 0644)) == ERROR) 
         perror (" Error opening file \"/pipe/1\"") ;
      else 
         printf ("Value of the fd for /pipe/2 = %d \n\n", inFd2);
 
     }    
 
 /******************************************************************************
  *
  * selectDemo -主函数
  *
  * 这个程序基于管道设备示范了select()的操作
  * selectDemo程序初始化管道设备并创建和激活selectOnReadFds任务.然后
  * 往管道设备中写入消息. selectOnReadFds任务基于select()函数,从处于可读
  * 状态的管道设备中读取消息.
  *
  * RETURNS: OK or ERROR
  */
 
 STATUS selectDemo ()
     {
     char input[80];
     int makeFdsReady;
     int notDone = TRUE;     /* 结束标志 */  
 
     selectDemoInit ();      /* 初始化管道设备*/
 
     /* 创建任务 selectOnReadFds */
     if ((taskSpawn ("selectOnReadFds", 100, VX_SUPERVISOR_MODE | VX_STDIO,
            20000, (FUNCPTR) selectOnReadFds, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0)) 
                                                                       == ERROR)
         {
         perror ("selectDemo: Spawning selectOnReadFds task failed");
         return (ERROR); 
         }
 
     while (notDone)
         {
         /* 释放CPU一段时间,以便selectOnReadFds能执行
          */
         taskDelay (sysClkRateGet () * ONE_SEC);
 
         makeFdsReady = NONE;
         printf ("0 : To quit this Demo\n");
         printf ("1 : To write a message to \"/pipe/1\"\n");
         printf ("2 : To write a message to \"/pipe/2\"\n");
         printf ("3 : To write a message to \"/pipe/1\" and \"/pipe/2\"\n");
         printf ("Enter your choice : ");
         gets (input);
         sscanf (input, "%d", &makeFdsReady);
         printf ("\n");    
 
         switch (makeFdsReady)
             {
             case 1:  /* 往 /pipe/1 设备写消息 */
                 printf ("Writing the message \"%s\" to /pipe/1 device\n", (char *) STRING1);
                 if (write (inFd1, STRING1, sizeof (STRING1)) == ERROR)
                     perror ("selectDemo: Writing msg to pipe 1 failed");
                 break;
 
             case 2:  /*往 /pipe/2 设备写消息*/
                 printf ("Writing the message \"%s\" to /pipe/2 device\n", (char *) STRING2);
                 if (write (inFd2, STRING2, sizeof (STRING2)) == ERROR)
                     perror ("selectDemo: Writing msg to pipe 2 failed");
                 break;         
 
             case 3:  /* 往 /pipe/1 and /pipe/2 设备中写消息*/
                 printf ("Writing the message \"%s\" to /pipe/1 device\n", (char *) STRING1);
                 if (write (inFd1, STRING1, sizeof (STRING1)) == ERROR)
                     perror ("selectDemo: Writing msg to pipe 1 failed");
                 printf ("Writing the message \"%s\" to /pipe/2 device\n", (char *) STRING2);
                 if (write (inFd2, STRING2, sizeof (STRING2)) == ERROR)
                     perror ("selectDemo: Writing msg to pipe 2 failed");
                 break;         
 
             case 0:  /* 往 /pipe/1设备中写停止演示消息 */
                 notDone = FALSE;
                 printf ("Writing the message \"%s\" to /pipe/1 device\n", (char *) STRING3);
                 if (write (inFd1, STRING3, sizeof (STRING3)) == ERROR)
                     perror ("selectDemo: Writing msg to pipe 1 failed");
                 taskDelay (sysClkRateGet () * ONE_SEC);
                 break;
 
             default :
                 printf ("Unrecognized Choice \n");
                 break;
             }
                 
             printf ("\n");
         }
 
         close (inFd1);
         close (inFd2); 
         return (OK);
     }