ttyld.hpp

一个嵌入式系统的C代码

//*************************************************************************
//  MODULE : LnDrv.hpp - Line Discipline Driver for terminal devices	  *
//  AUTHOR : Ron Chernich                                                 *
//  PURPOSE: This class used by RCOS processes which open a terminal	  *
//	     device in buffered mode [Bach, ch 10 - see CPP file].  Unix  *
//	     does this in the kernel through numerous lists - being able  *
//	     to do this with a class really simplifies matters. 	  *
//  HISTORY:                                                              *
//    20-APR-93	First version						  *
//    29-OCT-93 User break char changed to Control+C                      *
//    20-APR-94 Memory leak through Cblock destructor fixed		  *
//*************************************************************************

#ifndef _RCOS_LNDRV_

  #include "rcos.hpp"
  #include "dbllist.hpp"
  #include "tty.hpp"

  #define CBLOCK_LEN	8		// input block segment length
  #define BREAK_CHAR	3		// break detect on Ctrl+C


  /////////////
  // Like Unix, we hold edited input in Cblocks - but we have a reliable (?)
  // double linked list class to base this structure on. First, the struct..
  //
  typedef struct cblock {
    INT16 nStart, nEnd;
    char  cBuf[CBLOCK_LEN];
  } CBLOCK, *PCBLOCK;
  //
  // now define the class based on DblList to provide functionality..
  //
  class Cblock : private DblList {
  public:
    Cblock (void) { }
   ~Cblock (void)         { DblDrop();   }
    void    CbDrop (void) { DblDelete(); }
    PCBLOCK CbHead (void) { return (PCBLOCK)DblGetHead(); }
    PCBLOCK CbTail (void) { return (PCBLOCK)DblGetTail(); }
    PCBLOCK CbNext (void) { return (PCBLOCK)DblGetNext(); }
    PCBLOCK CbNew (void);
  };


  ///////////////////
  // This class processes user input commands from a terminal running
  // in full duplex mode.  It performs simple input editing by destructive
  // backspace, echoing the user's input and passing on the owner processes
  // output.  Edited input is held in a chain of CBLOCK structs (like Unix)
  // from which delimited blocks can be retrieved to satisfy data requests.
  //
  // This (initial) version performs line (CR delimited) buffering only
  // and does not expand TAB characters.
  //
  class LnDrv : public port {
    Cblock  Cblk;
    UINT16  uPid, uTerm;		// who makes 'em and who eats 'em
    INT16   nBlkReq, nChReq;		// outstanding request counts.
    char    cDelim;			// Data block delimiter char
    BOOL    bBreakOn;			// control break detection
    void LnReq (void);			// process User Process request
    void LnEdit (char); 		// process data from terminal
  public:
    LnDrv (UINT16, UINT16, Knl*);	// constructor
    ~LnDrv ();				// destructor
    void RxPort (PMSG); 		// Receive port body for virtual
  };


  #define _RCOS_LNDRV_

#endif

/********************************** eof **********************************/