4.3BSD - /usr/src/ucb/window/wwrint.c

   1: #ifndef lint
   2: static char sccsid[] = "@(#)wwrint.c	3.4 4/24/85";
   3: #endif
   4: 
   5: /*
   6:  * Copyright (c) 1983 Regents of the University of California,
   7:  * All rights reserved.  Redistribution permitted subject to
   8:  * the terms of the Berkeley Software License Agreement.
   9:  */
  10: 
  11: #include "ww.h"
  12: #include <fcntl.h>
  13: #include <sys/signal.h>
  14: 
  15: /*
  16:  * Tty input interrupt handler.
  17:  * (1) Read input into buffer (wwib*).
  18:  * (2) If the flag wwsetjmp is true, do longjmp(wwjmpbuf) for asyncronous
  19:  *     actions, and to avoid race conditions, clear wwsetjmp.
  20:  * Currently, the last is used to get out of the blocking
  21:  * select() in wwiomux().
  22:  * To avoid race conditions, we only modify wwibq in here, except
  23:  * when the buffer is empty; and everywhere else, we only change wwibp.
  24:  * It should be completely safe.
  25:  */
  26: wwrint()
  27: {
  28:     register n;
  29: 
  30:     if (wwibp == wwibq)
  31:         wwibp = wwibq = wwib;
  32:     wwnread++;
  33:     (void) fcntl(0, F_SETFL, FNDELAY|wwnewtty.ww_fflags);
  34:     n = read(0, wwibq, wwibe - wwibq);
  35:     (void) fcntl(0, F_SETFL, wwnewtty.ww_fflags);
  36:     if (n > 0) {
  37:         wwibq += n;
  38:         wwnreadc += n;
  39:     } else if (n == 0)
  40:         wwnreadz++;
  41:     else
  42:         wwnreade++;
  43:     if (wwinterrupt() && wwsetjmp) {
  44:         wwsetjmp = 0;
  45:         (void) sigsetmask(sigblock(0) & ~sigmask(SIGIO));
  46:         longjmp(wwjmpbuf, 1);
  47:     }
  48: }

Defined functions

Defined variables