BSD 4.4 Lite Usr.bin Sources

1 files changed, 203 insertions, 0 deletions

diff --git a/usr.bin/window/wwiomux.c b/usr.bin/window/wwiomux.c
new file mode 100644
index 0000000..ce6978b
--- /dev/null
+++ b/usr.bin/window/wwiomux.c
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+/*
+ * Copyright (c) 1983, 1993
+ *	The Regents of the University of California.  All rights reserved.
+ *
+ * This code is derived from software contributed to Berkeley by
+ * Edward Wang at The University of California, Berkeley.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by the University of
+ *	California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef lint
+static char sccsid[] = "@(#)wwiomux.c	8.1 (Berkeley) 6/6/93";
+#endif /* not lint */
+
+#include "ww.h"
+#include <sys/time.h>
+#include <sys/types.h>
+#if !defined(OLD_TTY) && !defined(TIOCPKT_DATA)
+#include <sys/ioctl.h>
+#endif
+#include <fcntl.h>
+
+/*
+ * Multiple window output handler.
+ * The idea is to copy window outputs to the terminal, via the
+ * display package.  We try to give wwcurwin highest priority.
+ * The only return conditions are when there is keyboard input
+ * and when a child process dies, which are serviced by signal
+ * catchers (wwrint() and wwchild()).
+ * When there's nothing to do, we sleep in a select().
+ * This can be done better with interrupt driven io.  But that's
+ * not supported on ptys, yet.
+ * The history of this routine is interesting.
+ */
+wwiomux()
+{
+	register struct ww *w;
+	fd_set imask;
+	register n;
+	register char *p;
+	char c;
+	struct timeval tv;
+	char noblock = 0;
+
+	for (;;) {
+		if (wwinterrupt()) {
+			wwclrintr();
+			return;
+		}
+
+		FD_ZERO(&imask);
+		n = -1;
+		for (w = wwhead.ww_forw; w != &wwhead; w = w->ww_forw) {
+			if (w->ww_pty < 0)
+				continue;
+			if (w->ww_obq < w->ww_obe) {
+				if (w->ww_pty > n)
+					n = w->ww_pty;
+				FD_SET(w->ww_pty, &imask);
+			}
+			if (w->ww_obq > w->ww_obp && !w->ww_stopped)
+				noblock = 1;
+		}
+
+		if (!noblock) {
+			if (wwcurwin != 0)
+				wwcurtowin(wwcurwin);
+			wwupdate();
+			wwflush();
+			(void) setjmp(wwjmpbuf);
+			wwsetjmp = 1;
+			if (wwinterrupt()) {
+				wwsetjmp = 0;
+				wwclrintr();
+				return;
+			}
+			/*
+			 * Defensive code.  If somebody else (for example,
+			 * wall) clears the ASYNC flag on us, we will block
+			 * forever.  So we need a finite timeout and set
+			 * the flag again.  Anything more clever will probably
+			 * need even more system calls.  (This is a bug
+			 * in the kernel.)
+			 * I don't like this one bit.
+			 */
+			(void) fcntl(0, F_SETFL, wwnewtty.ww_fflags);
+			tv.tv_sec = 30;
+			tv.tv_usec = 0;
+		} else {
+			tv.tv_sec = 0;
+			tv.tv_usec = 10000;
+		}
+		wwnselect++;
+		n = select(n + 1, &imask, (fd_set *)0, (fd_set *)0, &tv);
+		wwsetjmp = 0;
+		noblock = 0;
+
+		if (n < 0)
+			wwnselecte++;
+		else if (n == 0)
+			wwnselectz++;
+		else
+			for (w = wwhead.ww_forw; w != &wwhead; w = w->ww_forw) {
+				if (w->ww_pty < 0 ||
+				    !FD_ISSET(w->ww_pty, &imask))
+					continue;
+				wwnwread++;
+				p = w->ww_obq;
+				if (w->ww_ispty) {
+					if (p == w->ww_ob) {
+						w->ww_obp++;
+						w->ww_obq++;
+					} else
+						p--;
+					c = *p;
+				}
+				n = read(w->ww_pty, p, w->ww_obe - p);
+				if (n < 0) {
+					wwnwreade++;
+					(void) close(w->ww_pty);
+					w->ww_pty = -1;
+				} else if (n == 0) {
+					wwnwreadz++;
+					(void) close(w->ww_pty);
+					w->ww_pty = -1;
+				} else if (!w->ww_ispty) {
+					wwnwreadd++;
+					wwnwreadc += n;
+					w->ww_obq += n;
+				} else if (*p == TIOCPKT_DATA) {
+					n--;
+					wwnwreadd++;
+					wwnwreadc += n;
+					w->ww_obq += n;
+				} else {
+					wwnwreadp++;
+					if (*p & TIOCPKT_STOP)
+						w->ww_stopped = 1;
+					if (*p & TIOCPKT_START)
+						w->ww_stopped = 0;
+					if (*p & TIOCPKT_FLUSHWRITE) {
+						w->ww_stopped = 0;
+						w->ww_obq = w->ww_obp =
+							w->ww_ob;
+					}
+				}
+				if (w->ww_ispty)
+					*p = c;
+			}
+		/*
+		 * Try the current window first, if there is output
+		 * then process it and go back to the top to try again.
+		 * This can lead to starvation of the other windows,
+		 * but presumably that what we want.
+		 * Update will eventually happen when output from wwcurwin
+		 * dies down.
+		 */
+		if ((w = wwcurwin) != 0 && w->ww_pty >= 0 &&
+		    w->ww_obq > w->ww_obp && !w->ww_stopped) {
+			n = wwwrite(w, w->ww_obp, w->ww_obq - w->ww_obp);
+			if ((w->ww_obp += n) == w->ww_obq)
+				w->ww_obq = w->ww_obp = w->ww_ob;
+			noblock = 1;
+			continue;
+		}
+		for (w = wwhead.ww_forw; w != &wwhead; w = w->ww_forw)
+			if (w->ww_pty >= 0 && w->ww_obq > w->ww_obp &&
+			    !w->ww_stopped) {
+				n = wwwrite(w, w->ww_obp,
+					w->ww_obq - w->ww_obp);
+				if ((w->ww_obp += n) == w->ww_obq)
+					w->ww_obq = w->ww_obp = w->ww_ob;
+				if (wwinterrupt())
+					break;
+			}
+	}
+}