17293: support poll() as preferred alternative to select() in zle

3 files changed, 111 insertions, 17 deletions

diff --git a/ChangeLog b/ChangeLog
index 992c53b4f..618d31c41 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2002-06-06  Peter Stephenson  <pws@csr.com>
+
+	* 17293: Src/Zle/zle_main.c, Doc/Zsh/zle.yo: support poll()
+	as a (preferred) alternative to select() in zle.
+
 2002-06-06  Clint Adams  <clint@zsh.org>
 
 	* 17297: Src/Modules/zpty.c: 17265 continued.
diff --git a/Doc/Zsh/zle.yo b/Doc/Zsh/zle.yo
index 67e66830d..bfdbbd736 100644
--- a/Doc/Zsh/zle.yo
+++ b/Doc/Zsh/zle.yo
@@ -413,8 +413,8 @@ within this invocation of ZLE.  Any following invocation (e.g., the next
 command line) will start as usual with the `tt(main)' keymap selected.
 )
 item(tt(-F) [ tt(-L) ] [ var(fd) [ var(handler) ] ])(
-Only available if your system support the `select' system call; most
-modern systems do.
+Only available if your system supports one of the `poll' or `select' system
+calls; most modern systems do.
 
 Installs var(handler) (the name of a shell function) to handle input from
 file descriptor var(fd).  When zle is attempting to read data, it will
diff --git a/Src/Zle/zle_main.c b/Src/Zle/zle_main.c
index 56797a9a9..782bd472c 100644
--- a/Src/Zle/zle_main.c
+++ b/Src/Zle/zle_main.c
@@ -30,6 +30,13 @@
 #include "zle.mdh"
 #include "zle_main.pro"
 
+#ifdef HAVE_POLL_H
+# include <poll.h>
+#endif
+#if defined(HAVE_POLL) && !defined(POLLIN) && !defined(POLLNORM)
+# undef HAVE_POLL
+#endif
+
 /* != 0 if in a shell function called from completion, such that read -[cl]  *
  * will work (i.e., the line is metafied, and the above word arrays are OK). */
 
@@ -340,11 +347,13 @@ raw_getkey(int keytmout, char *cptr)
 {
     long exp100ths;
     int ret;
-#ifdef HAVE_SELECT
+#ifndef HAVE_POLL
+# ifdef HAVE_SELECT
     fd_set foofd;
-#else
-# ifdef HAS_TIO
+# else
+#  ifdef HAS_TIO
     struct ttyinfo ti;
+#  endif
 # endif
 #endif
 
@@ -364,18 +373,45 @@ raw_getkey(int keytmout, char *cptr)
 	    exp100ths = 500;
 	else
 	    exp100ths = keytimeout;
-#ifdef HAVE_SELECT
+#if defined(HAVE_SELECT) || defined(HAVE_POLL)
 	if (!keytmout || exp100ths) {
+	    int i, errtry = 0, selret;
+# ifdef HAVE_POLL
+	    int poll_timeout;
+	    int nfds = keytmout ? 1 : 1 + nwatch;
+	    /* First pollfd is SHTTY, following are the nwatch fds */
+	    struct pollfd *fds = zalloc(sizeof(struct pollfd) * nfds);
+	    if (exp100ths)
+		poll_timeout = exp100ths * 10;
+	    else
+		poll_timeout = -1;
+
+	    fds[0].fd = SHTTY;
+	    /*
+	     * POLLIN, POLLIN, POLLIN,
+	     * Keep those fd's POLLIN...
+	     */
+	    fds[0].events = POLLIN;
+	    if (!keytmout) {
+		for (i = 0; i < nwatch; i++) {
+		    fds[i+1].fd = watch_fds[i];
+		    fds[i+1].events = POLLIN;
+		}
+	    }
+# else
+	    int fdmax = SHTTY;
 	    struct timeval *tvptr = NULL;
 	    struct timeval expire_tv;
-	    int i, fdmax = SHTTY, errtry = 0;
 	    if (exp100ths) {
 		expire_tv.tv_sec = exp100ths / 100;
 		expire_tv.tv_usec = (exp100ths % 100) * 10000L;
 		tvptr = &expire_tv;
 	    }
+# endif
 	    do {
-		int selret;
+# ifdef HAVE_POLL
+		selret = poll(fds, errtry ? 1 : nfds, poll_timeout);
+# else
 		FD_ZERO(&foofd);
 		FD_SET(SHTTY, &foofd);
 		if (!keytmout && !errtry) {
@@ -388,11 +424,12 @@ raw_getkey(int keytmout, char *cptr)
 		}
 		selret = select(fdmax+1, (SELECT_ARG_2_T) & foofd,
 				NULL, NULL, tvptr);
+# endif
 		/*
 		 * Make sure a user interrupt gets passed on straight away.
 		 */
 		if (selret < 0 && errflag)
-		    return selret;
+		    break;
 		/*
 		 * Try to avoid errors on our special fd's from
 		 * messing up reads from the terminal.  Try first
@@ -404,9 +441,10 @@ raw_getkey(int keytmout, char *cptr)
 		}
 		if (selret == 0) {
 		    /* Special value -2 signals nothing ready */
-		    return -2;
-		} else if (selret < 0)
-		    return selret;
+		    selret = -2;
+		}
+		if (selret < 0)
+		    break;
 		if (!keytmout && nwatch) {
 		    /*
 		     * Copy the details of the watch fds in case the
@@ -418,7 +456,13 @@ raw_getkey(int keytmout, char *cptr)
 		    char **lwatch_funcs = zarrdup(watch_funcs);
 		    memcpy(lwatch_fds, watch_fds, lnwatch*sizeof(int));
 		    for (i = 0; i < lnwatch; i++) {
-			if (FD_ISSET(lwatch_fds[i], &foofd)) {
+			if (
+# ifdef HAVE_POLL
+			    (fds[i+1].revents & POLLIN)
+# else
+			    FD_ISSET(lwatch_fds[i], &foofd)
+# endif
+			    ) {
 			    /* Handle the fd. */
 			    LinkList funcargs = znewlinklist();
 			    zaddlinknode(funcargs, ztrdup(lwatch_funcs[i]));
@@ -427,6 +471,21 @@ raw_getkey(int keytmout, char *cptr)
 				convbase(buf, lwatch_fds[i], 10);
 				zaddlinknode(funcargs, ztrdup(buf));
 			    }
+# ifdef HAVE_POLL
+#  ifdef POLLERR
+			    if (fds[i+1].revents & POLLERR)
+				zaddlinknode(funcargs, ztrdup("err"));
+#  endif
+#  ifdef POLLHUP
+			    if (fds[i+1].revents & POLLHUP)
+				zaddlinknode(funcargs, ztrdup("hup"));
+#  endif
+#  ifdef POLLNVAL
+			    if (fds[i+1].revents & POLLNVAL)
+				zaddlinknode(funcargs, ztrdup("nval"));
+#  endif
+# endif
+
 
 			    callhookfunc(lwatch_funcs[i], funcargs);
 			    if (errflag) {
@@ -447,7 +506,18 @@ raw_getkey(int keytmout, char *cptr)
 		    zfree(lwatch_fds, lnwatch*sizeof(int));
 		    freearray(lwatch_funcs);
 		}
-	    } while (!FD_ISSET(SHTTY, &foofd));
+	    } while (!
+# ifdef HAVE_POLL
+		     (fds[0].revents & POLLIN)
+# else
+		     FD_ISSET(SHTTY, &foofd)
+# endif
+		);
+# ifdef HAVE_POLL
+	    zfree(fds, sizeof(struct pollfd) * nfds);
+# endif
+	    if (selret < 0)
+		return selret;
 	}
 #else
 # ifdef HAS_TIO
@@ -571,10 +641,13 @@ zleread(char *lp, char *rp, int flags)
     int old_errno = errno;
     int tmout = getiparam("TMOUT");
 
-#ifdef HAVE_SELECT
+#if defined(HAVE_SELECT) || defined(HAVE_POLL)
     long costmult;
+# ifdef HAVE_POLL
+# else
     struct timeval tv;
     fd_set foofd;
+# endif
 
     baud = getiparam("BAUD");
     costmult = (baud) ? 3840000L / baud : 0;
@@ -620,8 +693,10 @@ zleread(char *lp, char *rp, int flags)
 
     zlereadflags = flags;
     histline = curhist;
-#ifdef HAVE_SELECT
+#ifndef HAVE_POLL
+# ifdef HAVE_SELECT
     FD_ZERO(&foofd);
+# endif
 #endif
     undoing = 1;
     line = (unsigned char *)zalloc((linesz = 256) + 2);
@@ -683,7 +758,20 @@ zleread(char *lp, char *rp, int flags)
 	    errflag = 1;
 	    break;
 	}
-#ifdef HAVE_SELECT
+#ifdef HAVE_POLL
+	if (baud && !(lastcmd & ZLE_MENUCMP)) {
+	    struct pollfd pfd;
+	    int to = cost * costmult / 1000; /* milliseconds */
+
+	    if (to > 500)
+		to = 500;
+	    pfd.fd = SHTTY;
+	    pfd.events = POLLIN;
+	    if (!kungetct && poll(&pfd, 1, to) <= 0)
+		zrefresh();
+	} else
+#else
+# ifdef HAVE_SELECT
 	if (baud && !(lastcmd & ZLE_MENUCMP)) {
 	    FD_SET(SHTTY, &foofd);
 	    tv.tv_sec = 0;
@@ -693,6 +781,7 @@ zleread(char *lp, char *rp, int flags)
 				    NULL, NULL, &tv) <= 0)
 		zrefresh();
 	} else
+# endif
 #endif
 	    if (!kungetct)
 		zrefresh();