From: Michael Tokarev <mjt@tls.msk.ru>
Date: Tue, 17 Nov 2009 09:56:24 +0000 (+0100)
Subject: batched reads for lxc_console
X-Git-Tag: lxc_0_6_4~22
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=92db2bb00ce2acebc0b9818b56238aa5afe313ff;p=thirdparty%2Flxc.git

batched reads for lxc_console

Instead of doing I/O one-byte-at-a-time in lxc_console,
which is slow, let's do it in batches.  Only for output
(from container to the host system), since input is most
likely one-byte-at-a-time anyway (from a keyboard).

Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Signed-off-by: Daniel Lezcano <dlezcano@fr.ibm.com>
---

diff --git a/src/lxc/lxc_console.c b/src/lxc/lxc_console.c
index 8bdf6b12f..d6ba7e45c 100644
--- a/src/lxc/lxc_console.c
+++ b/src/lxc/lxc_console.c
@@ -141,7 +141,6 @@ int main(int argc, char *argv[])
 
 	/* let's proxy the tty */
 	for (;;) {
-		char c;
 		struct pollfd pfd[2] = {
 			{ .fd = 0,
 			  .events = POLLIN|POLLPRI,
@@ -161,6 +160,7 @@ int main(int argc, char *argv[])
 		/* read the "stdin" and write that to the master
 		 */
 		if (pfd[0].revents & POLLIN) {
+			char c;
 			if (read(0, &c, 1) < 0) {
 				SYSERROR("failed to read");
 				goto out_err;
@@ -188,12 +188,14 @@ int main(int argc, char *argv[])
 
 		/* read the master and write to "stdout" */
 		if (pfd[1].revents & POLLIN) {
-			if (read(master, &c, 1) < 0) {
+			char buf[1024];
+			int r;
+			r = read(master, buf, sizeof(buf));
+			if (r < 0) {
 				SYSERROR("failed to read");
 				goto out_err;
 			}
-			printf("%c", c);
-			fflush(stdout);
+			write(1, buf, r);
 		}
 	}
 out: