From 94dcfd8cc065b699081984d6f4b4bbfc811937b1 Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Fri, 17 Feb 2017 17:48:59 +0100 Subject: nc_bloaty: use poll() instead of select() function old new delta readwrite 829 715 -114 Signed-off-by: Denys Vlasenko --- networking/nc_bloaty.c | 55 ++++++++++++++++++++++---------------------------- 1 file changed, 24 insertions(+), 31 deletions(-) (limited to 'networking/nc_bloaty.c') diff --git a/networking/nc_bloaty.c b/networking/nc_bloaty.c index 192e42fe5..f8c375362 100644 --- a/networking/nc_bloaty.c +++ b/networking/nc_bloaty.c @@ -582,11 +582,10 @@ void oprint(int direction, unsigned char *p, unsigned bc); #endif /* readwrite: - handle stdin/stdout/network I/O. Bwahaha!! -- the select loop from hell. + handle stdin/stdout/network I/O. Bwahaha!! -- the i/o loop from hell. In this instance, return what might become our exit status. */ static int readwrite(void) { - int rr; char *zp = zp; /* gcc */ /* stdin buf ptr */ char *np = np; /* net-in buf ptr */ unsigned rzleft; @@ -594,45 +593,41 @@ static int readwrite(void) unsigned netretry; /* net-read retry counter */ unsigned fds_open; - /* if you don't have all this FD_* macro hair in sys/types.h, you'll have to - either find it or do your own bit-bashing: *ding1 |= (1 << fd), etc... */ - fd_set ding1; /* for select loop */ - fd_set ding2; - FD_ZERO(&ding1); - FD_SET(netfd, &ding1); - FD_SET(STDIN_FILENO, &ding1); - fds_open = 2; + struct pollfd pfds[2]; + pfds[0].fd = STDIN_FILENO; + pfds[0].events = POLLIN; + pfds[1].fd = netfd; + pfds[1].events = POLLIN; + fds_open = 2; netretry = 2; rzleft = rnleft = 0; if (o_interval) sleep(o_interval); /* pause *before* sending stuff, too */ - /* and now the big ol' select shoveling loop ... */ + /* and now the big ol' shoveling loop ... */ /* nc 1.10 has "while (FD_ISSET(netfd)" here */ while (fds_open) { + int rr; + int poll_tmout_ms; unsigned wretry = 8200; /* net-write sanity counter */ - ding2 = ding1; /* FD_COPY ain't portable... */ - /* some systems, notably linux, crap into their select timers on return, so - we create a expendable copy and give *that* to select. */ + poll_tmout_ms = -1; if (o_wait) { - struct timeval tmp_timer; - tmp_timer.tv_sec = o_wait; - tmp_timer.tv_usec = 0; - /* highest possible fd is netfd (3) */ - rr = select(netfd+1, &ding2, NULL, NULL, &tmp_timer); - } else - rr = select(netfd+1, &ding2, NULL, NULL, NULL); + poll_tmout_ms = INT_MAX; + if (o_wait < INT_MAX / 1000) + poll_tmout_ms = o_wait * 1000; + } + rr = poll(pfds, 2, poll_tmout_ms); if (rr < 0 && errno != EINTR) { /* might have gotten ^Zed, etc */ - holler_perror("select"); + holler_perror("poll"); close(netfd); return 1; } /* if we have a timeout AND stdin is closed AND we haven't heard anything from the net during that time, assume it's dead and close it too. */ if (rr == 0) { - if (!FD_ISSET(STDIN_FILENO, &ding1)) { + if (!pfds[0].revents) { netretry--; /* we actually try a coupla times. */ if (!netretry) { if (o_verbose > 1) /* normally we don't care */ @@ -641,19 +636,17 @@ static int readwrite(void) return 0; /* not an error! */ } } - } /* select timeout */ - /* xxx: should we check the exception fds too? The read fds seem to give - us the right info, and none of the examples I found bothered. */ + } /* timeout */ /* Ding!! Something arrived, go check all the incoming hoppers, net first */ - if (FD_ISSET(netfd, &ding2)) { /* net: ding! */ + if (pfds[1].revents) { /* net: ding! */ rr = read(netfd, bigbuf_net, BIGSIZ); if (rr <= 0) { if (rr < 0 && o_verbose > 1) { /* nc 1.10 doesn't do this */ bb_perror_msg("net read"); } - FD_CLR(netfd, &ding1); /* net closed */ + pfds[1].fd = -1; /* don't poll for netfd anymore */ fds_open--; rzleft = 0; /* can't write anymore: broken pipe */ } else { @@ -669,12 +662,12 @@ Debug("got %d from the net, errno %d", rr, errno); goto shovel; /* okay, suck more stdin */ - if (FD_ISSET(STDIN_FILENO, &ding2)) { /* stdin: ding! */ + if (pfds[0].revents) { /* stdin: ding! */ rr = read(STDIN_FILENO, bigbuf_in, BIGSIZ); /* Considered making reads here smaller for UDP mode, but 8192-byte mobygrams are kinda fun and exercise the reassembler. */ if (rr <= 0) { /* at end, or fukt, or ... */ - FD_CLR(STDIN_FILENO, &ding1); /* disable stdin */ + pfds[0].fd = -1; /* disable stdin */ /*close(STDIN_FILENO); - not really necessary */ /* Let peer know we have no more data */ /* nc 1.10 doesn't do this: */ @@ -718,7 +711,7 @@ Debug("wrote %d to net, errno %d", rr, errno); } /* rzleft */ if (o_interval) { /* cycle between slow lines, or ... */ sleep(o_interval); - continue; /* ...with hairy select loop... */ + continue; /* ...with hairy loop... */ } if (rzleft || rnleft) { /* shovel that shit till they ain't */ wretry--; /* none left, and get another load */ -- cgit v1.2.3