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| author | Denys Vlasenko | 2017-02-16 23:25:44 +0100 |
|---|---|---|
| committer | Denys Vlasenko | 2017-02-16 23:25:44 +0100 |
| commit | 52a515d18724bbb34e3ccbbb0218efcc4eccc0a8 (patch) | |
| tree | 16a5a05a328d7e0bd2b4b1bfbcaf543cf8a36d33 /networking/udhcp/dhcpc.c | |
| parent | dc207f669675a271812a21b0ddbe3b894adf8e4c (diff) | |
| download | busybox-52a515d18724bbb34e3ccbbb0218efcc4eccc0a8.zip busybox-52a515d18724bbb34e3ccbbb0218efcc4eccc0a8.tar.gz | |
udhcp: use poll() instead of select()
function old new delta
udhcp_sp_read 65 46 -19
udhcp_sp_fd_set 79 54 -25
udhcpd_main 1530 1482 -48
udhcpc_main 2780 2730 -50
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/4 up/down: 0/-142) Total: -142 bytes
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Diffstat (limited to 'networking/udhcp/dhcpc.c')
| -rw-r--r-- | networking/udhcp/dhcpc.c | 26 |
1 files changed, 12 insertions, 14 deletions
diff --git a/networking/udhcp/dhcpc.c b/networking/udhcp/dhcpc.c index 0e23626..8f7f59e 100644 --- a/networking/udhcp/dhcpc.c +++ b/networking/udhcp/dhcpc.c @@ -1281,9 +1281,7 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv) unsigned already_waited_sec; unsigned opt; IF_FEATURE_UDHCPC_ARPING(unsigned arpping_ms;) - int max_fd; int retval; - fd_set rfds; setup_common_bufsiz(); @@ -1432,7 +1430,8 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv) * "continue" statements in code below jump to the top of the loop. */ for (;;) { - struct timeval tv; + int tv; + struct pollfd pfds[2]; struct dhcp_packet packet; /* silence "uninitialized!" warning */ unsigned timestamp_before_wait = timestamp_before_wait; @@ -1446,16 +1445,15 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv) * to change_listen_mode(). Thus we open listen socket * BEFORE we send renew request (see "case BOUND:"). */ - max_fd = udhcp_sp_fd_set(&rfds, sockfd); + udhcp_sp_fd_set(pfds, sockfd); - tv.tv_sec = timeout - already_waited_sec; - tv.tv_usec = 0; + tv = timeout - already_waited_sec; retval = 0; /* If we already timed out, fall through with retval = 0, else... */ - if ((int)tv.tv_sec > 0) { - log1("waiting on select %u seconds", (int)tv.tv_sec); + if (tv > 0) { + log1("waiting on select %u seconds", tv); timestamp_before_wait = (unsigned)monotonic_sec(); - retval = select(max_fd + 1, &rfds, NULL, NULL, &tv); + retval = poll(pfds, 2, tv * 1000); if (retval < 0) { /* EINTR? A signal was caught, don't panic */ if (errno == EINTR) { @@ -1591,8 +1589,8 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv) /* select() didn't timeout, something happened */ /* Is it a signal? */ - /* note: udhcp_sp_read checks FD_ISSET before reading */ - switch (udhcp_sp_read(&rfds)) { + /* note: udhcp_sp_read checks poll result before reading */ + switch (udhcp_sp_read(pfds)) { case SIGUSR1: client_config.first_secs = 0; /* make secs field count from 0 */ already_waited_sec = 0; @@ -1627,7 +1625,7 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv) } /* Is it a packet? */ - if (listen_mode == LISTEN_NONE || !FD_ISSET(sockfd, &rfds)) + if (listen_mode == LISTEN_NONE || !pfds[1].revents) continue; /* no */ { @@ -1742,8 +1740,8 @@ int udhcpc_main(int argc UNUSED_PARAM, char **argv) /* paranoia: must not be too small and not prone to overflows */ if (lease_seconds < 0x10) lease_seconds = 0x10; - if (lease_seconds >= 0x10000000) - lease_seconds = 0x0fffffff; + if (lease_seconds > 0x7fffffff / 1000) + lease_seconds = 0x7fffffff / 1000; } #if ENABLE_FEATURE_UDHCPC_ARPING if (opt & OPT_a) { |