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>
This commit is contained in:
Denys Vlasenko
2017-02-16 23:25:44 +01:00
parent dc207f6696
commit 52a515d187
5 changed files with 45 additions and 53 deletions

View File

@@ -48,28 +48,29 @@ void FAST_FUNC udhcp_sp_setup(void)
, signal_handler);
}
/* Quick little function to setup the rfds. Will return the
* max_fd for use with select. Limited in that you can only pass
* one extra fd */
int FAST_FUNC udhcp_sp_fd_set(fd_set *rfds, int extra_fd)
/* Quick little function to setup the pfds.
* Limited in that you can only pass one extra fd.
*/
void FAST_FUNC udhcp_sp_fd_set(struct pollfd pfds[2], int extra_fd)
{
FD_ZERO(rfds);
FD_SET(signal_pipe.rd, rfds);
pfds[0].fd = signal_pipe.rd;
pfds[0].events = POLLIN;
pfds[1].fd = -1;
if (extra_fd >= 0) {
close_on_exec_on(extra_fd);
FD_SET(extra_fd, rfds);
pfds[1].fd = extra_fd;
pfds[1].events = POLLIN;
}
return signal_pipe.rd > extra_fd ? signal_pipe.rd : extra_fd;
}
/* Read a signal from the signal pipe. Returns 0 if there is
* no signal, -1 on error (and sets errno appropriately), and
* your signal on success */
int FAST_FUNC udhcp_sp_read(const fd_set *rfds)
int FAST_FUNC udhcp_sp_read(struct pollfd pfds[2])
{
unsigned char sig;
if (!FD_ISSET(signal_pipe.rd, rfds))
if (!pfds[0].revents)
return 0;
if (safe_read(signal_pipe.rd, &sig, 1) != 1)