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>

1 files changed, 11 insertions, 10 deletions

diff --git a/networking/udhcp/signalpipe.c b/networking/udhcp/signalpipe.c
index 30bccd6bf..b101b4ce4 100644
--- a/networking/udhcp/signalpipe.c
+++ b/networking/udhcp/signalpipe.c
@@ -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)