*: replace select-for-one descriptor with poll, it's smaller.

$ ./.cmk bloatcheck
function                                             old     new   delta
readit                                               406     364     -42
syslogd_main                                        1249    1206     -43
traceroute_main                                     4115    4060     -55
mysleep                                              112      45     -67
arpping                                              579     441    -138
tftp                                                1575    1182    -393
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/6 up/down: 0/-738)           Total: -738 bytes
   text    data     bss     dec     hex filename
 770580    1051   10764  782395   bf03b busybox_old
 769820    1051   10764  781635   bed43 busybox_unstripped

6 files changed, 61 insertions, 82 deletions

diff --git a/editors/vi.c b/editors/vi.c
index afbddc251..f7f84807d 100644
--- a/editors/vi.c
+++ b/editors/vi.c
@@ -237,7 +237,8 @@ static char *yank_delete(char *, char *, int, int);	// yank text[] into register
 static void show_help(void);    // display some help info
 static void rawmode(void);      // set "raw" mode on tty
 static void cookmode(void);     // return to "cooked" mode on tty
-static int mysleep(int);        // sleep for 'h' 1/100 seconds
+// sleep for 'h' 1/100 seconds, return 1/0 if stdin is (ready for read)/(not ready)
+static int mysleep(int);
 static char readit(void);       // read (maybe cursor) key from stdin
 static char get_one_char(void); // read 1 char from stdin
 static int file_size(const char *);   // what is the byte size of "fn"
@@ -2134,17 +2135,11 @@ static void catch_sig(int sig)
 
 static int mysleep(int hund)    // sleep for 'h' 1/100 seconds
 {
-        fd_set rfds;
-        struct timeval tv;
+        struct pollfd pfd[1];
 
-        // Don't hang- Wait 5/100 seconds-  1 Sec= 1000000
-        fflush(stdout);
-        FD_ZERO(&rfds);
-        FD_SET(0, &rfds);
-        tv.tv_sec = 0;
-        tv.tv_usec = hund * 10000;
-        select(1, &rfds, NULL, NULL, &tv);
-        return FD_ISSET(0, &rfds);
+        pfd[0].fd = 0;
+        pfd[0].events = POLLIN;
+        return poll(pfd, 1, hund*10) > 0;
 }
 
 #define readbuffer bb_common_bufsiz1
@@ -2217,25 +2212,20 @@ static char readit(void)	// read (maybe cursor) key from stdin
                 if (n <= 0)
                         return 0;       // error
                 if (readbuffer[0] == 27) {
-                        fd_set rfds;
-                        struct timeval tv;
-
                         // This is an ESC char. Is this Esc sequence?
                         // Could be bare Esc key. See if there are any
                         // more chars to read after the ESC. This would
                         // be a Function or Cursor Key sequence.
-                        FD_ZERO(&rfds);
-                        FD_SET(0, &rfds);
-                        tv.tv_sec = 0;
-                        tv.tv_usec = 50000;     // Wait 5/100 seconds- 1 Sec=1000000
-
+                        struct pollfd pfd[1];
+                        pfd[0].fd = 0;
+                        pfd[0].events = POLLIN;
+                        // Wait 50 ms
                         // keep reading while there are input chars and room in buffer
-                        while (select(1, &rfds, NULL, NULL, &tv) > 0 && n <= (MAX_LINELEN - 5)) {
+                        while (poll(pfd, 1, 50) > 0 && n <= (MAX_LINELEN - 5)) {
                                 // read the rest of the ESC string
-                                int r = read(0, (void *) (readbuffer + n), MAX_LINELEN - n);
-                                if (r > 0) {
+                                int r = read(0, readbuffer + n, MAX_LINELEN - n);
+                                if (r > 0)
                                         n += r;
-                                }
                         }
                 }
                 readed_for_parse = n;
diff --git a/networking/tftp.c b/networking/tftp.c
index 0b25f752d..ac3a86afb 100644
--- a/networking/tftp.c
+++ b/networking/tftp.c
@@ -23,10 +23,10 @@
 
 #if ENABLE_FEATURE_TFTP_GET || ENABLE_FEATURE_TFTP_PUT
 
-#define TFTP_BLOCKSIZE_DEFAULT 512      /* according to RFC 1350, don't change */
-#define TFTP_TIMEOUT 50000              /* 50ms, in microseconds */
-#define TFTP_MAXTIMEOUT 999000          /* about 1 second, in microseconds */
-#define TFTP_NUM_RETRIES 12             /* number of backed-off retries */
+#define TFTP_BLOCKSIZE_DEFAULT 512      /* according to RFC 1350, don't change */
+#define TFTP_TIMEOUT_MS         50
+#define TFTP_MAXTIMEOUT_MS    2000
+#define TFTP_NUM_RETRIES        12      /* number of backed-off retries */
 
 /* opcodes we support */
 #define TFTP_RRQ   1
@@ -114,9 +114,8 @@ static int tftp( USE_GETPUT(const int cmd,)
                 const char *remotefile, const int localfd,
                 unsigned port, int tftp_bufsize)
 {
-        struct timeval tv;
-        fd_set rfds;
-        int socketfd;
+        struct pollfd pfd[1];
+#define socketfd (pfd[0].fd)
         int len;
         int send_len;
         USE_FEATURE_TFTP_BLOCKSIZE(smallint want_option_ack = 0;)
@@ -124,7 +123,7 @@ static int tftp( USE_GETPUT(const int cmd,)
         uint16_t opcode;
         uint16_t block_nr = 1;
         uint16_t recv_blk;
-        int retries, waittime;
+        int retries, waittime_ms;
         char *cp;
 
         unsigned org_port;
@@ -208,7 +207,7 @@ static int tftp( USE_GETPUT(const int cmd,)
                  * for potential resend */
 
                 retries = TFTP_NUM_RETRIES;     /* re-initialize */
-                waittime = TFTP_TIMEOUT;
+                waittime_ms = TFTP_TIMEOUT_MS;
 
  send_again:
 #if ENABLE_DEBUG_TFTP
@@ -224,11 +223,9 @@ static int tftp( USE_GETPUT(const int cmd,)
 
  recv_again:
                 /* Receive packet */
-                tv.tv_sec = 0;
-                tv.tv_usec = waittime;
-                FD_ZERO(&rfds);
-                FD_SET(socketfd, &rfds);
-                switch (select(socketfd + 1, &rfds, NULL, NULL, &tv)) {
+                /*pfd[0].fd = socketfd;*/
+                pfd[0].events = POLLIN;
+                switch (poll(pfd, 1, waittime_ms)) {
                         unsigned from_port;
                 case 1:
                         from->len = peer_lsa->len;
@@ -258,14 +255,14 @@ static int tftp( USE_GETPUT(const int cmd,)
                         }
 
                         /* exponential backoff with limit */
-                        waittime += waittime/2;
-                        if (waittime > TFTP_MAXTIMEOUT) {
-                                waittime = TFTP_MAXTIMEOUT;
+                        waittime_ms += waittime_ms/2;
+                        if (waittime_ms > TFTP_MAXTIMEOUT_MS) {
+                                waittime_ms = TFTP_MAXTIMEOUT_MS;
                         }
 
                         goto send_again; /* resend last sent pkt */
                 default:
-                        bb_perror_msg("select");
+                        bb_perror_msg("poll");
                         goto ret;
                 }
  process_pkt:
diff --git a/networking/traceroute.c b/networking/traceroute.c
index 236ddbdaf..21921e56d 100644
--- a/networking/traceroute.c
+++ b/networking/traceroute.c
@@ -346,10 +346,10 @@ static int optlen;                     /* length of ip options */
 
 
 struct globals {
-        /* last inbound (icmp) packet */
-        unsigned char packet[512];
         struct sockaddr_storage whereto;        /* Who to try to reach */
         struct sockaddr_storage wherefrom;      /* Who we are */
+        /* last inbound (icmp) packet */
+        unsigned char packet[512];
 #if ENABLE_FEATURE_TRACEROUTE_SOURCE_ROUTE
         /* Maximum number of gateways (include room for one noop) */
 #define NGATEWAYS ((int)((MAX_IPOPTLEN - IPOPT_MINOFF - 1) / sizeof(uint32_t)))
@@ -359,7 +359,7 @@ struct globals {
 };
 
 #define G (*ptr_to_globals)
-
+#define INIT_G() PTR_TO_GLOBALS = xzalloc(sizeof(G))
 #define packet    (G.packet   )
 #define whereto   (G.whereto  )
 #define wherefrom (G.wherefrom)
@@ -537,21 +537,15 @@ findsaddr(const struct sockaddr_in *to, struct sockaddr_in *from)
 static int
 wait_for_reply(int sock, struct sockaddr_in *fromp)
 {
-        fd_set fds;
-        struct timeval tvwait;
+        struct pollfd pfd[1];
         int cc = 0;
         socklen_t fromlen = sizeof(*fromp);
 
-        FD_ZERO(&fds);
-        FD_SET(sock, &fds);
-
-        tvwait.tv_sec = waittime;
-        tvwait.tv_usec = 0;
-
-        if (select(sock + 1, &fds, NULL, NULL, &tvwait) > 0)
-                cc = recvfrom(sock, (char *)packet, sizeof(packet), 0,
+        pfd[0].fd = sock;
+        pfd[0].events = POLLIN;
+        if (poll(pfd, 1, waittime * 1000) > 0)
+                cc = recvfrom(sock, packet, sizeof(packet), 0,
                             (struct sockaddr *)fromp, &fromlen);
-
         return cc;
 }
 
@@ -930,7 +924,7 @@ int traceroute_main(int argc, char **argv)
         llist_t *source_route_list = NULL;
 #endif
 
-        PTR_TO_GLOBALS = xzalloc(sizeof(G));
+        INIT_G();
         from = (struct sockaddr_in *)&wherefrom;
         to = (struct sockaddr_in *)&whereto;
 
diff --git a/networking/udhcp/arpping.c b/networking/udhcp/arpping.c
index 4ac52c640..33518077b 100644
--- a/networking/udhcp/arpping.c
+++ b/networking/udhcp/arpping.c
@@ -37,14 +37,12 @@ struct arpMsg {
 
 int arpping(uint32_t test_ip, uint32_t from_ip, uint8_t *from_mac, const char *interface)
 {
-        int timeout = 2;
-        int s;                  /* socket */
+        int timeout_ms = 2000;
+        struct pollfd pfd[1];
+#define s (pfd[0].fd)           /* socket */
         int rv = 1;             /* "no reply received" yet */
         struct sockaddr addr;   /* for interface name */
         struct arpMsg arp;
-        fd_set fdset;
-        struct timeval tm;
-        unsigned prevTime;
 
         s = socket(PF_PACKET, SOCK_PACKET, htons(ETH_P_ARP));
         if (s == -1) {
@@ -80,18 +78,17 @@ int arpping(uint32_t test_ip, uint32_t from_ip, uint8_t *from_mac, const char *i
         /* wait for arp reply, and check it */
         do {
                 int r;
-                prevTime = monotonic_sec();
-                FD_ZERO(&fdset);
-                FD_SET(s, &fdset);
-                tm.tv_sec = timeout;
-                tm.tv_usec = 0;
-                r = select(s + 1, &fdset, NULL, NULL, &tm);
+                unsigned prevTime = monotonic_us();
+
+                pfd[0].events = POLLIN;
+                r = poll(pfd, 1, timeout_ms);
                 if (r < 0) {
-                        bb_perror_msg("error on ARPING request");
-                        if (errno != EINTR)
+                        if (errno != EINTR) {
+                                bb_perror_msg("poll");
                                 break;
+                        }
                 } else if (r) {
-                        if (recv(s, &arp, sizeof(arp), 0) < 0)
+                        if (read(s, &arp, sizeof(arp)) < 0)
                                 break;
                         if (arp.operation == htons(ARPOP_REPLY)
                          && memcmp(arp.tHaddr, from_mac, 6) == 0
@@ -101,8 +98,8 @@ int arpping(uint32_t test_ip, uint32_t from_ip, uint8_t *from_mac, const char *i
                                 break;
                         }
                 }
-                timeout -= monotonic_sec() - prevTime;
-        } while (timeout > 0);
+                timeout_ms -= (monotonic_us() - prevTime) / 1000;
+        } while (timeout_ms > 0);
 
  ret:
         close(s);
diff --git a/shell/ash.c b/shell/ash.c
index 46f00dd3d..ec3e17618 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -11589,6 +11589,7 @@ readcmd(int argc, char **argv)
 #endif
 #if ENABLE_ASH_READ_TIMEOUT
         if (ts.tv_sec || ts.tv_usec) {
+// TODO: replace with poll, it is smaller
                 FD_ZERO(&set);
                 FD_SET(0, &set);
 
diff --git a/sysklogd/syslogd.c b/sysklogd/syslogd.c
index 5b153f509..ae3f1a2eb 100644
--- a/sysklogd/syslogd.c
+++ b/sysklogd/syslogd.c
@@ -471,8 +471,8 @@ static void do_syslogd(void) ATTRIBUTE_NORETURN;
 static void do_syslogd(void)
 {
         struct sockaddr_un sunx;
-        int sock_fd;
-        fd_set fds;
+        struct pollfd pfd[1];
+#define sock_fd (pfd[0].fd)
         char *dev_log_name;
 
         /* Set up signal handlers */
@@ -526,20 +526,20 @@ static void do_syslogd(void)
                         (char*)"syslogd started: BusyBox v" BB_VER, 0);
 
         for (;;) {
-                FD_ZERO(&fds);
-                FD_SET(sock_fd, &fds);
-
-                if (select(sock_fd + 1, &fds, NULL, NULL, NULL) < 0) {
+                /*pfd[0].fd = sock_fd;*/
+                pfd[0].events = POLLIN;
+                pfd[0].revents = 0;
+                if (poll(pfd, 1, -1) < 0) { /* -1: no timeout */
                         if (errno == EINTR) {
                                 /* alarm may have happened */
                                 continue;
                         }
-                        bb_perror_msg_and_die("select");
+                        bb_perror_msg_and_die("poll");
                 }
 
-                if (FD_ISSET(sock_fd, &fds)) {
+                if (pfd[0].revents) {
                         int i;
-                        i = recv(sock_fd, G.recvbuf, MAX_READ - 1, 0);
+                        i = read(sock_fd, G.recvbuf, MAX_READ - 1);
                         if (i <= 0)
                                 bb_perror_msg_and_die("UNIX socket error");
                         /* TODO: maybe suppress duplicates? */
@@ -559,7 +559,7 @@ static void do_syslogd(void)
 #endif
                         G.recvbuf[i] = '\0';
                         split_escape_and_log(G.recvbuf, i);
-                } /* FD_ISSET() */
+                }
         } /* for */
 }