syslogd: do not need to poll(), we can just block in read().

function                                             old     new   delta
syslogd_main                                        1206    1106    -100
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-100)           Total: -100 bytes
   text    data     bss     dec     hex filename
 769820    1051   10764  781635   bed43 busybox_old
 769702    1051   10764  781517   beccd busybox_unstripped

diff --git a/sysklogd/syslogd.c b/sysklogd/syslogd.c
index ae3f1a2eb68d4bf232ac4127d1b51fd4b2670787..f27bd8379214c323a5bd8e32a65768d499f6a0ad 100644 (file)
--- a/sysklogd/syslogd.c
+++ b/sysklogd/syslogd.c
@@ -471,8 +471,7 @@ static void do_syslogd(void) ATTRIBUTE_NORETURN;
 static void do_syslogd(void)
 {
        struct sockaddr_un sunx;
-       struct pollfd pfd[1];
-#define sock_fd (pfd[0].fd)
+       int sock_fd;
        char *dev_log_name;
 
        /* Set up signal handlers */
@@ -526,40 +525,34 @@ static void do_syslogd(void)
                        (char*)"syslogd started: BusyBox v" BB_VER, 0);
 
        for (;;) {
-               /*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 */
+               size_t sz;
+
+               sz = read(sock_fd, G.recvbuf, MAX_READ - 1);
+               if (sz <= 0) {
+                       if (sz == 0)
+                               continue; /* EOF from unix socket??? */
+                       if (errno == EINTR) /* alarm may have happened */
                                continue;
-                       }
-                       bb_perror_msg_and_die("poll");
+                       bb_perror_msg_and_die("read from /dev/log");
                }
 
-               if (pfd[0].revents) {
-                       int i;
-                       i = read(sock_fd, G.recvbuf, MAX_READ - 1);
-                       if (i <= 0)
-                               bb_perror_msg_and_die("UNIX socket error");
-                       /* TODO: maybe suppress duplicates? */
+               /* TODO: maybe suppress duplicates? */
 #if ENABLE_FEATURE_REMOTE_LOG
-                       /* We are not modifying log messages in any way before send */
-                       /* Remote site cannot trust _us_ anyway and need to do validation again */
-                       if (G.remoteAddr) {
-                               if (-1 == G.remoteFD) {
-                                       G.remoteFD = socket(G.remoteAddr->sa.sa_family, SOCK_DGRAM, 0);
-                               }
-                               if (-1 != G.remoteFD) {
-                                       /* send message to remote logger, ignore possible error */
-                                       sendto(G.remoteFD, G.recvbuf, i, MSG_DONTWAIT,
-                                               &G.remoteAddr->sa, G.remoteAddr->len);
-                               }
+               /* We are not modifying log messages in any way before send */
+               /* Remote site cannot trust _us_ anyway and need to do validation again */
+               if (G.remoteAddr) {
+                       if (-1 == G.remoteFD) {
+                               G.remoteFD = socket(G.remoteAddr->sa.sa_family, SOCK_DGRAM, 0);
+                       }
+                       if (-1 != G.remoteFD) {
+                               /* send message to remote logger, ignore possible error */
+                               sendto(G.remoteFD, G.recvbuf, sz, MSG_DONTWAIT,
+                                       &G.remoteAddr->sa, G.remoteAddr->len);
                        }
-#endif
-                       G.recvbuf[i] = '\0';
-                       split_escape_and_log(G.recvbuf, i);
                }
+#endif
+               G.recvbuf[sz] = '\0';
+               split_escape_and_log(G.recvbuf, sz);
        } /* for */
 }