top: use poll instead of select for waiting on one descriptor
authorvda <vda@69ca8d6d-28ef-0310-b511-8ec308f3f277>
Tue, 28 Aug 2007 19:35:34 +0000 (19:35 +0000)
committervda <vda@69ca8d6d-28ef-0310-b511-8ec308f3f277>
Tue, 28 Aug 2007 19:35:34 +0000 (19:35 +0000)
smart_ulltoa5: make it more cryptic. -50 bytes.

function                                             old     new   delta
passwd_main                                         1095    1103      +8
getNum                                               557     565      +8
buffer_fill_and_print                                 73      76      +3
udhcpc_main                                         2393    2395      +2
mkfs_minix_main                                     3071    3070      -1
dname_enc                                            377     373      -4
expmeta                                              480     472      -8
smart_ulltoa5                                        334     283     -51
top_main                                             911     815     -96
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 4/5 up/down: 21/-160)          Total: -139 bytes
   text    data     bss     dec     hex filename
 770872    1063   10788  782723   bf183 busybox_old
 770732    1063   10788  782583   bf0f7 busybox_unstripped

git-svn-id: svn://busybox.net/trunk/busybox@19717 69ca8d6d-28ef-0310-b511-8ec308f3f277

include/libbb.h
libbb/xfuncs.c
procps/top.c

index 89a1695..678c561 100644 (file)
@@ -27,6 +27,7 @@
 #include <stddef.h>
 #include <string.h>
 /* #include <strings.h> - said to be obsolete */
+#include <sys/poll.h>
 #include <sys/ioctl.h>
 #include <sys/mman.h>
 #include <sys/socket.h>
index fa9fc10..140c7bb 100644 (file)
@@ -284,35 +284,44 @@ void smart_ulltoa5(unsigned long long ul, char buf[5])
 {
        const char *fmt;
        char c;
-       unsigned v,idx = 0;
-       ul *= 10;
-       if (ul > 9999*10) { // do not scale if 9999 or less
-               while (ul >= 10000) {
+       unsigned v, u, idx = 0;
+
+       if (ul > 9999) { // do not scale if 9999 or less
+               ul *= 10;
+               do {
                        ul /= 1024;
                        idx++;
-               }
+               } while (ul >= 10000);
        }
        v = ul; // ullong divisions are expensive, avoid them
 
        fmt = " 123456789";
-       if (!idx) {             // 9999 or less: use 1234 format
-               c = buf[0] = " 123456789"[v/10000];
+       u = v / 10;
+       v = v % 10;
+       if (!idx) {
+               // 9999 or less: use "1234" format
+               // u is value/10, v is last digit
+               c = buf[0] = " 123456789"[u/100];
                if (c != ' ') fmt = "0123456789";
-               c = buf[1] = fmt[v/1000%10];
+               c = buf[1] = fmt[u/10%10];
                if (c != ' ') fmt = "0123456789";
-               buf[2] = fmt[v/100%10];
-               buf[3] = "0123456789"[v/10%10];
+               buf[2] = fmt[u%10];
+               buf[3] = "0123456789"[v];
        } else {
-               if (v >= 10*10) {       // scaled value is >=10: use 123M format
-                       c = buf[0] = " 123456789"[v/1000];
+               // u is value, v is 1/10ths (allows for 9.2M format)
+               if (u >= 10) {
+                       // value is >= 10: use "123M', " 12M" formats
+                       c = buf[0] = " 123456789"[u/100];
                        if (c != ' ') fmt = "0123456789";
-                       buf[1] = fmt[v/100%10];
-                       buf[2] = "0123456789"[v/10%10];
-               } else {        // scaled value is <10: use 1.2M format
-                       buf[0] = "0123456789"[v/10];
+                       v = u % 10;
+                       u = u / 10;
+                       buf[1] = fmt[u%10];
+               } else {
+                       // value is < 10: use "9.2M" format
+                       buf[0] = "0123456789"[u];
                        buf[1] = '.';
-                       buf[2] = "0123456789"[v%10];
                }
+               buf[2] = "0123456789"[v];
                // see http://en.wikipedia.org/wiki/Tera
                buf[3] = " kMGTPEZY"[idx];
        }
@@ -470,7 +479,8 @@ char *xasprintf(const char *format, ...)
        va_end(p);
 #endif
 
-       if (r < 0) bb_error_msg_and_die(bb_msg_memory_exhausted);
+       if (r < 0)
+               bb_error_msg_and_die(bb_msg_memory_exhausted);
        return string_ptr;
 }
 
index c02a959..abc7a43 100644 (file)
@@ -448,7 +448,7 @@ static void display_status(int count, int scr_width)
 #endif
 
                if (s->vsz >= 100*1024)
-                       sprintf(vsz_str_buf, "%6ldM", s->vsz/1024);
+                       sprintf(vsz_str_buf, "%6ldm", s->vsz/1024);
                else
                        sprintf(vsz_str_buf, "%7ld", s->vsz);
                // PID PPID USER STAT VSZ %MEM [%CPU] COMMAND
@@ -519,23 +519,29 @@ int top_main(int argc, char **argv);
 int top_main(int argc, char **argv)
 {
        int count, lines, col;
-       unsigned interval = 5; /* default update rate is 5 seconds */
-       unsigned iterations = UINT_MAX; /* 2^32 iterations by default :) */
+       unsigned interval;
+       int iterations = -1; /* infinite */
        char *sinterval, *siterations;
 #if ENABLE_FEATURE_USE_TERMIOS
        struct termios new_settings;
-       struct timeval tv;
-       fd_set readfds;
+       struct pollfd pfd[1];
        unsigned char c;
+
+       pfd[0].fd = 0;
+       pfd[0].events = POLLIN;
 #endif /* FEATURE_USE_TERMIOS */
 
-       interval = 5;
+       interval = 5; /* default update rate is 5 seconds */
 
        /* do normal option parsing */
        opt_complementary = "-";
        getopt32(argv, "d:n:b", &sinterval, &siterations);
-       if (option_mask32 & 0x1) interval = xatou(sinterval); // -d
-       if (option_mask32 & 0x2) iterations = xatou(siterations); // -n
+       if (option_mask32 & 0x1) {
+               /* Need to limit it to not overflow poll timeout */
+               interval = xatou16(sinterval); // -d
+       }
+       if (option_mask32 & 0x2)
+               iterations = xatoi_u(siterations); // -n
        //if (option_mask32 & 0x4) // -b
 
        /* change to /proc */
@@ -584,9 +590,8 @@ int top_main(int argc, char **argv)
                                | PSSCAN_UTIME
                                | PSSCAN_STATE
                                | PSSCAN_COMM
-                               | PSSCAN_SID
                                | PSSCAN_UIDGID
-               ))) {
+               )) != NULL) {
                        int n = ntop;
                        top = xrealloc(top, (++ntop) * sizeof(*top));
                        top[n].pid = p->pid;
@@ -622,15 +627,9 @@ int top_main(int argc, char **argv)
                /* show status for each of the processes */
                display_status(count, col);
 #if ENABLE_FEATURE_USE_TERMIOS
-               tv.tv_sec = interval;
-               tv.tv_usec = 0;
-               FD_ZERO(&readfds);
-               FD_SET(0, &readfds);
-               select(1, &readfds, NULL, NULL, &tv);
-               if (FD_ISSET(0, &readfds)) {
-                       if (read(0, &c, 1) <= 0) {   /* signal */
-                               return EXIT_FAILURE;
-                       }
+               if (poll(pfd, 1, interval * 1000) != 0) {
+                       if (read(0, &c, 1) != 1)    /* signal */
+                               break;
                        if (c == 'q' || c == initial_settings.c_cc[VINTR])
                                break;
                        if (c == 'M') {
@@ -662,7 +661,7 @@ int top_main(int argc, char **argv)
 #endif
                        }
                }
-               if (!--iterations)
+               if (iterations >= 0 && !--iterations)
                        break;
 #else
                sleep(interval);