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hwclock: size optimizations

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libbb/time.c: new file, introducing monotonic_us()
pscan, traceroute, arping: use it instead of gettimeofday
ping, zcip: TODO

function                                             old     new   delta
monotonic_us                                           -      89     +89
find_pair                                            164     180     +16
.rodata                                           129747  129763     +16
refresh                                             1144    1152      +8
............
timeout                                                8       4      -4
static.start                                           8       4      -4
last                                                   8       4      -4
parse_conf                                          1303    1284     -19
time_main                                           1149    1124     -25
gettimeofday_us                                       39       -     -39
arping_main                                         2042    1969     -73
hwclock_main                                         594     501     -93
catcher                                              485     380    -105
traceroute_main                                     4300    4117    -183
------------------------------------------------------------------------------
(add/remove: 2/1 grow/shrink: 8/11 up/down: 157/-562)        Total: -405 bytes
This commit is contained in:
Denis Vlasenko
2007-06-17 19:09:05 +00:00
parent e79dd06782
commit 459be35234
10 changed files with 228 additions and 260 deletions
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28
networking/pscan.c
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@@ -17,19 +17,6 @@
#define DERR(...) ((void)0)
#endif
/* return time in usec */
// TODO: move to libbb and use in traceroute, zcip, arping etc
// (maybe also use absolute monotonic clock - no time warps
// due to admin resetting date/time?)
static unsigned gettimeofday_us(void)
{
struct timeval now;
if (gettimeofday(&now, NULL))
return 0;
return (now.tv_sec * 1000000 + now.tv_usec);
}
static const char *port_name(unsigned port)
{
struct servent *server;
@@ -40,6 +27,9 @@ static const char *port_name(unsigned port)
return "unknown";
}
/* We don't expect to see 1000+ seconds delay, unsigned is enough */
#define MONOTONIC_US() ((unsigned)monotonic_us())
int pscan_main(int argc, char **argv);
int pscan_main(int argc, char **argv)
{
@@ -91,7 +81,7 @@ int pscan_main(int argc, char **argv)
/* Nonblocking connect typically "fails" with errno == EINPROGRESS */
ndelay_on(s);
DMSG("connect to port %u", port);
start = gettimeofday_us();
start = MONOTONIC_US();
if (connect(s, &lsap->sa, lsap->len) == 0) {
/* Unlikely, for me even localhost fails :) */
DMSG("connect succeeded");
@@ -110,15 +100,15 @@ int pscan_main(int argc, char **argv)
closed_ports++;
break;
}
DERR("port %u errno %d @%u", port, errno, gettimeofday_us() - start);
if ((gettimeofday_us() - start) > rtt_4)
DERR("port %u errno %d @%u", port, errno, MONOTONIC_US() - start);
if ((MONOTONIC_US() - start) > rtt_4)
break;
/* Can sleep (much) longer than specified delay.
* We check rtt BEFORE we usleep, otherwise
* on localhost we'll do zero writes done (!)
* before we exceed (rather small) rtt */
usleep(rtt_4/8);
DMSG("write to port %u @%u", port, gettimeofday_us() - start);
DMSG("write to port %u @%u", port, MONOTONIC_US() - start);
if (write(s, " ", 1) >= 0) { /* We were able to write to the socket */
open:
open_ports++;
@@ -126,13 +116,13 @@ int pscan_main(int argc, char **argv)
break;
}
}
DMSG("out of loop @%u", gettimeofday_us() - start);
DMSG("out of loop @%u", MONOTONIC_US() - start);
/* Estimate new rtt - we don't want to wait entire timeout
* for each port. *4 allows for rise in net delay.
* We increase rtt quickly (*4), decrease slowly (4/8 == 1/2)
* because we don't want to accidentally miss ports. */
rtt_4 = (gettimeofday_us() - start) * 4;
rtt_4 = (MONOTONIC_US() - start) * 4;
if (rtt_4 < min_rtt)
rtt_4 = min_rtt;
if (rtt_4 > timeout)