Re: [PHP4] gettimeofday()

Interesting. What sort of box is this? SMP? -Rasmus On Mon, 7 Aug 2000, Remco Chang wrote: > hi, > > i've been testing out the performance of php4 with apache and odbc driver > (oob by easysoft.com) using gettimeofday() to find the amount of elapsed > time... i'm running php4.0.1pl2 on redhat 6.2 with apache 1.3.12. > > the problem that i'm having is that gettimeofday seems to return time that > "jumps backwards in time." here's an example of what i would get when i > write a for loop to grab the current time ten thousand times: > > time: 965666189.9983 > time: 965666189.99903 > time: 965666189.99976 > time: 965666181.00049 ********** > time: 965666181.00123 > time: 965666181.00197 > > note that this does not happen all the time... i would say in 10,000 > times, this happens about 5 times or so. also note that strange enough, > it always seems to jump backwards 9 seconds percisely... *boggle* > > i wrote a small program in c to test the <sys/time.h> gettimeofday() > function to make sure that it's not a hardware issue, and it's not. :) > > does any one know if this is a problem with apache, php, or a combination > of the two? is this a bug or is it due to some "smart forking" that php > does to optimize for loops? > > thanx in advance for any help! > > attached is the program i wrote for testing: > > <?php > > function getCurrentTime () { > $time_array = gettimeofday(); > return $time_array["sec"] + ($time_array["usec"]/100000); > } > > $cache_time = 0; > $cur_time = 0; > > echo "test starts..."; > > for ($i=0; $i<10000; $i++) { > $cur_time = getCurrentTime(); > echo "<br>time: $cur_time"; > if ($cur_time < $cache_time) { //if time starts going backwards > echo " **********"; > } > $cache_time = $cur_time; > } > > ?> > > > ---------------- > remco chang > bountyquest.com > > >