use threads;
use strict;

use Time::HiRes qw/clock_gettime CLOCK_REALTIME/;

# use this to control which CPU you assign this script
# (and in my system also the shell system command)
#use Sys::CpuAffinity; 
#my $success = Sys::CpuAffinity::setAffinity($$, [1]);

print "starting at ".clock_gettime(CLOCK_REALTIME)."\n";

my @pool;
for(1..50){
	push @pool, threads->create(\&mysub);
}

$_->join for (@pool);
 
sub mysub {
    print "spawned " . threads->tid . " at ".clock_gettime(CLOCK_REALTIME)."\n";
    #for(1..100){ select(undef, undef, undef, 0.001); }
    #my $x = 0.0001 + rand(0.0015);
    my $x = 0.001;
    my $id;
    for my $i (1..100){
	$id = "i=$i, tid=".threads->tid;
	print `
		echo -n "start($id/\$\$) on cpu "\`cat /proc/\$\$/stat | cut -d' ' -f39\`": "; date +%s.%N
		sleep $x
		echo -n " stop($id/\$\$) on cpu "\`cat /proc/\$\$/stat | cut -d' ' -f39\`": "; date +%s.%N
	`;
    }
    print "ended " . threads->tid . " at ".clock_gettime(CLOCK_REALTIME)."\n";
}
 
__END__

starting at 1626196220.80981
spawned 1 at 1626196220.81077
spawned 2 at 1626196220.81192
spawned 3 at 1626196220.81309
spawned 4 at 1626196220.81466
spawned 5 at 1626196220.81614
spawned 6 at 1626196220.818
start(i=1, tid=1/449647) on cpu 3: 1626196220.813910751
 stop(i=1, tid=1/449647) on cpu 3: 1626196220.818011634
start(i=1, tid=2/449649) on cpu 1: 1626196220.815133617
 stop(i=1, tid=2/449649) on cpu 3: 1626196220.819228058
start(i=1, tid=3/449654) on cpu 4: 1626196220.816404247
 stop(i=1, tid=3/449654) on cpu 2: 1626196220.820722313
spawned 7 at 1626196220.82161
spawned 8 at 1626196220.8235
start(i=1, tid=4/449665) on cpu 6: 1626196220.818088441
 stop(i=1, tid=4/449665) on cpu 4: 1626196220.825072117
spawned 9 at 1626196220.82603
spawned 10 at 1626196220.82844
start(i=1, tid=5/449675) on cpu 4: 1626196220.820177902
start(i=1, tid=6/449684) on cpu 4: 1626196220.824213073
...