The yield function in MCE::Child (ditto for MCE::Hobo) retains interval periods; i.e. do something at/near every N fractional seconds. It works quite well, even among many workers.

use strict;
use warnings;
use MCE::Child;
use Time::HiRes qw(sleep time);

STDOUT->autoflush(1);

# do something periodically in the background

my $child = MCE::Child->create(sub {
    while (1) {
        MCE::Child->yield(300.0);
        print "Inside child ", time, $/;
    }
});

# application code

print "Parent", $/;

# reap child

$child->kill;
$child->join;
[download]

Demonstration

Notice the output for the next demonstration where the child displays output every 0.2 seconds, even simulating work. It does a delta behind the scene from the last yield statement in order to retain near/exact intervals.

use strict;
use warnings;
use MCE::Child;
use Time::HiRes qw(sleep time);

STDOUT->autoflush(1);

my $child = MCE::Child->create(sub {
    while (1) {
        MCE::Child->yield(0.200);
        print "Inside child ", time, $/;
        sleep 0.1;   # simulate work
    }
});

for (1..5) {
    print "Parent ", $_, $/;
    sleep 1;
}

$child->kill;
$child->join;
[download]

Output

$ perl demo.pl 
Parent 1
Inside child 1646249559.98288
Inside child 1646249560.18285
Inside child 1646249560.38241
Inside child 1646249560.58239
Parent 2
Inside child 1646249560.78239
Inside child 1646249560.98283
Inside child 1646249561.18284
Inside child 1646249561.38284
Inside child 1646249561.58284
Inside child 1646249561.7825
Parent 3
Inside child 1646249561.98284
Inside child 1646249562.18284
Inside child 1646249562.38284
Inside child 1646249562.58284
Inside child 1646249562.78284
Parent 4
Inside child 1646249562.98284
Inside child 1646249563.18284
Inside child 1646249563.38284
Inside child 1646249563.58284
Inside child 1646249563.78283
Parent 5
Inside child 1646249563.98284
Inside child 1646249564.18284
Inside child 1646249564.38284
Inside child 1646249564.58284
Inside child 1646249564.78284
[download]

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