use POSIX qw(:signal_h);

# do something

# <criticalSection>
my $sigSet = POSIX::SigSet->new;
my $blockSet = POSIX::SigSet->new(SIGTERM, SIGHUP);
die "Error restoring signal set: $!"
  unless sigprocmask(SIG_BLOCK, $blockSet, $sigSet)

# do critical (uninterruptable) stuff

die "Error restoring original signal set: $!"
  unless sigprocmask(SIG_SETMASK, $sigSet)
# </criticalSection>

# do other stuff here