prime_main v0.3.8
加入了两个变量给write_db提供新prime数据的参数，其实现在这个方法并不高性能而且多消耗了内存。
不过为了简单起见先用这个方法处理好write_db。
下面write_db可以动工了。
#!/usr/bin/perl -w
#use strict;
# file:prime_main
# main program of prime_project.
# by:leon 05/10/26 v0.3.8
use Socket;
use IO::Handle;
use read_write_db qw(read_db write_db);
use cal_prime qw(cal_prime_by_step);
# Bidirectional communication using socketpair
socketpair(CHILD, PARENT, AF_UNIX, SOCK_STREAM, PF_UNSPEC) or die "socketpair: $!";
CHILD->autoflush(1);
PARENT->autoflush(1);
unless ($pid = fork) {
# This is Child,for calculate prime
die "cannot fork: $!" unless defined $pid;
close CHILD;
print "CHILD PID:$$\n";
# Child ignore "ctrl+c"
$SIG{INT} = ‘IGNORE’;
# Read date from database for prepare calculate
local (@prime_n_array,$prime_step_id,@new_prime_id_array,@new_prime_n_array);
read_db(*prime_n_array,*prime_step_id);
#print "@prime_n_array,$prime_step_id\n";
while (1) {
print PARENT "go_on?\n";
chomp($line = <PARENT>);
if ($line eq "go_on") {
# Parent didn’t catch "ctrl+c" so we go on next step calculate
$i = 0;
while (++$i<3) {
# Go into a calculate prime step
print "step:$prime_step_id\n";
cal_prime_by_step(*prime_n_array,*prime_step_id,*new_prime_id_array,*new_prime_n_array);
print "new_id: @new_prime_id_array\n";
print "new_n: @new_prime_n_array\n";
write_db();
}
last;
} elsif ($line eq "exit") {
# Parent catch "ctrl+c" so we stop
print "Child do something before exit\n";
write_db();
exit;
} else {
# For Extensions
print "Child:I don’t understand What Parent say.\n";
exit;
}
}
print "CHILD end\n";
close PARENT;
exit;
} else {
# This is Parent,for control Child
close PARENT;
# Catch ctrl+c,but don’t exit directly.Parent send a msg
# to Child then exit after Child finish ending work
$SIG{INT} = sub {$int_count++};
while (chomp($line = <CHILD>)) {
if ($int_count) {
print CHILD "exit\n";
last; #jump out of "while"
}
if ($line eq "go_on?") {
print CHILD "go_on\n";
} else {
# For Extensions
print "Parent:I don’t understand What Child say.\n";
}
}
print "Parent going to exit.\n";
close CHILD;
waitpid($pid,0);
}
