Perl 使用sysread时不可用sysread将返回可用内容，不再返回。我会在帖子中补充这一点。我的意思是，既然我确切地知道文件句柄上返回的是什么（并且一次返回所有文件），缓冲区真的很重要吗？@Lomsky，你关于一次返回所有文件的假设是不正确的。你无法控制。你

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使用

sysread

时不可用

sysread

将返回可用内容，不再返回。我会在帖子中补充这一点。我的意思是，既然我确切地知道文件句柄上返回的是什么（并且一次返回所有文件），缓冲区真的很重要吗？@Lomsky，你关于一次返回所有文件的假设是不正确的。你无法控制。你知道发送的是什么，而不是收到的是什么。如果您知道收到了什么，那么就没有理由使用

select

@Lomsky，这补充了解释为什么在我声称“缓冲不好”时使用您自己的缓冲区是安全的。

my $read_set = IO::Select()->new;
my $count = @agents_to_run; #array comes as an argument

for $agent ( @agents_to_run ) { 
    ( $sock, my $peerhost, my $peerport ) 
        = server($config_settings{ $agent }->
            { 'Host' },$config_settings{ $agent }->{ 'Port' };
    $read_set->add( $sock );

}

while ( $count > 0) {
    my @rh_set = IO::Select->can_read();

    for my $rh ( @{ $rh_set } ) {

            my %results = <$rh>;
            my $num_files = $results{'numFiles'};
            my @files = ();
            for (my i; i < $num_files; i++) {
                    $files[i]=<$rh>;
            }                 
            #process results, close fh, decrement count, etc
    }
}

use IO::Select qw( );
use IO::Handle qw( );

sub producer {
    my ($fh) = @_;
    for (;;) {
        print($fh time(), "\n") or die;
        print($fh time(), "\n") or die;
        sleep(3);
    }
}

sub consumer {
    my ($fh) = @_;
    my $sel = IO::Select->new($fh);
    while ($sel->can_read()) {
        my $got = <$fh>;
        last if !defined($got);
        chomp $got;
        print("It took ", (time()-$got), " seconds to get the msg\n");
    }
}

pipe(my $rfh, my $wfh) or die;
$wfh->autoflush(1);
fork() ? producer($wfh) : consumer($rfh);

It took 0 seconds to get the msg
It took 3 seconds to get the msg
It took 0 seconds to get the msg
It took 3 seconds to get the msg
It took 0 seconds to get the msg
...

sub consumer {
    my ($fh) = @_;
    my $sel = IO::Select->new($fh);
    my $buf = '';
    while ($sel->can_read()) {
        sysread($fh, $buf, 64*1024, length($buf)) or last;
        while ( my ($got) = $buf =~ s/^(.*)\n// ) {
            print("It took ", (time()-$got), " seconds to get the msg\n");
        }
    }
}

It took 0 seconds to get the msg
It took 0 seconds to get the msg
It took 0 seconds to get the msg
It took 0 seconds to get the msg
It took 0 seconds to get the msg
It took 0 seconds to get the msg
...

$select->add($fh);
$clients{fileno($fh)} = {
    buf  => '',
    ...
};

while (my @ready = $select->can_read) {
    for my $fh (@ready) {
        my $client = $clients{fileno($fh)};
        our $buf; local *buf = \($client->{buf});  # alias $buf = $client->{buf};

        my $rv = sysread($fh, $buf, 64*1024, length($buf));
        if (!$rv) {
            if (!defined($rv)) {
                ... # Handle error
            }
            elsif (length($buf)) {
                ... # Handle eof with partial message
            }
            else {
                ... # Handle eof
            }

            delete $clients{fileno($fh)};
            $sel->remove($fh);
            next;
        }

        while ( my ($msg) = $buf =~ s/^(.*)\n// )
            ... # Process message.
        }
    }
}