Question

我编写的程序生成＆＃34;随机＆＃34;文本文件，其中3个单词替换为存储在$keysfilename文件中的密钥。 Keys文件结构非常简单，如

ASD123ASD
QWE123QWE
XZC123ZXC

当我使用多个线程时会出现问题，例如

my @threads = (^32).map({

如果在任意文件上失败，则出现错误

    started
Thread<17>(14) got 1
Thread<18>(15) got 2
Thread<20>(17) got 17
Thread<5>(2) got 3
Thread<16>(13) got 4
Thread<21>(18) got 5
Thread<3>(0) got 6
Thread<8>(5) got 7
Thread<12>(9) got 10
Thread<11>(8) got 8
Thread<9>(6) got 9
Thread<14>(11) got 11
Thread<15>(12) got 12
Unhandled exception: Failed to open file C:\c\perltests\00000017.txt: no such file or directory
Thread<10>(7) got 13
Thread<13>(10) got 14
Thread<7>(4) got 15
Thread<19>(16) got 16
Thread<4>(1) got 0
Thread<6>(3) got 18
Thread<22>(19) got 19
   at <unknown>:1  (C:\rakudo/share/perl6/runtime/CORE.setting.moarvm:throw:4294967295)
Thread<23>(20) got 20
Thread<24>(21) got 21
 from gen/moar/m-CORE.setting:22337  (C:\rakudo/share/perl6/runtime/CORE.setting.moarvm:throw:34)
Thread<26>(23) got 22
Thread<25>(22) got 23
Thread<27>(24) got 24
 from gen/moar/m-CORE.setting:22374  (C:\rakudo/share/perl6/runtime/CORE.setting.moarvm:FALLBACK:35)
Thread<28>(25) got 25
Thread<29>(26) got 26
 from gen/moar/m-Metamodel.nqp:3041  (C:\rakudo\share\nqp\lib/Perl6/Metamodel.moarvm::13)
Thread<30>(27) got 27
Thread<16>(13) got 28
Thread<17>(14) got 29
Thread<5>(2) got 30
Thread<18>(15) got 31
Thread<14>(11) got 32
Thread<15>(12) got 33
 from gen/moar/m-CORE.setting:25189  (C:\rakudo/share/perl6/runtime/CORE.setting.moarvm:spurt:226)
Thread<30>(27) got 58
Thread<29>(26) got 57
Unhandled exception: Failed to open file C:\c\perltests\00000028.txt: no such file or directory
Thread<28>(25) got 56
 from gen/moar/m-CORE.setting:25203  (C:\rakudo/share/perl6/runtime/CORE.setting.moarvm:spurt:92)
Thread<25>(22) got 55
 from gen/moar/m-CORE.setting:25199  (C:\rakudo/share/perl6/runtime/CORE.setting.moarvm:spurt:44)
Thread<27>(24) got 54
 from gen/moar/m-CORE.setting:25506  (C:\rakudo/share/perl6/runtime/CORE.setting.moarvm:spurt:96)
Thread<26>(23) got 53
 from gentexts.pl:54  (<ephemeral file>::189)
Thread<24>(21) got 52
Thread<23>(20) got 51
Unhandled exception: Failed to open file C:\c\perltests\00000058.txt: no such file or directory
Thread<6>(3) got 50
Thread<22>(19) got 49
   at <unknown>:1  (C:\rakudo/share/perl6/runtime/CORE.setting.moarvm:throw:4294967295)
Thread<34>(31) got 48
 from gen/moar/m-CORE.setting:22337  (C:\rakudo/share/perl6/runtime/CORE.setting.moarvm:throw:34)
Thread<33>(30) got 47
Thread<4>(1) got 46
 from gen/moar/m-CORE.setting:22374  (C:\rakudo/share/perl6/runtime/CORE.setting.moarvm:FALLBACK:35)
Thread<7>(4) got 45
 from gen/moar/m-Metamodel.nqp:3041  (C:\rakudo\share\nqp\lib/Perl6/Metamodel.moarvm::13)
Thread<19>(16) got 44
Thread<11>(8) got 43
   at <unknown>:1  (C:\rakudo/share/perl6/runtime/CORE.setting.moarvm:throw:4294967295)
Thread<8>(5) got 42
 from gen/moar/m-CORE.setting:22337  (C:\rakudo/share/perl6/runtime/CORE.setting.moarvm:throw:34)
Thread<12>(9) got 41
Thread<10>(7) got 40
 from gen/moar/m-CORE.setting:25189  (C:\rakudo/share/perl6/runtime/CORE.setting.moarvm:spurt:226)
Thread<13>(10) got 39
 from gen/moar/m-CORE.setting:25203  (C:\rakudo/share/perl6/runtime/CORE.setting.moarvm:spurt:92)
Thread<31>(28) got 37
 from gen/moar/m-CORE.setting:25199  (C:\rakudo/share/perl6/runtime/CORE.setting.moarvm:spurt:44)
Thread<32>(29) got 38
Thread<9>(6) got 36
 from gentexts.pl:44  (<ephemeral file>::15)
Thread<3>(0) got 35
Thread<21>(18) got 34
 from gen/moar/m-CORE.setting:22374  (C:\rakudo/share/perl6/runtime/CORE.setting.moarvm:FALLBACK:35)
Thread<17>(14) got 59
 from gen/moar/m-CORE.setting:25506  (C:\rakudo/share/perl6/runtime/CORE.setting.moarvm:spurt:96)
Thread<5>(2) got 60
Thread<18>(15) got 61
 from gentexts.pl:54  (<ephemeral file>::189)
Thread<9>(6) got 85
Thread<32>(29) got 84
 from gen/moar/m-CORE.setting:30638  (C:\rakudo/share/perl6/runtime/CORE.setting.moarvm:THREAD-ENTRY:44)

System Win 10 x32，Rakudo 6.c

my $keysfilename := 'C:/c/keysfile.txt';
my $output       := 'C:/c/perltests';

my @keys = ();
for $keysfilename.IO.words {
    @keys.push($_);
}
my $len  := elems @keys;

my $lorem = q:to/END/; 
Lorem ipsum dolor sit amet, consectetur adipiscing elit. Donec malesuada purus vel tincidunt eleifend. Fusce sollicitudin augue augue, et gravida dolor varius a. Vestibulum iaculis, dui iaculis iaculis molestie, tellus ante hendrerit massa, at volutpat risus metus vitae nisi. Integer neque magna, ultrices eu erat at, efficitur sollicitudin sem. Aliquam sed purus malesuada, porta est eu, rutrum neque. Quisque dolor leo, condimentum non mollis eget, tristique eget odio. Donec dignissim magna nec imperdiet iaculis. Vestibulum lorem ligula, euismod ac porttitor faucibus, rutrum eu ex.

Donec scelerisque nisi eget risus condimentum ultrices. Integer porta maximus quam, in lobortis quam fermentum eu. Morbi eu ligula consequat, aliquam sem eget, sollicitudin eros. Suspendisse potenti. Cras finibus metus et eros accumsan, id vehicula libero lobortis. Aenean vulputate lacinia urna at fringilla. Nulla id tincidunt lectus, quis accumsan lorem. In posuere magna non purus hendrerit rutrum. Maecenas in mattis tellus. Maecenas vel feugiat enim. Lorem ipsum dolor sit amet, consectetur adipiscing elit. Proin convallis dapibus tellus vitae euismod. Nam eleifend dui quam, eget lobortis quam pulvinar id. Cras euismod posuere dolor non ultricies.

Ut dapibus porta faucibus. Duis velit ante, tincidunt id velit id, imperdiet egestas velit. Morbi efficitur enim dignissim interdum egestas. Vivamus eu urna condimentum, aliquam orci non, ullamcorper est. Phasellus egestas at tellus nec tristique. Fusce feugiat commodo faucibus. In hac habitasse platea dictumst. Quisque dignissim, mauris a pellentesque dictum, mauris velit tincidunt lorem, sed tincidunt libero enim vitae orci. Nam interdum, ante nec consequat vulputate, nisi turpis euismod nibh, sit amet elementum nunc diam non eros. Proin quis viverra risus. Vestibulum vestibulum diam in velit consectetur, eu elementum lacus sagittis. Morbi accumsan ac ante eget faucibus. In nec elit bibendum, tristique enim non, sodales ex. Donec sodales erat vitae odio cursus commodo.

Vestibulum felis lacus, mattis eget porta eget, mattis ut felis. Pellentesque aliquet, purus eu semper suscipit, sem ipsum euismod nunc, sed dapibus augue sem vel elit. Etiam tincidunt arcu ut nisi tempor commodo. Mauris at eros tincidunt, fringilla erat nec, sagittis ante. Integer et malesuada quam. Cras vel porta erat, sit amet efficitur erat. Praesent blandit purus quis urna consectetur, eget ultricies ipsum pulvinar. Phasellus ac molestie elit. Vestibulum et tincidunt velit. Aliquam a venenatis ipsum, nec commodo libero. Nullam eget consectetur lectus. Morbi placerat interdum erat nec interdum.

Morbi bibendum dui eu turpis pretium, eget aliquet augue aliquam. Aliquam eu dignissim mauris, vitae placerat augue. Ut sed tortor sit amet augue imperdiet rutrum. Aliquam erat volutpat. Morbi a turpis in sapien ultrices tristique. Proin quis vestibulum lorem, ut pharetra ex. Quisque tempor bibendum purus ac vehicula. Suspendisse tellus ipsum, imperdiet id sodales vel, congue a leo. Nulla gravida tincidunt nisi eu tempor. Mauris imperdiet tempor ante eget rutrum. Nam ut dui at augue laoreet mollis. Sed metus elit, viverra ac fringilla vel, fermentum et magna. Nam ligula purus, pretium vel dignissim vitae, fermentum at urna. Nullam ac ullamcorper felis. Maecenas dapibus consequat mi. 
END

my @words = $lorem.split(' ');
my $wordlen = @words.elems;

my &getNext = sub {
    my $counter = 0;
    my Lock $lock .= new;
    return sub (@filename) {
        $lock.lock;
        if ($counter < 100_000) {
            @filename[0] = $counter;
            $counter++;
        }
        $lock.unlock;
    };
}();

say "started";

my @threads = (^1).map({
    Thread.start(
        name => $_,
        sub {
            loop {              
                my @counter = (-1);
                getNext(@counter);
                last if @counter[0] < 0;
                say $*THREAD ~ " got " ~ @counter[0];
                my @copy = @words.clone;
                for (^3) {
                    my $pos = $wordlen.rand.round;
                    @copy[$pos] = @keys[$len.rand.round];
                }
                spurt sprintf($output ~ '/%08d.txt', @counter[0]), @copy.join(' ');
            }
        }
    );
}).join;

Answer 1

一些注释。

此：

my @keys = ();
for $keysfilename.IO.words {
    @keys.push($_);
}

就是这样：my @keys = $keysfilename.IO.words;

并且：@keys[$len.rand.round] 就是这样：@keys.pick

我似乎不太确定你对计数器阵列做了什么就像你只想要文件0..99999。

您正在为每个线程在子例程中进行锁定。如果你想要保持多个线程访问某些东西，进行一次锁定在外面并让他们每个人用它来锁定独家代码。

您还使用Thread制作主题，但这确实是一个相当低级别的界面。尝试使用更高级别的结构在可能的情况下降到那个水平之前。

在这种情况下，您似乎只想分割100,000个文件创建多个线程只是为了获得一些并行性。那里是一些使这非常容易的结构，hyper和 race。因为你甚至不关心文件的顺序创建于，你可以只使用种族，它会快速推出它们尽可能。

你可以使用＆＃39; degree＆＃39;参数race说明多少你想要使用的线程。（您可能需要将RAKUDO_MAX_THREADS设置为得到你想要的行为。

my $keysfilename := 'C:/c/keysfile.txt';
my $output       := 'C:/c/perltests';

my @keys = $keysfilename.IO.words;

my $lorem = q:to/END/; 
Lorem ipsum ...
END

my @words = $lorem.split(' ');
my $wordlen = @words.elems;

[^100000].race(degree => 32).map({ 
#    say $*THREAD ~ " got " ~ $_;

    my @copy = @words;

    for (^3) {
        my $pos = $wordlen.rand.round;
        @copy[$pos] = @keys.pick;
    }

    spurt sprintf($output ~ '/%08d.txt', $_), @copy.join(' ');
});

Answer 2

在Perl 6中几乎没有理由直接使用Threads，有很多功能可以帮助你。在大多数情况下，最简单的改进是仅使用start而不是Thread.start和await LIST而不是LIST».join或LIST.map(*.join)。

您正在呼叫List.join而不是Thread.join，这可能至少部分是您遇到问题的原因。

还有很多事情让人难以阅读和理解。

通过你如何写getNext，你似乎只知道或者大多只知道JavaScript。这就是我写它的方式。

sub get-next (@filename) {
    state Int $counter = 0;  # set to zero only the first time it is called
    state Lock $lock .= new;

    $lock.protect: ->{
        if $counter < 100_000 {
            @filename[0] = $counter++;
        }
    }
}

除了您只使用@filename来绕过参数的默认只读语义。

sub get-next ($filename is rw) {
    state Int $counter = 0;
    state Lock $lock .= new;

    $lock.protect: ->{
        if $counter < 100_000 {
            $filename = $counter++;
        }
    }
}

除了返回值更有意义。

sub get-next () {
    state Int $counter = 0;
    state Lock $lock .= new;

    $lock.protect: ->{
        $counter++ if $counter < 100_000
    } // Nil
    # the `if` will return `Empty` when $counter gets too big
    # but we want `Nil` instead
}

这会返回计数器或Nil，这是一个未定义的值，因此您可以像这样使用它：

loop {
    my $counter = get-next() orelse last;
    …
}

由于您只在循环中使用sub，因此它本身可以调用last 或者更好的是，如果您改为将声明计数器的行更改为

state Int $counter = 0 but True;

然后，您可以将loop更改为while循环，而无需在任何地方添加last。

while get-next() -> $counter { … }

现在我向您展示了如何改进getNext，我将把它扔掉并使用Perl 6的更好的功能。
（顺便使用Channel会更有意义）

# will probably still work with `use v6.c;`
# but v6.d has a better system backing `await`
use v6.d.PREVIEW;

# override the original default number of threads
# (16 threads currently)
BEGIN %*ENV<RAKUDO_MAX_THREADS> //= 32;
# the "correct" way to do this is setting $*SCHEDULER
# but this is easier

my $keys-filename = 'C:/c/keysfile.txt';
my $output-dir    = 'C:/c/perltests';

my @keys = $keys-filename.IO.words;

my @lorem = q:to/EOF/.split(' ');
…
EOF

say 'started';
END say 'finished';

for race ^100_000 -> $counter {
    say $*THREAD, " got ", $counter;
    my @copy = @lorem; # no need for .clone

    for (^+@copy).pick(3) -> $pos {
        @copy[$pos] = @keys.roll;
    }

    spurt $*SPEC.catfile($output-dir, $counter.fmt('/%08d.txt')), @copy.join(' ');
}

（我进行了一次测试，它的线程ID从未超过6）

我使用了race而不是hyper，因为无论如何都会丢弃返回值。

如果它不起作用，你有一个错误版本的Rakudo。如果是这样，我建议更新到最新版本v2017.02
（say $*PERL.compiler.version;）

+@array与@array.elems

相同

^ NUMBER与0 ..^ NUMBER相同，后者是

的糖

Range.new( 0, NUMBER, :excludes-max )

这仍然存在一些“单词”有额外字符的问题例如amet, elit.和ex.␤␤Donec

…

my @pos = ($lorem ~~ m:ex/ « \w+: /).map: { .from, .chars }
# @pos looks something like [(0,5),(6,5),(12,5),(18,3),…]

…

for race ^100_000 -> $counter {
    say $*THREAD, " got ", $counter;

    # vvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvvv
    my $copy = $lorem;

    # sort so that the transforms are done from the end of the string
    # towards the beginning of the string
    for @pos.pick(3).sort.reverse {
      $copy.substr-rw( |$_ ) = @keys.roll;
    }
    # ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

    spurt $*SPEC.catfile($output-dir, $counter.fmt('/%08d.txt')), $copy;
}

Perl6多线程突发问题

2 个答案: