Perl 子程序超时

Question

我有一个子程序通常需要 1 秒才能完成运行。有时，它可以运行无限。如果子例程花费的时间太长（> 10 秒），我想继续编写代码并忽略该子例程的运行。这是我到目前为止使用警报的结果。

use Win32::OLE;

eval { 
    local $SIG{ALRM} = sub { die "alarm\n" };
    alarm 10;                   # schedule alarm in 10 seconds 
    &do_the_subroutine;
    alarm 0;                    # cancel the alarm
};

if ($@) {
    $error_string .= $script;
    #Do something else if the subroutine took too long.
}

do_the_subroutine{
# use existing instance if Excel is already running
    eval {$ex = Win32::OLE->GetActiveObject('Excel.Application')};
    die "Excel not installed" if $@;
    unless (defined $ex) {
        $ex = Win32::OLE->new('Excel.Application', sub {$_[0]->Quit;})
                or die "Oops, cannot start Excel";
    }

    # get a new workbook
    $book = $ex->Workbooks->Add;

    # write to a particular cell
    $sheet = $book->Worksheets(1);
    $sheet->Cells(1,1)->{Value} = "foo";

    # write a 2 rows by 3 columns range
    $sheet->Range("A8:C9")->{Value} = [[ undef, 'Xyzzy', 'Plugh' ],
                                       [ 42,    'Perl',  3.1415  ]];

    # print "XyzzyPerl"
    $array = $sheet->Range("A8:C9")->{Value};
    for (@$array) {
        for (@$_) {
            print defined($_) ? "$_|" : "<undef>|";
        }
        print "\n";
    }

    # save and exit
    $book->SaveAs( 'test.xls' );
    undef $book;
    undef $ex;
}

&do_the_subroutine 从来没有 returns 所以我无法继续前进。我也无法将此代码块放入该子例程中。有什么想法吗？

Answer 1

我怀疑 alarm 在 Windows 上根本无法实现您想做的事情。

来自perldoc perlport：

alarm Emulated using timers that must be explicitly polled whenever Perl wants to dispatch "safe signals" and therefore cannot interrupt blocking system calls. (Win32)

Perl 子程序超时

Perl subroutine timeout

perl

time

timeout

ole

subroutine