NAME
    Coro::ProcessPool - an asynchronous process pool

SYNOPSIS
        use Coro::ProcessPool;

        my $pool = Coro::ProcessPool->new(
            max_procs => 4,
            max_reqs  => 100,
        );

        my %result;
        foreach my $i (1 .. 1000) {
            $result{$i} = $pool->process(sub { shift * 2 }, $i);
        }

        $pool->shutdown;

DESCRIPTION
    Processes tasks using a pool of external Perl processes.

METHODS
  new
    Creates a new process pool. Processes will be spawned as needed.

    max_procs
        This is the maximum number of child processes to maintain. If all
        processes are busy handling tasks, further calls to "process" in .
        will yield until a process becomes available. If not specified,
        defaults to the number of CPUs on the system.

    max_reqs
        If this is a positive number (defaults to 0), child processes will
        be terminated and replaced after handling "max_reqs" tasks. Choosing
        the correct value for "max_reqs" is a tradeoff between the need to
        clear memory leaks in the child process and the time it takes to
        spawn a new process and import any packages used by client code.

  process($f, $args)
    Processes code ref $f in a child process from the pool. If $args is
    provided, it is an array ref of arguments that will be passed to $f.
    Returns the result of calling "$f-"(@$args)>.

    This call will yield until the results become available. If all
    processes are busy, this method will block until one becomes available.
    Processes are spawned as needed, up to "max_procs", from this method.
    Also note that the use of "max_reqs" can cause this method to yield
    while a new process is spawned.

  shutdown
    Shuts down all processes and resets state on the process pool. After
    calling this method, the pool is effectively in a new state and may be
    used normally.

COMPATIBILITY
    "Coro::ProcessPool" will likely break on Win32 due to missing support
    for non-blocking file descriptors (Win32 can only call "select" and
    "poll" on actual network sockets). Without rewriting this as a network
    server, which would impact performance and be really annoying, it is
    likely this module will not support Win32 in the near future.

    The following modules will get you started if you wish to explore a
    synchronous process pool on Windows:

    Win32::Process
    Win32::IPC
    Win32::Pipe

AUTHOR
    Jeff Ober mailto:jeffober@gmail.com

LICENSE
    BSD License