NAME

       "Future::XS" - experimental XS implementation of "Future"

SYNOPSIS

          my $future = Future::XS->new;

          perform_some_operation(
             on_complete => sub {
                $future->done( @_ );
             }
          );

          $future->on_ready( sub {
             say "The operation is complete";
          } );

DESCRIPTION

       This module provides an XS-based implementation of the Future class. It is currently experimental and
       shipped in its own distribution for testing purposes, though once it seems stable the plan is to move it
       into the main "Future" distribution and load it automatically in favour of the pureperl implementation on
       supported systems.

   Future::XS and threads
       In a program not involving multiple threads, this module behaves entirely as expected, following the
       behaviour of the regular pure-perl "Future" implementation (regardless of whether or not the perl
       interpreter is actually built to support threads).

       When multiple threads are created, previous versions of this module would most likely crash. The current
       version (0.10) fixes enough of the logic, that future instances that are only ever accessed from one
       thread (either the initial main thread, or any additional sidecar threads) will work fine.  However,
       future instances cannot currently cross the boundary between threads.  Any instances that were created
       before a new thread is made will no longer be accessible within that thread, and instances may not be
       returned as the result of the thread exit value. Some of these restrictions may be relaxed in later
       versions.

       Attempts to access a future instance created in one thread from another thread will raise an exception:

          Future::XS instance IO::Async::Future=SCALAR(0x...) is not available in this thread at ...

       As a special case for process cleanup activities, the "->cancel" method does not throw this exception,
       but simply returns silently. This is because cleanup code such as "DESTROY" methods or "defer" blocks
       often attempt to call this on existing instances.

AUTHOR

       Paul Evans <leonerd@leonerd.org.uk>

perl v5.38.2                                       2024-04-01                                    Future::XS(3pm)