segfault during global destruction

[calid]

in some situations during global destruction, FFI::Platypus can dlclose libzmq before Socket/Context DEMOLISH routines have run... so when they do actually run they try to make ffi calls on a library that's no longer loaded leading to... kaboom.

this can (hopefully) be worked around by doing the FFI::Platypus attach equivlant of the FFI::Raw::Ptr trick of overriding the package DESTROY with a real underlying ffi destroy function:

    use base qw(FFI::Raw::Ptr);

    *_foo_new = FFI::Raw -> new(
      $shared, 'foo_new',
      FFI::Raw::ptr
    ) -> coderef;

    sub new {
      bless shift -> SUPER::new(_foo_new());
    }

    *DESTROY = FFI::Raw -> new(
      $shared, 'foo_free',
      FFI::Raw::void,
      FFI::Raw::ptr
    ) -> coderef;

    1;

    package main;

    my $foo = Foo -> new;

package Foo;

use FFI::Platypus::Declare;

attach [ foo_new => 'new' ] => [] => 'pointer';
attach [ foo_free => 'DESTROY' ] => [ 'pointer' ] => 'void';

1;

package main;

my $foo = Foo->new;

[calid]

Unfortunately it doesn't look like setting *DESTROY to the native cleanup routines directly will fix all the race conditions during global destruction that result in the segfault. Either ffi calls need to be avoided completely in the object destructors during global destruction, or an upstream change to FFI::Platypus needs to be made.