Registered callables like autoloader or error handler not taken into account

[BitOne]

These callables could be Closure, hence objects that take some space in memory.

[mathieuk]

The prototype I mention in #83 (comment) will detect closures that would be provided to set_error_handler(). It won't detect regular callables ( like 'myfunc' or [$this, 'myfunc'] ).

<?php

$b = 123;
set_error_handler(function () use ($b) { });

meminfo_dump(fopen('dump2.json', 'w+'));

would result in the following output/dump:

$ php -dextension=meminfo.so test3.php
Found unseen alive object: Closure #1 (0x7f0abea66640)
$ cat dump2.json
{
  "header" : {
    "memory_usage" : 391112,
    "memory_usage_real" : 2097152,
    "peak_memory_usage" : 427008,
    "peak_memory_usage_real" : 2097152
  },
  "items": {

...

    "0x7f0abea66640":	{
        "class" : "Closure",
        "is_root" : false,
        "frame" : "<OBJECTS_IN_OBJECT_STORE>",
        "object_handle" : "1",
        "type" : "object",
        "size" : "56"

    }
  }
}