DESCRIPTION¶
H_CLEAN_UP(H) defines a lfun or a closure used to clean up an object. In older drivers this was hardwired to the lfun clean_up(A).
The function is applied by the driver when an object hasn’t been used for a long time, to give it a chance to self-destruct. The refcount ref passed as argument will be 0 for clone objects, 1 for a simple loaded object, and greater when the object is cloned or inherited by some existing object. It is recommended not to self_destruct the object when the reference count is greater than one.
By convention, a refcount < 0 is used if some other object asks the called object to clean_up.
If the function is a closure, the second argument ob is the object to clean up.
If the hook specifies a non-existing lfun, or if the call returns 0, no further attempt to clean up this object will be made.
Returning a non-zero value is only recommended when the reason why the object can’t self-destruct is likely to vanish without the object being touched, that is, when no local function is called in it, (and in compat mode also when the object is not being moved around).
A typical mud configuration defines the time to wait for clean_up() so long that you can assert reset() has been called since the object has been touched last time.
USAGE¶
A clone of /std/drink defines clean_up() to self-destruct if it is empty, not carried a living being and not touched for a long time.
A room that inherits /std/room defines clean_up() to self-destruct if it is neither inherited nor used as a blueprint, is empty and was not entered for a long time.
HISTORY¶
- changed (3.2.1) – function no longer hardwired to the lfun
clean_up(A).
SEE ALSO¶
reset(A), heart_beat(A), call_out(E), destruct(E), remove(A), hook