Node:Garbage Collecting Simple Smobs, Next:A Complete Example, Previous:A Common Mistake In Allocating Smobs, Up:Defining New Types (Smobs)
It is often useful to define very simple smob types -- smobs which have
no data to mark, other than the cell itself, or smobs whose first data
word is simply an ordinary Scheme object, to be marked recursively.
Guile provides some functions to handle these common cases; you can use
this function as your smob type's
mark function, if your smob's
structure is simple enough.
If the smob refers to no other Scheme objects, then no action is necessary; the garbage collector has already marked the smob cell itself. In that case, you can use zero as your mark function.
|SCM scm_markcdr (SCM x)||Function|
Mark the references in the smob x, assuming that x's first
data word contains an ordinary Scheme object, and x refers to no
other objects. This function simply returns x's first data word.
This is only useful for simple smobs created by
|size_t scm_free0 (SCM x)||Function|
Do nothing; return zero. This function is appropriate for smobs that
use either zero or |
This function should not be needed anymore, because simply passing