When objects are added to a SegmentObjTable, it may cause the
internal storage for the table to expand and move to a new
region of memory. When this happens, all pointers to objects held
by a SegmentObjTable of the same type would be invalidated, due
to an implementation detail that should not be exposed. To prevent
this, objects are now allocated separately on the heap, so even if
the table's storage moves due to insertions, the objects owned by
the table will not, so references remain valid for the lifetime of
the object.
When new bitmaps are added and the underlying Common::Array needs
to move to expand, this invalidates all pointers to bitmaps, which
makes it basically impossible to use the bitmap segment since you
never know if a reference is going to be invalidated due to an
array move.
To solve this, BitmapTable is changed to hold pointers to
SciBitmaps that are allocated separately on the heap instead, so
when those bitmaps are looked up, the resulting pointers are valid
for the lifetime of the bitmap, instead of the lifetime of the
Common::Array used internally by BitmapTable.
Bitmaps in ScrollWindow and Robot code are managed by the kernel
and not by game scripts, although they must be able to be
referenced through a reg_t. To prevent incorrect GC of bitmaps
that are in use but not referenced by any game script, explicit
memory management of hunk entries can be enabled.
No functionality change has been made with this commit. This avoids
setting and getting the reg_t members directly, and is the basis of any
future work on large SCI3 scripts (larger than 64KB)
SCI scripts can contain stale pointers, which are used later on. We now delete
the contents of hunk entries without invalidating the relevant pointers and let
the GC clear the references. Many thanks to waltervn and wjp for all their work
and help on this.
- Maintain the state of the string heap space in saved games
- Merged SegManager::reconstructScripts() inside SegManager::saveLoadWithSerializer()
- Disabled a now unnecessary script patch for the cipher puzzle in Castle of Dr. Brain, and performed some cleanup for another disabled patch
- Removed direct access to the _baseObj variable of objects
svn-id: r54133
This command can be used to find the object methods (including their
corresponding objects and owner scripts) that call a specific kernel
call. This shall aid us track all the spots where a particular kernel
function is called from, therefore it'll be a bit easier to find
examples where unimplemented kernel functions are called
svn-id: r53646