roland/xo-alloc2
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

xo-gc stack: fix mutation setup + xo-reader2 utest

Browse source
This commit is contained in:
Roland Conybeare 2026-05-07 23:44:32 -04:00
commit f56b01e7b6
11 changed files with 234 additions and 23 deletions
Download patch file Download diff file Expand all files Collapse all files

10
include/xo/alloc2/alloc/AAllocator.hpp
View file

@ -64,6 +64,16 @@ namespace xo {
/** @defgroup mm-allocator-methods Allocator methods **/
///@{
/** An uninitialized AAllocator instance will have zero vtable pointer
* (per {linux,osx} abi).
* Use case for this is narrow.
* We go to some lengths to avoid null vtable pointers.
* For example obj<AFacet> will have non-null vtable (via IFacet_Any)
* with all methods terminating.
**/
bool _has_null_vptr() const noexcept {
return (*reinterpret_cast<const void * const *>(this) == nullptr);
}
/** RTTI: unique id# for actual runtime data representation **/
virtual typeseq _typeseq() const noexcept = 0;
/** destroy instance @p d. Calls c++ destructor for actual runtime type.

1
include/xo/alloc2/alloc/RAllocator.hpp
View file

@ -52,6 +52,7 @@ namespace xo {
return nullptr;
}
bool _has_null_vptr() const noexcept { return O::iface()->_has_null_vptr(); }
typeseq _typeseq() const noexcept { return O::iface()->_typeseq(); }
void _drop() const noexcept { O::iface()->_drop(O::data()); }
std::string_view name() const noexcept { return O::iface()->name(O::data()); }

26
include/xo/alloc2/alloc/RAllocator_aux.hpp
View file

@ -33,9 +33,14 @@ namespace xo {
obj<AGCObject> * p_lhs,
obj<AGCObject> rhs) noexcept
{
this->barrier_assign_aux(parent,
p_lhs->iface(), p_lhs->opaque_data_addr(),
rhs.iface(), rhs.opaque_data());
if (this->data()) {
this->barrier_assign_aux(parent,
p_lhs->iface(), p_lhs->opaque_data_addr(),
rhs.iface(), rhs.opaque_data());
} else {
// special case: for null allocator want no write-barrier
*p_lhs = rhs;
}
}
template <typename Object>
@ -48,11 +53,16 @@ namespace xo {
// need to get AGCObject i/face that goes with DRepr.
obj<AGCObject,DRepr> rhs_gco(rhs_data);
this->barrier_assign_aux(parent,
nullptr /*not needed*/,
lhs_data,
rhs_gco.iface(),
rhs_data);
if (this->data()) {
this->barrier_assign_aux(parent,
nullptr /*not needed*/,
lhs_data,
rhs_gco.iface(),
rhs_data);
} else {
// special case: for null allocator want no write-barrier
*lhs_data = rhs_data;
}
}
} /*namespace mm*/