xo-callback xo-alloc: + GC copy callbacks + unique_ptr cbset support

This commit is contained in:
Roland Conybeare 2025-08-12 12:53:06 -05:00
commit 4eae80295a
7 changed files with 405 additions and 285 deletions

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@ -7,6 +7,7 @@
#include "ListAlloc.hpp"
#include "GcStatistics.hpp"
#include "xo/callback/UpCallbackSet.hpp"
#include "xo/indentlog/print/array.hpp"
#include <vector>
#include <array>
@ -105,12 +106,31 @@ namespace xo {
using MutationLog = std::vector<MutationLogEntry>;
/** @class GcCopyCallback
* @brief optional callback to observe individual copy operations during GC
*
* For viz
**/
class GcCopyCallback {
public:
virtual void notify_gc_copy(std::size_t z, const void * src_addr, const void * dest_addr,
generation src_gen, generation dest_gen) = 0;
/** invoked when added to callback set (i.e. @ref GC::GcCopyCallbackSet) **/
void notify_add_callback() {}
/** invoked when removed from callback set **/
void notify_remove_callback() {}
};
/** @class GC
* @brief generational garbage collector
*
* Works with objects of type @ref xo::Object
**/
class GC : public IAlloc {
public:
using CallbackId = xo::fn::CallbackId;
using GcCopyCallbackSet = xo::fn::UpCallbackSet<GcCopyCallback>;
public:
/** create new GC instance with configuration @p config **/
explicit GC(const Config & config);
@ -160,6 +180,11 @@ namespace xo {
* from @c *addr
**/
void add_gc_root(Object ** addr);
/** may optionally use this to observe GC copy phase.
* Will be invoked once _per surviving object_, so not cheap.
* Intended for GC visualization.
**/
CallbackId add_gc_copy_callback(up<GcCopyCallback> fn);
/** request garbage collection. **/
void request_gc(generation g);
/** disable garbage collection until matching call to @ref enable_gc.
@ -335,6 +360,9 @@ namespace xo {
/** enabled when 0. disabled when <0 **/
int gc_enabled_ = 0;
/** for (optional) viz: invoke when copying individual objects **/
GcCopyCallbackSet gc_copy_cbset_;
};
} /*namespace gc*/

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@ -15,5 +15,6 @@ set(SELF_SRCS
xo_add_shared_library4(${SELF_LIB} ${PROJECT_NAME}Targets ${PROJECT_VERSION} 1 ${SELF_SRCS})
xo_dependency(${SELF_LIB} reflect)
xo_dependency(${SELF_LIB} callback)
#end CMakeLists.txt

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@ -289,6 +289,12 @@ namespace xo {
gc_root_v_.push_back(addr);
}
auto
GC::add_gc_copy_callback(up<GcCopyCallback> fn) -> CallbackId
{
return gc_copy_cbset_.add_callback(std::move(fn));
}
void
GC::checkpoint()
{
@ -322,16 +328,19 @@ namespace xo {
{
scope log(XO_DEBUG(config_.debug_flag_), xtag("z", z), xtag("+pad", IAlloc::alloc_padding(z)));
generation_result gr = this->fromspace_generation_of(src);
generation_result src_gr = this->fromspace_generation_of(src);
std::byte * retval = nullptr;
switch (gr) {
switch (src_gr) {
case generation_result::tenured:
{
log && log("tenured");
retval = this->tenured_to()->alloc(z);
gc_copy_cbset_.invoke(&GcCopyCallback::notify_gc_copy,
z, src, retval, generation::tenured, generation::tenured);
}
break;
case generation_result::nursery:
@ -347,11 +356,18 @@ namespace xo {
assert(this->tospace_generation_of(retval) == generation_result::tenured);
gc_copy_cbset_.invoke(&GcCopyCallback::notify_gc_copy,
z, src, retval, generation::nursery, generation::tenured);
this->gc_statistics_.total_promoted_ += IAlloc::with_padding(z);
} else {
log && log("nursery");
retval = this->nursery_to()->alloc(z);
gc_copy_cbset_.invoke(&GcCopyCallback::notify_gc_copy,
z, src, retval, generation::nursery, generation::nursery);
}
}
break;

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@ -1,290 +1,13 @@
// TOOD: rename to RpCallbackSet
/* @file CallbackSet.hpp */
#pragma once
//#include "indentlog/scope.hpp"
//#include "indentlog/print/tag.hpp"
#include <functional>
#include <vector>
#include <cstdint>
#include "CallbackSetImpl.hpp"
namespace xo {
namespace fn {
/* identifies a particular callback in a CallbackSet (see below).
* an unique id is created:
* CallbackSetImpl cbset = ...;
* CallbackId cb_id = cbset.add_callback(..);
*
* can use id to remove callback later:
* cbset.remove_callback(cb_id);
*
* Tag so xo-callback can be header-only
*/
template <typename Tag>
class CallbackIdImpl {
public:
CallbackIdImpl() = default;
explicit CallbackIdImpl(uint32_t id) : id_{id} {}
/* generate a globally-unique id (not threadsafe) */
static CallbackIdImpl generate() {
static CallbackIdImpl s_last_id;
s_last_id = CallbackIdImpl(s_last_id.id() + 1);
return s_last_id;
} /*generate*/
uint32_t id() const { return id_; }
private:
uint32_t id_ = 0;
}; /*CallbackIdImpl*/
template <typename Tag>
inline bool operator==(CallbackIdImpl<Tag> lhs, CallbackIdImpl<Tag> rhs) { return lhs.id() == rhs.id(); }
template <typename Tag>
inline bool operator!=(CallbackIdImpl<Tag> lhs, CallbackIdImpl<Tag> rhs) { return lhs.id() != rhs.id(); }
using CallbackId = CallbackIdImpl<class CallbackId_tag>;
/* queue add/remove callback instructions encountered during callback
* execution, to avoid invalidating vector iterator.
*
*/
template<typename Fn>
struct ReentrantCbsetCmd {
enum CbsetCmdEnum { AddCallback, RemoveCallback };
ReentrantCbsetCmd() = default;
ReentrantCbsetCmd(CbsetCmdEnum cmd, CallbackId id, Fn const & fn)
: cmd_{cmd}, id_{id}, fn_{fn} {}
static ReentrantCbsetCmd add(CallbackId id, Fn const & fn) {
return ReentrantCbsetCmd{AddCallback, id, fn};
} /*add*/
static ReentrantCbsetCmd remove(CallbackId id) {
return ReentrantCbsetCmd{RemoveCallback, id, Fn()};
} /*remove*/
bool is_add() const { return cmd_ == AddCallback; }
bool is_remove() const { return cmd_ == RemoveCallback; }
CallbackId id() const { return id_; }
Fn const & fn() const { return fn_; }
private:
/* AddCallback: deferred CallbackSet<Fn>::add_callback(.fn)
* RemoveCallback: deferred CallbackSet<Fn>::remove_callback(.fn)
*/
CbsetCmdEnum cmd_ = AddCallback;
/* operate on callback with this id */
CallbackId id_;
/* callback function to add/remove */
Fn fn_;
}; /*ReentrantCbsetCmd*/
/* record for remembering a single callback.
* callbacks are given unique ids so they can be removed later
*/
template<typename Fn>
struct CbRecd {
CbRecd(CallbackId id, Fn const & fn) : id_{id}, fn_{fn} {}
CallbackId id_;
Fn fn_;
}; /*CbRecd*/
/* If Fnptr is a type such that this works:
* Fnptr fn = ...;
* using Fn = Fnptr::element_type;
* Fn * native_fn = fn.get();
* (native_fn->*member_fn)(args ...);
*
* then
* CallbackSet<Fnptr> cbset = ...;
* cbset.invoke(&Fn::member_fn, args...)
*
* calls
* (cb->*member_fn)(args...)
*
* for each callback cb in this set.
*
* In addition, calls hook methods:
* cb->notify_add_callback()
* cb->notify_remove_callback()
* when adding/removing callback.
*
* Require:
* - Fnptr::element_type
* - Fnptr::get() -> Fnptr::element_type const *
* - can invoke (Fnptr->*member_fn)(...)
*
* implementation is reentrant: running callbacks can safely make
* add/remove calls on the cbset that invoked them.
*
* not threadsafe.
*/
template<typename Fn>
class CallbackSetImpl {
public:
using callback_type = typename Fn::element_type;
//using scope = xo::scope;
public:
CallbackSetImpl() = default;
/* support for range iterators */
typename std::vector<CbRecd<Fn>>::const_iterator begin() const { return cb_v_.begin(); }
typename std::vector<CbRecd<Fn>>::const_iterator end() const { return cb_v_.end(); }
/* invoke callbacks registered with this callback set */
template<typename ... Tn, typename ... Sn>
void invoke(void (callback_type::* member_fn)(Sn... args), Tn&&... args) {
this->cb_running_ = true;
try {
for(CbRecd<Fn> const & cb_recd : this->cb_v_) {
callback_type * native_cb = cb_recd.fn_.get();
/* clang11 doesn't like (with cb=cb_recd.fn_)
* cb->*member_fn
* when cb-> is overloaded
*/
(native_cb->*member_fn)(args...);
}
this->make_deferred_changes();
} catch(...) {
this->make_deferred_changes();
throw;
}
} /*operator()*/
/* call fn(cb) for each callback present in this set */
void visit_callbacks(std::function<void (Fn const &)> fn) const {
CallbackSetImpl * self = const_cast<CallbackSetImpl *>(this);
self->cb_running_ = true;
try {
for(Fn const & cb : this->cb_v_)
fn(cb);
this->make_deferred_changes();
} catch(...) {
this->make_deferred_changes();
throw;
}
} /*visit_callbacks*/
/* add callback target_fn to this callback set.
* reentrant
*/
CallbackId add_callback(Fn const & target_fn) {
CallbackId id = CallbackId::generate();
if(this->cb_running_) {
/* defer until callback execution completes */
this->reentrant_cmd_v_.push_back(ReentrantCbsetCmd<Fn>::add(id, target_fn));
} else {
#ifdef NOT_USING
constexpr bool c_debug_enabled_flag = false;
scope lscope(reflect::type_name<CallbackSetImpl>(),
"::add_callback", c_debug_enabled_flag);
if (c_debug_enabled_flag) {
lscope.log("before appending .cb_v[]",
xo::xtag("target_fn", (void*)target_fn.get()),
xo::xtag("target_fn.refcnt",
target_fn->reference_counter()));
}
#endif
this->cb_v_.push_back(CbRecd(id, target_fn));
#ifdef NOT_USING
if (c_debug_enabled_flag) {
lscope.log("after appending .cb_v[]",
xo::xtag("target_fn", (void *)target_fn.get()),
xo::xtag("target_fn.refcnt",
target_fn->reference_counter()));
}
#endif
}
return id;
} /*add_callback*/
void remove_callback(CallbackId id) {
if(this->cb_running_) {
/* defer until callback execution completes */
this->reentrant_cmd_v_.push_back(ReentrantCbsetCmd<Fn>::remove(id));
} else {
this->remove_callback_impl(id);
}
} /*remove_callback*/
#ifdef NOT_USING
/* remove callback target_fn from this callback set.
* noop if callback is not present
*/
void remove_callback(Fn const & target_fn) {
if(this->cb_running_) {
/* defer until callback execution completes */
this->reentrant_cmd_v_.push_back(ReentrantCbsetCmd<Fn>::remove(target_fn));
} else {
this->remove_callback_impl(target_fn);
}
} /*remove_callback*/
#endif
private:
/* apply deferred changes to .cb_v[] */
void make_deferred_changes() {
this->cb_running_ = false;
std::vector<ReentrantCbsetCmd<Fn>> cmd_v;
std::swap(cmd_v, this->reentrant_cmd_v_);
for(ReentrantCbsetCmd<Fn> const & cmd : cmd_v) {
if(cmd.is_add()) {
this->cb_v_.push_back(CbRecd(cmd.id(), cmd.fn()));
cmd.fn()->notify_add_callback();
} else if(cmd.is_remove()) {
this->remove_callback_impl(cmd.id());
}
}
} /*make_deferred_changes*/
void remove_callback_impl(CallbackId target_id) {
for (auto ix = this->cb_v_.begin(); ix != this->cb_v_.end(); ++ix) {
if (ix->id_ == target_id) {
Fn target_fn = ix->fn_;
this->cb_v_.erase(ix);
target_fn->notify_remove_callback();
break;
}
}
} /*remove_callback_impl*/
private:
bool cb_running_ = false;
/* collection of callback functions */
std::vector<CbRecd<Fn>> cb_v_;
/* when a callback registered with *this, while running,
* attempts to add/remove a callback to/from this set
* (including removing itself),
* must defer until all callbacks have executed.
* remember deferred instructions here.
*/
std::vector<ReentrantCbsetCmd<Fn>> reentrant_cmd_v_;
}; /*CallbackSetImpl*/
template<typename NativeFn>
using RpCallbackSet = CallbackSetImpl<rp<NativeFn>>;
@ -300,18 +23,19 @@ namespace xo {
template<typename ... Tn>
void operator()(Tn&&... args) {
this->invoke(this->privileged_member_fn_, args...);
} /*operator()*/
}
private:
/* implements NotifyCallbackSet's operator()(...) */
/** implements NotifyCallbackSet's operator()(...) **/
MemberFn privileged_member_fn_;
}; /*NotifyCallbackSet*/
};
template<typename NativeFn, typename Sret, typename ... Sn>
inline NotifyCallbackSet<NativeFn, Sret (NativeFn::*)(Sn...)>
make_notify_cbset(Sret (NativeFn::* member_fn)(Sn...)) {
return NotifyCallbackSet<NativeFn, Sret (NativeFn::*)(Sn...)>(member_fn);
} /*make_notify_cbset*/
} /*namespace fn*/
} /*namespace xo*/

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@ -0,0 +1,293 @@
/* file CallbackSetImpl.hpp */
#pragma once
//#include "indentlog/scope.hpp"
//#include "indentlog/print/tag.hpp"
#include <functional>
#include <vector>
#include <cstdint>
namespace xo {
namespace fn {
/* identifies a particular callback in a CallbackSet (see below).
* an unique id is created:
* CallbackSetImpl cbset = ...;
* CallbackId cb_id = cbset.add_callback(..);
*
* can use id to remove callback later:
* cbset.remove_callback(cb_id);
*
* Tag so xo-callback can be header-only
*/
template <typename Tag>
class CallbackIdImpl {
public:
CallbackIdImpl() = default;
explicit CallbackIdImpl(uint32_t id) : id_{id} {}
/* generate a globally-unique id (not threadsafe) */
static CallbackIdImpl generate() {
static CallbackIdImpl s_last_id;
s_last_id = CallbackIdImpl(s_last_id.id() + 1);
return s_last_id;
} /*generate*/
uint32_t id() const { return id_; }
private:
uint32_t id_ = 0;
}; /*CallbackIdImpl*/
template <typename Tag>
inline bool operator==(CallbackIdImpl<Tag> lhs, CallbackIdImpl<Tag> rhs) { return lhs.id() == rhs.id(); }
template <typename Tag>
inline bool operator!=(CallbackIdImpl<Tag> lhs, CallbackIdImpl<Tag> rhs) { return lhs.id() != rhs.id(); }
using CallbackId = CallbackIdImpl<class CallbackId_tag>;
/* queue add/remove callback instructions encountered during callback
* execution, to avoid invalidating vector iterator.
*
*/
template<typename Fn>
struct ReentrantCbsetCmd {
enum CbsetCmdEnum { AddCallback, RemoveCallback };
ReentrantCbsetCmd() = default;
ReentrantCbsetCmd(CbsetCmdEnum cmd, CallbackId id, Fn fn)
: cmd_{cmd}, id_{id}, fn_{std::move(fn)} {}
static ReentrantCbsetCmd add(CallbackId id, Fn fn) {
return ReentrantCbsetCmd{AddCallback, id, std::move(fn)};
} /*add*/
static ReentrantCbsetCmd remove(CallbackId id) {
return ReentrantCbsetCmd{RemoveCallback, id, Fn()};
} /*remove*/
bool is_add() const { return cmd_ == AddCallback; }
bool is_remove() const { return cmd_ == RemoveCallback; }
CallbackId id() const { return id_; }
Fn const & fn() const { return fn_; }
Fn & fn() { return fn_; }
private:
/* AddCallback: deferred CallbackSet<Fn>::add_callback(.fn)
* RemoveCallback: deferred CallbackSet<Fn>::remove_callback(.fn)
*/
CbsetCmdEnum cmd_ = AddCallback;
/* operate on callback with this id */
CallbackId id_;
/* callback function to add/remove */
Fn fn_;
}; /*ReentrantCbsetCmd*/
/* record for remembering a single callback.
* callbacks are given unique ids so they can be removed later
*/
template<typename Fn>
struct CbRecd {
CbRecd(CallbackId id, Fn fn) : id_{id}, fn_{std::move(fn)} {}
CallbackId id_;
Fn fn_;
}; /*CbRecd*/
/* If Fnptr is a type such that this works:
* Fnptr fn = ...;
* using Fn = Fnptr::element_type;
* Fn * native_fn = fn.get();
* (native_fn->*member_fn)(args ...);
*
* then
* CallbackSet<Fnptr> cbset = ...;
* cbset.invoke(&Fn::member_fn, args...)
*
* calls
* (cb->*member_fn)(args...)
*
* for each callback cb in this set.
*
* In addition, calls hook methods:
* cb->notify_add_callback()
* cb->notify_remove_callback()
* when adding/removing callback.
*
* Require:
* - Fnptr::element_type
* - Fnptr::get() -> Fnptr::element_type const *
* - can invoke (Fnptr->*member_fn)(...)
*
* implementation is reentrant: running callbacks can safely make
* add/remove calls on the cbset that invoked them.
*
* not threadsafe.
*/
template<typename Fn>
class CallbackSetImpl {
public:
using callback_type = typename Fn::element_type;
//using scope = xo::scope;
public:
CallbackSetImpl() = default;
/* support for range iterators */
typename std::vector<CbRecd<Fn>>::const_iterator begin() const { return cb_v_.begin(); }
typename std::vector<CbRecd<Fn>>::const_iterator end() const { return cb_v_.end(); }
/* invoke callbacks registered with this callback set */
template<typename ... Tn, typename ... Sn>
void invoke(void (callback_type::* member_fn)(Sn... args), Tn&&... args) {
this->cb_running_ = true;
try {
for(CbRecd<Fn> const & cb_recd : this->cb_v_) {
callback_type * native_cb = cb_recd.fn_.get();
/* clang11 doesn't like (with cb=cb_recd.fn_)
* cb->*member_fn
* when cb-> is overloaded
*/
(native_cb->*member_fn)(args...);
}
this->make_deferred_changes();
} catch(...) {
this->make_deferred_changes();
throw;
}
} /*operator()*/
/* call fn(cb) for each callback present in this set */
void visit_callbacks(std::function<void (Fn const &)> fn) const {
CallbackSetImpl * self = const_cast<CallbackSetImpl *>(this);
self->cb_running_ = true;
try {
for(Fn const & cb : this->cb_v_)
fn(cb);
this->make_deferred_changes();
} catch(...) {
this->make_deferred_changes();
throw;
}
} /*visit_callbacks*/
/* add callback target_fn to this callback set.
* reentrant
*/
CallbackId add_callback(Fn target_fn) {
CallbackId id = CallbackId::generate();
if(this->cb_running_) {
/* defer until callback execution completes */
this->reentrant_cmd_v_.emplace_back(ReentrantCbsetCmd<Fn>::add(id, std::move(target_fn)));
} else {
#ifdef NOT_USING
constexpr bool c_debug_enabled_flag = false;
scope lscope(reflect::type_name<CallbackSetImpl>(),
"::add_callback", c_debug_enabled_flag);
if (c_debug_enabled_flag) {
lscope.log("before appending .cb_v[]",
xo::xtag("target_fn", (void*)target_fn.get()),
xo::xtag("target_fn.refcnt",
target_fn->reference_counter()));
}
#endif
this->cb_v_.push_back(CbRecd(id, std::move(target_fn)));
#ifdef NOT_USING
if (c_debug_enabled_flag) {
lscope.log("after appending .cb_v[]",
xo::xtag("target_fn", (void *)target_fn.get()),
xo::xtag("target_fn.refcnt",
target_fn->reference_counter()));
}
#endif
}
return id;
} /*add_callback*/
void remove_callback(CallbackId id) {
if(this->cb_running_) {
/* defer until callback execution completes */
this->reentrant_cmd_v_.push_back(ReentrantCbsetCmd<Fn>::remove(id));
} else {
this->remove_callback_impl(id);
}
} /*remove_callback*/
#ifdef NOT_USING
/* remove callback target_fn from this callback set.
* noop if callback is not present
*/
void remove_callback(Fn const & target_fn) {
if(this->cb_running_) {
/* defer until callback execution completes */
this->reentrant_cmd_v_.push_back(ReentrantCbsetCmd<Fn>::remove(target_fn));
} else {
this->remove_callback_impl(target_fn);
}
} /*remove_callback*/
#endif
private:
/* apply deferred changes to .cb_v[] */
void make_deferred_changes() {
this->cb_running_ = false;
std::vector<ReentrantCbsetCmd<Fn>> cmd_v;
std::swap(cmd_v, this->reentrant_cmd_v_);
for(ReentrantCbsetCmd<Fn> & cmd : cmd_v) {
if(cmd.is_add()) {
this->cb_v_.push_back(CbRecd(cmd.id(), std::move(cmd.fn())));
cmd.fn()->notify_add_callback();
} else if(cmd.is_remove()) {
this->remove_callback_impl(cmd.id());
}
}
} /*make_deferred_changes*/
void remove_callback_impl(CallbackId target_id) {
for (auto ix = this->cb_v_.begin(); ix != this->cb_v_.end(); ++ix) {
if (ix->id_ == target_id) {
Fn target_fn = std::move(ix->fn_);
this->cb_v_.erase(ix);
target_fn->notify_remove_callback();
break;
}
}
} /*remove_callback_impl*/
private:
bool cb_running_ = false;
/* collection of callback functions */
std::vector<CbRecd<Fn>> cb_v_;
/* when a callback registered with *this, while running,
* attempts to add/remove a callback to/from this set
* (including removing itself),
* must defer until all callbacks have executed.
* remember deferred instructions here.
*/
std::vector<ReentrantCbsetCmd<Fn>> reentrant_cmd_v_;
}; /*CallbackSetImpl*/
} /*namespace fn*/
} /*namespace xo*/
/* CallbackSetImpl.hpp */

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@ -0,0 +1,34 @@
/* @file UpCallbackSet.hpp
*
* author: Roland Conybeare, Aug 2025
*/
#include "CallbackSetImpl.hpp"
#include "callback_concept.hpp"
#include <memory>
namespace xo {
namespace fn {
template <typename NativeFn>
using UpCallbackSet = CallbackSetImpl<std::unique_ptr<NativeFn>>;
template <typename NativeFn, typename MemberFn>
requires(callback_concept<NativeFn>)
class UpNotifyCallbackSet : public UpCallbackSet<NativeFn> {
public:
explicit UpNotifyCallbackSet(MemberFn fn)
: privileged_member_fn_{fn} {}
template <typename... Tn>
void operator()(Tn&&... args) {
this->invoke(this->privileged_member_fn_, args...);
}
private:
/** implements UpNotifyCallbackSet's call operator **/
MemberFn privileged_member_fn_;
};
} /*namespace fn*/
} /*namespace xo*/
/* end UpCallbackSet.hpp */

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@ -0,0 +1,24 @@
/* @file callback_concept.hpp
*
* author: Roland Conybeare, Aug 2025
*/
namespace xo {
namespace fn {
/** @concept callback_concept
* @brief Concept for functors that can be used with @ref CallbackSetImpl
*
**/
template <typename Callback>
concept callback_concept = requires(Callback cb)
{
// no constraints on how callback is invoked.
{ cb.notify_add_callback() };
{ cb.notify_remove_callback() };
};
}
}
/* callback_concept.hpp */