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xo-object: improve GC unittest + prep to integrate w/ xo::reflect

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This commit is contained in:
Roland Conybeare 2025-08-06 13:53:31 -05:00
commit 432e0efce2
8 changed files with 305 additions and 120 deletions
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116
include/xo/alloc/GC.hpp
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@ -6,6 +6,7 @@
#pragma once
#include "ListAlloc.hpp"
#include "GcStatistics.hpp"
#include "xo/indentlog/print/array.hpp"
#include <vector>
#include <array>
@ -15,20 +16,6 @@ namespace xo {
class Object;
namespace gc {
enum class generation {
nursery,
tenured,
N
};
constexpr std::size_t gen2int(generation x) { return static_cast<std::size_t>(x); }
enum class generation_result {
nursery,
tenured,
not_found
};
enum class role {
/** nursery: generation for new objects **/
from_space,
@ -59,104 +46,6 @@ namespace xo {
bool debug_flag_ = false;
};
/** @class ObjectStatistics
* @brief placeholder for type-driven allocation statistics
*
* Passed to @ref Object::deep_move for example
**/
class ObjectStatistics {
};
/** @class PerGenerationStatistics
* @brief garbage collection statistics for particular GC generation
**/
class PerGenerationStatistics {
public:
/** update statistics after a GC cycle
* @param alloc_z. new allocations (since preceding GC)
* @param before_z. generation size (bytes allocated) before collection
* @param after_z. generation size after collection
* @param promote_z. bytes promoted to next generation
**/
void include_gc(std::size_t alloc_z, std::size_t before_z, std::size_t after_z,
std::size_t promote_z);
/** update with current state (use at end of gc cycle) **/
void update_snapshot(std::size_t after_z);
/** @param os. write stats on this output stream **/
void display(std::ostream & os) const;
/** number of bytes currently in use **/
std::size_t used_z_ = 0;
/** number of collection cycles completed **/
std::size_t n_gc_ = 0;
/** sum of new alloc bytes, sampled at start of each collection cycle **/
std::size_t new_alloc_z_ = 0;
/** sum of allocated bytes sampled at beginning of each collection cycle **/
std::size_t scanned_z_ = 0;
/** sum of bytes remaining after collection cycle **/
std::size_t survive_z_ = 0;
/** sum of bytes promoted to next generation **/
std::size_t promote_z_ = 0;
};
inline std::ostream & operator<< (std::ostream & os, const PerGenerationStatistics & x) {
x.display(os);
return os;
}
/** @class GcStatistics
* @brief garbage collection statistics
**/
class GcStatistics {
public:
/** update statistics after a GC cycle
* @param upto. nursery -> incremental collection; tenured -> full collection
* @param alloc_z. new allocations (since preceding GC)
* @param before_z. generation size (bytes allocated) before collection
* @param after_z. generation size after collection
* @param promote_z. bytes promoted to next generation
**/
void include_gc(generation upto, std::size_t alloc_z,
std::size_t before_z, std::size_t after_z, std::size_t promote_z);
/** update snapshot for current state.
* Use with tenured stats after incremental gc
**/
void update_snapshot(generation upto, std::size_t after_z);
/** @param os. write stats on this output stream **/
void display(std::ostream & os) const;
/** statistics gathered across {incr, full} GCs respectively **/
std::array<PerGenerationStatistics, static_cast<std::size_t>(generation::N)> gen_v_;
/** total bytes allocated since inception **/
std::size_t total_allocated_ = 0;
/** snapshot of total bytes promoted asof beginning of last gc cycle **/
std::size_t total_promoted_sab_ = 0;
/** total bytes promoted from nursery->tenured since inception **/
std::size_t total_promoted_ = 0;
/** total number of mutations to already-allocated objects,
* whether or not GC needs to log them.
**/
std::size_t n_mutation_ = 0;
/** total number of mutation eligible for logging **/
std::size_t n_logged_mutation_ = 0;
/** total number of cross-generation mutations (tenured->nursery when reported) **/
std::size_t n_xgen_mutation_ = 0;
/** total number of cross-checkpoint mutations (N0 -> N1 when reported) **/
std::size_t n_xckp_mutation_ = 0;
/** per-type statistics (placeholder) **/
ObjectStatistics per_type_stats_;
};
inline std::ostream & operator<< (std::ostream & os, const GcStatistics & x) {
x.display(os);
return os;
}
/** @class GCRunstate
* @brief encapsulate state needed while GC is running
*
@ -228,7 +117,8 @@ namespace xo {
static up<GC> make(const Config & config);
const GCRunstate & runstate() const { return runstate_; }
const GcStatistics & gc_statistics() const { return gc_statistics_; }
const GcStatistics & native_gc_statistics() const { return gc_statistics_; }
GcStatisticsExt get_gc_statistics() const;
/** true iff GC permitted in current state **/
bool is_gc_enabled() const { return gc_enabled_ == 0; }