xo-gc: refactor: migrate verify impl DX1Collector -> GCObjectStore

This commit is contained in:
Roland Conybeare 2026-04-10 20:32:55 -04:00
commit 53d9ab7747
5 changed files with 149 additions and 23 deletions

View file

@ -358,10 +358,12 @@ namespace xo {
/** cleanup after gc **/
void _cleanup_phase(Generation upto);
#ifdef OBSOLETE
/** Verify that pointer {@p iface, @p data} is valid:
* destination either in to-space, or somewhere outside this collector
**/
void _verify_aux(AGCObject * iface, void * data);
#endif
public:
/** garbage collector configuration **/

View file

@ -55,6 +55,9 @@ namespace xo {
**/
Generation generation_of(Role r, const void * addr) const noexcept;
/** return details from last error (i.e. from g0 to-space) **/
AllocError last_error() const noexcept;
/** get allocation size from header **/
std::size_t header2size(header_type hdr) const noexcept;
/** get generation counter from alloc header **/
@ -167,6 +170,15 @@ namespace xo {
void ** lhs_data,
Generation upto);
/** categorize fop {@p lhs_iface, @p lhs_data}
* based on location of @p lhs_data.
* Update @p *p_verify_stats based on the result:
* increment exactly one of {n_from_, n_to_, n_ext_}
**/
void verify_aux(AGCObject * lhs_iface,
void * lhs_data,
X1VerifyStats * p_verify_stats);
/** Cleanup at the end of a gc cycle.
* Reset from-space
* (current from-space is former to-space,

View file

@ -604,7 +604,7 @@ namespace xo {
}
case VisitReason::code::verify:
// called during verify_ok
this->_verify_aux(lhs_iface, *lhs_data);
gco_store_.verify_aux(lhs_iface, *lhs_data, &verify_stats_);
break;
default:
// should be unreachable
@ -612,6 +612,7 @@ namespace xo {
}
}
#ifdef OBSOLETE
void
DX1Collector::_verify_aux(AGCObject * iface, void * data)
{
@ -640,6 +641,7 @@ namespace xo {
++(verify_stats_.n_to_);
}
}
#endif
auto
DX1Collector::alloc(typeseq t, size_type z) noexcept -> value_type

View file

@ -164,6 +164,12 @@ namespace xo {
return Generation::sentinel();
}
AllocError
GCObjectStore::last_error() const noexcept
{
return this->get_space(Role::to_space(), Generation{0})->last_error();
}
auto
GCObjectStore::header2size(header_type hdr) const noexcept -> size_type
{
@ -364,16 +370,35 @@ namespace xo {
(void)error_mm;
std::uint64_t n_age = config_.arena_config_.header_.max_age() + 1;
std::uint32_t hard_n_age = config_.arena_config_.header_.max_age() + 1;
// maximum age of a still-existing object
std::uint32_t soft_max_age = 0;
// first pass, establish max age
for (Generation g{0}; g < config_.n_generation_; ++g) {
const DArena * arena = this->get_space(Role::to_space(), g);
for (AllocInfo info : *arena) {
if (info.is_forwarding_tseq()) {
assert(false);
return false;
}
uint32_t age = info.age();
assert(age < hard_n_age);
soft_max_age = std::max(soft_max_age, age);
}
}
// stats, indexed by age
DArray * stats_v = DArray::empty(mm, n_age);
DArray * stats_v = DArray::empty(mm, soft_max_age + 1);
if (!stats_v)
return false;
// pre-populate with empty dictionaries for each age bucket
for (std::uint64_t a = 0; a < n_age; ++a) {
for (std::uint32_t a = 0; a <= soft_max_age; ++a) {
DDictionary * recd = DDictionary::make(mm);
if (!recd)
@ -386,14 +411,12 @@ namespace xo {
stats_v->push_back(obj<AGCObject,DDictionary>(recd));
}
log && log(xtag("n_age", n_age),
log && log(xtag("soft_max_age", soft_max_age),
xtag("stats_v.size", stats_v->size()));
// second pass, populate
// scan to-space, count objects by age
// track largest age with at least one object
std::int64_t max_age_present = 0;
//
for (Generation g{0}; g < config_.n_generation_; ++g) {
const DArena * arena = this->get_space(Role::to_space(), g);
@ -406,9 +429,6 @@ namespace xo {
uint32_t age = info.age();
size_t z = info.size();
if (static_cast<std::int64_t>(age) > max_age_present)
max_age_present = age;
auto recd = obj<AGCObject,DDictionary>::from(stats_v->at(age));
assert(recd);
@ -428,9 +448,6 @@ namespace xo {
}
}
// trim to only report ages up to max observed
stats_v->resize(max_age_present + 1);
*p_output = obj<AGCObject,DArray>(stats_v);
return true;
@ -642,6 +659,36 @@ namespace xo {
}
} /*_forward_inplace_aux*/
void
GCObjectStore::verify_aux(AGCObject * iface,
void * data,
X1VerifyStats * p_verify_stats)
{
//scope log(XO_DEBUG(config_.debug_flag_), xtag("data", data));
(void)iface;
Generation g1 = this->generation_of(Role::to_space(), data);
if (g1.is_sentinel()) {
assert(this->contains(Role::to_space(), data) == false);
Generation g2 = this->generation_of(Role::from_space(), data);
if (!g2.is_sentinel()) {
// verify failure - live pointer still refers to from-space
++(p_verify_stats->n_from_);
} else {
++(p_verify_stats->n_ext_);
}
} else {
assert(this->contains(Role::to_space(), data));
++(p_verify_stats->n_to_);
}
}
void
GCObjectStore::swap_roles(Generation upto) noexcept
{

View file

@ -13,6 +13,7 @@
#include <xo/alloc2/GCObjectVisitor.hpp>
#include <xo/alloc2/GCObject.hpp>
#include <xo/alloc2/Arena.hpp>
#include <xo/arena/print.hpp>
#include <xo/indentlog/scope.hpp>
#include <xo/indentlog/print/tag.hpp>
#include <xo/randomgen/xoshiro256.hpp>
@ -53,6 +54,8 @@ namespace ut {
explicit Testcase(uint32_t n_gen, uint32_t n_survive,
size_t gc_z, uint32_t type_z,
bool do_type_registration,
size_t report_z,
size_t error_z,
uint32_t n_test_obj,
uint32_t n_test_assign)
: n_gen_{n_gen},
@ -60,6 +63,8 @@ namespace ut {
gc_size_{gc_z},
object_type_z_{type_z},
do_type_registration_{do_type_registration},
report_size_{report_z},
error_size_{error_z},
n_test_obj_{n_test_obj},
n_test_assign_{n_test_assign}
{}
@ -80,20 +85,29 @@ namespace ut {
* (i.e. DBoolean)
**/
bool do_type_registration_ = false;
/** size for report-output arena **/
size_t report_size_ = 0;
/** size for error-output arena **/
size_t error_size_ = 0;
/** #of cells in random object graph **/
uint32_t n_test_obj_ = 0;
/** #of random assignments to attempt (these may create cycles, for example) **/
uint32_t n_test_assign_ = 0;
};
constexpr uint32_t c_report_z1 = 64 * 1024;
constexpr uint32_t c_error_z1 = 16 * 1024;
static std::vector<Testcase> s_testcase_v = {
/** n_gen, n_survive, gc_size, object_type_z, do_type_registration, n_obj **/
Testcase(2, 4, 16 * 1024, 8 * 128, false, 0, 0),
Testcase(2, 4, 16 * 1024, 8 * 128, true, 1, 0),
Testcase(2, 4, 16 * 1024, 8 * 128, true, 2, 0),
Testcase(2, 4, 16 * 1024, 8 * 128, true, 4, 0),
Testcase(2, 4, 16 * 1024, 8 * 128, true, 8, 4),
Testcase(2, 4, 16 * 1024, 8 * 128, true, 16, 7),
// note: report_z: 64k not sufficient for report_object_ages()
/** n_gen, n_survive, gc_size, object_type_z, do_type_registration, report_z, error_z, n_obj, n_test_assign **/
Testcase(2, 4, 16 * 1024, 8 * 128, false, c_report_z1, c_error_z1, 0, 0),
Testcase(2, 4, 16 * 1024, 8 * 128, true, c_report_z1, c_error_z1, 1, 0),
Testcase(2, 4, 16 * 1024, 8 * 128, true, c_report_z1, c_error_z1, 2, 0),
Testcase(2, 4, 16 * 1024, 8 * 128, true, c_report_z1, c_error_z1, 4, 0),
Testcase(2, 4, 16 * 1024, 8 * 128, true, c_report_z1, c_error_z1, 8, 4),
Testcase(2, 4, 16 * 1024, 8 * 128, true, c_report_z1, c_error_z1, 16, 7),
};
/** record capturing some stats for a (randomly created) gc-aware object **/
@ -300,6 +314,22 @@ namespace ut {
.with_size(tc.gc_size_ * tc.n_gen_)
.with_store_header_flag(true));
/** Arena for holding report output:
* See GCObjectStore methods .report_object_types(), .report_object_ages()
**/
DArena report_arena
= DArena::map(ArenaConfig().with_name("report-arena")
.with_size(tc.report_size_)
.with_store_header_flag(true));
obj<AAllocator,DArena> report_mm(&report_arena);
/** Arena for holding error messages **/
DArena error_arena
= DArena::map(ArenaConfig().with_name("error-arena")
.with_size(tc.error_size_)
.with_store_header_flag(true));
obj<AAllocator,DArena> error_mm(&error_arena);
// object type storage will be empty unless we install a type.
GCObjectStore gcos(gcos_config);
@ -611,6 +641,39 @@ namespace ut {
#endif
// - verify_ok
{
obj<AGCObject> report_gco;
bool ok = gcos.report_object_types(report_mm, error_mm, &report_gco);
REQUIRE(ok);
REQUIRE(report_gco);
// TODO: print report_gco, verify output
// discard report
report_gco.reset();
report_mm->clear();
}
{
obj<AGCObject> report_gco;
bool ok = gcos.report_object_ages(report_mm, error_mm, &report_gco);
if (!ok) {
log.retroactively_enable();
log && log(xtag("error", report_mm.last_error()));
}
REQUIRE(ok);
REQUIRE(report_gco);
// TODO: print report_gco, verify output
report_gco.reset();
report_mm->clear();
}
}
}