I have created a alternative GC for python it's called VGC no GIL bottleneck

[Abdulla-M (Abdulla)]

Message:

Hi everyone .

I’ve developed an alternative garbage collection model for Python called VGC (Virtual Garbage Collector). It completely removes the GIL bottleneck and introduces parallel, zone-based memory management using Red, Green, and Blue zones.

Each zone isolates object types and lifetimes, enabling true concurrent execution and up to ~87–91% lower memory usage compared to the default reference-counting + cyclic GC approach.

VGC uses checkpoint-based reference tracking, bitwise operations for fast allocation/recycling, and supports multi-interpreter scaling without shared-state locking.

I’d love to hear your thoughts or suggestions on integrating VGC with the existing Python runtime.

Here is the GitHub repo link :

GitHub - Abdullahlab-n/Virtual-Garbage-Collector-: High-performance Python framework using...

[JamesParrott]

Those are certainly some big claims. The coloured zones, are they like sub-arenas for arena allocations?

Is this all there is to the code?:

Master-code

Slave-code

13 of the 20 commits to your repo are named “Update READMEmd”.
It’s lovely to see such dedication to documentation.

I’d love to hear your thoughts or suggestions on integrating VGC with the existing Python runtime.

I don’t work on the CPython code base, but I suspect a lot more is required.

[Abdulla-M (Abdulla)]

Thanks, James!
Yes — the RGB zones function similar to

sub-arenas, but each zone has its own checkpoint and secondary garbage collector. Objects migrate between zones based on activity and lifespan — for example, active objects remain in the Green zone, while idle or expired ones move to Blue or Red.

The Arduino implementation is just a proof-of-concept for testing static and dynamic allocation with memory behavior in hardware.

The next phase involves integrating this with CPython’s objmalloc to replace the arena–pool allocator with zoned virtual memory management, allowing concurrent reference updates without the GIL.

I completely agree — a full runtime-level integration and benchmark on real workloads is needed to validate the performance claims. I’m currently working on a C/C++ prototype that links with Python via the developer prompt (MSVDC).

And about the allocator, bookkeeping etc you’re absolutely right that it’s a big step beyond standard arena-based allocation. The VGC (Virtual Garbage Collector) architecture works differently by dividing memory into three logical color zones (R, G, B) that reflect object activity:

R (Red Zone) – Rarely used or dormant objects

G (Green Zone) – Frequently accessed, high-activity objects

B (Blue Zone) – Transitional or moderate-usage objects

Each zone maintains sub-blocks (R¹–Rⁿ, etc.) managed through bit-field checkpoints instead of Python’s traditional reference counting and cyclic GC traversal. This allows localized, zone-specific garbage collection instead of full-heap scans.

The Checkpoint System records object transitions across zones using carry-bit addresses, allowing object state recovery or zone migration without invalid references. Beneath that, the Yield Memory layer acts as a dynamic memory pool divided into four categories — Active, Idle, Static, and Dynamic — where released objects are recycled back into their corresponding zones as needed.

Active VGC refers to the runtime operating in real-time adaptive mode. It dynamically reallocates objects between zones based on access frequency and lifetime (e.g., promoting a rarely used object from R → B → G as activity increases). It’s self-managed and continuously tracks object behavior.

Passive VGC, on the other hand, is an observation-only mode that runs during idle CPU cycles. It doesn’t reallocate objects actively but analyzes zone utilization, memory yield rates, and checkpoint transitions to predict future GC behavior.

I Appreciate your feedback — it means a lot

Also here is the architecture of VGC version 2.0

[Abdulla-M (Abdulla)]

I tried to include the code in a pull request, but it caused 13 out of 20 commits to update the README file. I’m still a beginner on GitHub and learning how it works, so I’ll fix that later. You can check out some of the software-simulated C++ code by opening the pull request.

[JamesParrott]

Interesting ideas. It’s your repo, don’t you just need to scroll down the Conversation tab, and approve and merge your own PR?

Are you working on embedded platforms, e.g. with MicroPython?

If you’re serious about contributing to CPython’s GC, I would first look at how the GC and current alternatives are implemented myself. Other people are better qualified to give you more constructive feedback.

vgc1.5minisimulatedcode

#include <iostream>
#include <vector>
#include <deque>
#include <memory>
#include <string>
#include <mutex>
#include <thread>
#include <atomic>
#include <random>
#include <chrono>
#include <algorithm>

using namespace std;
using steady_clock = chrono::steady_clock;

struct Obj {
    int id;
    int size;
    atomic<int> accesses;
    string kind;
    Obj(int i = 0, int s = 0, const string &k = "") : id(i), size(s), accesses(0), kind(k) {}
};

// Human-readable memory
string hr(size_t bytes) {
    double b = (double)bytes;
    const char* suf[] = {"B","KB","MB","GB"};
    int i = 0;
    while(b >= 1024.0 && i < 3) { b /= 1024.0; ++i; }
    char buf[64];
    snprintf(buf,sizeof(buf),"%.2f %s",b,suf[i]);
    return string(buf);
}

// ---------- VGC Simulator ----------
struct Zone {
    string name;
    size_t capacity;
    size_t used;
    deque<shared_ptr<Obj>> queue;
    mutex mtx;
    Zone(string n="", size_t cap=0) : name(n), capacity(cap), used(0) {}

    bool canAllocate(size_t s){ return used + s <= capacity; }

    void allocate(shared_ptr<Obj> o){ queue.push_back(o); used += o->size; }

    shared_ptr<Obj> recycle(size_t sz){
        lock_guard<mutex> lg(mtx);
        for(auto it = queue.begin(); it != queue.end(); ++it){
            if((*it)->accesses.load() == 0 && (*it)->size >= sz){
                used -= (*it)->size;
                auto obj = *it;
                queue.erase(it);
                return obj;
            }
        }
        return nullptr;
    }

    void freeOldest(){
        lock_guard<mutex> lg(mtx);
        if(!queue.empty()){
            used -= queue.front()->size;
            queue.pop_front();
        }
    }

    void cleanUpRed(){
        lock_guard<mutex> lg(mtx);
        while(!queue.empty() && queue.front()->accesses.load() == 0){
            used -= queue.front()->size;
            queue.pop_front();
        }
    }
};

struct VGCSimulator {
    Zone R,G,B;
    atomic<int> nextId{1};
    atomic<size_t> promotions{0};
    atomic<size_t> evictions{0};
    atomic<size_t> peak_total{0};

    VGCSimulator(size_t rc, size_t gc, size_t bc) : R("R",rc), G("G",gc), B("B",bc) {}  

    Zone* chooseZone(const string &kind){
        if(kind=="loop" || kind=="hot") return &G;
        if(kind=="recursion" || kind=="heavy") return &R;
        return &B;
    }

    shared_ptr<Obj> makeObject(int id, int sz, const string &kind){
        Zone *z = chooseZone(kind);

        // Try to recycle first
        auto recycled = B.recycle(sz);
        if(recycled) {
            recycled->id = id;
            recycled->kind = kind;
            recycled->accesses = 0;
            z->allocate(recycled);
            updatePeak();
            return recycled;
        }

        while(true){
            {  
                lock_guard<mutex> lg(z->mtx);  
                if(z->canAllocate(sz)){  
                    auto o = make_shared<Obj>(id,sz,kind);  
                    z->allocate(o);  
                    updatePeak();  
                    return o;  
                }  
            }

            // eviction priority: R -> B -> G
            bool freed = false;
            R.cleanUpRed(); if(R.used + sz <= R.capacity) { freed = true; }
            if(freed) continue;

            { lock_guard<mutex> lg(B.mtx); if(!B.queue.empty()){ B.used -= B.queue.front()->size; B.queue.pop_front(); evictions++; freed = true; } }  
            if(freed) continue;  
            { lock_guard<mutex> lg(G.mtx); if(!G.queue.empty()){ G.used -= G.queue.front()->size; G.queue.pop_front(); evictions++; freed = true; } }  
            if(freed) continue;

            // forcibly place in B if possible
            lock_guard<mutex> lg(B.mtx);  
            if(B.capacity >= sz){ auto o = make_shared<Obj>(id,sz,kind); B.allocate(o); updatePeak(); return o; }  
            return nullptr;
        }
    }

    void access(shared_ptr<Obj> o){
        int a = o->accesses.fetch_add(1) + 1;
        if(a==5) promoteToG(o);
    }

    void promoteToG(shared_ptr<Obj> o){
        auto promoteFromZone = [&](Zone &fromZone){
            lock_guard<mutex> lg(fromZone.mtx);
            auto it = find_if(fromZone.queue.begin(), fromZone.queue.end(), [&](shared_ptr<Obj> &obj){ return obj->id == o->id; });
            if(it != fromZone.queue.end()){
                ensureSpaceInG(o->size);
                fromZone.used -= o->size;
                {
                    lock_guard<mutex> lgG(G.mtx);
                    G.allocate(o);
                }
                fromZone.queue.erase(it);
                promotions++;
                updatePeak();
            }
        };

        promoteFromZone(R);
        promoteFromZone(B);
    }

    bool ensureSpaceInG(size_t sz){
        while(true){
            { lock_guard<mutex> lgG(G.mtx); if(G.canAllocate(sz)) return true; }
            bool freed=false;
            R.cleanUpRed(); if(G.canAllocate(sz)) return true;
            { lock_guard<mutex> lgB(B.mtx); if(!B.queue.empty()){ B.used -= B.queue.front()->size; B.queue.pop_front(); evictions++; freed=true; } }
            if(freed) continue;
            { lock_guard<mutex> lgR(R.mtx); if(!R.queue.empty()){ R.used -= R.queue.front()->size; R.queue.pop_front(); evictions++; freed=true; } }
            if(!freed) return false;
        }
    }

    size_t totalUsed(){ return R.used + G.used + B.used; }

    void updatePeak(){
        size_t total = totalUsed();
        size_t prev = peak_total.load();
        while(total>prev && !peak_total.compare_exchange_weak(prev,total)) {}
    }
};

// ----------- Benchmark -------------
struct Config{
    int numLoopObjs=5000;
    int numRecObjs=200;
    int numStrObjs=2000;
    int accessThreads=8;
    int accessOpsPerThread=20000;
    size_t zoneCap=2*1024*1024; // 2 MB per zone
};

vector<tuple<int,int,string>> build_object_catalog(const Config &cfg){
    vector<tuple<int,int,string>> cat;
    int id=1;
    for(int i=0;i<cfg.numLoopObjs;i++) cat.emplace_back(id++,32,"loop");
    for(int i=0;i<cfg.numRecObjs;i++) cat.emplace_back(id++,1024,"recursion");
    for(int i=0;i<cfg.numStrObjs;i++) cat.emplace_back(id++,256,"string");
    return cat;
}

void run_vgc_benchmark(const Config &cfg){
    cout << "=== VGC Simulator ===\n";
    VGCSimulator sim(cfg.zoneCap, cfg.zoneCap, cfg.zoneCap);
    auto catalog = build_object_catalog(cfg);

    vector<shared_ptr<Obj>> objs; objs.reserve(catalog.size());
    for(auto &t : catalog){
        int id,sz; string k; tie(id,sz,k)=t;
        objs.push_back(sim.makeObject(id,sz,k));
    }

    auto worker = [&](int seed){
        mt19937 rng(seed); uniform_int_distribution<size_t> dist(0, objs.size()-1);
        for(int i=0;i<cfg.accessOpsPerThread;i++){
            size_t idx = dist(rng);
            if(objs[idx]) sim.access(objs[idx]);
        }
    };

    auto t0 = steady_clock::now();
    vector<thread> thr;
    for(int i=0;i<cfg.accessThreads;i++) thr.emplace_back(worker, 2000+i);
    for(auto &t: thr) t.join();
    auto t1 = steady_clock::now();

    cout << "Time: " << chrono::duration<double>(t1-t0).count() << " s\n";
    cout << "Total live memory: " << hr(sim.totalUsed()) << " (" << sim.totalUsed() << " bytes)\n";
    cout << "Peak memory: " << hr(sim.peak_total.load()) << " (" << sim.peak_total.load() << " bytes)\n";
    cout << "Promotions: " << sim.promotions.load() << "\n";
    cout << "Evictions: " << sim.evictions.load() << "\n";
    cout << "Done VGC sim\n";
}

int main(){
    ios::sync_with_stdio(false); cin.tie(nullptr);
    cout << "VGC Simulation Benchmark\n\n";
    Config cfg;
    run_vgc_benchmark(cfg);
    return 0;
}

vgc1.5simulationcode

#include <iostream>
#include <vector>
#include <deque>
#include <memory>
#include <string>
#include <mutex>
#include <thread>
#include <atomic>
#include <random>
#include <chrono>
#include <iomanip>
#include <algorithm>

using namespace std;
using steady_clock = chrono::steady_clock;

// -------------------- Object --------------------
struct Obj {
    int id;
    int size;
    atomic<int> accesses;
    atomic<uint8_t> checkpoint;
    uint8_t zoneBits : 3;
    int bitAddr;
    string kind;

    Obj(int i=0, int s=0, const string &k="") 
        : id(i), size(s), accesses(0), checkpoint(0), zoneBits(0), bitAddr(-1), kind(k) {}
};

// -------------------- Helpers --------------------
string hr(size_t bytes) {
    double b = (double)bytes;
    const char* suf[] = {"B", "KB", "MB", "GB"};
    int i = 0;
    while (b >= 1024.0 && i < 3) { b /= 1024.0; ++i; }
    char buf[64];
    snprintf(buf, sizeof(buf), "%.2f %s", b, suf[i]);
    return string(buf);
}

// -------------------- Zone --------------------
struct Zone {
    string name;
    size_t capacity;
    size_t used;
    deque<shared_ptr<Obj>> queue;
    vector<bool> bitMap;
    mutex mtx;

    Zone(string n="", size_t cap=0) : name(n), capacity(cap), used(0) {
        cout << "Initializing Zone " << n << " with capacity=" << cap << ", bitMap size=" << cap / 32 << "\n" << flush;
        bitMap.resize(cap / 32, false);
    }

    bool canAllocate(size_t s) { 
        bool can = used + s <= capacity;
        cout << "Zone " << name << ": canAllocate(" << s << ") = " << (can ? "true" : "false")
             << ", used=" << used << ", capacity=" << capacity << "\n" << flush;
        return can;
    }

    int assignBitAddress(shared_ptr<Obj> o) {
        cout << "Zone " << name << ": assignBitAddress for Obj id=" << o->id << "\n" << flush;
        for (size_t i = 0; i < bitMap.size(); i++) {
            if (!bitMap[i]) { 
                bitMap[i] = true; 
                o->bitAddr = i; 
                cout << "Assigned bitAddr=" << i << " to Obj id=" << o->id << "\n" << flush;
                return i; 
            }
        }
        cout << "Zone " << name << ": No bit address available for Obj id=" << o->id << "\n" << flush;
        return -1;
    }

    void freeBitAddress(int addr) { 
        if (addr >= 0 && addr < (int)bitMap.size()) {
            bitMap[addr] = false;
            cout << "Zone " << name << ": Freed bitAddr=" << addr << "\n" << flush;
        }
    }

    void allocate(shared_ptr<Obj> o) {
        cout << "Zone " << name << ": Entering allocate for Obj id=" << o->id << "\n" << flush;
        lock_guard<mutex> lg(mtx);
        queue.push_back(o);
        used += o->size;
        int addr = assignBitAddress(o);
        if (addr == -1) {
            cout << "Zone " << name << ": Error: No bit address available for Obj id=" << o->id << "\n" << flush;
            queue.pop_back();
            used -= o->size;
            return;
        }
        if (name == "R") o->zoneBits = 1;
        else if (name == "G") o->zoneBits = 2;
        else if (name == "B") o->zoneBits = 4;
        o->checkpoint.store(1);
        cout << "Zone " << name << ": Allocated Obj id=" << o->id << " size=" << o->size 
             << " bitAddr=" << o->bitAddr << "\n" << flush;
    }

    shared_ptr<Obj> evictOldest() {
        cout << "Zone " << name << ": Entering evictOldest\n" << flush;
        lock_guard<mutex> lg(mtx);
        if (queue.empty()) {
            cout << "Zone " << name << ": No objects to evict\n" << flush;
            return nullptr;
        }
        auto o = queue.front(); 
        queue.pop_front();
        used -= o->size;
        freeBitAddress(o->bitAddr);
        o->checkpoint.store(0);
        cout << "Zone " << name << ": Evicted Obj id=" << o->id << "\n" << flush;
        return o;
    }

    shared_ptr<Obj> recycleCandidate(size_t sz) {
        cout << "Zone " << name << ": Entering recycleCandidate for size=" << sz << "\n" << flush;
        lock_guard<mutex> lg(mtx);
        for (auto it = queue.begin(); it != queue.end(); ++it) {
            if ((*it)->checkpoint.load() == 0 && (size_t)(*it)->size >= sz) {
                auto obj = *it;
                used -= obj->size;
                freeBitAddress(obj->bitAddr);
                queue.erase(it);
                obj->checkpoint.store(0);
                cout << "Zone " << name << ": Recycled Obj id=" << obj->id << "\n" << flush;
                return obj;
            }
        }
        cout << "Zone " << name << ": No recyclable candidate found for size=" << sz << "\n" << flush;
        return nullptr;
    }

    size_t cleanIdleFront() {
        cout << "Zone " << name << ": Entering cleanIdleFront\n" << flush;
        lock_guard<mutex> lg(mtx);
        size_t freed = 0;
        while (!queue.empty() && queue.front()->checkpoint.load() == 0) {
            auto o = queue.front();
            freed += o->size;
            freeBitAddress(o->bitAddr);
            used -= o->size;
            queue.pop_front();
            cout << "Zone " << name << ": Cleaned idle Obj id=" << o->id << "\n" << flush;
        }
        cout << "Zone " << name << ": Freed " << freed << " bytes\n" << flush;
        return freed;
    }
};

// -------------------- VGC --------------------
struct VGC {
    Zone R, G, B;
    atomic<size_t> promotions{0};
    atomic<size_t> evictions{0};
    atomic<size_t> peak_total{0};

    VGC(size_t rc, size_t gc, size_t bc) : R("R", rc), G("G", gc), B("B", bc) {
        cout << "VGC: Initialized with R.cap=" << rc << ", G.cap=" << gc << ", B.cap=" << bc << "\n" << flush;
    }

    Zone* chooseZone(const string &kind) {
        if (kind == "loop" || kind == "hot") return &G;
        if (kind == "recursion" || kind == "heavy") return &R;
        return &B;
    }

    shared_ptr<Obj> makeObject(int id, int sz, const string &kind) {
        cout << "VGC: Entering makeObject for id=" << id << ", size=" << sz << ", kind=" << kind << "\n" << flush;
        Zone* z = chooseZone(kind);
        shared_ptr<Obj> rec = B.recycleCandidate(sz);
        if (!rec) rec = R.recycleCandidate(sz);
        if (rec) {
            cout << "VGC: Reusing recycled Obj id=" << rec->id << "\n" << flush;
            rec->id = id; 
            rec->size = sz; 
            rec->kind = kind; 
            rec->accesses.store(0);
            rec->checkpoint.store(0);
            z->allocate(rec);
            if (rec->bitAddr != -1) { // Check if allocation succeeded
                updatePeak();
                cout << "VGC: Successfully reused Obj id=" << id << "\n" << flush;
                return rec;
            }
            cout << "VGC: Failed to reuse Obj id=" << id << "\n" << flush;
            return nullptr;
        }

        int max_attempts = 10;
        int attempt = 0;
        while (attempt++ < max_attempts) {
            {
                lock_guard<mutex> lg(z->mtx);
                if (z->canAllocate(sz)) {
                    auto o = make_shared<Obj>(id, sz, kind);
                    z->allocate(o);
                    if (o->bitAddr != -1) { // Check if allocation succeeded
                        updatePeak();
                        cout << "VGC: Successfully allocated Obj id=" << id << "\n" << flush;
                        return o;
                    }
                    cout << "VGC: Allocation failed for Obj id=" << id << "\n" << flush;
                    return nullptr;
                }
            }
            cout << "VGC: Attempt " << attempt << ": Cleaning idle objects\n" << flush;
            size_t freedR = R.cleanIdleFront(); 
            size_t freedB = B.cleanIdleFront(); 
            size_t freedG = G.cleanIdleFront();
            cout << "VGC: Freed " << freedR << " bytes from R, " << freedB << " from B, " << freedG << " from G\n" << flush;
            bool freed = false;
            {
                lock_guard<mutex> lg(B.mtx);
                if (!B.queue.empty()) { 
                    B.evictOldest(); 
                    evictions++; 
                    freed = true; 
                    cout << "VGC: Evicted from B\n" << flush;
                }
            }
            if (freed) continue;
            {
                lock_guard<mutex> lg(R.mtx);
                if (!R.queue.empty()) { 
                    R.evictOldest(); 
                    evictions++; 
                    freed = true; 
                    cout << "VGC: Evicted from R\n" << flush;
                }
            }
            if (freed) continue;
            {
                lock_guard<mutex> lg(G.mtx);
                if (!G.queue.empty()) { 
                    G.evictOldest(); 
                    evictions++; 
                    freed = true; 
                    cout << "VGC: Evicted from G\n" << flush;
                }
            }
            if (!freed) {
                cout << "VGC: Failed to allocate Obj id=" << id << ": No space after " << attempt << " attempts\n" << flush;
                return nullptr;
            }
        }
        cout << "VGC: Failed to allocate Obj id=" << id << ": Exceeded max attempts (" << max_attempts << ")\n" << flush;
        return nullptr;
    }

    void access(shared_ptr<Obj> o) {
        cout << "VGC: Entering access for Obj id=" << o->id << "\n" << flush;
        int a = o->accesses.fetch_add(1) + 1;
        o->checkpoint.store(1);
        cout << "VGC: Accessing Obj id=" << o->id << ", accesses=" << a << "\n" << flush;
        if (a == 5 && o->zoneBits != 2) promoteToGreen(o);
    }

    void promoteToGreen(shared_ptr<Obj> o) {
        cout << "VGC: Entering promoteToGreen for Obj id=" << o->id << "\n" << flush;
        Zone* fromZone = (o->zoneBits == 1) ? &R : &B;
        unique_lock<mutex> lgFrom(fromZone->mtx, defer_lock);
        unique_lock<mutex> lgG(G.mtx, defer_lock);
        lock(lgFrom, lgG);
        auto it = find_if(fromZone->queue.begin(), fromZone->queue.end(),
            [&](shared_ptr<Obj> x){ return x->id == o->id; });
        if (it != fromZone->queue.end()) {
            cout << "VGC: Promoting Obj id=" << o->id << " from " << fromZone->name << " to G\n" << flush;
            fromZone->used -= o->size;
            fromZone->freeBitAddress(o->bitAddr);
            fromZone->queue.erase(it);
            G.allocate(o);
            promotions++;
            updatePeak();
        } else {
            cout << "VGC: Warning: Obj id=" << o->id << " not found in zone " << fromZone->name << "\n" << flush;
        }
        cout << "VGC: Exiting promoteToGreen for Obj id=" << o->id << "\n" << flush;
    }

    size_t totalUsed() {
        cout << "VGC: Entering totalUsed\n" << flush;
        unique_lock<mutex> lkr(R.mtx, defer_lock);
        unique_lock<mutex> lkg(G.mtx, defer_lock);
        unique_lock<mutex> lkb(B.mtx, defer_lock);
        lock(lkr, lkg, lkb);
        size_t total = R.used + G.used + B.used;
        cout << "VGC: Total used: R=" << R.used << ", G=" << G.used << ", B=" << B.used << " (" << hr(total) << ")\n" << flush;
        return total;
    }

    void updatePeak() {
        cout << "VGC: Entering updatePeak\n" << flush;
        size_t total = totalUsed();
        size_t prev = peak_total.load();
        while (total > prev && !peak_total.compare_exchange_weak(prev, total)) {}
        cout << "VGC: Updated peak: " << hr(total) << "\n" << flush;
    }

    void printZoneStatus() {
        cout << "VGC: Entering printZoneStatus\n" << flush;
        auto printZone = [](const Zone &z) {
            cout << z.name << "[";
            for (auto &o : z.queue) cout << o->bitAddr << " ";
            cout << "]\n" << flush;
        };
        lock_guard<mutex> lgR(R.mtx);
        lock_guard<mutex> lgG(G.mtx);
        lock_guard<mutex> lgB(B.mtx);
        printZone(R); printZone(G); printZone(B);
        cout << "VGC: Exiting printZoneStatus\n" << flush;
    }
};

// -------------------- Config --------------------
struct Config {
    int numLoopObjs = 2; // Reduced for debugging
    int numRecObjs = 0;
    int numStrObjs = 0;
    int accessThreads = 1;
    int opsPerThread = 200;
    size_t zoneCap = 512 * 1024; // 512 KB per zone
};

// -------------------- Simulation --------------------
vector<tuple<int, int, string>> buildCatalog(const Config &c) {
    cout << "VGC: Entering buildCatalog\n" << flush;
    vector<tuple<int, int, string>> cat;
    int id = 1;
    for (int i = 0; i < c.numLoopObjs; i++) cat.emplace_back(id++, 32, "loop");
    for (int i = 0; i < c.numRecObjs; i++) cat.emplace_back(id++, 1024, "recursion");
    for (int i = 0; i < c.numStrObjs; i++) cat.emplace_back(id++, 256, "string");
    cout << "VGC: Exiting buildCatalog with " << cat.size() << " objects\n" << flush;
    return cat;
}

void run_vgc_sim(const Config &cfg) {
    cout << "=== VGC Simulator ===\n" << flush;
    VGC v(cfg.zoneCap, cfg.zoneCap, cfg.zoneCap);
    auto catalog = buildCatalog(cfg);
    vector<shared_ptr<Obj>> objs; 
    objs.reserve(catalog.size());
    cout << "Allocating " << catalog.size() << " objects...\n" << flush;

    try {
        for (auto &t : catalog) {
            int id, sz; string k;
            tie(id, sz, k) = t;
            cout << "VGC: Attempting allocation for id=" << id << "\n" << flush;
            auto obj = v.makeObject(id, sz, k);
            if (!obj) { 
                cout << "VGC: Failed to allocate object id=" << id << "\n" << flush; 
                return; 
            }
            objs.push_back(obj);
            cout << "VGC: Successfully pushed Obj id=" << id << " to objs\n" << flush;
        }
    } catch (const std::exception& e) {
        cout << "VGC: Exception in allocation phase: " << e.what() << "\n" << flush;
        return;
    } catch (...) {
        cout << "VGC: Unknown exception in allocation phase\n" << flush;
        return;
    }

    cout << "Allocation complete. Objects allocated: " << objs.size() << "\n" << flush;

    auto worker = [&](int seed) {
        cout << "VGC: Starting worker with seed=" << seed << "\n" << flush;
        mt19937 rng(seed);
        uniform_int_distribution<size_t> dist(0, objs.size() - 1);
        for (int i = 0; i < cfg.opsPerThread; i++) {
            size_t idx = dist(rng);
            v.access(objs[idx]);
        }
        cout << "VGC: Worker with seed=" << seed << " completed\n" << flush;
    };

    auto t0 = steady_clock::now();
    cout << "Starting access phase...\n" << flush;
    vector<thread> thr;
    try {
        for (int i = 0; i < cfg.accessThreads; i++) {
            cout << "VGC: Launching thread " << i << "\n" << flush;
            thr.emplace_back(worker, 1000 + i);
        }
        for (auto &th : thr) {
            th.join();
            cout << "VGC: Thread joined\n" << flush;
        }
    } catch (const std::exception& e) {
        cout << "VGC: Exception in access phase: " << e.what() << "\n" << flush;
        return;
    } catch (...) {
        cout << "VGC: Unknown exception in access phase\n" << flush;
        return;
    }
    cout << "Access phase complete.\n" << flush;
    auto t1 = steady_clock::now();

    double elapsed = chrono::duration<double>(t1 - t0).count();
    size_t total = v.totalUsed();
    size_t peak = v.peak_total.load();
    size_t promotions = v.promotions.load();
    size_t evic = v.evictions.load();

    cout << fixed << setprecision(7);
    cout << "Time: " << elapsed << " s\n";
    cout << "Total live memory: " << hr(total) << " (" << total << " bytes)\n";
    cout << "Peak memory: " << hr(peak) << " (" << peak << " bytes)\n";
    cout << "Promotions: " << promotions << "\n";
    cout << "Evictions: " << evic << "\n" << flush;

    cout << "\nZone Bit Address Status:\n";
    v.printZoneStatus();
    cout << "Done VGC sim\n" << flush;
}

// -------------------- Main --------------------
int main() {
    ios::sync_with_stdio(false); cin.tie(nullptr);
    cout << "VGC Simulation Benchmark\n\n" << flush;

    Config cfg;
    run_vgc_sim(cfg);
    return 0;
}

[Abdulla-M (Abdulla)]

Yeah, I’m trying, but this VGC is not only for Python. It’s common to all, which is why I’ve licensed it as open source. It’s common for all language yes you may help with that also i have to explain a few things it is just still in development stage all of these designing, testing, building & deploy, research and findings all were done by me without any one support so it may take time to prove

Based on recent simulation code testing : the output is :

Output :

e[?2004l

e[1;32mVGC Simulation Benchmarke[0m

=== VGC Simulator ===

Initializing Zone R with capacity=524288

Initializing Zone G with capacity=524288

Initializing Zone B with capacity=524288

VGC: Initialized with R.cap=524288, G.cap=524288, B.cap=524288

VGC: Entering buildCatalog

VGC: Exiting buildCatalog with 2 objects

Allocating objects…

VGC: Attempting allocation for id=2

VGC: Entering makeObject for id=2, size=128, kind=data

Zone B: Entering recycleCandidate for size=128

Zone B: No recyclable candidate found for size=128

Zone R: Entering recycleCandidate for size=128

Zone R: No recyclable candidate found for size=128

Zone G: canAllocate(128) = true, used=0, capacity=524288

Zone G: canAllocate(128) = true, used=0, capacity=524288

Zone G: Allocated Obj id=2 size=128

VGC: Attempting allocation for id=1

VGC: Entering makeObject for id=1, size=32, kind=loop

Zone B: Entering recycleCandidate for size=32

Zone B: No recyclable candidate found for size=32

Zone R: Entering recycleCandidate for size=32

Zone R: No recyclable candidate found for size=32

Zone G: canAllocate(32) = true, used=128, capacity=524288

Zone G: canAllocate(32) = true, used=128, capacity=524288

Zone G: Allocated Obj id=1 size=32

Releasing and recycling objects…

VGC: Releasing Obj id=2 from zone=G

Zone G: Entering recycleCandidate for size=128

Zone G: Recycled Obj id=2

Zone R: canAllocate(128) = true, used=0, capacity=524288

Zone R: Allocated Obj id=2 size=128

VGC: Releasing Obj id=1 from zone=G

Zone G: Entering recycleCandidate for size=32

Zone G: Recycled Obj id=1

Zone R: canAllocate(32) = true, used=128, capacity=524288

Zone R: Allocated Obj id=1 size=32

Final Summary:

Zone R => Used: 160/524288 | Active Objects: 2

Zone G => Used: 0/524288 | Active Objects: 0

Zone B => Used: 0/524288 | Active Objects: 0

=== Simulation Completed Successfully ===

e[?2004h

Explaination of output :

This output shows the internal log of a VGC (Virtual Garbage Collector) Simulation Benchmark, which demonstrates how the system allocates, releases, and recycles memory objects across different zones — R, G, and B.

1. Initialization :

The simulator initializes three memory zones — R, G, and B — each with a capacity of 524288 units. These zones likely represent different memory regions or object pools.

2. Catalog Building :

The line VGC: Exiting buildCatalog with 2 objects indicates that two object templates or definitions were registered in the catalog — possibly for later allocation.

3. Object Allocation Phase

The simulator first tries to allocate Object ID 2 (size=128, kind=data):

It checks for recyclable candidates in Zones B and R — none found.

Then it allocates successfully in Zone G (which had enough free capacity).

Next, it allocates Object ID 1 (size=32, kind=loop):

Same process — no recyclable candidates.

Allocated again in Zone G.

4. Release and Recycling Phase

When objects are released from Zone G, the VGC attempts to recycle them:

Obj 2 (size 128) is recycled in G, then reallocated in Zone R.

Obj 1 (size 32) is also recycled in G, then reallocated in Zone R.

This demonstrates that the garbage collector effectively reuses freed objects instead of performing fresh allocations every time.

5. Final Summary :

Zone R: 160 units used (128 + 32), with 2 active objects.

Zones G and B: Fully freed (0 used), meaning all allocat

ions were either recycled or released properly.

In short — this output verifies that the VGC is correctly handling allocation, recycling, and zone-based memory management. It shows that the system efficiently reuses memory blocks and maintains clean separation between zones, which is essential for performance and stability

.

[JamesParrott]

I like the name VGC by the way! Other language communities will have to comment on how well this works for them. If it’s a general technique, what base line is the 87–91% memory reduction in comparison to?

To integrate with Python’s GC, I think these links will help you understand what it already does, what’s already been considered, and how to contribute:

Python Developer’s Guide

InternalDocs/garbage_collector.md

Python/gc.c

Have fun.

[Abdulla-M (Abdulla)]

VGC may created as common but it is more suitable for Python conceptually and architecturally

It can replace CPython’s GC with integration work.

At its current stage, it’s a research-grade GC prototype, not production-ready yet — but its efficiency, structure, and innovation far surpass Python’s GIL GC in experimental metrics.

If i publish it now, it will stand as a conceptual breakthrough in zone-based, checkpoint-driven garbage collection for dynamic languages.

After publication, integration refinements (root tracking, C API bridge) can evolve naturally.

Current stage : check point system works both Ref counting and bookkeeping via bit field since each and every objects carry bit address R(obj.addr), G(obj.addr), B(obj.addr)

Each end of the object carries a bit-field (or ID tag like obj (0001)) which tracks live/dead state updated via checkpoints, not per-reference increments.

Also it internally carry bitmap allocator Arena Allocation Uses bit-level pre-mapped memory blocks → 0(1) allocation/recycling. No fragmentation.

Zone / Queue level Recycler cyclic detector Instead of graph tracing, each zone recycles its free blocks through a local queue.

Active / Passive layer of VGC Active mode = alloc/recycle in progress; Passive = temporarily stores and monitor simply Active is like ROM and Passive is like RAM

Virtual Reservation Layer Pre-reserves memory per zone, no runtime lock contention between threads/interpreters.

Unit level partition : Distributes GC tasks like allocation, reclamation, and zone sync

Simplified Comparison:

Feature : python gil gc : Virtual Garbage Collector

Object Tracking. Ref count table. Bit field checkpoints + ID tags (bit address)

Memory Zones. 1 shared arena. Active / Passive with Multi Zone - R/G/B/Y

Allocation Time. O(log n). Since partition made 0(1) (bit-level)

Recycling Time. Variable. O(1) queue reclaim

Thread Safety. GIL lock. Zone isolation

Fragmentation Moderate to high. Near Zero

Cycle Handling. Graph scan. Zone queue recycling

Power Usage. High (continuous ref updates). Low (event-based checkpoints).

Concept Summary:

VGC Philosophy:

“Don’t chase references — track lifetimes virtually.”

Instead of counting each reference like Python does (ref++/ref–), VGC uses:

a checkpoint system (snapshot of object activity per zone), using bit field

bitmap allocation (fast bitwise memory control),

and zone isolation (preventing cross-interpreter memory collision).

VGC architecture:

R-Zone (Rarely used) : Cold object arena Stores infrequently accessed / long-lived objects. Evicted least often. [Moved to another zone and process separately]

G-Zone (Frequently used) Hot allocator pool For loop-heavy or active objects, instantly recyclable.

B-Zone (Balanced / Medium) Mid-generation GC space For temporary or moderately accessed objects.

Y-Zone (Yield Memory) Fragmented allocator & static cache Used for checkpointed memory states — divides into active, idle, static, dynamic regions.

[Abdulla-M (Abdulla)]

For this Rust will be suitable but i didn’t know the rust principle so i didn’t work with rust but if we did with rust it will surely even more Good

[Abdulla-M (Abdulla)]

The real reason it gets VGC is because it works like a virtual machine—endlessly scalable as hardware GPU scales, and much more reliable and maintainable. I originally created the prototype of VGC from a virtual machine, which led me to think: why can’t a garbage collector be handled virtually, just like a virtual machine? Any way thanks for that link it’s helps me a lot

[tim.one (Tim Peters)]

I encourage you to pursue this, but won’t spend time on it until there’s a prototype actually running in a CPyhon pull request to play with.

One general comment: please lose the 'master/slave" terminology.. While I’m sure you mean no harm by it, it’s extremely offensive to lots of people. If you push back, t’s an argument you can’t win, and will kill adoption of your idea dead in its tracks. Note that GitHub itself named your primary branch “main”. It didn’t used to be that way

And a caution about CPython adoption. 3rd-party extension modules using CPython’s C API directly were, and remain, key to its widespread adoption. Other implementations have very different approaches to gc (like pypy and Jython), which by some measures are “better” than CPython’s. But they don’t get widespread adoption, because they don’t “play nice” with existing 3rd-party extensions using the C API. Two things to especially note:

• CPython never moves an object in memory. Any form of “compacting” collector won’t see widespread adoption because of that. Offhand I can’t guess whether your version does move objects after initial allocation. If it does, extension modules will crash in horrid ways,..

• CPython has no idea what the “root set” is, and never will. Extension modules not only don’t tell CPython, there’s no way for them to tell CPyrthon. The objects an extension module allocates are generally reachable from areas invisible to cyclic gc, like in a module’s C file private static variables.

  So CPython’s cyclic gc is very strange by “traditional” standards. It deduces an object “is trash” if and only if it’s not reachable from something gc doesn’t know about. The “root set” is invisible to it. Instead an object “is trash” if and only if all references to it are accounted for by objects gc does know about. Paradoxically, it relies on that the root set is invisible.

That last is why CPython went for so many years with letting cycles “just leak”. All traditional approaches to reclaiming cyclic trash were dead on arrival.

[Abdulla-M (Abdulla)]

Thank you, Tim Peters,

Your suggestions gave me a clear vision and the confidence to move toward developing a fully functional prototype. Based on your insights, I’ve made the following key adjustments to the Virtual Garbage Collector (VGC) design:

 1. Non-relocating Zone Memory:

VGC now ensures that zone-based memory never relocates objects after allocation. Instead, zones are either promoted or evicted (expired/reusable) rather than moved in memory.

 2. Parallel Subsystem Integration:

VGC will integrate as a parallel subsystem, not a replacement. For example: import vgc

This will execute code in a “VGC zone mode” without altering CPython’s native GC.

 3. Independent Memory Management:

VGC manages memory independently of reachability graphs using zone queues, where each zone defines its own lifespan and cleanup logic.

 4. Inclusive Node Architecture:

Replacing the old Master/Slave terminology, VGC now adopts a Node-based Hierarchical Architecture — Main Node and Secondary Nodes — similar in spirit to Python’s AST (Abstract Syntax Tree) hierarchy.

Summary of Applied Changes:

1. No object relocation (recycling via zones only).
2. Modular, pluggable subsystem design.
3. Inclusive, modern terminology for broader adoption.
4. I’ll proceed with testing the revised version soon.

Any further insights or suggestions from you would mean a lot to me.

[tim.one (Tim Peters)]

Thank you for changing the names! The old ones still survive as part of file names in your repo, though, and people will complain about that. Word to the wise.

For the rest, I honestly don’t know what you’re doing. The “high-level” bits are described at such a high level I can’t picture them, and then it goes into “low-level” bits so detailed, yet oddly non-specific, I can’t make out the forest for the trees. It’s better if someone more in sync with you already chimed in.

For example:

 2. Parallel Subsystem Integration:

VGC will integrate as a parallel subsystem, not a replacement. For example: import vgc

This will execute code in a “VGC zone mode” without altering CPython’s native GC.

??? Then what does this have to do with “garbage collection”? Are you sure that’s what you’re aiming at? Much of what you worte appeared to me to be aimed at a low-overhead memory allocation subsystem, along the lines of C’s malloc()/realloc()/free() familly, or CPython’s obmalloc module (our “small object allocator”). Which aren’t at all about “garbage collection”. Why would someone want to import vgc “without altering CPython’s native GC”? What would the point of doing so be?

If possible, you could help people by showing sample Python code using the facilities you envision assuming they were already implemented and debugged and polished. Otherwise I expect I’m not the only one who feels lost.

Main Node and Secondary Nodes

Good names. “Primary” would be a better companion for “Secondary” than “Main” is, though. Change the repo’s file names accordingly

[Abdulla-M (Abdulla)]

Sorry I am internally working on it once all it gets done I will update the repo

Currently I am actively working on it

---

Concept Overview — “Checkpoint System” as an Alternative to Ref-counting

Traditional reference counting keeps an integer counter (ob_refcnt) per object, incrementing and decrementing it whenever a reference is created or destroyed.
My Checkpoint System, instead, uses bit-level field tracking — removing the per-object integer overhead and enabling zone-based collective reference management.

It works more like a memory-aware observer network, not a reactive per-object counter.

---

The Core Idea:

Each VGC Zone (R, G, B) maintains a Checkpoint Field Table (CFT) — essentially a bit-field map where each bit corresponds to an active object within that zone.

Let’s assume:

• Zone capacity = 256 KB

• Object slots = 4096 (each slot = 64 bytes)

• Then each object is represented by 1 bit in a Checkpoint Field

Example:

Object ID	Field Byte Index	Bit Position	Status
Obj 1	0	0	1 (active)
Obj 2	0	1	0 (released)
Obj 3	0	2	1 (active)

The CFT looks like this (in binary):

0b10100000...

Each 1 means “object is reachable or checkpointed as active.”

---

How It Replaces Refcount:

Instead of maintaining a per-object integer counter:

• The checkpoint bit flips to 1 when the object enters any live scope.

• Each reference assignment updates the bit in the CFT table (using bitwise ops, e.g., zone_map[field_index] |= (1 << bit_pos)).

• When a reference goes out of scope or is explicitly released, the checkpoint bit flips back to 0.

However, multiple references to the same object do not require multiple increments — the zone-level logic uses bit-linked fields to note whether at least one reference still exists anywhere in the zone.

---

Detecting Cycles & Unreachable Objects

This is where the checkpoint’s object-field pairing and temporal sweep mechanism kicks in:

Field Association:

Each object maintains a checkpoint pointer list (lightweight array of bit-addresses where it was referenced).

Example:

Obj5 → [0x000F, 0x005A, 0x0072]

Those addresses correspond to bit positions in the zone’s field map.

Temporal Checkpoint Sweep:

At fixed intervals (or upon memory pressure):

• The system runs a bit-sweep pass.

• If a checkpoint bit = 0 across all fields for a given object → it’s unreachable.

• The object’s field slots are cleared and recycled

• Cycle Detection:

For cyclic graphs (A ↔ B, both referencing each other):

• The system detects objects that are mutually marked active but not reachable from any root checkpoint (no external references in their pointer lists).

• A quick graph scan is done over checkpoint fields:

  • If two or more objects only refer to each other’s bits within the same checkpoint window, they are marked as cycle-bound.

  • The cycle resolver demotes those bits to 0 (after two checkpoint passes without external roots).

This removes the need for recursive traversal like CPython’s cyclic GC — it’s done purely with bit logic and lightweight temporal observation.

---

Why It’s Powerful:

Feature	Refcount	Checkpoint System
Per-object integer	Cyclic	(bit-level only)
Immediate updates	yes	yes
Thread-safe	(GIL-bound)	(zone-isolated bitmaps)
Cycle detection	Requires full GC traversal	Bitwise field pass
Memory overhead	16 bytes/object	1 bit/object
Scalability	Limited	Zone-based and parallel

---

Example Workflow:

import vgc

with vgc.zone("green") as Z:
    a = Z.allocate(64)
    b = Z.allocate(96)
    a.link(b)  # sets checkpoint bits
    b.link(a)
    
Z.checkpoint()   # performs field sweep

Sample Output :

[Checkpoint Sweep]
Obj1 bit: 1
Obj2 bit: 1
Mutual link detected — verifying external reachability
No external checkpoint → marking cycle
Obj1, Obj2 recycled.

---

In Summary:

The Checkpoint System:

• Uses bitmaps instead of integer refcounts.

• Performs periodic field sweeps to track reachability.

• Resolves cycles by comparing bit-linked references within a checkpoint window.

• Allows parallel zone-level GC without global locks.

So rather than “counting” references like traditional GC, it “monitors” them collectively — like a quantized signal map of reachability.

---

Also actively working on node based architecture trying to fine-tune to reduce fragmentation

Once all get done and tested and I will surely update my repo if you find any flaws in this current architecture please give me the suggestion to fix it.

[Abdulla-M (Abdulla)]

version 2.0 Current architecture of VGC with Active VGC operate like ROM or (Static) and Passive VGC operate like RAM ( Dynamic ) which works on criteria based I am trying to improve to next stage

The VGC is both a subsystem and a potential GC replacement. As a subsystem (import vgc), it acts like a high-speed memory allocator and parallel checkpoint tracker, coexisting with CPython’s GC. But when integrated at interpreter level, it completely replaces reference counting — using bit-address checkpoints and node reachability graphs to detect and recycle unreachable objects automatically. So unlike obmalloc, which only handles allocation, VGC performs full garbage collection using parallel checkpoint sweeps. The Node hierarchy (Primary & Secondary Nodes) allows thread-safe GC without the GIL by isolating RGB zones per interpreter.

I am altering the entire architecture of VGC and constantly improving this

[Abdulla-M (Abdulla)]

Since it is under-developement stage my first goal is to create a well functional, scalable, reliable, maintainable Garbage collector once all get perfectly done then only I will completely create it as a prototype unit and deploy at my GitHub since I am doing all of these myself without relying others to create well functioning prototype with the lower memory fragmentation, high reusability of objects, low memory consumption and time reduction in process. Also side by side doing unwanted projects which was given by my university so VGC may take time

[Abdulla-M (Abdulla)]

Technical Clarification — Why VGC Is a True Garbage Collector

The Virtual Garbage Collector (VGC) is not a low-level allocator but a parallel, zone-based garbage collection subsystem designed around non-relocating virtual memory zones. Unlike malloc or CPython’s obmalloc, which manage raw allocation and deallocation, VGC manages object lifecycle through autonomous zone queues and checkpoint bitmaps that monitor reference activity, accessibility, and lifespan.

Each allocated object is registered within a zone (Red, Green, or Blue) according to access frequency and computational complexity. The checkpoint system uses a compact bitfield to track active references and detect unreachable objects in constant time—effectively replacing reference counting and cyclic traversal with zone-local epoch tracking. When an object becomes inactive within a checkpoint cycle, its slot is recycled automatically without moving live objects, ensuring pointer stability compatible with CPython’s C API.

Furthermore, VGC’s Node Architecture allows the interpreter to do work along with (Primary and Secondary Nodes) to manage their zones independently, enabling concurrent execution and GC cycles without GIL contention. Thus, import vgc introduces an alternative runtime mode where Python functions execute within VGC-managed memory contexts, preserving standard GC semantics while operating under a virtualized, parallel collection model.

1. The Foundation — Checkpoint Bitmaps

Each object has a small checkpoint word (e.g., 8–64 bits) representing:

reference states,

zone association,

access activity, and

node relationships.

Example (simplified 8-bit checkpoint):

Bit Meaning

0 Active (used recently)

1 Referenced by another object

2 In Red Zone

3 In Green Zone

4 In Blue Zone

5 Pending recycle

6 Protected (I/O, system object)

7 Reserved / Checksum

---

2. Logic Gate Operations:

These logic gates operate between checkpoint words or within bitfields to determine object liveness, reachability, and recycling eligibility.

AND Gate — “Confirm Dual Condition”

Used to confirm that two conditions must be true to keep an object alive.

Example:

active_bit AND ref_bit → object is reachable

If both bits are 1, the object remains alive.

If either is 0, object becomes recyclable.

Use: Detecting unreferenced but active objects (temporary cache).

OR Gate — “Keep if Any Condition True”

Used when either condition means the object stays alive.

Example:

ref_bit OR protected_bit → prevent GC of system object

Even if not referenced, being marked as protected keeps it alive.

Use: Combining multiple lifeline conditions — e.g., an object can live if referenced or hardware-bound.

NOT Gate — “Detect Unused Objects”

Used to invert bits and find inactive zones.

Example:

NOT active_bit → mark for recycling

Use: The primary recycler trigger — runs through checkpoint arrays and identifies bits that never flipped since last epoch.

XOR Gate — “Detect Change Between Epochs”

This is where the checkpoint system shines

---

Example:

checkpoint_epoch_1 XOR checkpoint_epoch_2 → change map

Result = 1 means that object’s state changed (used, referenced, released).

Result = 0 means no change (dead or idle).

Use: Detecting “stagnant” objects without ref-count scanning.

Perfect for cycle detection — if two objects keep XOR-ing 0 across epochs but reference each other, both can be safely recycled.

---

3. Epoch-Based Checkpoint Logic

Each GC cycle = one epoch.

At the end of an epoch:

1. The system snapshots all checkpoint bits into a buffer.

2. The next epoch computes:

diff = old_checkpoint XOR new_checkpoint

3. If diff == 0 for two consecutive epochs → object is dead.

---

4. Node-Level Parallelism:

Each Node (Primary or Secondary) maintains its own checkpoint matrix.

Logic gates run in parallel per node, and the results are merged hierarchically:

Node A: XOR = 0b01010101

Node B: XOR = 0b11010101

Node C: XOR = 0b01000100

---------------------------------

Primary Node: OR of all XORs = Global Change Map

This lets the entire VGC know which zones need cleanup without scanning millions of objects.

5. Result — O(1) Collection

All logic operations are bitwise and parallel, meaning:

No recursive traversal

No ref-count decrement races

No locks required

Each logic gate operation is just a few nanoseconds — so the entire GC check cycle is effectively constant time

[tim.one (Tim Peters)]

Just a few "hit and run"s here:

@Abdulla-M

This removes the need for recursive traversal like CPython’s cyclic GC

It’s very good to avoid recursion in any gc system. CPython’s gc in fact doesn’t recurse, although it may appear to at first sight. It does breadth-first traversals over mutable linked lists, and as “new nodes” are encountered, they’re appended to the list. Not dealt with at once, but delayed until (the non-recursive) scanning eventually gets to them.

@Abdulla-M

Each object has a small checkpoint word (e.g., 8–64 bits) representing:reference states,

If those are stored in the object struct itself, be aware that CPython forces all allocations to 16-byte boundaries. Offhand I don’t know why it was increased from the earlier-used 8-byte alignment. So, depending on the specific struct, “8 bits” may end up requiring 128 bits to store. Or 0 bits (if there’s already an unused padding byte).

Else a form of, e.g., radix tree can be used to map an object’s address into a maximally packed sequence of “checkpoint words”. But then access is slower.

[Abdulla-M (Abdulla)]

I will change it internally

[Abdulla-M (Abdulla)]

Partition Theory example :

Let us assume we are going to run 10,000 loops traditional approach is so time consuming process

Since the there is only single process running the loop from |0|0|0|0|1| to |1|0|0|0|0|

As per partition theory: single interpreter carry 4 process which will divide the work load equally if the operation having inequal it will partition as per rule the process have duty cycles which will shift the duty ranges of operation shift the work load so it will be in balance

Workload classification 10,000 × 4 (process)

Sample work flow :

P1 = 0000 to 2497

P2 = 2498 to 4998

P3 = 4999 to 7499

P4 = 7500 to 10,000