diff --git a/uppsrc/Core/App.cpp b/uppsrc/Core/App.cpp
index 297713d24..5ffbace2f 100644
--- a/uppsrc/Core/App.cpp
+++ b/uppsrc/Core/App.cpp
@@ -416,7 +416,9 @@ void AppInit__(int argc, const char **argv)
 void AppExit__()
 {
 #ifdef _MULTITHREADED
+#ifndef COWORK2
 	Thread::ShutdownThreads();
+#endif
 #endif
 	sMainRunning = false;
 #ifdef PLATFORM_POSIX
diff --git a/uppsrc/Core/CoWork.cpp b/uppsrc/Core/CoWork.cpp
index 302734301..f0f75250d 100644
--- a/uppsrc/Core/CoWork.cpp
+++ b/uppsrc/Core/CoWork.cpp
@@ -2,6 +2,8 @@
 
 NAMESPACE_UPP
 
+#ifndef COWORK2
+
 #ifdef _MULTITHREADED
 
 #define LLOG(x)      // DLOG(x)
@@ -252,4 +254,6 @@ CoWork::~CoWork()
 
 #endif
 
+#endif
+
 END_UPP_NAMESPACE
diff --git a/uppsrc/Core/CoWork.h b/uppsrc/Core/CoWork.h
index 715c4c437..21c2f94a8 100644
--- a/uppsrc/Core/CoWork.h
+++ b/uppsrc/Core/CoWork.h
@@ -1,5 +1,83 @@
 #ifdef _MULTITHREADED
 
+#define COWORK2
+
+#ifdef COWORK2
+
+class CoWork : NoCopy {
+	struct MJob : Moveable<MJob>, Link<MJob, 2> {
+		Function<void ()> fn;
+		CoWork           *work = NULL;
+	};
+	
+	enum { SCHEDULED_MAX = 2048 };
+
+public:
+	struct Pool {
+		MJob             *free;
+		Link<MJob, 2>     jobs;
+		MJob              slot[SCHEDULED_MAX];
+		int               waiting_threads;
+		Array<Thread>     threads;
+		bool              quit;
+
+		Mutex             lock;
+		ConditionVariable waitforjob;
+		
+		void              Free(MJob& m);
+		void              DoJob(MJob& m);
+		void              PushJob(Function<void ()>&& fn, CoWork *work);
+
+		Pool();
+		~Pool();
+		
+		static thread__ bool finlock;
+
+		bool DoJob();
+		static void ThreadRun(int tno);
+	};
+	
+	friend struct Pool;
+
+	static Pool& GetPool();
+
+	static thread_local bool is_worker;
+
+//	byte magic[sizeof(ConditionVariable)];
+	ConditionVariable waitforfinish;
+	Link<MJob, 2> jobs;
+	int todo;
+
+	Mutex stepmutex;
+	Array<BiVector<Function<void ()>>> step;
+	Vector<bool> steprunning;
+	
+public:
+	static void Start(Function<void ()>&& fn);
+
+	void     Do(Function<void ()>&& fn);
+	void     Do(const Function<void ()>& fn)                  { Do(clone(fn)); }
+
+	CoWork&  operator&(const Function<void ()>& fn)           { Do(fn); return *this; }
+	CoWork&  operator&(Function<void ()>&& fn)                { Do(pick(fn)); return *this; }
+
+	void Pipe(int stepi, Function<void ()>&& lambda); // experimental
+
+	static void FinLock();
+
+	void Finish();
+	
+	bool IsFinished();
+
+	static bool IsWorker()                                    { return is_worker; }
+//	static void StartPool(int n);
+//	static void ShutdownPool();
+
+	CoWork();
+	~CoWork();
+};
+
+#else
 class CoWork : NoCopy {
 	typedef StaticCriticalSection Lock;
 
@@ -74,6 +152,8 @@ public:
 	~CoWork();
 };
 
+#endif
+
 #else
 
 class CoWork : NoCopy {
diff --git a/uppsrc/Core/CoWork2.cpp b/uppsrc/Core/CoWork2.cpp
new file mode 100644
index 000000000..1252db5fc
--- /dev/null
+++ b/uppsrc/Core/CoWork2.cpp
@@ -0,0 +1,238 @@
+#include "Core.h"
+
+#ifdef COWORK2
+
+#include "Core.h"
+
+NAMESPACE_UPP
+
+#ifdef _MULTITHREADED
+
+#define LLOG(x)       DLOG(x)
+#define LDUMP(x)      DDUMP(x)
+
+#define LHITCOUNT(x) // RHITCOUNT(x)
+
+thread_local bool CoWork::Pool::finlock;
+thread_local bool CoWork::is_worker;
+
+CoWork::Pool& CoWork::GetPool()
+{
+	static CoWork::Pool pool;
+	return pool;
+}
+
+void CoWork::Pool::Free(MJob& job)
+{
+	job.link_next[0] = free;
+	free = &job;
+}
+
+CoWork::Pool::Pool()
+{
+	ASSERT(!is_worker);
+
+	int nthreads = CPU_Cores() + 2;
+	LLOG("CoWork INIT pool: " << nthreads);
+	for(int i = 0; i < nthreads; i++)
+		threads.Add().Run([=] { is_worker = true; ThreadRun(i); });
+
+	free = NULL;
+	for(int i = 0; i < SCHEDULED_MAX; i++)
+		Free(slot[i]);
+	
+	quit = false;
+}
+
+CoWork::Pool::~Pool()
+{
+	ASSERT(!IsWorker());
+	LLOG("Quit");
+	lock.Enter();
+	quit = true;
+	lock.Leave();
+	for(int i = 0; i < threads.GetCount(); i++) {
+		waitforjob.Broadcast();
+		threads[i].Wait();
+	}
+	for(int i = 0; i < SCHEDULED_MAX; i++)
+		slot[i].LinkSelf();
+	LLOG("Quit ended");
+}
+
+void CoWork::FinLock()
+{
+	Pool::finlock = true;
+	GetPool().lock.Enter();
+}
+
+void CoWork::Pool::DoJob(MJob& job)
+{
+	job.UnlinkAll();
+	LLOG("DoJob (CoWork " << FormatIntHex(job.work) << ")");
+	finlock = false;
+	Function<void ()> fn = pick(job.fn);
+	Free(job);
+	CoWork *work = job.work;
+	lock.Leave();
+	fn();
+	if(!finlock)
+		lock.Enter();
+	if(!work)
+		return;
+	if(--work->todo == 0) {
+		LLOG("Releasing waitforfinish of (CoWork " << FormatIntHex(work) << ")");
+		work->waitforfinish.Signal();
+	}
+	LLOG("DoJobA, todo: " << work->todo << " (CoWork " << FormatIntHex(work) << ")");
+	ASSERT(work->todo >= 0);
+	LLOG("Finished, remaining todo " << work->todo);
+}
+
+void CoWork::Pool::ThreadRun(int tno)
+{
+	LLOG("CoWork thread #" << tno << " started");
+	Pool& p = GetPool();
+	p.lock.Enter();
+	for(;;) {
+		while(!p.jobs.InList()) {
+			LHITCOUNT("CoWork: Parking thread to Wait");
+			p.waiting_threads++;
+			LLOG("#" << tno << " Waiting for job");
+			p.waitforjob.Wait(p.lock);
+			LLOG("#" << tno << " Waiting ended");
+			p.waiting_threads--;
+			if(p.quit) {
+				p.lock.Leave();
+				return;
+			}
+		}
+		LLOG("#" << tno << " Job acquired");
+		LHITCOUNT("CoWork: Running new job");
+		p.DoJob(*p.jobs.GetNext());
+		LLOG("#" << tno << " Job finished");
+	}
+	p.lock.Leave();
+	LLOG("CoWork thread #" << tno << " finished");
+}
+
+void CoWork::Pool::PushJob(Function<void ()>&& fn, CoWork *work)
+{
+	ASSERT(free);
+	MJob& job = *free;
+	free = job.link_next[0];
+	job.LinkAfter(&jobs);
+	if(work)
+		job.LinkAfter(&work->jobs, 1);
+	job.fn = pick(fn);
+	job.work = work;
+	LLOG("Adding job");
+	if(waiting_threads) {
+		LLOG("Releasing thread waiting for job, waiting threads: " << waiting_threads);
+		waitforjob.Signal();
+	}
+}
+
+void CoWork::Start(Function<void ()>&& fn)
+{
+	Pool& p = GetPool();
+	Mutex::Lock __(p.lock);
+	while(!p.free) { // this is quite unlikely, so we can be ugly here
+		p.lock.Leave();
+		Sleep(0);
+		p.lock.Enter();
+	}
+	p.PushJob(pick(fn), NULL);
+}
+
+void CoWork::Do(Function<void ()>&& fn)
+{
+	LHITCOUNT("CoWork: Sheduling callback");
+	Pool& p = GetPool();
+	p.lock.Enter();
+	if(!p.free) {
+		LLOG("Stack full: running in the originating thread");
+		LHITCOUNT("CoWork: Stack full: Running in originating thread");
+		p.lock.Leave();
+		fn();
+		if(Pool::finlock)
+			p.lock.Leave();
+		return;
+	}
+	p.PushJob(pick(fn), this);
+	todo++;
+	p.lock.Leave();
+}
+
+void CoWork::Finish() {
+	Pool& p = GetPool();
+	p.lock.Enter();
+	while(!jobs.IsEmpty(1)) {
+		LLOG("Finish: todo: " << todo << " (CoWork " << FormatIntHex(this) << ")");
+		p.DoJob(*jobs.GetNext(1));
+	}
+	while(todo) {
+		LLOG("WaitForFinish (CoWork " << FormatIntHex(this) << ")");
+		waitforfinish.Wait(p.lock);
+	}
+	p.lock.Leave();
+	LLOG("CoWork " << FormatIntHex(this) << " finished");
+}
+
+bool CoWork::IsFinished()
+{
+	Pool& p = GetPool();
+	p.lock.Enter();
+	bool b = jobs.IsEmpty(1);
+	p.lock.Leave();
+	return b;
+}
+
+void CoWork::Pipe(int stepi, Function<void ()>&& fn)
+{
+	Mutex::Lock __(stepmutex);
+	auto& q = step.At(stepi);
+	LLOG("Step " << stepi << ", count: " << q.GetCount() << ", running: " << steprunning.GetCount());
+	q.AddHead(pick(fn));
+	if(!steprunning.At(stepi, false)) {
+		steprunning.At(stepi) = true;
+		*this & [=]() {
+			LLOG("Starting step " << stepi << " processor");
+			stepmutex.Enter();
+			for(;;) {
+				Function<void ()> f;
+				auto& q = step[stepi];
+				LLOG("StepWork " << stepi << ", todo:" << q.GetCount());
+				if(q.GetCount() == 0)
+					break;
+				f = pick(q.Tail());
+				q.DropTail();
+				stepmutex.Leave();
+				f();
+				stepmutex.Enter();
+			}
+			steprunning.At(stepi) = false;
+			stepmutex.Leave();
+			LLOG("Exiting step " << stepi << " processor");
+		};
+	}
+}
+
+CoWork::CoWork()
+{
+	LLOG("CoWork constructed " << FormatHex(this));
+	todo = 0;
+}
+
+CoWork::~CoWork()
+{
+	Finish();
+	LLOG("~CoWork " << FormatIntHex(this));
+}
+
+#endif
+
+END_UPP_NAMESPACE
+
+#endif
+
diff --git a/uppsrc/Core/Core.upp b/uppsrc/Core/Core.upp
index 907b6c093..5db210d34 100644
--- a/uppsrc/Core/Core.upp
+++ b/uppsrc/Core/Core.upp
@@ -161,6 +161,7 @@ file
 	Topic.cpp,
 	CoWork.h,
 	CoWork.cpp,
+	CoWork2.cpp,
 	Hash.h,
 	MD5.cpp,
 	SHA1.cpp,
diff --git a/uppsrc/Core/Mt.cpp b/uppsrc/Core/Mt.cpp
index 45dd50f7c..e3560e661 100644
--- a/uppsrc/Core/Mt.cpp
+++ b/uppsrc/Core/Mt.cpp
@@ -88,7 +88,9 @@ sThreadRoutine(void *arg)
 	delete cb;
 	if(sExit)
 		(*sExit)();
+#ifndef COWORK2
 	CoWork::ShutdownPool();
+#endif
 #ifdef UPP_HEAP
 	MemoryFreeThread();
 #endif
@@ -208,7 +210,9 @@ void Thread::EndShutdownThreads()
 
 void Thread::ShutdownThreads()
 {
+#ifndef COWORK2
 	CoWork::ShutdownPool();
+#endif
 	BeginShutdownThreads();
 	while(GetCount())
 		Sleep(100);
diff --git a/uppsrc/Core/Other.h b/uppsrc/Core/Other.h
index c25a39444..74b4dcb1d 100644
--- a/uppsrc/Core/Other.h
+++ b/uppsrc/Core/Other.h
@@ -227,11 +227,11 @@ void Mitor<T>::Shrink()
 
 //#
 template <class T, int N = 1>
-class Link {
-protected:
+struct Link {
 	T *link_prev[N];
 	T *link_next[N];
 
+protected:
 	void LPN(int i)                      { link_prev[i]->link_next[i] = link_next[i]->link_prev[i] = (T *)this; }
 
 public: