From 20d28e80a5c861a9d5f449ea911ab75b4f37ad0d Mon Sep 17 00:00:00 2001
From: Jef <jef@targetspot.com>
Date: Tue, 24 Sep 2024 14:54:57 +0200
Subject: Initial community commit

---
 Src/replicant/nu/win-amd64/LockFreeLIFO.h | 34 +++++++++++++++
 Src/replicant/nu/win-amd64/ThreadLoop.cpp | 70 +++++++++++++++++++++++++++++++
 Src/replicant/nu/win-amd64/ThreadLoop.h   | 38 +++++++++++++++++
 3 files changed, 142 insertions(+)
 create mode 100644 Src/replicant/nu/win-amd64/LockFreeLIFO.h
 create mode 100644 Src/replicant/nu/win-amd64/ThreadLoop.cpp
 create mode 100644 Src/replicant/nu/win-amd64/ThreadLoop.h

(limited to 'Src/replicant/nu/win-amd64')

diff --git a/Src/replicant/nu/win-amd64/LockFreeLIFO.h b/Src/replicant/nu/win-amd64/LockFreeLIFO.h
new file mode 100644
index 00000000..5cf087e7
--- /dev/null
+++ b/Src/replicant/nu/win-amd64/LockFreeLIFO.h
@@ -0,0 +1,34 @@
+#pragma once
+
+
+#include "nu/queue_node.h"
+#include <windows.h>
+#include <malloc.h>
+
+/* lock free stack object 
+multiple threads can push and pop without locking
+note that order is not guaranteed.  that is, if Thread 1 calls Insert before Thread 2, Thread 2's item might still make it in before.
+*/
+
+#ifdef __cplusplus
+#define NU_LIFO_INLINE inline
+extern "C" {
+#else
+#define NX_ATOMIC_INLINE
+#endif
+
+	typedef SLIST_HEADER lifo_t;
+		
+	/* use this to allocate an object that will go into this */
+	NU_LIFO_INLINE static queue_node_t *lifo_malloc(size_t bytes) { return (queue_node_t *)_aligned_malloc(bytes, MEMORY_ALLOCATION_ALIGNMENT); }
+	NU_LIFO_INLINE static void lifo_free(queue_node_t *ptr) { _aligned_free(ptr); }
+
+	NU_LIFO_INLINE static lifo_t *lifo_create() { return (lifo_t *)_aligned_malloc(sizeof(SLIST_HEADER), MEMORY_ALLOCATION_ALIGNMENT); }
+	NU_LIFO_INLINE static void lifo_destroy(lifo_t *lifo) { _aligned_free(lifo); }
+	NU_LIFO_INLINE static void lifo_init(lifo_t *lifo) { InitializeSListHead(lifo); }
+	NU_LIFO_INLINE static void lifo_push(lifo_t *lifo, queue_node_t *cl) { InterlockedPushEntrySList(lifo, cl); }
+	NU_LIFO_INLINE static queue_node_t *lifo_pop(lifo_t *lifo) { return InterlockedPopEntrySList(lifo); }
+
+#ifdef __cplusplus
+}
+#endif
diff --git a/Src/replicant/nu/win-amd64/ThreadLoop.cpp b/Src/replicant/nu/win-amd64/ThreadLoop.cpp
new file mode 100644
index 00000000..4c78a431
--- /dev/null
+++ b/Src/replicant/nu/win-amd64/ThreadLoop.cpp
@@ -0,0 +1,70 @@
+#include "ThreadLoop.h"
+
+lifo_t ThreadLoop::procedure_cache = {0,};
+lifo_t ThreadLoop::cache_bases= {0,};
+
+#define PROCEDURE_CACHE_SEED 64
+ThreadLoop::ThreadLoop()
+{
+	mpscq_init(&procedure_queue);
+	procedure_notification = CreateSemaphore(0, 0, LONG_MAX, 0);
+	kill_switch = CreateEvent(0, TRUE, FALSE, 0);
+}
+
+void ThreadLoop::RefillCache()
+{
+	threadloop_node_t *cache_seed = (threadloop_node_t *)lifo_malloc(PROCEDURE_CACHE_SEED*sizeof(threadloop_node_t));
+	if (cache_seed)
+	{
+		memset(cache_seed, 0, PROCEDURE_CACHE_SEED*sizeof(threadloop_node_t));
+		for (int i=0;i<PROCEDURE_CACHE_SEED;i++)
+		{			
+			lifo_push(&procedure_cache, &cache_seed[i]);
+		}
+		lifo_push(&cache_bases, cache_seed);
+	}
+}
+
+void ThreadLoop::Run()
+{
+	HANDLE events[] = {kill_switch, procedure_notification};
+	while (WaitForMultipleObjects(2, events, FALSE, INFINITE) == WAIT_OBJECT_0 + 1)
+	{
+		threadloop_node_t *apc;
+		for (;;)
+		{
+			apc = (threadloop_node_t *)mpscq_pop(&procedure_queue);
+			if (!apc)
+			{
+				Sleep(0);
+				continue;
+			}
+			apc->func(apc->param1, apc->param2, apc->real_value);
+		}
+		lifo_push(&procedure_cache, apc);
+	}
+}
+
+threadloop_node_t *ThreadLoop::GetAPC()
+{
+	threadloop_node_t *apc = 0;
+
+	do 
+	{
+		apc = (threadloop_node_t *)lifo_pop(&procedure_cache);
+		if (!apc)
+			RefillCache();
+	} while (!apc);
+	return apc;
+}
+
+void ThreadLoop::Schedule(threadloop_node_t *apc)
+{
+	mpscq_push(&procedure_queue, apc);
+	ReleaseSemaphore(procedure_notification, 1, 0);
+}
+
+void ThreadLoop::Kill()
+{
+	SetEvent(kill_switch);
+}
diff --git a/Src/replicant/nu/win-amd64/ThreadLoop.h b/Src/replicant/nu/win-amd64/ThreadLoop.h
new file mode 100644
index 00000000..f1552b51
--- /dev/null
+++ b/Src/replicant/nu/win-amd64/ThreadLoop.h
@@ -0,0 +1,38 @@
+#pragma once
+#include "nu/lfmpscq.h"
+#include "nu/LockFreeLIFO.h"
+#define WIN32_LEAN_AND_MEAN
+#include <windows.h>
+
+struct threadloop_node_t : public queue_node_t
+{
+	void (*func)(void *param1, void *param2, double real_value);
+
+	void *param1;
+	void *param2;
+	double real_value;
+};
+
+class ThreadLoop
+{
+public:
+	ThreadLoop();
+	threadloop_node_t *GetAPC(); // returns a node for you to fill out
+	void Schedule(threadloop_node_t *apc);
+	void Run();
+	void Kill();
+private:
+	void RefillCache();
+
+	HANDLE procedure_notification;
+	HANDLE kill_switch;
+	mpscq_t procedure_queue;
+
+	/* Memory cache to be able to run APCs without having the memory manager lock 
+	we'll allocate 100 at a time (#defined by PROCEDURE_CACHE_SEED)
+	and allocate new ones only if the cache is empty (which unfortunately will lock)
+	cache_bases holds the pointers we've allocated (to free on destruction of this object)
+	and procedure_cache holds the individual pointers */
+	static lifo_t procedure_cache;
+	static lifo_t cache_bases;
+};
\ No newline at end of file
-- 
cgit