1 files changed, 121 insertions, 0 deletions
diff --git a/Src/replicant/nu/win/MessageLoop.cpp b/Src/replicant/nu/win/MessageLoop.cpp
new file mode 100644
index 00000000..2353801c
--- /dev/null
+++ b/Src/replicant/nu/win/MessageLoop.cpp
@@ -0,0 +1,121 @@
+#include "MessageLoop.h"
+#include <assert.h>
+
+lifo_t nu::MessageLoop::message_cache = {0,};
+lifo_t nu::MessageLoop::cache_bases= {0,};
+
+#define MESSAAGE_CACHE_SEED 64
+
+typedef uint8_t message_data_t[64]; // ensure all messages are this size
+
+nu::MessageLoop::MessageLoop()
+{
+	mpscq_init(&message_queue);
+	message_notification = CreateEvent(0, FALSE, FALSE, 0);
+}
+
+nu::MessageLoop::~MessageLoop()
+{
+	CloseHandle(message_notification);
+}
+
+void nu::MessageLoop::RefillCache()
+{
+	message_data_t *cache_seed = (message_data_t *)_aligned_malloc(MESSAAGE_CACHE_SEED*sizeof(message_data_t), 64);
+	
+	if (cache_seed)
+	{
+		int i=MESSAAGE_CACHE_SEED;
+		while (--i)
+		{
+			lifo_push(&message_cache, (queue_node_t *)&cache_seed[i]);
+		}
+		lifo_push(&cache_bases, (queue_node_t *)cache_seed);
+	}
+	else
+	{
+		Sleep(0); // yield and hope that someone else pops something off soon		
+	}
+}
+
+nu::message_node_t *nu::MessageLoop::AllocateMessage()
+{
+	message_node_t *apc = 0;
+
+	do 
+	{
+		apc = (message_node_t *)lifo_pop(&message_cache);
+		if (!apc)
+			RefillCache();
+	} while (!apc);
+	return apc;
+}
+
+void nu::MessageLoop::PostMessage(nu::message_node_t *message)
+{
+	if (mpscq_push(&message_queue, message) == 0)
+		SetEvent(message_notification);
+}
+
+void nu::MessageLoop::FreeMessage(nu::message_node_t *message)
+{
+	lifo_push(&message_cache, message);
+}
+
+nu::message_node_t *nu::MessageLoop::GetMessage()
+{
+	message_node_t *message = PeekMessage();
+	if (message)
+	{
+		return message;
+	}
+
+	while (WaitForSingleObject(message_notification, INFINITE) ==  WAIT_OBJECT_0)
+	{
+		message = PeekMessage();
+		if (message)
+		{
+			return message;
+		}
+	}
+	return 0;
+}
+
+nu::message_node_t *nu::MessageLoop::PeekMessage()
+{
+	for (;;) // loop because we need to handle 'busy' from the queue
+	{
+		message_node_t *message = (message_node_t *)mpscq_pop(&message_queue);
+		if (message == (message_node_t *)1) /* special return value that indicates a busy list */
+		{
+			// benski> although it's tempting to return 0 here, doing so will mess up the Event logic
+			Sleep(0); // yield so that the thread that got pre-empted during push can finish
+		}
+		else
+		{
+			if (message)
+			{
+				return message;
+			}
+			else
+			{
+				return 0;
+			}
+		}
+	}				
+}
+
+nu::message_node_t *nu::MessageLoop::PeekMessage(unsigned int milliseconds)
+{
+	message_node_t *message = PeekMessage();
+	if (message)
+		return message;
+
+	if (WaitForSingleObject(message_notification, milliseconds) == WAIT_OBJECT_0)
+	{
+		message = PeekMessage();
+		if (message)
+			return message;
+	}
+	return 0;
+}