1 files changed, 169 insertions, 0 deletions
diff --git a/sc4pd/headers/server/MsgFifo.h b/sc4pd/headers/server/MsgFifo.h
new file mode 100644
index 0000000..cdc8578
--- /dev/null
+++ b/sc4pd/headers/server/MsgFifo.h
@@ -0,0 +1,169 @@
+/*
+	SuperCollider real time audio synthesis system
+    Copyright (c) 2002 James McCartney. All rights reserved.
+	http://www.audiosynth.com
+
+    This program is free software; you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+*/
+
+#ifndef _MsgFifo_
+#define _MsgFifo_
+
+#ifdef SC_DARWIN
+# include <CoreServices/CoreServices.h>
+#endif
+
+/////////////////////////////////////////////////////////////////////
+
+template <class MsgType, int N>
+class MsgFifo
+{
+public:
+	MsgFifo()
+			: mReadHead(0), mWriteHead(0), mFreeHead(0)
+	{}
+
+	void MakeEmpty() { mFreeHead = mReadHead = mWriteHead; }
+	bool IsEmpty() { return mReadHead == mWriteHead; }
+	bool HasData() { return mReadHead != mWriteHead; }
+	bool NeedsFree() { return mFreeHead != mReadHead; }
+
+	bool Write(MsgType& data)
+	{
+		unsigned int next = NextPos(mWriteHead);
+		if (next == mFreeHead) return false; // fifo is full
+		mItems[next] = data;
+#ifdef SC_DARWIN
+		// we don't really need a compare and swap, but this happens to call 
+		// the PowerPC memory barrier instruction lwsync.
+		CompareAndSwap(mWriteHead, next, &mWriteHead);
+#elif defined SC_WIN32
+    InterlockedExchange(reinterpret_cast<volatile LONG*>(&mWriteHead),next);
+#else
+		mWriteHead = next;
+#endif
+		return true;
+	}
+
+	void Perform() // get next and advance
+	{
+		while (HasData()) {
+			unsigned int next = NextPos(mReadHead);
+			mItems[next].Perform();
+#ifdef SC_DARWIN
+			// we don't really need a compare and swap, but this happens to call 
+			// the PowerPC memory barrier instruction lwsync.
+			CompareAndSwap(mReadHead, next, &mReadHead);
+#elif defined SC_WIN32
+      InterlockedExchange(reinterpret_cast<volatile LONG*>(&mReadHead),next);
+#else
+			mReadHead = next;
+#endif
+		}
+	}
+	void Free() // reclaim messages
+	{
+		while (NeedsFree()) {
+			unsigned int next = NextPos(mFreeHead);
+			mItems[next].Free();
+#ifdef SC_DARWIN
+			// we don't really need a compare and swap, but this happens to call 
+			// the PowerPC memory barrier instruction lwsync.
+			CompareAndSwap(mFreeHead, next, &mFreeHead);
+#elif defined SC_WIN32
+      InterlockedExchange(reinterpret_cast<volatile LONG*>(&mFreeHead),next);
+#else
+      mFreeHead = next;
+#endif
+		}
+	}
+
+private:
+	int NextPos(int inPos) { return (inPos + 1) & (N - 1); }
+
+#ifdef SC_DARWIN
+	UInt32 mReadHead, mWriteHead, mFreeHead;
+#else
+	volatile unsigned int mReadHead, mWriteHead, mFreeHead;
+#endif
+	MsgType mItems[N];
+};
+
+/////////////////////////////////////////////////////////////////////
+
+template <class MsgType, int N>
+class MsgFifoNoFree
+{
+public:
+	MsgFifoNoFree()
+			: mReadHead(0), mWriteHead(0)
+	{
+	}
+
+	void MakeEmpty() { mReadHead = mWriteHead; }
+	bool IsEmpty() { return mReadHead == mWriteHead; }
+	bool HasData() { return mReadHead != mWriteHead; }
+
+	bool Write(MsgType& data)
+	{
+		unsigned int next = NextPos(mWriteHead);
+		if (next == mReadHead) return false; // fifo is full
+		mItems[next] = data;
+#ifdef SC_DARWIN
+			// we don't really need a compare and swap, but this happens to call 
+			// the PowerPC memory barrier instruction lwsync.
+			CompareAndSwap(mWriteHead, next, &mWriteHead);
+#elif defined SC_WIN32
+      InterlockedExchange(reinterpret_cast<volatile LONG*>(&mWriteHead),next);
+#else
+			mWriteHead = next;
+#endif
+		return true;
+	}
+
+	void Perform() // get next and advance
+	{
+		while (HasData()) {
+			unsigned int next = NextPos(mReadHead);
+			mItems[next].Perform();
+#ifdef SC_DARWIN
+			// we don't really need a compare and swap, but this happens to call 
+			// the PowerPC memory barrier instruction lwsync.
+			CompareAndSwap(mReadHead, next, &mReadHead);
+#elif defined SC_WIN32
+      InterlockedExchange(reinterpret_cast<volatile LONG*>(&mReadHead),next);
+#else
+			mReadHead = next;
+#endif
+		}
+	}
+
+private:
+	int NextPos(int inPos) { return (inPos + 1) & (N - 1); }
+
+#ifdef SC_DARWIN
+	UInt32 mReadHead, mWriteHead;
+#else
+	volatile unsigned int mReadHead, mWriteHead;
+#endif
+	MsgType mItems[N];
+};
+
+/////////////////////////////////////////////////////////////////////
+
+
+#endif
+
+