Open source Star Ruler 2 source code!

source/game/memory/AllocOnlyPool.h

@@ -0,0 +1,103 @@
+#pragma once
+#include <memory>
+
+namespace memory {
+
+//A pre-allocated pool of uniformly sized objects
+//Allocated memory is only cleared when all objects in the pool are deleted
+//When all memory is used up, falls back on global operator new/delete
+template<class T, class L>
+class AllocOnlyPool {
+	L lock;
+	T* pStart, *pNext, *pEnd;
+	unsigned allocated;
+
+public:
+	AllocOnlyPool(unsigned count) : allocated(0) {
+		pStart = (T*)new unsigned char[count * sizeof(T)];
+		pNext = pStart;
+		pEnd = pStart + count;
+	}
+
+	~AllocOnlyPool() {
+		delete[] (unsigned char*)pStart;
+	}
+
+	void* alloc() {
+		lock.lock();
+
+		void* r;
+		if(pNext != pEnd) {
+			++allocated;
+			r = pNext++;
+			lock.release();
+		}
+		else {
+			lock.release();
+			r = ::operator new(sizeof(T));
+		}
+
+		return r;
+	}
+
+	void dealloc(T* p) {
+		if(p >= pStart && p < pEnd) {
+			lock.lock();
+			if(--allocated == 0)
+				pNext = pStart;
+			lock.release();
+		}
+		else {
+			::operator delete(p);
+		}
+	}
+};
+
+//A pre-allocated region for any data types
+//Allocated memory is only cleared when all objects in the pool are deleted
+//When all memory is used up, falls back on global operator new/delete
+template<class Lock>
+class AllocOnlyRegion {
+	unsigned char* pStart, *pNext, *pEnd;
+	unsigned allocated;
+	Lock lock;
+public:
+	AllocOnlyRegion(unsigned bytes) : allocated(0) {
+		pStart = new unsigned char[bytes];
+		pNext = pStart;
+		pEnd = pStart + bytes;
+	}
+
+	~AllocOnlyRegion() {
+		delete[] (unsigned char*)pStart;
+	}
+
+	void* alloc(size_t size) {
+		lock.lock();
+		if(size < (size_t)(pEnd - pNext)) {
+			++allocated;
+			auto pCopy = pNext;
+			pNext += size;
+			lock.release();
+			return pCopy;
+		}
+		else {
+			lock.release();
+			return ::operator new(size);
+		}
+	}
+
+	void dealloc(void* p) {
+		if(p >= pStart && p < pEnd) {
+			lock.lock();
+			if(--allocated == 0)
+				pNext = pStart;
+			lock.release();
+		}
+		else {
+			::operator delete(p);
+		}
+	}
+};
+
+};