dvander@2226: #include "KePageAllocator.h"
dvander@2226: 
dvander@2226: using namespace Knight;
dvander@2226: 
dvander@2226: struct PageInfo
dvander@2226: {
dvander@2226: 	PageInfo *next;
dvander@2226: 	void *base;
dvander@2226: };
dvander@2226: 
dvander@2226: class Knight::KePageAllocator
dvander@2226: {
dvander@2226: public:
dvander@2226: 	size_t page_size;
dvander@2226: 	size_t page_granularity;
dvander@2226: 	PageInfo *free_pages;
dvander@2226: 	PageInfo *page_blocks;
dvander@2226: };
dvander@2226: 
dvander@2226: static void *ke_LumpPageAlloc(KePageAllocator *alloc)
dvander@2226: {
dvander@2226: 	void *base;
dvander@2226: 	char *page;
dvander@2226: 	PageInfo *lump;
dvander@2226: 	size_t pagesInBlock;
dvander@2226: 
dvander@2226: #if defined KE_PLATFORM_WINDOWS
dvander@2226: 	base = VirtualAlloc(
dvander@2226: 		NULL,
dvander@2226: 		alloc->page_granularity,
dvander@2226: 		MEM_COMMIT|MEM_RESERVE,
dvander@2226: 		PAGE_READWRITE);
dvander@2226: #elif defined KE_PLATFORM_POSIX
dvander@2226: 	base = valloc(alloc->page_granularity);
dvander@2226: #else 
dvander@2226: #error "Unsupported platform"
dvander@2226: #endif
dvander@2226: 
dvander@2226: 	if (base == NULL)
dvander@2226: 	{
dvander@2226: 		return NULL;
dvander@2226: 	}
dvander@2226: 
dvander@2226: 	lump = new PageInfo;
dvander@2226: 	lump->base = base;
dvander@2226: 	lump->next = alloc->page_blocks;
dvander@2226: 	alloc->page_blocks = lump->next;
dvander@2226: 
dvander@2226: 	page = (char *)base + alloc->page_size;
dvander@2226: 	pagesInBlock = alloc->page_granularity / alloc->page_size;
dvander@2226: 
dvander@2226: 	for (size_t i = 1; i < pagesInBlock; i++)
dvander@2226: 	{
dvander@2226: 		lump = new PageInfo;
dvander@2226: 		lump->base = page;
dvander@2226: 		lump->next = alloc->free_pages;
dvander@2226: 		alloc->free_pages = lump;
dvander@2226: 		page += alloc->page_size;
dvander@2226: 	}
dvander@2226: 
dvander@2226: 	return base;
dvander@2226: }
dvander@2226: 
dvander@2226: KePageAllocator *Knight::KE_CreatePageAllocator()
dvander@2226: {
dvander@2226: 	KePageAllocator *alloc;
dvander@2226: 
dvander@2226: 	alloc = new KePageAllocator;
dvander@2226: 	
dvander@2226: #if defined KE_PLATFORM_WINDOWS
dvander@2226: 	SYSTEM_INFO info;
dvander@2226: 	
dvander@2226: 	GetSystemInfo(&info);
dvander@2226: 	alloc->page_size = info.dwPageSize;
dvander@2226: 	alloc->page_granularity = info.dwAllocationGranularity;
dvander@2226: #elif defined KE_PLATFORM_POSIX
dvander@2226: 	alloc->page_size = sysconf(_SC_PAGESIZE);
dvander@2226: 	alloc->page_granularity = alloc->page_size * 16;
dvander@2226: #else 
dvander@2226: #error "Unsupported platform"
dvander@2226: #endif
dvander@2226: 
dvander@2226: 	alloc->free_pages = NULL;
dvander@2226: 	alloc->page_blocks = NULL;
dvander@2226: 
dvander@2226: 	return alloc;
dvander@2226: }
dvander@2226: 
dvander@2226: void Knight::KE_DestroyPageAllocator(KePageAllocator *alloc)
dvander@2226: {
dvander@2226: 	PageInfo *info, *next;
dvander@2226: 
dvander@2226: 	info = alloc->page_blocks;
dvander@2226: 	while (info != NULL)
dvander@2226: 	{
dvander@2226: 		next = info->next;
dvander@2226: #if defined KE_PLATFORM_WINDOWS
dvander@2226: 		VirtualFree(info->base, 0, MEM_RELEASE);
dvander@2226: #elif defined KE_PLATFORM_WINDOWS
dvander@2226: 		free(info->base);
dvander@2226: #else 
dvander@2226: #error "Unsupported platform"
dvander@2226: #endif
dvander@2226: 		delete info;
dvander@2226: 		next = info;
dvander@2226: 	}
dvander@2226: 
dvander@2226: 	info = alloc->free_pages;
dvander@2226: 	while (info != NULL)
dvander@2226: 	{
dvander@2226: 		next = info->next;
dvander@2226: 		delete info;
dvander@2226: 		info = next;
dvander@2226: 	}
dvander@2226: }
dvander@2226: 
dvander@2226: void *Knight::KE_PageAlloc(KePageAllocator *alloc)
dvander@2226: {
dvander@2226: 	if (alloc->free_pages != NULL)
dvander@2226: 	{
dvander@2226: 		void *base;
dvander@2226: 		PageInfo *info;
dvander@2226: 
dvander@2226: 		info = alloc->free_pages;
dvander@2226: 		alloc->free_pages = info->next;
dvander@2226: 		base = info->base;
dvander@2226: 		delete info;
dvander@2226: 
dvander@2226: 		return base;
dvander@2226: 	}
dvander@2226: 
dvander@2226: 	return ke_LumpPageAlloc(alloc);
dvander@2226: }
dvander@2226: 
dvander@2226: void Knight::KE_PageFree(KePageAllocator *alloc, void *page)
dvander@2226: {
dvander@2226: 	PageInfo *info;
dvander@2226: 
dvander@2226: 	info = new PageInfo;
dvander@2226: 	info->base = page;
dvander@2226: 	info->next = alloc->free_pages;
dvander@2226: 	alloc->free_pages = info->next;
dvander@2226: }
dvander@2226: 
dvander@2226: size_t Knight::KE_PageSize(KePageAllocator *alloc)
dvander@2226: {
dvander@2226: 	return alloc->page_size;
dvander@2226: }