ObjFW  Diff

#import "OFOutOfRangeException.h"

#if defined(HAVE_MMAP) && defined(HAVE_MLOCK) && defined(MAP_ANON)
static const size_t chunkSize = 16;

struct Page {
	struct Page *next, *previous;
	unsigned long *map;
	unsigned char *page;
};

# if defined(OF_HAVE_COMPILER_TLS)
static thread_local struct Page *firstPage = NULL;
static thread_local struct Page *lastPage = NULL;
static thread_local struct Page **preallocatedPages = NULL;

	munmap(pointer, numPages * pageSize);
}

static struct Page *
addPage(bool allowPreallocated)
{
	size_t pageSize = [OFSystemInfo pageSize];
	size_t mapSize = OFRoundUpToPowerOf2(OF_ULONG_BIT,
	    pageSize / chunkSize) / OF_ULONG_BIT;
	struct Page *page;
# if !defined(OF_HAVE_COMPILER_TLS) && defined(OF_HAVE_THREADS)
	struct Page *lastPage;
# endif

	if (allowPreallocated) {
# if !defined(OF_HAVE_COMPILER_TLS) && defined(OF_HAVE_THREADS)

			return page;
		}
	}

	page = OFAllocMemory(1, sizeof(*page));
	@try {
		page->map = OFAllocZeroedMemory(mapSize, sizeof(unsigned long));
	} @catch (id e) {
		OFFreeMemory(page);
		@throw e;
	}
	@try {
		page->page = mapPages(1);
	} @catch (id e) {

	return page;
}

static void
removePageIfEmpty(struct Page *page)
{
	unsigned long *map = page->map;
	size_t pageSize = [OFSystemInfo pageSize];
	size_t mapSize = OFRoundUpToPowerOf2(OF_ULONG_BIT,
	    pageSize / chunkSize) / OF_ULONG_BIT;

	for (size_t i = 0; i < mapSize; i++)
		if (map[i] != 0)
			return;

	unmapPages(page->page, 1);
	OFFreeMemory(page->map);

	bytes = OFRoundUpToPowerOf2(chunkSize, bytes);
	chunks = chunksLeft = bytes / chunkSize;
	firstChunk = 0;
	pageSize = [OFSystemInfo pageSize];

	for (i = 0; i < pageSize / chunkSize; i++) {
		if (OFBitSetIsSet(page->map, i)) {
			chunksLeft = chunks;
			firstChunk = i + 1;
			continue;
		}

		if (--chunksLeft == 0)
			break;
	}

	if (chunksLeft == 0) {
		for (size_t j = firstChunk; j < firstChunk + chunks; j++)
			OFBitSetSet(page->map, j);

		return page->page + (chunkSize * firstChunk);
	}

	return NULL;
}

static void
freeMemory(struct Page *page, void *pointer, size_t bytes)
{
	size_t chunks, chunkIndex;

	bytes = OFRoundUpToPowerOf2(chunkSize, bytes);
	chunks = bytes / chunkSize;
	chunkIndex = ((uintptr_t)pointer - (uintptr_t)page->page) / chunkSize;

	OFZeroMemory(pointer, bytes);

	for (size_t i = 0; i < chunks; i++)
		OFBitSetClear(page->map, chunkIndex + i);
}
#endif

@implementation OFSecureData
@synthesize allowsSwappableMemory = _allowsSwappableMemory;

#if defined(HAVE_MMAP) && defined(HAVE_MLOCK) && defined(MAP_ANON) && \