ObjFW  Diff

#import "OFNotImplementedException.h"
#import "OFOutOfMemoryException.h"
#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;
	void *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;
static thread_local size_t numPreallocatedPages = 0;
# elif defined(OF_HAVE_THREADS)
static OFTLSKey firstPageKey, lastPageKey;
static OFTLSKey preallocatedPagesKey, numPreallocatedPagesKey;
# else
static struct page *firstPage = NULL;
static struct page *lastPage = NULL;
static struct page **preallocatedPages = NULL;
static size_t numPreallocatedPages = 0;
# endif

static void *
mapPages(size_t numPages)
{
	size_t pageSize = [OFSystemInfo pageSize];

	if (numPages > SIZE_MAX / pageSize)
		@throw [OFOutOfRangeException exception];

	munlock(pointer, numPages * pageSize);
	munmap(pointer, numPages * pageSize);
}

static struct page *
addPage(bool allowPreallocated)
{
	size_t pageSize = [OFSystemInfo pageSize];
	size_t mapSize = OFRoundUpToPowerOf2(CHAR_BIT, pageSize / chunkSize) /
	    CHAR_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)
		uintptr_t numPreallocatedPages =
		    (uintptr_t)OFTLSKeyGet(numPreallocatedPagesKey);
# endif

		if (numPreallocatedPages > 0) {
# if !defined(OF_HAVE_COMPILER_TLS) && defined(OF_HAVE_THREADS)
			struct page **preallocatedPages =
			    OFTLSKeyGet(preallocatedPagesKey);
# endif

			numPreallocatedPages--;
# if !defined(OF_HAVE_COMPILER_TLS) && defined(OF_HAVE_THREADS)
			OFEnsure(OFTLSKeySet(numPreallocatedPagesKey,
			    (void *)numPreallocatedPages) == 0);

		OFEnsure(OFTLSKeySet(firstPageKey, page) == 0);
# endif

	return page;
}

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

	for (size_t i = 0; i < mapSize; i++)

		OFEnsure(OFTLSKeySet(lastPageKey, page->previous) == 0);
# endif

	OFFreeMemory(page);
}

static void *
allocateMemory(struct page *page, size_t bytes)
{
	size_t chunks, chunksLeft, pageSize, i, firstChunk;

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

		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;

+ (void)preallocateUnswappableMemoryWithSize: (size_t)size
{
#if defined(HAVE_MMAP) && defined(HAVE_MLOCK) && defined(MAP_ANON)
	size_t pageSize = [OFSystemInfo pageSize];
	size_t numPages = OFRoundUpToPowerOf2(pageSize, size) / pageSize;
# if !defined(OF_HAVE_COMPILER_TLS) && defined(OF_HAVE_THREADS)
	struct page **preallocatedPages = OFTLSKeyGet(preallocatedPagesKey);
	size_t numPreallocatedPages;
# endif
	size_t i;

	if (preallocatedPages != NULL)
		@throw [OFInvalidArgumentException exception];

	preallocatedPages = OFAllocZeroedMemory(numPages, sizeof(struct page));
# if !defined(OF_HAVE_COMPILER_TLS) && defined(OF_HAVE_THREADS)
	OFEnsure(OFTLSKeySet(preallocatedPagesKey, preallocatedPages) == 0);
# endif

	@try {
		for (i = 0; i < numPages; i++)
			preallocatedPages[i] = addPage(false);

			memset(_items, 0, count * itemSize);
#if defined(HAVE_MMAP) && defined(HAVE_MLOCK) && defined(MAP_ANON)
		} else if (count * itemSize >= pageSize)
			_items = mapPages(OFRoundUpToPowerOf2(pageSize,
			    count * itemSize) / pageSize);
		else {
# if !defined(OF_HAVE_COMPILER_TLS) && defined(OF_HAVE_THREADS)
			struct page *lastPage = OFTLSKeyGet(lastPageKey);
# endif

			for (struct page *page = lastPage; page != NULL;
			    page = page->previous) {
				_items = allocateMemory(page, count * itemSize);

				if (_items != NULL) {
					_page = page;
					break;
				}