X-Git-Url: http://de.git.xonotic.org/?p=xonotic%2Fdarkplaces.git;a=blobdiff_plain;f=zone.c;h=2aa575e786b442cd96a59f683c856f4f89bac3da;hp=a6b7cf2bc09ba8defb975355b01a3df2e2807da3;hb=2075ae43356d724bae305ce8fd36ea570718b14a;hpb=d57be67cb00229acb8564b92c8b7c58eeed8a0cb

diff --git a/zone.c b/zone.c
index a6b7cf2b..2aa575e7 100644
--- a/zone.c
+++ b/zone.c
@@ -20,300 +20,870 @@ Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 // Z_zone.c
 
 #include "quakedef.h"
+#include "thread.h"
 
-mempool_t *poolchain = NULL;
+#ifdef WIN32
+#include <windows.h>
+#include <winbase.h>
+#else
+#include <unistd.h>
+#endif
 
-void *_Mem_Alloc(mempool_t *pool, int size, char *filename, int fileline)
+#ifdef _MSC_VER
+#include <vadefs.h>
+#else
+#include <stdint.h>
+#endif
+#define MEMHEADER_SENTINEL_FOR_ADDRESS(p) ((sentinel_seed ^ (unsigned int) (uintptr_t) (p)) + sentinel_seed)
+unsigned int sentinel_seed;
+
+qboolean mem_bigendian = false;
+void *mem_mutex = NULL;
+
+// divVerent: enables file backed malloc using mmap to conserve swap space (instead of malloc)
+#ifndef FILE_BACKED_MALLOC
+# define FILE_BACKED_MALLOC 0
+#endif
+
+// LordHavoc: enables our own low-level allocator (instead of malloc)
+#ifndef MEMCLUMPING
+# define MEMCLUMPING 0
+#endif
+#ifndef MEMCLUMPING_FREECLUMPS
+# define MEMCLUMPING_FREECLUMPS 0
+#endif
+
+#if MEMCLUMPING
+// smallest unit we care about is this many bytes
+#define MEMUNIT 128
+// try to do 32MB clumps, but overhead eats into this
+#ifndef MEMWANTCLUMPSIZE
+# define MEMWANTCLUMPSIZE (1<<27)
+#endif
+// give malloc padding so we can't waste most of a page at the end
+#define MEMCLUMPSIZE (MEMWANTCLUMPSIZE - MEMWANTCLUMPSIZE/MEMUNIT/32 - 128)
+#define MEMBITS (MEMCLUMPSIZE / MEMUNIT)
+#define MEMBITINTS (MEMBITS / 32)
+
+typedef struct memclump_s
 {
-	int i, j, k, needed, endbit, largest;
-	memclump_t *clump, **clumpchainpointer;
-	memheader_t *mem;
-	if (size <= 0)
+	// contents of the clump
+	unsigned char block[MEMCLUMPSIZE];
+	// should always be MEMCLUMP_SENTINEL
+	unsigned int sentinel1;
+	// if a bit is on, it means that the MEMUNIT bytes it represents are
+	// allocated, otherwise free
+	unsigned int bits[MEMBITINTS];
+	// should always be MEMCLUMP_SENTINEL
+	unsigned int sentinel2;
+	// if this drops to 0, the clump is freed
+	size_t blocksinuse;
+	// largest block of memory available (this is reset to an optimistic
+	// number when anything is freed, and updated when alloc fails the clump)
+	size_t largestavailable;
+	// next clump in the chain
+	struct memclump_s *chain;
+}
+memclump_t;
+
+#if MEMCLUMPING == 2
+static memclump_t masterclump;
+#endif
+static memclump_t *clumpchain = NULL;
+#endif
+
+
+cvar_t developer_memory = {0, "developer_memory", "0", "prints debugging information about memory allocations"};
+cvar_t developer_memorydebug = {0, "developer_memorydebug", "0", "enables memory corruption checks (very slow)"};
+cvar_t developer_memoryreportlargerthanmb = {0, "developer_memorylargerthanmb", "16", "prints debugging information about memory allocations over this size"};
+cvar_t sys_memsize_physical = {CVAR_READONLY, "sys_memsize_physical", "", "physical memory size in MB (or empty if unknown)"};
+cvar_t sys_memsize_virtual = {CVAR_READONLY, "sys_memsize_virtual", "", "virtual memory size in MB (or empty if unknown)"};
+
+static mempool_t *poolchain = NULL;
+
+void Mem_PrintStats(void);
+void Mem_PrintList(size_t minallocationsize);
+
+#if FILE_BACKED_MALLOC
+#include <stdlib.h>
+#include <sys/mman.h>
+typedef struct mmap_data_s
+{
+	size_t len;
+}
+mmap_data_t;
+static void *mmap_malloc(size_t size)
+{
+	char vabuf[MAX_OSPATH + 1];
+	char *tmpdir = getenv("TEMP");
+	mmap_data_t *data;
+	int fd;
+	size += sizeof(mmap_data_t); // waste block
+	dpsnprintf(vabuf, sizeof(vabuf), "%s/darkplaces.XXXXXX", tmpdir ? tmpdir : "/tmp");
+	fd = mkstemp(vabuf);
+	if(fd < 0)
 		return NULL;
-	if (pool == NULL)
-		Host_Error("Mem_Alloc: pool == NULL");
-	pool->totalsize += size;
-	if (size < 4096)
+	ftruncate(fd, size);
+	data = (unsigned char *) mmap(NULL, size, PROT_READ | PROT_WRITE, MAP_SHARED | MAP_NORESERVE, fd, 0);
+	close(fd);
+	unlink(vabuf);
+	if(!data)
+		return NULL;
+	data->len = size;
+	return (void *) (data + 1);
+}
+static void mmap_free(void *mem)
+{
+	mmap_data_t *data;
+	if(!mem)
+		return;
+	data = ((mmap_data_t *) mem) - 1;
+	munmap(data, data->len);
+}
+#define malloc mmap_malloc
+#define free mmap_free
+#endif
+
+#if MEMCLUMPING != 2
+// some platforms have a malloc that returns NULL but succeeds later
+// (Windows growing its swapfile for example)
+static void *attempt_malloc(size_t size)
+{
+	void *base;
+	// try for half a second or so
+	unsigned int attempts = 500;
+	while (attempts--)
+	{
+		base = (void *)malloc(size);
+		if (base)
+			return base;
+		Sys_Sleep(1000);
+	}
+	return NULL;
+}
+#endif
+
+#if MEMCLUMPING
+static memclump_t *Clump_NewClump(void)
+{
+	memclump_t **clumpchainpointer;
+	memclump_t *clump;
+#if MEMCLUMPING == 2
+	if (clumpchain)
+		return NULL;
+	clump = &masterclump;
+#else
+	clump = (memclump_t*)attempt_malloc(sizeof(memclump_t));
+	if (!clump)
+		return NULL;
+#endif
+
+	// initialize clump
+	if (developer_memorydebug.integer)
+		memset(clump, 0xEF, sizeof(*clump));
+	clump->sentinel1 = MEMHEADER_SENTINEL_FOR_ADDRESS(&clump->sentinel1);
+	memset(clump->bits, 0, sizeof(clump->bits));
+	clump->sentinel2 = MEMHEADER_SENTINEL_FOR_ADDRESS(&clump->sentinel2);
+	clump->blocksinuse = 0;
+	clump->largestavailable = 0;
+	clump->chain = NULL;
+
+	// link clump into chain
+	for (clumpchainpointer = &clumpchain;*clumpchainpointer;clumpchainpointer = &(*clumpchainpointer)->chain)
+		;
+	*clumpchainpointer = clump;
+
+	return clump;
+}
+#endif
+
+// low level clumping functions, all other memory functions use these
+static void *Clump_AllocBlock(size_t size)
+{
+	unsigned char *base;
+#if MEMCLUMPING
+	if (size <= MEMCLUMPSIZE)
 	{
-		// clumping
-		needed = (sizeof(memheader_t) + size + sizeof(int) + (MEMUNIT - 1)) / MEMUNIT;
-		endbit = MEMBITS - needed;
-		for (clumpchainpointer = &pool->clumpchain;*clumpchainpointer;clumpchainpointer = &(*clumpchainpointer)->chain)
+		int index;
+		unsigned int bit;
+		unsigned int needbits;
+		unsigned int startbit;
+		unsigned int endbit;
+		unsigned int needints;
+		int startindex;
+		int endindex;
+		unsigned int value;
+		unsigned int mask;
+		unsigned int *array;
+		memclump_t **clumpchainpointer;
+		memclump_t *clump;
+		needbits = (size + MEMUNIT - 1) / MEMUNIT;
+		needints = (needbits+31)>>5;
+		for (clumpchainpointer = &clumpchain;;clumpchainpointer = &(*clumpchainpointer)->chain)
 		{
 			clump = *clumpchainpointer;
-			if (clump->sentinel1 != MEMCLUMP_SENTINEL)
-				Sys_Error("Mem_Alloc: trashed clump sentinel 1\n");
-			if (clump->sentinel2 != MEMCLUMP_SENTINEL)
-				Sys_Error("Mem_Alloc: trashed clump sentinel 2\n");
-			if (clump->largestavailable >= needed)
+			if (!clump)
 			{
-				largest = 0;
-				for (i = 0;i < endbit;i++)
+				clump = Clump_NewClump();
+				if (!clump)
+					return NULL;
+			}
+			if (clump->sentinel1 != MEMHEADER_SENTINEL_FOR_ADDRESS(&clump->sentinel1))
+				Sys_Error("Clump_AllocBlock: trashed sentinel1\n");
+			if (clump->sentinel2 != MEMHEADER_SENTINEL_FOR_ADDRESS(&clump->sentinel2))
+				Sys_Error("Clump_AllocBlock: trashed sentinel2\n");
+			startbit = 0;
+			endbit = startbit + needbits;
+			array = clump->bits;
+			// do as fast a search as possible, even if it means crude alignment
+			if (needbits >= 32)
+			{
+				// large allocations are aligned to large boundaries
+				// furthermore, they are allocated downward from the top...
+				endindex = MEMBITINTS;
+				startindex = endindex - needints;
+				index = endindex;
+				while (--index >= startindex)
 				{
-					if (clump->bits[i >> 5] & (1 << (i & 31)))
-						continue;
-					k = i + needed;
-					for (j = i;i < k;i++)
-						if (clump->bits[i >> 5] & (1 << (i & 31)))
-							goto loopcontinue;
-					goto choseclump;
-	loopcontinue:;
-					if (largest < j - i)
-						largest = j - i;
+					if (array[index])
+					{
+						endindex = index;
+						startindex = endindex - needints;
+						if (startindex < 0)
+							goto nofreeblock;
+					}
+				}
+				startbit = startindex*32;
+				goto foundblock;
+			}
+			else
+			{
+				// search for a multi-bit gap in a single int
+				// (not dealing with the cases that cross two ints)
+				mask = (1<<needbits)-1;
+				endbit = 32-needbits;
+				bit = endbit;
+				for (index = 0;index < MEMBITINTS;index++)
+				{
+					value = array[index];
+					if (value != 0xFFFFFFFFu)
+					{
+						// there may be room in this one...
+						for (bit = 0;bit < endbit;bit++)
+						{
+							if (!(value & (mask<<bit)))
+							{
+								startbit = index*32+bit;
+								goto foundblock;
+							}
+						}
+					}
 				}
-				// since clump falsely advertised enough space (nothing wrong
-				// with that), update largest count to avoid wasting time in
-				// later allocations
-				clump->largestavailable = largest;
+				goto nofreeblock;
 			}
+foundblock:
+			endbit = startbit + needbits;
+			// mark this range as used
+			// TODO: optimize
+			for (bit = startbit;bit < endbit;bit++)
+				if (clump->bits[bit>>5] & (1<<(bit & 31)))
+					Sys_Error("Clump_AllocBlock: internal error (%i needbits)\n", needbits);
+			for (bit = startbit;bit < endbit;bit++)
+				clump->bits[bit>>5] |= (1<<(bit & 31));
+			clump->blocksinuse += needbits;
+			base = clump->block + startbit * MEMUNIT;
+			if (developer_memorydebug.integer)
+				memset(base, 0xBF, needbits * MEMUNIT);
+			return base;
+nofreeblock:
+			;
 		}
-		pool->realsize += sizeof(memclump_t);
-		clump = malloc(sizeof(memclump_t));
-		if (clump == NULL)
-			Host_Error("Mem_Alloc: out of memory");
-		memset(clump, 0, sizeof(memclump_t));
-		*clumpchainpointer = clump;
-		clump->sentinel1 = MEMCLUMP_SENTINEL;
-		clump->sentinel2 = MEMCLUMP_SENTINEL;
-		clump->chain = NULL;
-		clump->blocksinuse = 0;
-		clump->largestavailable = MEMBITS - needed;
-		j = 0;
-choseclump:
-		mem = (memheader_t *)((long) clump->block + j * MEMUNIT);
-		mem->clump = clump;
-		clump->blocksinuse += needed;
-		for (i = j + needed;j < i;j++)
-			clump->bits[j >> 5] |= (1 << (j & 31));
+		// never reached
+		return NULL;
 	}
-	else
+	// too big, allocate it directly
+#endif
+#if MEMCLUMPING == 2
+	return NULL;
+#else
+	base = (unsigned char *)attempt_malloc(size);
+	if (base && developer_memorydebug.integer)
+		memset(base, 0xAF, size);
+	return base;
+#endif
+}
+static void Clump_FreeBlock(void *base, size_t size)
+{
+#if MEMCLUMPING
+	unsigned int needbits;
+	unsigned int startbit;
+	unsigned int endbit;
+	unsigned int bit;
+	memclump_t **clumpchainpointer;
+	memclump_t *clump;
+	unsigned char *start = (unsigned char *)base;
+	for (clumpchainpointer = &clumpchain;(clump = *clumpchainpointer);clumpchainpointer = &(*clumpchainpointer)->chain)
+	{
+		if (start >= clump->block && start < clump->block + MEMCLUMPSIZE)
+		{
+			if (clump->sentinel1 != MEMHEADER_SENTINEL_FOR_ADDRESS(&clump->sentinel1))
+				Sys_Error("Clump_FreeBlock: trashed sentinel1\n");
+			if (clump->sentinel2 != MEMHEADER_SENTINEL_FOR_ADDRESS(&clump->sentinel2))
+				Sys_Error("Clump_FreeBlock: trashed sentinel2\n");
+			if (start + size > clump->block + MEMCLUMPSIZE)
+				Sys_Error("Clump_FreeBlock: block overrun\n");
+			// the block belongs to this clump, clear the range
+			needbits = (size + MEMUNIT - 1) / MEMUNIT;
+			startbit = (start - clump->block) / MEMUNIT;
+			endbit = startbit + needbits;
+			// first verify all bits are set, otherwise this may be misaligned or a double free
+			for (bit = startbit;bit < endbit;bit++)
+				if ((clump->bits[bit>>5] & (1<<(bit & 31))) == 0)
+					Sys_Error("Clump_FreeBlock: double free\n");
+			for (bit = startbit;bit < endbit;bit++)
+				clump->bits[bit>>5] &= ~(1<<(bit & 31));
+			clump->blocksinuse -= needbits;
+			memset(base, 0xFF, needbits * MEMUNIT);
+			// if all has been freed, free the clump itself
+			if (clump->blocksinuse == 0)
+			{
+				*clumpchainpointer = clump->chain;
+				if (developer_memorydebug.integer)
+					memset(clump, 0xFF, sizeof(*clump));
+#if MEMCLUMPING != 2
+				free(clump);
+#endif
+			}
+			return;
+		}
+	}
+	// does not belong to any known chunk...  assume it was a direct allocation
+#endif
+#if MEMCLUMPING != 2
+	memset(base, 0xFF, size);
+	free(base);
+#endif
+}
+
+void *_Mem_Alloc(mempool_t *pool, void *olddata, size_t size, size_t alignment, const char *filename, int fileline)
+{
+	unsigned int sentinel1;
+	unsigned int sentinel2;
+	size_t realsize;
+	size_t sharedsize;
+	size_t remainsize;
+	memheader_t *mem;
+	memheader_t *oldmem;
+	unsigned char *base;
+
+	if (size <= 0)
+	{
+		if (olddata)
+			_Mem_Free(olddata, filename, fileline);
+		return NULL;
+	}
+	if (pool == NULL)
+	{
+		if(olddata)
+			pool = ((memheader_t *)((unsigned char *) olddata - sizeof(memheader_t)))->pool;
+		else
+			Sys_Error("Mem_Alloc: pool == NULL (alloc at %s:%i)", filename, fileline);
+	}
+	if (mem_mutex)
+		Thread_LockMutex(mem_mutex);
+	if (developer_memory.integer || size >= developer_memoryreportlargerthanmb.value * 1048576)
+		Con_DPrintf("Mem_Alloc: pool %s, file %s:%i, size %f bytes (%f MB)\n", pool->name, filename, fileline, (double)size, (double)size / 1048576.0f);
+	//if (developer.integer > 0 && developer_memorydebug.integer)
+	//	_Mem_CheckSentinelsGlobal(filename, fileline);
+	pool->totalsize += size;
+	realsize = alignment + sizeof(memheader_t) + size + sizeof(sentinel2);
+	pool->realsize += realsize;
+	base = (unsigned char *)Clump_AllocBlock(realsize);
+	if (base == NULL)
 	{
-		// big allocations are not clumped
-		pool->realsize += sizeof(memheader_t) + size + sizeof(int);
-		mem = malloc(sizeof(memheader_t) + size + sizeof(int));
-		if (mem == NULL)
-			Host_Error("Mem_Alloc: out of memory");
-		mem->clump = NULL;
+		Mem_PrintList(0);
+		Mem_PrintStats();
+		Mem_PrintList(1<<30);
+		Mem_PrintStats();
+		Sys_Error("Mem_Alloc: out of memory (alloc of size %f (%.3fMB) at %s:%i)", (double)realsize, (double)realsize / (1 << 20), filename, fileline);
 	}
+	// calculate address that aligns the end of the memheader_t to the specified alignment
+	mem = (memheader_t*)((((size_t)base + sizeof(memheader_t) + (alignment-1)) & ~(alignment-1)) - sizeof(memheader_t));
+	mem->baseaddress = (void*)base;
 	mem->filename = filename;
 	mem->fileline = fileline;
 	mem->size = size;
 	mem->pool = pool;
-	mem->sentinel1 = MEMHEADER_SENTINEL;
-	*((int *)((long) mem + sizeof(memheader_t) + mem->size)) = MEMHEADER_SENTINEL;
+
+	// calculate sentinels (detects buffer overruns, in a way that is hard to exploit)
+	sentinel1 = MEMHEADER_SENTINEL_FOR_ADDRESS(&mem->sentinel);
+	sentinel2 = MEMHEADER_SENTINEL_FOR_ADDRESS((unsigned char *) mem + sizeof(memheader_t) + mem->size);
+	mem->sentinel = sentinel1;
+	memcpy((unsigned char *) mem + sizeof(memheader_t) + mem->size, &sentinel2, sizeof(sentinel2));
+
 	// append to head of list
-	mem->chain = pool->chain;
+	mem->next = pool->chain;
+	mem->prev = NULL;
 	pool->chain = mem;
-	memset((void *)((long) mem + sizeof(memheader_t)), 0, mem->size);
-	return (void *)((long) mem + sizeof(memheader_t));
+	if (mem->next)
+		mem->next->prev = mem;
+
+	if (mem_mutex)
+		Thread_UnlockMutex(mem_mutex);
+
+	// copy the shared portion in the case of a realloc, then memset the rest
+	sharedsize = 0;
+	remainsize = size;
+	if (olddata)
+	{
+		oldmem = (memheader_t*)olddata - 1;
+		sharedsize = min(oldmem->size, size);
+		memcpy((void *)((unsigned char *) mem + sizeof(memheader_t)), olddata, sharedsize);
+		remainsize -= sharedsize;
+		_Mem_Free(olddata, filename, fileline);
+	}
+	memset((void *)((unsigned char *) mem + sizeof(memheader_t) + sharedsize), 0, remainsize);
+	return (void *)((unsigned char *) mem + sizeof(memheader_t));
 }
 
-void Mem_Free(void *data)
+// only used by _Mem_Free and _Mem_FreePool
+static void _Mem_FreeBlock(memheader_t *mem, const char *filename, int fileline)
 {
-	int i, firstblock, endblock;
-	memclump_t *clump, **clumpchainpointer;
-	memheader_t *mem, **memchainpointer;
 	mempool_t *pool;
-	if (data == NULL)
-		Host_Error("Mem_Free: data == NULL");
+	size_t size;
+	size_t realsize;
+	unsigned int sentinel1;
+	unsigned int sentinel2;
 
+	// check sentinels (detects buffer overruns, in a way that is hard to exploit)
+	sentinel1 = MEMHEADER_SENTINEL_FOR_ADDRESS(&mem->sentinel);
+	sentinel2 = MEMHEADER_SENTINEL_FOR_ADDRESS((unsigned char *) mem + sizeof(memheader_t) + mem->size);
+	if (mem->sentinel != sentinel1)
+		Sys_Error("Mem_Free: trashed head sentinel (alloc at %s:%i, free at %s:%i)", mem->filename, mem->fileline, filename, fileline);
+	if (memcmp((unsigned char *) mem + sizeof(memheader_t) + mem->size, &sentinel2, sizeof(sentinel2)))
+		Sys_Error("Mem_Free: trashed tail sentinel (alloc at %s:%i, free at %s:%i)", mem->filename, mem->fileline, filename, fileline);
 
-	mem = (memheader_t *)((long) data - sizeof(memheader_t));
-	if (mem->sentinel1 != MEMHEADER_SENTINEL)
-		Sys_Error("Mem_Free: trashed header sentinel 1 (block allocated in %s:%i)\n", mem->filename, mem->fileline);
-	if (*((int *)((long) mem + sizeof(memheader_t) + mem->size)) != MEMHEADER_SENTINEL)
-		Sys_Error("Mem_Free: trashed header sentinel 2 (block allocated in %s:%i)\n", mem->filename, mem->fileline);
 	pool = mem->pool;
-	for (memchainpointer = &pool->chain;*memchainpointer;memchainpointer = &(*memchainpointer)->chain)
+	if (developer_memory.integer)
+		Con_DPrintf("Mem_Free: pool %s, alloc %s:%i, free %s:%i, size %i bytes\n", pool->name, mem->filename, mem->fileline, filename, fileline, (int)(mem->size));
+	// unlink memheader from doubly linked list
+	if ((mem->prev ? mem->prev->next != mem : pool->chain != mem) || (mem->next && mem->next->prev != mem))
+		Sys_Error("Mem_Free: not allocated or double freed (free at %s:%i)", filename, fileline);
+	if (mem_mutex)
+		Thread_LockMutex(mem_mutex);
+	if (mem->prev)
+		mem->prev->next = mem->next;
+	else
+		pool->chain = mem->next;
+	if (mem->next)
+		mem->next->prev = mem->prev;
+	// memheader has been unlinked, do the actual free now
+	size = mem->size;
+	realsize = sizeof(memheader_t) + size + sizeof(sentinel2);
+	pool->totalsize -= size;
+	pool->realsize -= realsize;
+	Clump_FreeBlock(mem->baseaddress, realsize);
+	if (mem_mutex)
+		Thread_UnlockMutex(mem_mutex);
+}
+
+void _Mem_Free(void *data, const char *filename, int fileline)
+{
+	if (data == NULL)
 	{
-		if (*memchainpointer == mem)
-		{
-			*memchainpointer = mem->chain;
-			pool->totalsize -= mem->size;
-			if ((clump = mem->clump))
-			{
-				if (clump->sentinel1 != MEMCLUMP_SENTINEL)
-					Sys_Error("Mem_Alloc: trashed clump sentinel 1\n");
-				if (clump->sentinel2 != MEMCLUMP_SENTINEL)
-					Sys_Error("Mem_Alloc: trashed clump sentinel 2\n");
-				firstblock = ((long) mem - (long) clump->block);
-				if (firstblock & (MEMUNIT - 1))
-					Host_Error("Mem_Free: address not valid in clump\n");
-				firstblock /= MEMUNIT;
-				endblock = firstblock + ((sizeof(memheader_t) + mem->size + sizeof(int) + (MEMUNIT - 1)) / MEMUNIT);
-				clump->blocksinuse -= endblock - firstblock;
-				// could use &, but we know the bit is set
-				for (i = firstblock;i < endblock;i++)
-					clump->bits[i >> 5] -= (1 << (i & 31));
-				if (clump->blocksinuse <= 0)
-				{
-					// unlink from chain
-					for (clumpchainpointer = &pool->clumpchain;*clumpchainpointer;clumpchainpointer = &(*clumpchainpointer)->chain)
-					{
-						if (*clumpchainpointer == clump)
-						{
-							*clumpchainpointer = clump->chain;
-							break;
-						}
-					}
-					pool->realsize -= sizeof(memclump_t);
-					memset(clump, 0xBF, sizeof(memclump_t));
-					free(clump);
-				}
-				else
-				{
-					// clump still has some allocations
-					// force re-check of largest available space on next alloc
-					clump->largestavailable = MEMBITS - clump->blocksinuse;
-				}
-			}
-			else
-			{
-				pool->realsize -= sizeof(memheader_t) + mem->size + sizeof(int);
-				memset(mem, 0xBF, sizeof(memheader_t) + mem->size + sizeof(int));
-				free(mem);
-			}
-			return;
-		}
+		Con_DPrintf("Mem_Free: data == NULL (called at %s:%i)\n", filename, fileline);
+		return;
 	}
-	Host_Error("Mem_Free: not allocated\n");
+
+	if (developer_memorydebug.integer)
+	{
+		//_Mem_CheckSentinelsGlobal(filename, fileline);
+		if (!Mem_IsAllocated(NULL, data))
+			Sys_Error("Mem_Free: data is not allocated (called at %s:%i)", filename, fileline);
+	}
+
+	_Mem_FreeBlock((memheader_t *)((unsigned char *) data - sizeof(memheader_t)), filename, fileline);
 }
 
-mempool_t *Mem_AllocPool(char *name)
+mempool_t *_Mem_AllocPool(const char *name, int flags, mempool_t *parent, const char *filename, int fileline)
 {
-//	int i;
 	mempool_t *pool;
-	pool = malloc(sizeof(mempool_t));
+	if (developer_memorydebug.integer)
+		_Mem_CheckSentinelsGlobal(filename, fileline);
+	pool = (mempool_t *)Clump_AllocBlock(sizeof(mempool_t));
 	if (pool == NULL)
-		Host_Error("Mem_AllocPool: out of memory");
+	{
+		Mem_PrintList(0);
+		Mem_PrintStats();
+		Mem_PrintList(1<<30);
+		Mem_PrintStats();
+		Sys_Error("Mem_AllocPool: out of memory (allocpool at %s:%i)", filename, fileline);
+	}
 	memset(pool, 0, sizeof(mempool_t));
+	pool->sentinel1 = MEMHEADER_SENTINEL_FOR_ADDRESS(&pool->sentinel1);
+	pool->sentinel2 = MEMHEADER_SENTINEL_FOR_ADDRESS(&pool->sentinel2);
+	pool->filename = filename;
+	pool->fileline = fileline;
+	pool->flags = flags;
 	pool->chain = NULL;
 	pool->totalsize = 0;
 	pool->realsize = sizeof(mempool_t);
-	strcpy(pool->name, name);
-//	for (i = 0;i < (POOLNAMESIZE - 1) && name[i];i++)
-//		pool->name[i] = name[i];
-//	for (i = 0;i < POOLNAMESIZE;i++)
-//		pool->name[i] = 0;
+	strlcpy (pool->name, name, sizeof (pool->name));
+	pool->parent = parent;
 	pool->next = poolchain;
 	poolchain = pool;
 	return pool;
 }
 
-void Mem_FreePool(mempool_t **pool)
+void _Mem_FreePool(mempool_t **poolpointer, const char *filename, int fileline)
 {
-	mempool_t **chainaddress;
-	if (*pool)
+	mempool_t *pool = *poolpointer;
+	mempool_t **chainaddress, *iter, *temp;
+
+	if (developer_memorydebug.integer)
+		_Mem_CheckSentinelsGlobal(filename, fileline);
+	if (pool)
 	{
 		// unlink pool from chain
-		for (chainaddress = &poolchain;*chainaddress && *chainaddress != *pool;chainaddress = &((*chainaddress)->next));
-		if (*chainaddress != *pool)
-			Host_Error("Mem_FreePool: pool already free");
-		*chainaddress = (*pool)->next;
+		for (chainaddress = &poolchain;*chainaddress && *chainaddress != pool;chainaddress = &((*chainaddress)->next));
+		if (*chainaddress != pool)
+			Sys_Error("Mem_FreePool: pool already free (freepool at %s:%i)", filename, fileline);
+		if (pool->sentinel1 != MEMHEADER_SENTINEL_FOR_ADDRESS(&pool->sentinel1))
+			Sys_Error("Mem_FreePool: trashed pool sentinel 1 (allocpool at %s:%i, freepool at %s:%i)", pool->filename, pool->fileline, filename, fileline);
+		if (pool->sentinel2 != MEMHEADER_SENTINEL_FOR_ADDRESS(&pool->sentinel2))
+			Sys_Error("Mem_FreePool: trashed pool sentinel 2 (allocpool at %s:%i, freepool at %s:%i)", pool->filename, pool->fileline, filename, fileline);
+		*chainaddress = pool->next;
 
 		// free memory owned by the pool
-		while ((*pool)->chain)
-			Mem_Free((void *)((long) (*pool)->chain + sizeof(memheader_t)));
+		while (pool->chain)
+			_Mem_FreeBlock(pool->chain, filename, fileline);
+
+		// free child pools, too
+		for(iter = poolchain; iter; iter = temp) {
+			temp = iter->next;
+			if(iter->parent == pool)
+				_Mem_FreePool(&temp, filename, fileline);
+		}
 
 		// free the pool itself
-		memset(*pool, 0xBF, sizeof(mempool_t));
-		free(*pool);
-		*pool = NULL;
+		Clump_FreeBlock(pool, sizeof(*pool));
+
+		*poolpointer = NULL;
 	}
 }
 
-void Mem_EmptyPool(mempool_t *pool)
+void _Mem_EmptyPool(mempool_t *pool, const char *filename, int fileline)
 {
+	mempool_t *chainaddress;
+
+	if (developer_memorydebug.integer)
+	{
+		//_Mem_CheckSentinelsGlobal(filename, fileline);
+		// check if this pool is in the poolchain
+		for (chainaddress = poolchain;chainaddress;chainaddress = chainaddress->next)
+			if (chainaddress == pool)
+				break;
+		if (!chainaddress)
+			Sys_Error("Mem_EmptyPool: pool is already free (emptypool at %s:%i)", filename, fileline);
+	}
 	if (pool == NULL)
-		Con_Printf("Mem_EmptyPool: pool == NULL\n");
+		Sys_Error("Mem_EmptyPool: pool == NULL (emptypool at %s:%i)", filename, fileline);
+	if (pool->sentinel1 != MEMHEADER_SENTINEL_FOR_ADDRESS(&pool->sentinel1))
+		Sys_Error("Mem_EmptyPool: trashed pool sentinel 1 (allocpool at %s:%i, emptypool at %s:%i)", pool->filename, pool->fileline, filename, fileline);
+	if (pool->sentinel2 != MEMHEADER_SENTINEL_FOR_ADDRESS(&pool->sentinel2))
+		Sys_Error("Mem_EmptyPool: trashed pool sentinel 2 (allocpool at %s:%i, emptypool at %s:%i)", pool->filename, pool->fileline, filename, fileline);
 
 	// free memory owned by the pool
 	while (pool->chain)
-		Mem_Free((void *)((long) pool->chain + sizeof(memheader_t)));
+		_Mem_FreeBlock(pool->chain, filename, fileline);
+
+	// empty child pools, too
+	for(chainaddress = poolchain; chainaddress; chainaddress = chainaddress->next)
+		if(chainaddress->parent == pool)
+			_Mem_EmptyPool(chainaddress, filename, fileline);
+
 }
 
-void _Mem_CheckSentinels(void *data, char *filename, int fileline)
+void _Mem_CheckSentinels(void *data, const char *filename, int fileline)
 {
 	memheader_t *mem;
+	unsigned int sentinel1;
+	unsigned int sentinel2;
 
 	if (data == NULL)
-		Host_Error("Mem_CheckSentinels: data == NULL\n");
+		Sys_Error("Mem_CheckSentinels: data == NULL (sentinel check at %s:%i)", filename, fileline);
 
-	mem = (memheader_t *)((long) data - sizeof(memheader_t));
-	if (mem->sentinel1 != MEMHEADER_SENTINEL)
-		Host_Error("Mem_CheckSentinels: trashed header sentinel 1 (block allocated at %s:%i, sentinel check at %s:%i)\n", mem->filename, mem->fileline, filename, fileline);
-	if (*((int *)((long) mem + sizeof(memheader_t) + mem->size)) != MEMHEADER_SENTINEL)
-		Host_Error("Mem_CheckSentinels: trashed header sentinel 2 (block allocated at %s:%i, sentinel check at %s:%i)\n", mem->filename, mem->fileline, filename, fileline);
+	mem = (memheader_t *)((unsigned char *) data - sizeof(memheader_t));
+	sentinel1 = MEMHEADER_SENTINEL_FOR_ADDRESS(&mem->sentinel);
+	sentinel2 = MEMHEADER_SENTINEL_FOR_ADDRESS((unsigned char *) mem + sizeof(memheader_t) + mem->size);
+	if (mem->sentinel != sentinel1)
+		Sys_Error("Mem_Free: trashed head sentinel (alloc at %s:%i, sentinel check at %s:%i)", mem->filename, mem->fileline, filename, fileline);
+	if (memcmp((unsigned char *) mem + sizeof(memheader_t) + mem->size, &sentinel2, sizeof(sentinel2)))
+		Sys_Error("Mem_Free: trashed tail sentinel (alloc at %s:%i, sentinel check at %s:%i)", mem->filename, mem->fileline, filename, fileline);
 }
 
-static void _Mem_CheckClumpSentinels(memclump_t *clump, char *filename, int fileline)
+#if MEMCLUMPING
+static void _Mem_CheckClumpSentinels(memclump_t *clump, const char *filename, int fileline)
 {
 	// this isn't really very useful
-	if (clump->sentinel1 != MEMCLUMP_SENTINEL)
-		Host_Error("Mem_CheckClumpSentinels: trashed sentinel 1 (sentinel check at %s:%i)\n", filename, fileline);
-	if (clump->sentinel2 != MEMCLUMP_SENTINEL)
-		Host_Error("Mem_CheckClumpSentinels: trashed sentinel 2 (sentinel check at %s:%i)\n", filename, fileline);
+	if (clump->sentinel1 != MEMHEADER_SENTINEL_FOR_ADDRESS(&clump->sentinel1))
+		Sys_Error("Mem_CheckClumpSentinels: trashed sentinel 1 (sentinel check at %s:%i)", filename, fileline);
+	if (clump->sentinel2 != MEMHEADER_SENTINEL_FOR_ADDRESS(&clump->sentinel2))
+		Sys_Error("Mem_CheckClumpSentinels: trashed sentinel 2 (sentinel check at %s:%i)", filename, fileline);
 }
+#endif
 
-void _Mem_CheckSentinelsGlobal(char *filename, int fileline)
+void _Mem_CheckSentinelsGlobal(const char *filename, int fileline)
 {
 	memheader_t *mem;
+#if MEMCLUMPING
 	memclump_t *clump;
+#endif
 	mempool_t *pool;
 	for (pool = poolchain;pool;pool = pool->next)
 	{
-		for (mem = pool->chain;mem;mem = mem->chain)
-			_Mem_CheckSentinels((void *)((long) mem + sizeof(memheader_t)), filename, fileline);
-		for (clump = pool->clumpchain;clump;clump = clump->chain)
+		if (pool->sentinel1 != MEMHEADER_SENTINEL_FOR_ADDRESS(&pool->sentinel1))
+			Sys_Error("Mem_CheckSentinelsGlobal: trashed pool sentinel 1 (allocpool at %s:%i, sentinel check at %s:%i)", pool->filename, pool->fileline, filename, fileline);
+		if (pool->sentinel2 != MEMHEADER_SENTINEL_FOR_ADDRESS(&pool->sentinel2))
+			Sys_Error("Mem_CheckSentinelsGlobal: trashed pool sentinel 2 (allocpool at %s:%i, sentinel check at %s:%i)", pool->filename, pool->fileline, filename, fileline);
+	}
+	for (pool = poolchain;pool;pool = pool->next)
+		for (mem = pool->chain;mem;mem = mem->next)
+			_Mem_CheckSentinels((void *)((unsigned char *) mem + sizeof(memheader_t)), filename, fileline);
+#if MEMCLUMPING
+	for (pool = poolchain;pool;pool = pool->next)
+		for (clump = clumpchain;clump;clump = clump->chain)
 			_Mem_CheckClumpSentinels(clump, filename, fileline);
+#endif
+}
+
+qboolean Mem_IsAllocated(mempool_t *pool, void *data)
+{
+	memheader_t *header;
+	memheader_t *target;
+
+	if (pool)
+	{
+		// search only one pool
+		target = (memheader_t *)((unsigned char *) data - sizeof(memheader_t));
+		for( header = pool->chain ; header ; header = header->next )
+			if( header == target )
+				return true;
+	}
+	else
+	{
+		// search all pools
+		for (pool = poolchain;pool;pool = pool->next)
+			if (Mem_IsAllocated(pool, data))
+				return true;
+	}
+	return false;
+}
+
+void Mem_ExpandableArray_NewArray(memexpandablearray_t *l, mempool_t *mempool, size_t recordsize, int numrecordsperarray)
+{
+	memset(l, 0, sizeof(*l));
+	l->mempool = mempool;
+	l->recordsize = recordsize;
+	l->numrecordsperarray = numrecordsperarray;
+}
+
+void Mem_ExpandableArray_FreeArray(memexpandablearray_t *l)
+{
+	size_t i;
+	if (l->maxarrays)
+	{
+		for (i = 0;i != l->numarrays;i++)
+			Mem_Free(l->arrays[i].data);
+		Mem_Free(l->arrays);
+	}
+	memset(l, 0, sizeof(*l));
+}
+
+void *Mem_ExpandableArray_AllocRecord(memexpandablearray_t *l)
+{
+	size_t i, j;
+	for (i = 0;;i++)
+	{
+		if (i == l->numarrays)
+		{
+			if (l->numarrays == l->maxarrays)
+			{
+				memexpandablearray_array_t *oldarrays = l->arrays;
+				l->maxarrays = max(l->maxarrays * 2, 128);
+				l->arrays = (memexpandablearray_array_t*) Mem_Alloc(l->mempool, l->maxarrays * sizeof(*l->arrays));
+				if (oldarrays)
+				{
+					memcpy(l->arrays, oldarrays, l->numarrays * sizeof(*l->arrays));
+					Mem_Free(oldarrays);
+				}
+			}
+			l->arrays[i].numflaggedrecords = 0;
+			l->arrays[i].data = (unsigned char *) Mem_Alloc(l->mempool, (l->recordsize + 1) * l->numrecordsperarray);
+			l->arrays[i].allocflags = l->arrays[i].data + l->recordsize * l->numrecordsperarray;
+			l->numarrays++;
+		}
+		if (l->arrays[i].numflaggedrecords < l->numrecordsperarray)
+		{
+			for (j = 0;j < l->numrecordsperarray;j++)
+			{
+				if (!l->arrays[i].allocflags[j])
+				{
+					l->arrays[i].allocflags[j] = true;
+					l->arrays[i].numflaggedrecords++;
+					memset(l->arrays[i].data + l->recordsize * j, 0, l->recordsize);
+					return (void *)(l->arrays[i].data + l->recordsize * j);
+				}
+			}
+		}
+	}
+}
+
+/*****************************************************************************
+ * IF YOU EDIT THIS:
+ * If this function was to change the size of the "expandable" array, you have
+ * to update r_shadow.c
+ * Just do a search for "range =", R_ShadowClearWorldLights would be the first
+ * function to look at. (And also seems like the only one?) You  might have to
+ * move the  call to Mem_ExpandableArray_IndexRange  back into for(...) loop's
+ * condition
+ */
+void Mem_ExpandableArray_FreeRecord(memexpandablearray_t *l, void *record) // const!
+{
+	size_t i, j;
+	unsigned char *p = (unsigned char *)record;
+	for (i = 0;i != l->numarrays;i++)
+	{
+		if (p >= l->arrays[i].data && p < (l->arrays[i].data + l->recordsize * l->numrecordsperarray))
+		{
+			j = (p - l->arrays[i].data) / l->recordsize;
+			if (p != l->arrays[i].data + j * l->recordsize)
+				Sys_Error("Mem_ExpandableArray_FreeRecord: no such record %p\n", p);
+			if (!l->arrays[i].allocflags[j])
+				Sys_Error("Mem_ExpandableArray_FreeRecord: record %p is already free!\n", p);
+			l->arrays[i].allocflags[j] = false;
+			l->arrays[i].numflaggedrecords--;
+			return;
+		}
+	}
+}
+
+size_t Mem_ExpandableArray_IndexRange(const memexpandablearray_t *l)
+{
+	size_t i, j, k, end = 0;
+	for (i = 0;i < l->numarrays;i++)
+	{
+		for (j = 0, k = 0;k < l->arrays[i].numflaggedrecords;j++)
+		{
+			if (l->arrays[i].allocflags[j])
+			{
+				end = l->numrecordsperarray * i + j + 1;
+				k++;
+			}
+		}
 	}
+	return end;
 }
 
-// used for temporary memory allocations around the engine, not for longterm storage
+void *Mem_ExpandableArray_RecordAtIndex(const memexpandablearray_t *l, size_t index)
+{
+	size_t i, j;
+	i = index / l->numrecordsperarray;
+	j = index % l->numrecordsperarray;
+	if (i >= l->numarrays || !l->arrays[i].allocflags[j])
+		return NULL;
+	return (void *)(l->arrays[i].data + j * l->recordsize);
+}
+
+
+// used for temporary memory allocations around the engine, not for longterm
+// storage, if anything in this pool stays allocated during gameplay, it is
+// considered a leak
 mempool_t *tempmempool;
 // only for zone
 mempool_t *zonemempool;
 
 void Mem_PrintStats(void)
 {
-	int count = 0, size = 0;
+	size_t count = 0, size = 0, realsize = 0;
 	mempool_t *pool;
+	memheader_t *mem;
+	Mem_CheckSentinelsGlobal();
 	for (pool = poolchain;pool;pool = pool->next)
 	{
 		count++;
 		size += pool->totalsize;
+		realsize += pool->realsize;
+	}
+	Con_Printf("%lu memory pools, totalling %lu bytes (%.3fMB)\n", (unsigned long)count, (unsigned long)size, size / 1048576.0);
+	Con_Printf("total allocated size: %lu bytes (%.3fMB)\n", (unsigned long)realsize, realsize / 1048576.0);
+	for (pool = poolchain;pool;pool = pool->next)
+	{
+		if ((pool->flags & POOLFLAG_TEMP) && pool->chain)
+		{
+			Con_Printf("Memory pool %p has sprung a leak totalling %lu bytes (%.3fMB)!  Listing contents...\n", (void *)pool, (unsigned long)pool->totalsize, pool->totalsize / 1048576.0);
+			for (mem = pool->chain;mem;mem = mem->next)
+				Con_Printf("%10lu bytes allocated at %s:%i\n", (unsigned long)mem->size, mem->filename, mem->fileline);
+		}
 	}
-	Con_Printf("%i memory pools, totalling %i bytes (%.3fMB)\n", count, size, size / 1048576.0);
-	if (tempmempool == NULL)
-		Con_Printf("Error: no tempmempool allocated\n");
-	else if (tempmempool->chain)
-		Con_Printf("%i bytes (%.3fMB) of temporary memory still allocated (Leak!)\n", tempmempool->totalsize, tempmempool->totalsize / 1048576.0);
 }
 
-void Mem_PrintList_f(void)
+void Mem_PrintList(size_t minallocationsize)
 {
 	mempool_t *pool;
-	Con_Printf("memory pool list:\n"
+	memheader_t *mem;
+	Mem_CheckSentinelsGlobal();
+	Con_Print("memory pool list:\n"
 	           "size    name\n");
 	for (pool = poolchain;pool;pool = pool->next)
 	{
-		if (pool->lastchecksize != 0 && pool->totalsize != pool->lastchecksize)
-			Con_Printf("%6ik (%6ik actual) %s (%i byte change)\n", (pool->totalsize + 1023) / 1024, (pool->realsize + 1023) / 1024, pool->name, pool->totalsize - pool->lastchecksize);
-		else
-			Con_Printf("%6ik (%6ik actual) %s\n", (pool->totalsize + 1023) / 1024, (pool->realsize + 1023) / 1024, pool->name);
+		Con_Printf("%10luk (%10luk actual) %s (%+li byte change) %s\n", (unsigned long) ((pool->totalsize + 1023) / 1024), (unsigned long)((pool->realsize + 1023) / 1024), pool->name, (long)(pool->totalsize - pool->lastchecksize), (pool->flags & POOLFLAG_TEMP) ? "TEMP" : "");
 		pool->lastchecksize = pool->totalsize;
+		for (mem = pool->chain;mem;mem = mem->next)
+			if (mem->size >= minallocationsize)
+				Con_Printf("%10lu bytes allocated at %s:%i\n", (unsigned long)mem->size, mem->filename, mem->fileline);
 	}
-	Mem_PrintStats();
 }
 
-extern void R_TextureStats_PrintTotal(void);
-void Memstats_f(void)
+static void MemList_f(void)
 {
-	R_TextureStats_PrintTotal();
+	switch(Cmd_Argc())
+	{
+	case 1:
+		Mem_PrintList(1<<30);
+		Mem_PrintStats();
+		break;
+	case 2:
+		Mem_PrintList(atoi(Cmd_Argv(1)) * 1024);
+		Mem_PrintStats();
+		break;
+	default:
+		Con_Print("MemList_f: unrecognized options\nusage: memlist [all]\n");
+		break;
+	}
+}
+
+static void MemStats_f(void)
+{
+	Mem_CheckSentinelsGlobal();
+	R_TextureStats_Print(false, false, true);
+	GL_Mesh_ListVBOs(false);
 	Mem_PrintStats();
 }
 
 
+char* Mem_strdup (mempool_t *pool, const char* s)
+{
+	char* p;
+	size_t sz;
+	if (s == NULL)
+		return NULL;
+	sz = strlen (s) + 1;
+	p = (char*)Mem_Alloc (pool, sz);
+	strlcpy (p, s, sz);
+	return p;
+}
+
 /*
 ========================
 Memory_Init
@@ -321,13 +891,98 @@ Memory_Init
 */
 void Memory_Init (void)
 {
-	tempmempool = Mem_AllocPool("Temporary Memory");
-	zonemempool = Mem_AllocPool("Zone");
+	static union {unsigned short s;unsigned char b[2];} u;
+	u.s = 0x100;
+	mem_bigendian = u.b[0] != 0;
+
+	sentinel_seed = rand();
+	poolchain = NULL;
+	tempmempool = Mem_AllocPool("Temporary Memory", POOLFLAG_TEMP, NULL);
+	zonemempool = Mem_AllocPool("Zone", 0, NULL);
+
+	if (Thread_HasThreads())
+		mem_mutex = Thread_CreateMutex();
+}
+
+void Memory_Shutdown (void)
+{
+//	Mem_FreePool (&zonemempool);
+//	Mem_FreePool (&tempmempool);
+
+	if (mem_mutex)
+		Thread_DestroyMutex(mem_mutex);
+	mem_mutex = NULL;
 }
 
 void Memory_Init_Commands (void)
 {
-	Cmd_AddCommand ("memstats", Memstats_f);
-	Cmd_AddCommand ("memlist", Mem_PrintList_f);
+	Cmd_AddCommand ("memstats", MemStats_f, "prints memory system statistics");
+	Cmd_AddCommand ("memlist", MemList_f, "prints memory pool information (or if used as memlist 5 lists individual allocations of 5K or larger, 0 lists all allocations)");
+	Cvar_RegisterVariable (&developer_memory);
+	Cvar_RegisterVariable (&developer_memorydebug);
+	Cvar_RegisterVariable (&developer_memoryreportlargerthanmb);
+	Cvar_RegisterVariable (&sys_memsize_physical);
+	Cvar_RegisterVariable (&sys_memsize_virtual);
+
+#if defined(WIN32)
+#ifdef _WIN64
+	{
+		MEMORYSTATUSEX status;
+		// first guess
+		Cvar_SetValueQuick(&sys_memsize_virtual, 8388608);
+		// then improve
+		status.dwLength = sizeof(status);
+		if(GlobalMemoryStatusEx(&status))
+		{
+			Cvar_SetValueQuick(&sys_memsize_physical, status.ullTotalPhys / 1048576.0);
+			Cvar_SetValueQuick(&sys_memsize_virtual, min(sys_memsize_virtual.value, status.ullTotalVirtual / 1048576.0));
+		}
+	}
+#else
+	{
+		MEMORYSTATUS status;
+		// first guess
+		Cvar_SetValueQuick(&sys_memsize_virtual, 2048);
+		// then improve
+		status.dwLength = sizeof(status);
+		GlobalMemoryStatus(&status);
+		Cvar_SetValueQuick(&sys_memsize_physical, status.dwTotalPhys / 1048576.0);
+		Cvar_SetValueQuick(&sys_memsize_virtual, min(sys_memsize_virtual.value, status.dwTotalVirtual / 1048576.0));
+	}
+#endif
+#else
+	{
+		// first guess
+		Cvar_SetValueQuick(&sys_memsize_virtual, (sizeof(void*) == 4) ? 2048 : 268435456);
+		// then improve
+		{
+			// Linux, and BSD with linprocfs mounted
+			FILE *f = fopen("/proc/meminfo", "r");
+			if(f)
+			{
+				static char buf[1024];
+				while(fgets(buf, sizeof(buf), f))
+				{
+					const char *p = buf;
+					if(!COM_ParseToken_Console(&p))
+						continue;
+					if(!strcmp(com_token, "MemTotal:"))
+					{
+						if(!COM_ParseToken_Console(&p))
+							continue;
+						Cvar_SetValueQuick(&sys_memsize_physical, atof(com_token) / 1024.0);
+					}
+					if(!strcmp(com_token, "SwapTotal:"))
+					{
+						if(!COM_ParseToken_Console(&p))
+							continue;
+						Cvar_SetValueQuick(&sys_memsize_virtual, min(sys_memsize_virtual.value , atof(com_token) / 1024.0 + sys_memsize_physical.value));
+					}
+				}
+				fclose(f);
+			}
+		}
+	}
+#endif
 }