diff --git a/vm/code_block.cpp b/vm/code_block.cpp
index bd7a93bf6d..507dd3bd61 100755
--- a/vm/code_block.cpp
+++ b/vm/code_block.cpp
@@ -93,9 +93,9 @@ void factor_vm::undefined_symbol()
 	general_error(ERROR_UNDEFINED_SYMBOL,F,F,NULL);
 }
 
-void undefined_symbol(factor_vm *myvm)
+void undefined_symbol()
 {
-	return myvm->undefined_symbol();
+	return SIGNAL_VM_PTR()->undefined_symbol();
 }
 
 /* Look up an external library symbol referenced by a compiled code block */
diff --git a/vm/contexts.cpp b/vm/contexts.cpp
index 6e51ed8ba9..d2d9db2b51 100644
--- a/vm/contexts.cpp
+++ b/vm/contexts.cpp
@@ -43,9 +43,9 @@ context *factor_vm::alloc_context()
 	}
 	else
 	{
-		new_context = (context *)safe_malloc(sizeof(context));
-		new_context->datastack_region = alloc_segment(ds_size);
-		new_context->retainstack_region = alloc_segment(rs_size);
+		new_context = new context;
+		new_context->datastack_region = new segment(this,ds_size);
+		new_context->retainstack_region = new segment(this,rs_size);
 	}
 
 	return new_context;
diff --git a/vm/data_gc.cpp b/vm/data_gc.cpp
index 011cc1f5f3..07f457b447 100755
--- a/vm/data_gc.cpp
+++ b/vm/data_gc.cpp
@@ -455,7 +455,7 @@ void factor_vm::end_gc(cell gc_elapsed)
 
 	if(growing_data_heap)
 	{
-		dealloc_data_heap(old_data_heap);
+		delete old_data_heap;
 		old_data_heap = NULL;
 		growing_data_heap = false;
 	}
diff --git a/vm/data_heap.cpp b/vm/data_heap.cpp
index 5eaa715e6c..ecc891b369 100755
--- a/vm/data_heap.cpp
+++ b/vm/data_heap.cpp
@@ -3,14 +3,6 @@
 namespace factor
 {
 
-cell factor_vm::init_zone(zone *z, cell size, cell start)
-{
-	z->size = size;
-	z->start = z->here = start;
-	z->end = start + size;
-	return z->end;
-}
-
 void factor_vm::init_card_decks()
 {
 	cell start = align(data->seg->start,deck_size);
@@ -19,89 +11,86 @@ void factor_vm::init_card_decks()
 	decks_offset = (cell)data->decks - (start >> deck_bits);
 }
 
-data_heap *factor_vm::alloc_data_heap(cell gens, cell young_size,cell aging_size,cell tenured_size)
+data_heap::data_heap(factor_vm *myvm, cell gen_count_, cell young_size_, cell aging_size_, cell tenured_size_)
 {
-	young_size = align(young_size,deck_size);
-	aging_size = align(aging_size,deck_size);
-	tenured_size = align(tenured_size,deck_size);
+	young_size_ = align(young_size_,deck_size);
+	aging_size_ = align(aging_size_,deck_size);
+	tenured_size_ = align(tenured_size_,deck_size);
 
-	data_heap *data = (data_heap *)safe_malloc(sizeof(data_heap));
-	data->young_size = young_size;
-	data->aging_size = aging_size;
-	data->tenured_size = tenured_size;
-	data->gen_count = gens;
+	young_size = young_size_;
+	aging_size = aging_size_;
+	tenured_size = tenured_size_;
+	gen_count = gen_count_;
 
 	cell total_size;
-	if(data->gen_count == 2)
+	if(gen_count == 2)
 		total_size = young_size + 2 * tenured_size;
-	else if(data->gen_count == 3)
+	else if(gen_count == 3)
 		total_size = young_size + 2 * aging_size + 2 * tenured_size;
 	else
 	{
-		fatal_error("Invalid number of generations",data->gen_count);
-		return NULL; /* can't happen */
+		total_size = 0;
+		fatal_error("Invalid number of generations",gen_count);
 	}
 
 	total_size += deck_size;
 
-	data->seg = alloc_segment(total_size);
+	seg = new segment(myvm,total_size);
 
-	data->generations = (zone *)safe_malloc(sizeof(zone) * data->gen_count);
-	data->semispaces = (zone *)safe_malloc(sizeof(zone) * data->gen_count);
+	generations = new zone[gen_count];
+	semispaces = new zone[gen_count];
 
 	cell cards_size = total_size >> card_bits;
-	data->allot_markers = (cell *)safe_malloc(cards_size);
-	data->allot_markers_end = data->allot_markers + cards_size;
+	allot_markers = new char[cards_size];
+	allot_markers_end = allot_markers + cards_size;
 
-	data->cards = (cell *)safe_malloc(cards_size);
-	data->cards_end = data->cards + cards_size;
+	cards = new char[cards_size];
+	cards_end = cards + cards_size;
 
 	cell decks_size = total_size >> deck_bits;
-	data->decks = (cell *)safe_malloc(decks_size);
-	data->decks_end = data->decks + decks_size;
+	decks = new char[decks_size];
+	decks_end = decks + decks_size;
 
-	cell alloter = align(data->seg->start,deck_size);
+	cell alloter = align(seg->start,deck_size);
 
-	alloter = init_zone(&data->generations[data->tenured()],tenured_size,alloter);
-	alloter = init_zone(&data->semispaces[data->tenured()],tenured_size,alloter);
+	alloter = generations[tenured()].init_zone(tenured_size,alloter);
+	alloter = semispaces[tenured()].init_zone(tenured_size,alloter);
 
-	if(data->gen_count == 3)
+	if(gen_count == 3)
 	{
-		alloter = init_zone(&data->generations[data->aging()],aging_size,alloter);
-		alloter = init_zone(&data->semispaces[data->aging()],aging_size,alloter);
+		alloter = generations[aging()].init_zone(aging_size,alloter);
+		alloter = semispaces[aging()].init_zone(aging_size,alloter);
 	}
 
-	if(data->gen_count >= 2)
+	if(gen_count >= 2)
 	{
-		alloter = init_zone(&data->generations[data->nursery()],young_size,alloter);
-		alloter = init_zone(&data->semispaces[data->nursery()],0,alloter);
+		alloter = generations[nursery()].init_zone(young_size,alloter);
+		alloter = semispaces[nursery()].init_zone(0,alloter);
 	}
 
-	if(data->seg->end - alloter > deck_size)
-		critical_error("Bug in alloc_data_heap",alloter);
-
-	return data;
+	if(seg->end - alloter > deck_size)
+		myvm->critical_error("Bug in alloc_data_heap",alloter);
 }
 
 data_heap *factor_vm::grow_data_heap(data_heap *data, cell requested_bytes)
 {
 	cell new_tenured_size = (data->tenured_size * 2) + requested_bytes;
 
-	return alloc_data_heap(data->gen_count,
+	return new data_heap(this,
+		data->gen_count,
 		data->young_size,
 		data->aging_size,
 		new_tenured_size);
 }
 
-void factor_vm::dealloc_data_heap(data_heap *data)
+data_heap::~data_heap()
 {
-	dealloc_segment(data->seg);
-	free(data->generations);
-	free(data->semispaces);
-	free(data->allot_markers);
-	free(data->cards);
-	free(data->decks);
-	free(data);
+	delete seg;
+	delete[] generations;
+	delete[] semispaces;
+	delete[] allot_markers;
+	delete[] cards;
+	delete[] decks;
 }
 
 void factor_vm::clear_cards(cell from, cell to)
@@ -162,7 +151,7 @@ void factor_vm::set_data_heap(data_heap *data_)
 
 void factor_vm::init_data_heap(cell gens,cell young_size,cell aging_size,cell tenured_size,bool secure_gc_)
 {
-	set_data_heap(alloc_data_heap(gens,young_size,aging_size,tenured_size));
+	set_data_heap(new data_heap(this,gens,young_size,aging_size,tenured_size));
 	secure_gc = secure_gc_;
 	init_data_gc();
 }
diff --git a/vm/data_heap.hpp b/vm/data_heap.hpp
index 81a3405d42..8b8ca59185 100755
--- a/vm/data_heap.hpp
+++ b/vm/data_heap.hpp
@@ -9,6 +9,14 @@ struct zone {
 	cell here;
 	cell size;
 	cell end;
+	
+	cell init_zone(cell size_, cell start_)
+	{
+		size = size_;
+		start = here = start_;
+		end = start_ + size_;
+		return end;
+	}
 };
 
 struct data_heap {
@@ -23,14 +31,14 @@ struct data_heap {
 	zone *generations;
 	zone *semispaces;
 
-	cell *allot_markers;
-	cell *allot_markers_end;
+	char *allot_markers;
+	char *allot_markers_end;
 
-	cell *cards;
-	cell *cards_end;
+	char *cards;
+	char *cards_end;
 
-	cell *decks;
-	cell *decks_end;
+	char *decks;
+	char *decks_end;
 	
 	/* the 0th generation is where new objects are allocated. */
 	cell nursery() { return 0; }
@@ -42,6 +50,9 @@ struct data_heap {
 	cell tenured() { return gen_count - 1; }
 	
 	bool have_aging_p() { return gen_count > 2; }
+
+	data_heap(factor_vm *myvm, cell gen_count, cell young_size, cell aging_size, cell tenured_size);
+	~data_heap();
 };
 
 static const cell max_gen_count = 3;
@@ -51,11 +62,6 @@ inline static bool in_zone(zone *z, object *pointer)
 	return (cell)pointer >= z->start && (cell)pointer < z->end;
 }
 
-/* set up guard pages to check for under/overflow.
-size must be a multiple of the page size */
-segment *alloc_segment(cell size);    //  defined in OS-*.cpp files PD
-void dealloc_segment(segment *block);
-
 PRIMITIVE(data_room);
 PRIMITIVE(size);
 
diff --git a/vm/heap.cpp b/vm/heap.cpp
index 0905d7c190..c8262cb7f5 100644
--- a/vm/heap.cpp
+++ b/vm/heap.cpp
@@ -14,7 +14,7 @@ void heap::clear_free_list()
 heap::heap(factor_vm *myvm_, cell size)
 {
 	myvm = myvm_;
-	seg = myvm->alloc_segment(myvm->align_page(size));
+	seg = new segment(myvm,align_page(size));
 	if(!seg) fatal_error("Out of memory in new_heap",size);
 	clear_free_list();
 }
diff --git a/vm/inlineimpls.hpp b/vm/inlineimpls.hpp
index db6ef8abf4..7074f0d33a 100644
--- a/vm/inlineimpls.hpp
+++ b/vm/inlineimpls.hpp
@@ -4,13 +4,6 @@ namespace factor
 // I've had to copy inline implementations here to make dependencies work. Am hoping to move this code back into include files
 // once the rest of the reentrant changes are done. -PD
 
-// segments.hpp
-
-inline cell factor_vm::align_page(cell a)
-{
-	return align(a,getpagesize());
-}
-
 // write_barrier.hpp
 
 inline card *factor_vm::addr_to_card(cell a)
diff --git a/vm/os-genunix.cpp b/vm/os-genunix.cpp
index 7f2429e46a..015a76f842 100644
--- a/vm/os-genunix.cpp
+++ b/vm/os-genunix.cpp
@@ -18,6 +18,7 @@ void early_init() { }
 #define SUFFIX ".image"
 #define SUFFIX_LEN 6
 
+/* You must delete[] the result yourself. */
 const char *default_image_path()
 {
 	const char *path = vm_executable_path();
@@ -31,7 +32,7 @@ const char *default_image_path()
 	const char *iter = path;
 	while(*iter) { len++; iter++; }
 
-	char *new_path = (char *)safe_malloc(PATH_MAX + SUFFIX_LEN + 1);
+	char *new_path = new char[PATH_MAX + SUFFIX_LEN + 1];
 	memcpy(new_path,path,len + 1);
 	memcpy(new_path + len,SUFFIX,SUFFIX_LEN + 1);
 	return new_path;
diff --git a/vm/os-linux.cpp b/vm/os-linux.cpp
index 66b197e7c9..2d26fba390 100644
--- a/vm/os-linux.cpp
+++ b/vm/os-linux.cpp
@@ -3,10 +3,10 @@
 namespace factor
 {
 
-/* Snarfed from SBCL linux-so.c. You must free() this yourself. */
+/* Snarfed from SBCL linux-so.c. You must delete[] the result yourself. */
 const char *vm_executable_path()
 {
-	char *path = (char *)safe_malloc(PATH_MAX + 1);
+	char *path = new char[PATH_MAX + 1];
 
 	int size = readlink("/proc/self/exe", path, PATH_MAX);
 	if (size < 0)
diff --git a/vm/os-unix.cpp b/vm/os-unix.cpp
index c829c3570c..d1af5cb565 100644
--- a/vm/os-unix.cpp
+++ b/vm/os-unix.cpp
@@ -83,8 +83,11 @@ inline void factor_vm::primitive_existsp()
 
 PRIMITIVE_FORWARD(existsp)
 
-segment *factor_vm::alloc_segment(cell size)
+segment::segment(factor_vm *myvm_, cell size_)
 {
+	myvm = myvm_;
+	size = size_;
+
 	int pagesize = getpagesize();
 
 	char *array = (char *)mmap(NULL,pagesize + size + pagesize,
@@ -92,7 +95,7 @@ segment *factor_vm::alloc_segment(cell size)
 		MAP_ANON | MAP_PRIVATE,-1,0);
 
 	if(array == (char*)-1)
-		out_of_memory();
+		myvm->out_of_memory();
 
 	if(mprotect(array,pagesize,PROT_NONE) == -1)
 		fatal_error("Cannot protect low guard page",(cell)array);
@@ -100,26 +103,16 @@ segment *factor_vm::alloc_segment(cell size)
 	if(mprotect(array + pagesize + size,pagesize,PROT_NONE) == -1)
 		fatal_error("Cannot protect high guard page",(cell)array);
 
-	segment *retval = (segment *)safe_malloc(sizeof(segment));
-
-	retval->start = (cell)(array + pagesize);
-	retval->size = size;
-	retval->end = retval->start + size;
-
-	return retval;
+	start = (cell)(array + pagesize);
+	end = start + size;
 }
 
-void dealloc_segment(segment *block)
+segment::~segment()
 {
 	int pagesize = getpagesize();
-
-	int retval = munmap((void*)(block->start - pagesize),
-		pagesize + block->size + pagesize);
-	
+	int retval = munmap((void*)(start - pagesize),pagesize + size + pagesize);
 	if(retval)
-		fatal_error("dealloc_segment failed",0);
-
-	free(block);
+		fatal_error("Segment deallocation failed",0);
 }
   
 stack_frame *factor_vm::uap_stack_pointer(void *uap)
diff --git a/vm/os-windows.cpp b/vm/os-windows.cpp
index 7d4b345da6..077bc48aa1 100644
--- a/vm/os-windows.cpp
+++ b/vm/os-windows.cpp
@@ -98,14 +98,17 @@ inline void factor_vm::primitive_existsp()
 
 PRIMITIVE_FORWARD(existsp)
 
-segment *factor_vm::alloc_segment(cell size)
+segment::segment(factor_vm *myvm_, cell size_)
 {
+	myvm = myvm_;
+	size = size_;
+
 	char *mem;
 	DWORD ignore;
 
 	if((mem = (char *)VirtualAlloc(NULL, getpagesize() * 2 + size,
 		MEM_COMMIT, PAGE_EXECUTE_READWRITE)) == 0)
-		out_of_memory();
+		myvm->out_of_memory();
 
 	if (!VirtualProtect(mem, getpagesize(), PAGE_NOACCESS, &ignore))
 		fatal_error("Cannot allocate low guard page", (cell)mem);
@@ -114,22 +117,16 @@ segment *factor_vm::alloc_segment(cell size)
 		getpagesize(), PAGE_NOACCESS, &ignore))
 		fatal_error("Cannot allocate high guard page", (cell)mem);
 
-	segment *block = (segment *)safe_malloc(sizeof(segment));
-
-	block->start = (cell)mem + getpagesize();
-	block->size = size;
-	block->end = block->start + size;
-
-	return block;
+	start = (cell)mem + getpagesize();
+	end = start + size;
 }
 
-void factor_vm::dealloc_segment(segment *block)
+segment::~segment()
 {
 	SYSTEM_INFO si;
 	GetSystemInfo(&si);
-	if(!VirtualFree((void*)(block->start - si.dwPageSize), 0, MEM_RELEASE))
-		fatal_error("dealloc_segment failed",0);
-	free(block);
+	if(!VirtualFree((void*)(start - si.dwPageSize), 0, MEM_RELEASE))
+		myvm->fatal_error("Segment deallocation failed",0);
 }
 
 long factor_vm::getpagesize()
diff --git a/vm/segments.hpp b/vm/segments.hpp
index a715b4dabc..1884526ad2 100644
--- a/vm/segments.hpp
+++ b/vm/segments.hpp
@@ -1,10 +1,23 @@
 namespace factor
 {
 
+struct factor_vm;
+
+inline cell align_page(cell a)
+{
+	return align(a,getpagesize());
+}
+
+/* segments set up guard pages to check for under/overflow.
+size must be a multiple of the page size */
 struct segment {
+	factor_vm *myvm;
 	cell start;
 	cell size;
 	cell end;
+
+	segment(factor_vm *myvm, cell size);
+	~segment();
 };
 
 }
diff --git a/vm/vm.hpp b/vm/vm.hpp
index 056393edb4..d75c3e0eaf 100644
--- a/vm/vm.hpp
+++ b/vm/vm.hpp
@@ -5,9 +5,6 @@ namespace factor
 
 struct factor_vm : factor_vm_data {
 
-	// segments
-	inline cell align_page(cell a);
-
 	// contexts
 	void reset_datastack();
 	void reset_retainstack();
@@ -127,11 +124,8 @@ struct factor_vm : factor_vm_data {
 	bignum *digit_stream_to_bignum(unsigned int n_digits, unsigned int (*producer)(unsigned int, factor_vm *), unsigned int radix, int negative_p);
 
 	//data_heap
-	cell init_zone(zone *z, cell size, cell start);
 	void init_card_decks();
-	data_heap *alloc_data_heap(cell gens, cell young_size,cell aging_size,cell tenured_size);
 	data_heap *grow_data_heap(data_heap *data, cell requested_bytes);
-	void dealloc_data_heap(data_heap *data);
 	void clear_cards(cell from, cell to);
 	void clear_decks(cell from, cell to);
 	void clear_allot_markers(cell from, cell to);
@@ -560,14 +554,12 @@ struct factor_vm : factor_vm_data {
 	void ffi_dlopen(dll *dll);
 	void *ffi_dlsym(dll *dll, symbol_char *symbol);
 	void ffi_dlclose(dll *dll);
-	segment *alloc_segment(cell size);
 	void c_to_factor_toplevel(cell quot);
 
 	// os-windows
   #if defined(WINDOWS)
 	void sleep_micros(u64 usec);
 	long getpagesize();
-	void dealloc_segment(segment *block);
 	const vm_char *vm_executable_path();
 	const vm_char *default_image_path();
 	void windows_image_path(vm_char *full_path, vm_char *temp_path, unsigned int length);