5 context::context(cell ds_size, cell rs_size, cell cs_size)
11 datastack_seg(new segment(ds_size, false)),
12 retainstack_seg(new segment(rs_size, false)),
13 callstack_seg(new segment(cs_size, false)) {
17 void context::reset_datastack() {
18 datastack = datastack_seg->start - sizeof(cell);
19 fill_stack_seg(datastack, datastack_seg, 0x11111111);
22 void context::reset_retainstack() {
23 retainstack = retainstack_seg->start - sizeof(cell);
24 fill_stack_seg(retainstack, retainstack_seg, 0x22222222);
27 void context::reset_callstack() {
28 callstack_top = callstack_bottom = CALLSTACK_BOTTOM(this);
31 void context::reset_context_objects() {
32 memset_cell(context_objects, false_object,
33 context_object_count * sizeof(cell));
36 void context::fill_stack_seg(cell top_ptr, segment* seg, cell pattern) {
38 cell clear_start = top_ptr + sizeof(cell);
39 cell clear_size = seg->end - clear_start;
40 memset_cell((void*)clear_start, pattern, clear_size);
48 vm_error_type context::address_to_error(cell addr) {
49 if (datastack_seg->underflow_p(addr))
50 return ERROR_DATASTACK_UNDERFLOW;
51 if (datastack_seg->overflow_p(addr))
52 return ERROR_DATASTACK_OVERFLOW;
53 if (retainstack_seg->underflow_p(addr))
54 return ERROR_RETAINSTACK_UNDERFLOW;
55 if (retainstack_seg->overflow_p(addr))
56 return ERROR_RETAINSTACK_OVERFLOW;
57 // These are flipped because the callstack grows downwards.
58 if (callstack_seg->underflow_p(addr))
59 return ERROR_CALLSTACK_OVERFLOW;
60 if (callstack_seg->overflow_p(addr))
61 return ERROR_CALLSTACK_UNDERFLOW;
65 void context::reset() {
69 reset_context_objects();
72 void context::fix_stacks() {
73 if (datastack + sizeof(cell) < datastack_seg->start ||
74 datastack + stack_reserved >= datastack_seg->end)
77 if (retainstack + sizeof(cell) < retainstack_seg->start ||
78 retainstack + stack_reserved >= retainstack_seg->end)
84 delete retainstack_seg;
88 context* factor_vm::new_context() {
91 if (unused_contexts.empty()) {
92 new_context = new context(datastack_size, retainstack_size, callstack_size);
94 new_context = unused_contexts.back();
95 unused_contexts.pop_back();
100 active_contexts.insert(new_context);
106 void factor_vm::init_context(context* ctx) {
107 ctx->context_objects[OBJ_CONTEXT] = allot_alien((cell)ctx);
110 // Allocates memory (init_context(), but not parent->new_context()
111 VM_C_API context* new_context(factor_vm* parent) {
112 context* new_context = parent->new_context();
113 parent->init_context(new_context);
117 void factor_vm::delete_context() {
118 unused_contexts.push_back(ctx);
119 active_contexts.erase(ctx);
121 while (unused_contexts.size() > 10) {
122 context* stale_context = unused_contexts.front();
123 unused_contexts.pop_front();
124 delete stale_context;
128 VM_C_API void delete_context(factor_vm* parent) {
129 parent->delete_context();
132 // Allocates memory (init_context())
133 VM_C_API void reset_context(factor_vm* parent) {
135 // The function is used by (start-context-and-delete) which expects
136 // the top two datastack items to be preserved after the context has
139 context* ctx = parent->ctx;
140 cell arg1 = ctx->pop();
141 cell arg2 = ctx->pop();
145 parent->init_context(ctx);
149 cell factor_vm::begin_callback(cell quot_) {
150 data_root<object> quot(quot_, this);
153 spare_ctx = new_context();
154 callback_ids.push_back(callback_id++);
162 cell begin_callback(factor_vm* parent, cell quot) {
163 cout << "begin_callback called" << endl;
164 return parent->begin_callback(quot);
167 void factor_vm::end_callback() {
168 callback_ids.pop_back();
172 void end_callback(factor_vm* parent) { parent->end_callback(); }
174 void factor_vm::primitive_current_callback() {
175 ctx->push(tag_fixnum(callback_ids.back()));
178 void factor_vm::primitive_context_object() {
179 fixnum n = untag_fixnum(ctx->peek());
180 ctx->replace(ctx->context_objects[n]);
183 void factor_vm::primitive_set_context_object() {
184 fixnum n = untag_fixnum(ctx->pop());
185 cell value = ctx->pop();
186 ctx->context_objects[n] = value;
189 void factor_vm::primitive_context_object_for() {
190 context* other_ctx = (context*)pinned_alien_offset(ctx->pop());
191 fixnum n = untag_fixnum(ctx->peek());
192 ctx->replace(other_ctx->context_objects[n]);
196 cell factor_vm::stack_to_array(cell bottom, cell top, vm_error_type error) {
197 fixnum depth = (fixnum)(top - bottom + sizeof(cell));
200 general_error(error, false_object, false_object);
202 array* a = allot_uninitialized_array<array>(depth / sizeof(cell));
203 memcpy(a + 1, (void*)bottom, depth);
204 return tag<array>(a);
208 cell factor_vm::datastack_to_array(context* ctx) {
209 return stack_to_array(ctx->datastack_seg->start,
211 ERROR_DATASTACK_UNDERFLOW);
215 void factor_vm::primitive_datastack_for() {
216 data_root<alien> alien_ctx(ctx->pop(), this);
217 context* other_ctx = (context*)pinned_alien_offset(alien_ctx.value());
218 cell array = datastack_to_array(other_ctx);
223 cell factor_vm::retainstack_to_array(context* ctx) {
224 return stack_to_array(ctx->retainstack_seg->start,
226 ERROR_RETAINSTACK_UNDERFLOW);
230 void factor_vm::primitive_retainstack_for() {
231 context* other_ctx = (context*)pinned_alien_offset(ctx->peek());
232 ctx->replace(retainstack_to_array(other_ctx));
235 // returns pointer to top of stack
236 static cell array_to_stack(array* array, cell bottom) {
237 cell depth = array_capacity(array) * sizeof(cell);
238 memcpy((void*)bottom, array + 1, depth);
239 return bottom + depth - sizeof(cell);
242 void factor_vm::primitive_set_datastack() {
243 array* arr = untag_check<array>(ctx->pop());
244 ctx->datastack = array_to_stack(arr, ctx->datastack_seg->start);
247 void factor_vm::primitive_set_retainstack() {
248 array* arr = untag_check<array>(ctx->pop());
249 ctx->retainstack = array_to_stack(arr, ctx->retainstack_seg->start);
252 // Used to implement call(
253 void factor_vm::primitive_check_datastack() {
254 fixnum out = to_fixnum(ctx->pop());
255 fixnum in = to_fixnum(ctx->pop());
256 fixnum height = out - in;
257 array* saved_datastack = untag_check<array>(ctx->pop());
258 fixnum saved_height = array_capacity(saved_datastack);
259 fixnum current_height =
260 (ctx->datastack - ctx->datastack_seg->start + sizeof(cell)) /
262 if (current_height - height != saved_height)
263 ctx->push(false_object);
265 cell* ds_bot = (cell*)ctx->datastack_seg->start;
266 for (fixnum i = 0; i < saved_height - in; i++) {
267 if (ds_bot[i] != array_nth(saved_datastack, i)) {
268 ctx->push(false_object);
272 ctx->push(special_objects[OBJ_CANONICAL_TRUE]);
276 void factor_vm::primitive_load_locals() {
277 fixnum count = untag_fixnum(ctx->pop());
278 memcpy((cell*)(ctx->retainstack + sizeof(cell)),
279 (cell*)(ctx->datastack - sizeof(cell) * (count - 1)),
280 sizeof(cell) * count);
281 ctx->datastack -= sizeof(cell) * count;
282 ctx->retainstack += sizeof(cell) * count;