/vm/contexts.cpp
http://github.com/abeaumont/factor · C++ · 365 lines · 301 code · 56 blank · 8 comment · 22 complexity · dcba44a66b7b7ee4a7a19abb1f9a4b72 MD5 · raw file
- #include "master.hpp"
- namespace factor
- {
- context::context(cell datastack_size, cell retainstack_size, cell callstack_size) :
- callstack_top(NULL),
- callstack_bottom(NULL),
- datastack(0),
- retainstack(0),
- callstack_save(0),
- datastack_seg(new segment(datastack_size,false)),
- retainstack_seg(new segment(retainstack_size,false)),
- callstack_seg(new segment(callstack_size,false))
- {
- reset();
- }
- void context::reset_datastack()
- {
- datastack = datastack_seg->start - sizeof(cell);
- }
- void context::reset_retainstack()
- {
- retainstack = retainstack_seg->start - sizeof(cell);
- }
- void context::reset_callstack()
- {
- callstack_top = callstack_bottom = CALLSTACK_BOTTOM(this);
- }
- void context::reset_context_objects()
- {
- memset_cell(context_objects,false_object,context_object_count * sizeof(cell));
- }
- void context::reset()
- {
- reset_datastack();
- reset_retainstack();
- reset_callstack();
- reset_context_objects();
- }
- void context::fix_stacks()
- {
- if(datastack + sizeof(cell) < datastack_seg->start
- || datastack + stack_reserved >= datastack_seg->end)
- reset_datastack();
- if(retainstack + sizeof(cell) < retainstack_seg->start
- || retainstack + stack_reserved >= retainstack_seg->end)
- reset_retainstack();
- }
- void context::scrub_stacks(gc_info *info, cell index)
- {
- u8 *bitmap = info->gc_info_bitmap();
- {
- cell base = info->callsite_scrub_d(index);
- for(cell loc = 0; loc < info->scrub_d_count; loc++)
- {
- if(bitmap_p(bitmap,base + loc))
- {
- #ifdef DEBUG_GC_MAPS
- std::cout << "scrubbing datastack location " << loc << std::endl;
- #endif
- *((cell *)datastack - loc) = 0;
- }
- }
- }
- {
- cell base = info->callsite_scrub_r(index);
- for(cell loc = 0; loc < info->scrub_r_count; loc++)
- {
- if(bitmap_p(bitmap,base + loc))
- {
- #ifdef DEBUG_GC_MAPS
- std::cout << "scrubbing retainstack location " << loc << std::endl;
- #endif
- *((cell *)retainstack - loc) = 0;
- }
- }
- }
- }
- context::~context()
- {
- delete datastack_seg;
- delete retainstack_seg;
- delete callstack_seg;
- }
- /* called on startup */
- void factor_vm::init_contexts(cell datastack_size_, cell retainstack_size_, cell callstack_size_)
- {
- datastack_size = datastack_size_;
- retainstack_size = retainstack_size_;
- callstack_size = callstack_size_;
- ctx = NULL;
- spare_ctx = new_context();
- }
- void factor_vm::delete_contexts()
- {
- FACTOR_ASSERT(!ctx);
- std::list<context *>::const_iterator iter = unused_contexts.begin();
- std::list<context *>::const_iterator end = unused_contexts.end();
- while(iter != end)
- {
- delete *iter;
- iter++;
- }
- }
- context *factor_vm::new_context()
- {
- context *new_context;
- if(unused_contexts.empty())
- {
- new_context = new context(datastack_size,
- retainstack_size,
- callstack_size);
- }
- else
- {
- new_context = unused_contexts.back();
- unused_contexts.pop_back();
- }
- new_context->reset();
- active_contexts.insert(new_context);
- return new_context;
- }
- /* Allocates memory */
- void factor_vm::init_context(context *ctx)
- {
- ctx->context_objects[OBJ_CONTEXT] = allot_alien(ctx);
- }
- /* Allocates memory */
- context *new_context(factor_vm *parent)
- {
- context *new_context = parent->new_context();
- parent->init_context(new_context);
- return new_context;
- }
- void factor_vm::delete_context(context *old_context)
- {
- unused_contexts.push_back(old_context);
- active_contexts.erase(old_context);
- while(unused_contexts.size() > 10)
- {
- context *stale_context = unused_contexts.front();
- unused_contexts.pop_front();
- delete stale_context;
- }
- }
- VM_C_API void delete_context(factor_vm *parent, context *old_context)
- {
- parent->delete_context(old_context);
- }
- /* Allocates memory */
- VM_C_API void reset_context(factor_vm *parent, context *ctx)
- {
- ctx->reset();
- parent->init_context(ctx);
- }
- /* Allocates memory */
- cell factor_vm::begin_callback(cell quot_)
- {
- data_root<object> quot(quot_,this);
- ctx->reset();
- spare_ctx = new_context();
- callback_ids.push_back(callback_id++);
- init_context(ctx);
- return quot.value();
- }
- cell begin_callback(factor_vm *parent, cell quot)
- {
- return parent->begin_callback(quot);
- }
- void factor_vm::end_callback()
- {
- callback_ids.pop_back();
- delete_context(ctx);
- }
- void end_callback(factor_vm *parent)
- {
- parent->end_callback();
- }
- void factor_vm::primitive_current_callback()
- {
- ctx->push(tag_fixnum(callback_ids.back()));
- }
- void factor_vm::primitive_context_object()
- {
- fixnum n = untag_fixnum(ctx->peek());
- ctx->replace(ctx->context_objects[n]);
- }
- void factor_vm::primitive_set_context_object()
- {
- fixnum n = untag_fixnum(ctx->pop());
- cell value = ctx->pop();
- ctx->context_objects[n] = value;
- }
- void factor_vm::primitive_context_object_for()
- {
- context *other_ctx = (context *)pinned_alien_offset(ctx->pop());
- fixnum n = untag_fixnum(ctx->pop());
- ctx->push(other_ctx->context_objects[n]);
- }
- /* Allocates memory */
- cell factor_vm::stack_to_array(cell bottom, cell top)
- {
- fixnum depth = (fixnum)(top - bottom + sizeof(cell));
- if(depth < 0)
- return false_object;
- else
- {
- array *a = allot_uninitialized_array<array>(depth / sizeof(cell));
- memcpy(a + 1,(void*)bottom,depth);
- return tag<array>(a);
- }
- }
- cell factor_vm::datastack_to_array(context *ctx)
- {
- cell array = stack_to_array(ctx->datastack_seg->start,ctx->datastack);
- if(array == false_object)
- {
- general_error(ERROR_DATASTACK_UNDERFLOW,false_object,false_object);
- return false_object;
- }
- else
- return array;
- }
- void factor_vm::primitive_datastack()
- {
- ctx->push(datastack_to_array(ctx));
- }
- void factor_vm::primitive_datastack_for()
- {
- context *other_ctx = (context *)pinned_alien_offset(ctx->pop());
- ctx->push(datastack_to_array(other_ctx));
- }
- cell factor_vm::retainstack_to_array(context *ctx)
- {
- cell array = stack_to_array(ctx->retainstack_seg->start,ctx->retainstack);
- if(array == false_object)
- {
- general_error(ERROR_RETAINSTACK_UNDERFLOW,false_object,false_object);
- return false_object;
- }
- else
- return array;
- }
- void factor_vm::primitive_retainstack()
- {
- ctx->push(retainstack_to_array(ctx));
- }
- void factor_vm::primitive_retainstack_for()
- {
- context *other_ctx = (context *)pinned_alien_offset(ctx->pop());
- ctx->push(retainstack_to_array(other_ctx));
- }
- /* returns pointer to top of stack */
- cell factor_vm::array_to_stack(array *array, cell bottom)
- {
- cell depth = array_capacity(array) * sizeof(cell);
- memcpy((void*)bottom,array + 1,depth);
- return bottom + depth - sizeof(cell);
- }
- void factor_vm::set_datastack(context *ctx, array *array)
- {
- ctx->datastack = array_to_stack(array,ctx->datastack_seg->start);
- }
- void factor_vm::primitive_set_datastack()
- {
- set_datastack(ctx,untag_check<array>(ctx->pop()));
- }
- void factor_vm::set_retainstack(context *ctx, array *array)
- {
- ctx->retainstack = array_to_stack(array,ctx->retainstack_seg->start);
- }
- void factor_vm::primitive_set_retainstack()
- {
- set_retainstack(ctx,untag_check<array>(ctx->pop()));
- }
- /* Used to implement call( */
- void factor_vm::primitive_check_datastack()
- {
- fixnum out = to_fixnum(ctx->pop());
- fixnum in = to_fixnum(ctx->pop());
- fixnum height = out - in;
- array *saved_datastack = untag_check<array>(ctx->pop());
- fixnum saved_height = array_capacity(saved_datastack);
- fixnum current_height = (ctx->datastack - ctx->datastack_seg->start + sizeof(cell)) / sizeof(cell);
- if(current_height - height != saved_height)
- ctx->push(false_object);
- else
- {
- cell *ds_bot = (cell *)ctx->datastack_seg->start;
- for(fixnum i = 0; i < saved_height - in; i++)
- {
- if(ds_bot[i] != array_nth(saved_datastack,i))
- {
- ctx->push(false_object);
- return;
- }
- }
- ctx->push(true_object);
- }
- }
- void factor_vm::primitive_load_locals()
- {
- fixnum count = untag_fixnum(ctx->pop());
- memcpy((cell *)(ctx->retainstack + sizeof(cell)),
- (cell *)(ctx->datastack - sizeof(cell) * (count - 1)),
- sizeof(cell) * count);
- ctx->datastack -= sizeof(cell) * count;
- ctx->retainstack += sizeof(cell) * count;
- }
- }