factor/vm/image.cpp

303 lines
9.0 KiB
C++

#include "master.hpp"
namespace factor {
/* Certain special objects in the image are known to the runtime */
void factor_vm::init_objects(image_header* h) {
memcpy(special_objects, h->special_objects, sizeof(special_objects));
true_object = h->true_object;
bignum_zero = h->bignum_zero;
bignum_pos_one = h->bignum_pos_one;
bignum_neg_one = h->bignum_neg_one;
}
void factor_vm::load_data_heap(FILE* file, image_header* h, vm_parameters* p) {
p->tenured_size = std::max((h->data_size * 3) / 2, p->tenured_size);
init_data_heap(p->young_size, p->aging_size, p->tenured_size);
fixnum bytes_read =
raw_fread((void*)data->tenured->start, 1, h->data_size, file);
if ((cell)bytes_read != h->data_size) {
std::cout << "truncated image: " << bytes_read << " bytes read, ";
std::cout << h->data_size << " bytes expected\n";
fatal_error("load_data_heap failed", 0);
}
data->tenured->initial_free_list(h->data_size);
}
void factor_vm::load_code_heap(FILE* file, image_header* h, vm_parameters* p) {
if (h->code_size > p->code_size)
fatal_error("Code heap too small to fit image", h->code_size);
code = new code_heap(p->code_size);
if (h->code_size != 0) {
size_t bytes_read =
raw_fread((void*)code->allocator->start, 1, h->code_size, file);
if (bytes_read != h->code_size) {
std::cout << "truncated image: " << bytes_read << " bytes read, ";
std::cout << h->code_size << " bytes expected\n";
fatal_error("load_code_heap failed", 0);
}
}
code->allocator->initial_free_list(h->code_size);
code->initialize_all_blocks_set();
}
struct startup_fixup {
static const bool translated_code_block_map = true;
cell data_offset;
cell code_offset;
startup_fixup(cell data_offset, cell code_offset)
: data_offset(data_offset), code_offset(code_offset) {}
object* fixup_data(object* obj) {
return (object*)((cell)obj + data_offset);
}
code_block* fixup_code(code_block* obj) {
return (code_block*)((cell)obj + code_offset);
}
object* translate_data(const object* obj) { return fixup_data((object*)obj); }
code_block* translate_code(const code_block* compiled) {
return fixup_code((code_block*)compiled);
}
cell size(const object* obj) { return obj->size(*this); }
cell size(code_block* compiled) { return compiled->size(*this); }
};
void factor_vm::fixup_data(cell data_offset, cell code_offset) {
startup_fixup fixup(data_offset, code_offset);
slot_visitor<startup_fixup> visitor(this, fixup);
visitor.visit_all_roots();
auto start_object_updater = [&](object *obj, cell size) {
data->tenured->starts.record_object_start_offset(obj);
visitor.visit_slots(obj);
switch (obj->type()) {
case ALIEN_TYPE: {
alien* ptr = (alien*)obj;
if (to_boolean(ptr->base))
ptr->update_address();
else
ptr->expired = true_object;
break;
}
case DLL_TYPE: {
ffi_dlopen((dll*)obj);
break;
}
default: {
visitor.visit_object_code_block(obj);
break;
}
}
};
data->tenured->iterate(start_object_updater, fixup);
}
void factor_vm::fixup_code(cell data_offset, cell code_offset) {
startup_fixup fixup(data_offset, code_offset);
auto updater = [&](code_block* compiled, cell size) {
slot_visitor<startup_fixup> visitor(this, fixup);
visitor.visit_code_block_objects(compiled);
cell rel_base = compiled->entry_point() - fixup.code_offset;
visitor.visit_instruction_operands(compiled, rel_base);
};
code->allocator->iterate(updater, fixup);
}
bool factor_vm::read_embedded_image_footer(FILE* file,
embedded_image_footer* footer) {
safe_fseek(file, -(off_t)sizeof(embedded_image_footer), SEEK_END);
safe_fread(footer, (off_t)sizeof(embedded_image_footer), 1, file);
return footer->magic == image_magic;
}
char *threadsafe_strerror(int errnum) {
char *buf = (char *) malloc(STRERROR_BUFFER_SIZE);
if(!buf) {
fatal_error("Out of memory in threadsafe_strerror, errno", errnum);
}
THREADSAFE_STRERROR(errnum, buf, STRERROR_BUFFER_SIZE);
return buf;
}
FILE* factor_vm::open_image(vm_parameters* p) {
if (p->embedded_image) {
FILE* file = OPEN_READ(p->executable_path);
if (file == NULL) {
std::cout << "Cannot open embedded image" << std::endl;
char *msg = threadsafe_strerror(errno);
std::cout << "strerror:1: " << msg << std::endl;
free(msg);
exit(1);
}
embedded_image_footer footer;
if (!read_embedded_image_footer(file, &footer)) {
std::cout << "No embedded image" << std::endl;
exit(1);
}
safe_fseek(file, (off_t)footer.image_offset, SEEK_SET);
return file;
} else
return OPEN_READ(p->image_path);
}
/* Read an image file from disk, only done once during startup */
/* This function also initializes the data and code heaps */
void factor_vm::load_image(vm_parameters* p) {
FILE* file = open_image(p);
if (file == NULL) {
std::cout << "Cannot open image file: " << p->image_path << std::endl;
char *msg = threadsafe_strerror(errno);
std::cout << "strerror:2: " << msg << std::endl;
free(msg);
exit(1);
}
image_header h;
if (raw_fread(&h, sizeof(image_header), 1, file) != 1)
fatal_error("Cannot read image header", 0);
if (h.magic != image_magic)
fatal_error("Bad image: magic number check failed", h.magic);
if (h.version != image_version)
fatal_error("Bad image: version number check failed", h.version);
load_data_heap(file, &h, p);
load_code_heap(file, &h, p);
raw_fclose(file);
init_objects(&h);
cell data_offset = data->tenured->start - h.data_relocation_base;
cell code_offset = code->allocator->start - h.code_relocation_base;
fixup_data(data_offset, code_offset);
fixup_code(data_offset, code_offset);
/* Store image path name */
special_objects[OBJ_IMAGE] = allot_alien(false_object, (cell)p->image_path);
}
/* Save the current image to disk */
bool factor_vm::save_image(const vm_char* saving_filename,
const vm_char* filename) {
FILE* file;
image_header h;
file = OPEN_WRITE(saving_filename);
if (file == NULL) {
std::cout << "Cannot open image file for writing: " << saving_filename << std::endl;
char *msg = threadsafe_strerror(errno);
std::cout << "strerror:3: " << msg << std::endl;
free(msg);
return false;
}
h.magic = image_magic;
h.version = image_version;
h.data_relocation_base = data->tenured->start;
h.data_size = data->tenured->occupied_space();
h.code_relocation_base = code->allocator->start;
h.code_size = code->allocator->occupied_space();
h.true_object = true_object;
h.bignum_zero = bignum_zero;
h.bignum_pos_one = bignum_pos_one;
h.bignum_neg_one = bignum_neg_one;
for (cell i = 0; i < special_object_count; i++)
h.special_objects[i] =
(save_special_p(i) ? special_objects[i] : false_object);
bool ok = true;
if (safe_fwrite(&h, sizeof(image_header), 1, file) != 1)
ok = false;
if (safe_fwrite((void*)data->tenured->start, h.data_size, 1, file) != 1)
ok = false;
if (safe_fwrite((void*)code->allocator->start, h.code_size, 1, file) != 1)
ok = false;
safe_fclose(file);
if (!ok) {
std::cout << "save-image failed." << std::endl;
char *msg = threadsafe_strerror(errno);
std::cout << "strerror:4: " << msg << std::endl;
free(msg);
}
else
move_file(saving_filename, filename);
return ok;
}
/* Allocates memory */
void factor_vm::primitive_save_image() {
/* We unbox this before doing anything else. This is the only point
where we might throw an error, so we have to throw an error here since
later steps destroy the current image. */
bool then_die = to_boolean(ctx->pop());
byte_array* path2 = untag_check<byte_array>(ctx->pop());
byte_array* path1 = untag_check<byte_array>(ctx->pop());
/* Copy the paths to non-gc memory to avoid them hanging around in
the saved image. */
vm_char* path1_saved = safe_strdup(path1->data<vm_char>());
vm_char* path2_saved = safe_strdup(path2->data<vm_char>());
if (then_die) {
/* strip out special_objects data which is set on startup anyway */
for (cell i = 0; i < special_object_count; i++)
if (!save_special_p(i))
special_objects[i] = false_object;
/* dont trace objects only reachable from context stacks so we don't
get volatile data saved in the image. */
active_contexts.clear();
code->uninitialized_blocks.clear();
}
/* do a full GC to push everything remaining into tenured space */
primitive_compact_gc();
/* Save the image */
bool ret = save_image(path1_saved, path2_saved);
if (then_die) {
exit(ret ? 0 : 1);
}
free(path1_saved);
free(path2_saved);
}
bool factor_vm::embedded_image_p() {
const vm_char* vm_path = vm_executable_path();
if (!vm_path)
return false;
FILE* file = OPEN_READ(vm_path);
if (!file)
return false;
embedded_image_footer footer;
bool embedded_p = read_embedded_image_footer(file, &footer);
fclose(file);
return embedded_p;
}
}