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dart / sdk / a474f49adad1204ba6f4fe9e74a4cb97881dacf1 / . / runtime / vm / isolate_reload.cc
blob: 231aa102da01a1fb4c4d042175b9514af1ed15fb [file] [log] [blame]
// Copyright (c) 2016, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.
#include "vm/isolate_reload.h"
#include "vm/bit_vector.h"
#include "vm/compiler/jit/compiler.h"
#include "vm/dart_api_impl.h"
#if !defined(PRODUCT) && !defined(DART_PRECOMPILED_RUNTIME)
#include "vm/hash.h"
#endif
#include "vm/hash_table.h"
#include "vm/heap/become.h"
#include "vm/heap/safepoint.h"
#include "vm/isolate.h"
#include "vm/kernel_isolate.h"
#include "vm/kernel_loader.h"
#include "vm/log.h"
#include "vm/object.h"
#include "vm/object_store.h"
#include "vm/parser.h"
#include "vm/runtime_entry.h"
#include "vm/service_event.h"
#include "vm/stack_frame.h"
#include "vm/thread.h"
#include "vm/timeline.h"
#include "vm/type_testing_stubs.h"
#include "vm/visitor.h"
namespace dart {
DEFINE_FLAG(int, reload_every, 0, "Reload every N stack overflow checks.");
DEFINE_FLAG(bool, trace_reload, false, "Trace isolate reloading");
#if !defined(PRODUCT) && !defined(DART_PRECOMPILED_RUNTIME)
DEFINE_FLAG(bool,
trace_reload_verbose,
false,
"trace isolate reloading verbose");
DEFINE_FLAG(bool, identity_reload, false, "Enable checks for identity reload.");
DEFINE_FLAG(bool, reload_every_optimized, true, "Only from optimized code.");
DEFINE_FLAG(bool,
reload_every_back_off,
false,
"Double the --reload-every value after each reload.");
DEFINE_FLAG(bool,
reload_force_rollback,
false,
"Force all reloads to fail and rollback.");
DEFINE_FLAG(bool,
check_reloaded,
false,
"Assert that an isolate has reloaded at least once.")
DECLARE_FLAG(bool, trace_deoptimization);
#define I (isolate())
#define Z (thread->zone())
#define TIMELINE_SCOPE(name) \
TimelineDurationScope tds##name(Thread::Current(), \
Timeline::GetIsolateStream(), #name)
InstanceMorpher::InstanceMorpher(Zone* zone, const Class& from, const Class& to)
: from_(Class::Handle(zone, from.raw())),
to_(Class::Handle(zone, to.raw())),
mapping_(zone, 0) {
before_ = new (zone) ZoneGrowableArray<const Instance*>(zone, 0);
after_ = new (zone) ZoneGrowableArray<const Instance*>(zone, 0);
new_fields_ = new (zone) ZoneGrowableArray<const Field*>(zone, 0);
ASSERT(from_.id() == to_.id());
cid_ = from_.id();
ComputeMapping();
}
void InstanceMorpher::AddObject(RawObject* object) const {
ASSERT(object->GetClassId() == cid());
const Instance& instance = Instance::Cast(Object::Handle(object));
before_->Add(&instance);
}
void InstanceMorpher::ComputeMapping() {
if (from_.NumTypeArguments()) {
// Add copying of the optional type argument field.
intptr_t from_offset = from_.type_arguments_field_offset();
ASSERT(from_offset != Class::kNoTypeArguments);
intptr_t to_offset = to_.type_arguments_field_offset();
ASSERT(to_offset != Class::kNoTypeArguments);
mapping_.Add(from_offset);
mapping_.Add(to_offset);
}
// Add copying of the instance fields if matching by name.
// Note: currently the type of the fields are ignored.
const Array& from_fields =
Array::Handle(from_.OffsetToFieldMap(true /* original classes */));
const Array& to_fields = Array::Handle(to_.OffsetToFieldMap());
Field& from_field = Field::Handle();
Field& to_field = Field::Handle();
String& from_name = String::Handle();
String& to_name = String::Handle();
// Scan across all the fields in the new class definition.
for (intptr_t i = 0; i < to_fields.Length(); i++) {
if (to_fields.At(i) == Field::null()) {
continue; // Ignore non-fields.
}
// Grab the field's name.
to_field = Field::RawCast(to_fields.At(i));
ASSERT(to_field.is_instance());
to_name = to_field.name();
// Did this field not exist in the old class definition?
bool new_field = true;
// Find this field in the old class.
for (intptr_t j = 0; j < from_fields.Length(); j++) {
if (from_fields.At(j) == Field::null()) {
continue; // Ignore non-fields.
}
from_field = Field::RawCast(from_fields.At(j));
ASSERT(from_field.is_instance());
from_name = from_field.name();
if (from_name.Equals(to_name)) {
// Success
mapping_.Add(from_field.Offset());
mapping_.Add(to_field.Offset());
// Field did exist in old class deifnition.
new_field = false;
}
}
if (new_field) {
if (to_field.has_initializer()) {
// This is a new field with an initializer.
const Field& field = Field::Handle(to_field.raw());
new_fields_->Add(&field);
}
}
}
}
RawInstance* InstanceMorpher::Morph(const Instance& instance) const {
const Instance& result = Instance::Handle(Instance::New(to_));
// Morph the context from instance to result using mapping_.
for (intptr_t i = 0; i < mapping_.length(); i += 2) {
intptr_t from_offset = mapping_.At(i);
intptr_t to_offset = mapping_.At(i + 1);
const Object& value =
Object::Handle(instance.RawGetFieldAtOffset(from_offset));
result.RawSetFieldAtOffset(to_offset, value);
}
// Convert the instance into a filler object.
Become::MakeDummyObject(instance);
return result.raw();
}
void InstanceMorpher::RunNewFieldInitializers() const {
if ((new_fields_->length() == 0) || (after_->length() == 0)) {
return;
}
TIR_Print("Running new field initializers for class: %s\n", to_.ToCString());
Thread* thread = Thread::Current();
Zone* zone = thread->zone();
String& initializing_expression = String::Handle(zone);
Function& eval_func = Function::Handle(zone);
Object& result = Object::Handle(zone);
Class& owning_class = Class::Handle(zone);
// For each new field.
for (intptr_t i = 0; i < new_fields_->length(); i++) {
// Create a function that returns the expression.
const Field* field = new_fields_->At(i);
if (field->kernel_offset() > 0) {
eval_func ^= kernel::CreateFieldInitializerFunction(thread, zone, *field);
} else {
owning_class ^= field->Owner();
ASSERT(!owning_class.IsNull());
// Extract the initializing expression.
initializing_expression = field->InitializingExpression();
TIR_Print("New `%s` has initializing expression `%s`\n",
field->ToCString(), initializing_expression.ToCString());
eval_func ^= Function::EvaluateHelper(
owning_class, initializing_expression, Array::empty_array(), true);
}
for (intptr_t j = 0; j < after_->length(); j++) {
const Instance* instance = after_->At(j);
TIR_Print("Initializing instance %" Pd " / %" Pd "\n", j + 1,
after_->length());
// Run the function and assign the field.
result = DartEntry::InvokeFunction(eval_func, Array::empty_array());
if (result.IsError()) {
// TODO(johnmccutchan): Report this error in the reload response?
OS::PrintErr(
"RELOAD: Running initializer for new field `%s` resulted in "
"an error: %s\n",
field->ToCString(), Error::Cast(result).ToErrorCString());
continue;
}
instance->RawSetFieldAtOffset(field->Offset(), result);
}
}
}
void InstanceMorpher::CreateMorphedCopies() const {
for (intptr_t i = 0; i < before()->length(); i++) {
const Instance& copy = Instance::Handle(Morph(*before()->At(i)));
after()->Add(&copy);
}
}
void InstanceMorpher::DumpFormatFor(const Class& cls) const {
THR_Print("%s\n", cls.ToCString());
if (cls.NumTypeArguments()) {
intptr_t field_offset = cls.type_arguments_field_offset();
ASSERT(field_offset != Class::kNoTypeArguments);
THR_Print(" - @%" Pd " <type arguments>\n", field_offset);
}
const Array& fields = Array::Handle(cls.OffsetToFieldMap());
Field& field = Field::Handle();
String& name = String::Handle();
for (intptr_t i = 0; i < fields.Length(); i++) {
if (fields.At(i) != Field::null()) {
field = Field::RawCast(fields.At(i));
ASSERT(field.is_instance());
name = field.name();
THR_Print(" - @%" Pd " %s\n", field.Offset(), name.ToCString());
}
}
THR_Print("Mapping: ");
for (int i = 0; i < mapping_.length(); i += 2) {
THR_Print(" %" Pd "->%" Pd, mapping_.At(i), mapping_.At(i + 1));
}
THR_Print("\n");
}
void InstanceMorpher::Dump() const {
LogBlock blocker;
THR_Print("Morphing from ");
DumpFormatFor(from_);
THR_Print("To ");
DumpFormatFor(to_);
THR_Print("\n");
}
void InstanceMorpher::AppendTo(JSONArray* array) {
JSONObject jsobj(array);
jsobj.AddProperty("type", "ShapeChangeMapping");
jsobj.AddProperty("class", to_);
jsobj.AddProperty("instanceCount", before()->length());
JSONArray map(&jsobj, "fieldOffsetMappings");
for (int i = 0; i < mapping_.length(); i += 2) {
JSONArray pair(&map);
pair.AddValue(mapping_.At(i));
pair.AddValue(mapping_.At(i + 1));
}
}
void ReasonForCancelling::Report(IsolateReloadContext* context) {
const Error& error = Error::Handle(ToError());
context->ReportError(error);
}
RawError* ReasonForCancelling::ToError() {
// By default create the error returned from ToString.
const String& message = String::Handle(ToString());
return LanguageError::New(message);
}
RawString* ReasonForCancelling::ToString() {
UNREACHABLE();
return NULL;
}
void ReasonForCancelling::AppendTo(JSONArray* array) {
JSONObject jsobj(array);
jsobj.AddProperty("type", "ReasonForCancelling");
const String& message = String::Handle(ToString());
jsobj.AddProperty("message", message.ToCString());
}
ClassReasonForCancelling::ClassReasonForCancelling(Zone* zone,
const Class& from,
const Class& to)
: ReasonForCancelling(zone),
from_(Class::ZoneHandle(zone, from.raw())),
to_(Class::ZoneHandle(zone, to.raw())) {}
void ClassReasonForCancelling::AppendTo(JSONArray* array) {
JSONObject jsobj(array);
jsobj.AddProperty("type", "ReasonForCancelling");
jsobj.AddProperty("class", from_);
const String& message = String::Handle(ToString());
jsobj.AddProperty("message", message.ToCString());
}
RawError* IsolateReloadContext::error() const {
ASSERT(reload_aborted());
// Report the first error to the surroundings.
return reasons_to_cancel_reload_.At(0)->ToError();
}
class ScriptUrlSetTraits {
public:
static bool ReportStats() { return false; }
static const char* Name() { return "ScriptUrlSetTraits"; }
static bool IsMatch(const Object& a, const Object& b) {
if (!a.IsString() || !b.IsString()) {
return false;
}
return String::Cast(a).Equals(String::Cast(b));
}
static uword Hash(const Object& obj) { return String::Cast(obj).Hash(); }
};
class ClassMapTraits {
public:
static bool ReportStats() { return false; }
static const char* Name() { return "ClassMapTraits"; }
static bool IsMatch(const Object& a, const Object& b) {
if (!a.IsClass() || !b.IsClass()) {
return false;
}
return IsolateReloadContext::IsSameClass(Class::Cast(a), Class::Cast(b));
}
static uword Hash(const Object& obj) {
uword class_name_hash = String::HashRawSymbol(Class::Cast(obj).Name());
RawLibrary* raw_library = Class::Cast(obj).library();
if (raw_library == Library::null()) {
return class_name_hash;
}
return FinalizeHash(
CombineHashes(class_name_hash,
String::Hash(Library::Handle(raw_library).private_key())),
/* hashbits= */ 30);
}
};
class LibraryMapTraits {
public:
static bool ReportStats() { return false; }
static const char* Name() { return "LibraryMapTraits"; }
static bool IsMatch(const Object& a, const Object& b) {
if (!a.IsLibrary() || !b.IsLibrary()) {
return false;
}
return IsolateReloadContext::IsSameLibrary(Library::Cast(a),
Library::Cast(b));
}
static uword Hash(const Object& obj) { return Library::Cast(obj).UrlHash(); }
};
class BecomeMapTraits {
public:
static bool ReportStats() { return false; }
static const char* Name() { return "BecomeMapTraits"; }
static bool IsMatch(const Object& a, const Object& b) {
return a.raw() == b.raw();
}
static uword Hash(const Object& obj) {
if (obj.IsLibrary()) {
return Library::Cast(obj).UrlHash();
} else if (obj.IsClass()) {
if (Class::Cast(obj).id() == kFreeListElement) {
return 0;
}
return String::HashRawSymbol(Class::Cast(obj).Name());
} else if (obj.IsField()) {
return String::HashRawSymbol(Field::Cast(obj).name());
} else if (obj.IsInstance()) {
Object& hashObj = Object::Handle(Instance::Cast(obj).HashCode());
if (hashObj.IsError()) {
Exceptions::PropagateError(Error::Cast(hashObj));
}
return Smi::Cast(hashObj).Value();
}
return 0;
}
};
bool IsolateReloadContext::IsSameField(const Field& a, const Field& b) {
if (a.is_static() != b.is_static()) {
return false;
}
const Class& a_cls = Class::Handle(a.Owner());
const Class& b_cls = Class::Handle(b.Owner());
if (!IsSameClass(a_cls, b_cls)) {
return false;
}
const String& a_name = String::Handle(a.name());
const String& b_name = String::Handle(b.name());
return a_name.Equals(b_name);
}
bool IsolateReloadContext::IsSameClass(const Class& a, const Class& b) {
if (a.is_patch() != b.is_patch()) {
// TODO(johnmccutchan): Should we just check the class kind bits?
return false;
}
// TODO(turnidge): We need to look at generic type arguments for
// synthetic mixin classes. Their names are not necessarily unique
// currently.
const String& a_name = String::Handle(a.Name());
const String& b_name = String::Handle(b.Name());
if (!a_name.Equals(b_name)) {
return false;
}
const Library& a_lib = Library::Handle(a.library());
const Library& b_lib = Library::Handle(b.library());
if (a_lib.IsNull() || b_lib.IsNull()) {
return a_lib.raw() == b_lib.raw();
}
return (a_lib.private_key() == b_lib.private_key());
}
bool IsolateReloadContext::IsSameLibrary(const Library& a_lib,
const Library& b_lib) {
const String& a_lib_url =
String::Handle(a_lib.IsNull() ? String::null() : a_lib.url());
const String& b_lib_url =
String::Handle(b_lib.IsNull() ? String::null() : b_lib.url());
return a_lib_url.Equals(b_lib_url);
}
IsolateReloadContext::IsolateReloadContext(Isolate* isolate, JSONStream* js)
: zone_(Thread::Current()->zone()),
start_time_micros_(OS::GetCurrentMonotonicMicros()),
reload_timestamp_(OS::GetCurrentTimeMillis()),
isolate_(isolate),
reload_skipped_(false),
reload_aborted_(false),
reload_finalized_(false),
js_(js),
saved_num_cids_(-1),
saved_class_table_(NULL),
num_saved_libs_(-1),
instance_morphers_(zone_, 0),
reasons_to_cancel_reload_(zone_, 0),
cid_mapper_(),
modified_libs_(NULL),
script_url_(String::null()),
error_(Error::null()),
old_classes_set_storage_(Array::null()),
class_map_storage_(Array::null()),
old_libraries_set_storage_(Array::null()),
library_map_storage_(Array::null()),
become_map_storage_(Array::null()),
become_enum_mappings_(GrowableObjectArray::null()),
saved_root_library_(Library::null()),
saved_libraries_(GrowableObjectArray::null()),
root_url_prefix_(String::null()),
old_root_url_prefix_(String::null()) {
// NOTE: DO NOT ALLOCATE ANY RAW OBJECTS HERE. The IsolateReloadContext is not
// associated with the isolate yet and if a GC is triggered here the raw
// objects will not be properly accounted for.
ASSERT(zone_ != NULL);
}
IsolateReloadContext::~IsolateReloadContext() {
ASSERT(zone_ == Thread::Current()->zone());
ASSERT(saved_class_table_ == NULL);
}
void IsolateReloadContext::ReportError(const Error& error) {
if (!FLAG_support_service || Isolate::IsVMInternalIsolate(I)) {
return;
}
if (FLAG_trace_reload) {
THR_Print("ISO-RELOAD: Error: %s\n", error.ToErrorCString());
}
ServiceEvent service_event(I, ServiceEvent::kIsolateReload);
service_event.set_reload_error(&error);
Service::HandleEvent(&service_event);
}
void IsolateReloadContext::ReportSuccess() {
if (!FLAG_support_service || Isolate::IsVMInternalIsolate(I)) {
return;
}
ServiceEvent service_event(I, ServiceEvent::kIsolateReload);
Service::HandleEvent(&service_event);
}
class Aborted : public ReasonForCancelling {
public:
Aborted(Zone* zone, const Error& error)
: ReasonForCancelling(zone),
error_(Error::ZoneHandle(zone, error.raw())) {}
private:
const Error& error_;
RawError* ToError() { return error_.raw(); }
RawString* ToString() {
return String::NewFormatted("%s", error_.ToErrorCString());
}
};
static intptr_t CommonSuffixLength(const char* a, const char* b) {
const intptr_t a_length = strlen(a);
const intptr_t b_length = strlen(b);
intptr_t a_cursor = a_length;
intptr_t b_cursor = b_length;
while ((a_cursor >= 0) && (b_cursor >= 0)) {
if (a[a_cursor] != b[b_cursor]) {
break;
}
a_cursor--;
b_cursor--;
}
ASSERT((a_length - a_cursor) == (b_length - b_cursor));
return (a_length - a_cursor);
}
template <class T>
class ResourceHolder : ValueObject {
T* resource_;
public:
ResourceHolder() : resource_(NULL) {}
void set(T* resource) { resource_ = resource; }
T* get() { return resource_; }
~ResourceHolder() { delete (resource_); }
};
static void AcceptCompilation(Thread* thread) {
TransitionVMToNative transition(thread);
Dart_KernelCompilationResult result = KernelIsolate::AcceptCompilation();
if (result.status != Dart_KernelCompilationStatus_Ok) {
FATAL1(
"An error occurred in the CFE while accepting the most recent"
" compilation results: %s",
result.error);
}
}
// NOTE: This function returns *after* FinalizeLoading is called.
// If [root_script_url] is null, attempt to load from [kernel_buffer].
void IsolateReloadContext::Reload(bool force_reload,
const char* root_script_url,
const char* packages_url_,
const uint8_t* kernel_buffer,
intptr_t kernel_buffer_size) {
TIMELINE_SCOPE(Reload);
Thread* thread = Thread::Current();
ASSERT(isolate() == thread->isolate());
// Grab root library before calling CheckpointBeforeReload.
const Library& old_root_lib = Library::Handle(object_store()->root_library());
ASSERT(!old_root_lib.IsNull());
const String& old_root_lib_url = String::Handle(old_root_lib.url());
// Root library url.
const String& root_lib_url =
(root_script_url == NULL) ? old_root_lib_url
: String::Handle(String::New(root_script_url));
bool root_lib_modified = false;
// Check to see if the base url of the loaded libraries has moved.
if (!old_root_lib_url.Equals(root_lib_url)) {
root_lib_modified = true;
const char* old_root_library_url_c = old_root_lib_url.ToCString();
const char* root_library_url_c = root_lib_url.ToCString();
const intptr_t common_suffix_length =
CommonSuffixLength(root_library_url_c, old_root_library_url_c);
root_url_prefix_ = String::SubString(
root_lib_url, 0, root_lib_url.Length() - common_suffix_length + 1);
old_root_url_prefix_ =
String::SubString(old_root_lib_url, 0,
old_root_lib_url.Length() - common_suffix_length + 1);
}
Object& result = Object::Handle(thread->zone());
ResourceHolder<kernel::Program> kernel_program;
String& packages_url = String::Handle();
if (packages_url_ != NULL) {
packages_url = String::New(packages_url_);
}
bool did_kernel_compilation = false;
bool skip_reload = false;
{
// Load the kernel program and figure out the modified libraries.
const GrowableObjectArray& libs =
GrowableObjectArray::Handle(object_store()->libraries());
intptr_t num_libs = libs.Length();
modified_libs_ = new (Z) BitVector(Z, num_libs);
// ReadKernelFromFile checks to see if the file at
// root_script_url is a valid .dill file. If that's the case, a Program*
// is returned. Otherwise, this is likely a source file that needs to be
// compiled, so ReadKernelFromFile returns NULL.
kernel_program.set(kernel::Program::ReadFromFile(root_script_url));
if (kernel_program.get() == NULL) {
Dart_KernelCompilationResult retval;
if (kernel_buffer != NULL && kernel_buffer_size != 0) {
retval.kernel = const_cast<uint8_t*>(kernel_buffer);
retval.kernel_size = kernel_buffer_size;
retval.status = Dart_KernelCompilationStatus_Ok;
} else {
Dart_SourceFile* modified_scripts = NULL;
intptr_t modified_scripts_count = 0;
FindModifiedSources(thread, force_reload, &modified_scripts,
&modified_scripts_count, packages_url_);
{
TransitionVMToNative transition(thread);
retval = KernelIsolate::CompileToKernel(
root_lib_url.ToCString(), NULL, 0, modified_scripts_count,
modified_scripts, true, NULL);
did_kernel_compilation = true;
}
}
if (retval.status != Dart_KernelCompilationStatus_Ok) {
TIR_Print("---- LOAD FAILED, ABORTING RELOAD\n");
const String& error_str = String::Handle(String::New(retval.error));
free(retval.error);
const ApiError& error = ApiError::Handle(ApiError::New(error_str));
if (retval.kernel != NULL) {
free(const_cast<uint8_t*>(retval.kernel));
}
AddReasonForCancelling(new Aborted(zone_, error));
ReportReasonsForCancelling();
CommonFinalizeTail();
return;
}
// The ownership of the kernel buffer goes now to the VM.
const ExternalTypedData& typed_data = ExternalTypedData::Handle(
Z,
ExternalTypedData::New(kExternalTypedDataUint8ArrayCid, retval.kernel,
retval.kernel_size, Heap::kOld));
typed_data.AddFinalizer(
retval.kernel,
[](void* isolate_callback_data, Dart_WeakPersistentHandle handle,
void* data) { free(data); },
retval.kernel_size);
// TODO(dartbug.com/33973): Change the heap objects to have a proper
// retaining path to the kernel blob and ensure the finalizer will free it
// once there are no longer references to it.
// (The [ExternalTypedData] currently referenced by e.g. functions point
// into the middle of c-allocated buffer and don't have a finalizer).
I->RetainKernelBlob(typed_data);
kernel_program.set(kernel::Program::ReadFromTypedData(typed_data));
}
kernel::KernelLoader::FindModifiedLibraries(
kernel_program.get(), I, modified_libs_, force_reload, &skip_reload);
}
if (skip_reload) {
ASSERT(modified_libs_->IsEmpty());
reload_skipped_ = true;
// Inform GetUnusedChangesInLastReload that a reload has happened.
I->object_store()->set_changed_in_last_reload(
GrowableObjectArray::Handle(GrowableObjectArray::New()));
ReportOnJSON(js_);
// If we use the CFE and performed a compilation, we need to notify that
// we have accepted the compilation to clear some state in the incremental
// compiler.
if (did_kernel_compilation) {
AcceptCompilation(thread);
}
TIR_Print("---- SKIPPING RELOAD (No libraries were modified)\n");
return;
}
TIR_Print("---- STARTING RELOAD\n");
// Preallocate storage for maps.
old_classes_set_storage_ =
HashTables::New<UnorderedHashSet<ClassMapTraits> >(4);
class_map_storage_ = HashTables::New<UnorderedHashMap<ClassMapTraits> >(4);
old_libraries_set_storage_ =
HashTables::New<UnorderedHashSet<LibraryMapTraits> >(4);
library_map_storage_ =
HashTables::New<UnorderedHashMap<LibraryMapTraits> >(4);
become_map_storage_ = HashTables::New<UnorderedHashMap<BecomeMapTraits> >(4);
// Keep a separate array for enum mappings to avoid having to invoke
// hashCode on the instances.
become_enum_mappings_ = GrowableObjectArray::New(Heap::kOld);
// Disable the background compiler while we are performing the reload.
BackgroundCompiler::Disable(I);
// Ensure all functions on the stack have unoptimized code.
EnsuredUnoptimizedCodeForStack();
// Deoptimize all code that had optimizing decisions that are dependent on
// assumptions from field guards or CHA or deferred library prefixes.
// TODO(johnmccutchan): Deoptimizing dependent code here (before the reload)
// is paranoid. This likely can be moved to the commit phase.
DeoptimizeDependentCode();
Checkpoint();
// WEIRD CONTROL FLOW BEGINS.
//
// The flow of execution until we return from the tag handler can be complex.
//
// On a successful load, the following will occur:
// 1) Tag Handler is invoked and the embedder is in control.
// 2) All sources and libraries are loaded.
// 3) Dart_FinalizeLoading is called by the embedder.
// 4) Dart_FinalizeLoading invokes IsolateReloadContext::FinalizeLoading
// and we are temporarily back in control.
// This is where we validate the reload and commit or reject.
// 5) Dart_FinalizeLoading invokes Dart code related to deferred libraries.
// 6) The tag handler returns and we move on.
//
// Even after a successful reload the Dart code invoked in (5) can result
// in an Unwind error or an UnhandledException error. This error will be
// returned by the tag handler. The tag handler can return other errors,
// for example, top level parse errors. We want to capture these errors while
// propagating the UnwindError or an UnhandledException error.
{
const Object& tmp =
kernel::KernelLoader::LoadEntireProgram(kernel_program.get());
if (!tmp.IsError()) {
Library& lib = Library::Handle(thread->zone());
lib ^= tmp.raw();
// If main method disappeared or were not there to begin with then
// KernelLoader will return null. In this case lookup library by
// URL.
if (lib.IsNull()) {
lib = Library::LookupLibrary(thread, root_lib_url);
}
isolate()->object_store()->set_root_library(lib);
FinalizeLoading();
result = Object::null();
// If we use the CFE and performed a compilation, we need to notify that
// we have accepted the compilation to clear some state in the incremental
// compiler.
if (did_kernel_compilation) {
AcceptCompilation(thread);
}
} else {
result = tmp.raw();
}
}
//
// WEIRD CONTROL FLOW ENDS.
// Re-enable the background compiler. Do this before propagating any errors.
BackgroundCompiler::Enable(I);
if (result.IsUnwindError()) {
if (thread->top_exit_frame_info() == 0) {
// We can only propagate errors when there are Dart frames on the stack.
// In this case there are no Dart frames on the stack and we set the
// thread's sticky error. This error will be returned to the message
// handler.
thread->set_sticky_error(Error::Cast(result));
} else {
// If the tag handler returns with an UnwindError error, propagate it and
// give up.
Exceptions::PropagateError(Error::Cast(result));
UNREACHABLE();
}
}
// Other errors (e.g. a parse error) are captured by the reload system.
if (result.IsError()) {
FinalizeFailedLoad(Error::Cast(result));
}
}
void IsolateReloadContext::RegisterClass(const Class& new_cls) {
const Class& old_cls = Class::Handle(OldClassOrNull(new_cls));
if (old_cls.IsNull()) {
I->class_table()->Register(new_cls);
if (FLAG_identity_reload) {
TIR_Print("Could not find replacement class for %s\n",
new_cls.ToCString());
UNREACHABLE();
}
// New class maps to itself.
AddClassMapping(new_cls, new_cls);
return;
}
VTIR_Print("Registering class: %s\n", new_cls.ToCString());
new_cls.set_id(old_cls.id());
isolate()->class_table()->SetAt(old_cls.id(), new_cls.raw());
if (!old_cls.is_enum_class()) {
new_cls.CopyCanonicalConstants(old_cls);
}
new_cls.CopyCanonicalType(old_cls);
AddBecomeMapping(old_cls, new_cls);
AddClassMapping(new_cls, old_cls);
}
// FinalizeLoading will be called *before* Reload() returns but will not be
// called if the embedder fails to load sources.
void IsolateReloadContext::FinalizeLoading() {
if (reload_skipped_ || reload_finalized_) {
return;
}
BuildLibraryMapping();
TIR_Print("---- LOAD SUCCEEDED\n");
if (ValidateReload()) {
Commit();
PostCommit();
isolate()->set_last_reload_timestamp(reload_timestamp_);
} else {
ReportReasonsForCancelling();
Rollback();
}
// ValidateReload mutates the direct subclass information and does
// not remove dead subclasses. Rebuild the direct subclass
// information from scratch.
RebuildDirectSubclasses();
CommonFinalizeTail();
}
// FinalizeFailedLoad will be called *before* Reload() returns and will only
// be called if the embedder fails to load sources.
void IsolateReloadContext::FinalizeFailedLoad(const Error& error) {
TIR_Print("---- LOAD FAILED, ABORTING RELOAD\n");
AddReasonForCancelling(new Aborted(zone_, error));
ReportReasonsForCancelling();
if (!reload_finalized_) {
Rollback();
}
CommonFinalizeTail();
}
void IsolateReloadContext::CommonFinalizeTail() {
ReportOnJSON(js_);
reload_finalized_ = true;
}
void IsolateReloadContext::ReportOnJSON(JSONStream* stream) {
JSONObject jsobj(stream);
jsobj.AddProperty("type", "ReloadReport");
jsobj.AddProperty("success", reload_skipped_ || !HasReasonsForCancelling());
{
JSONObject details(&jsobj, "details");
if (reload_skipped_) {
// Reload was skipped.
const GrowableObjectArray& libs =
GrowableObjectArray::Handle(object_store()->libraries());
const intptr_t final_library_count = libs.Length();
details.AddProperty("savedLibraryCount", final_library_count);
details.AddProperty("loadedLibraryCount", static_cast<intptr_t>(0));
details.AddProperty("finalLibraryCount", final_library_count);
} else if (HasReasonsForCancelling()) {
// Reload was rejected.
JSONArray array(&jsobj, "notices");
for (intptr_t i = 0; i < reasons_to_cancel_reload_.length(); i++) {
ReasonForCancelling* reason = reasons_to_cancel_reload_.At(i);
reason->AppendTo(&array);
}
} else {
// Reload was successful.
const GrowableObjectArray& libs =
GrowableObjectArray::Handle(object_store()->libraries());
const intptr_t final_library_count = libs.Length();
const intptr_t loaded_library_count =
final_library_count - num_saved_libs_;
details.AddProperty("savedLibraryCount", num_saved_libs_);
details.AddProperty("loadedLibraryCount", loaded_library_count);
details.AddProperty("finalLibraryCount", final_library_count);
JSONArray array(&jsobj, "shapeChangeMappings");
for (intptr_t i = 0; i < instance_morphers_.length(); i++) {
instance_morphers_.At(i)->AppendTo(&array);
}
}
}
}
void IsolateReloadContext::EnsuredUnoptimizedCodeForStack() {
TIMELINE_SCOPE(EnsuredUnoptimizedCodeForStack);
StackFrameIterator it(ValidationPolicy::kDontValidateFrames,
Thread::Current(),
StackFrameIterator::kNoCrossThreadIteration);
Function& func = Function::Handle();
while (it.HasNextFrame()) {
StackFrame* frame = it.NextFrame();
if (frame->IsDartFrame()) {
func = frame->LookupDartFunction();
ASSERT(!func.IsNull());
if (!frame->is_interpreted()) {
func.EnsureHasCompiledUnoptimizedCode();
}
}
}
}
void IsolateReloadContext::DeoptimizeDependentCode() {
TIMELINE_SCOPE(DeoptimizeDependentCode);
ClassTable* class_table = I->class_table();
const intptr_t bottom = Dart::vm_isolate()->class_table()->NumCids();
const intptr_t top = I->class_table()->NumCids();
Class& cls = Class::Handle();
Array& fields = Array::Handle();
Field& field = Field::Handle();
for (intptr_t cls_idx = bottom; cls_idx < top; cls_idx++) {
if (!class_table->HasValidClassAt(cls_idx)) {
// Skip.
continue;
}
// Deoptimize CHA code.
cls = class_table->At(cls_idx);
ASSERT(!cls.IsNull());
cls.DisableAllCHAOptimizedCode();
// Deoptimize field guard code.
fields = cls.fields();
ASSERT(!fields.IsNull());
for (intptr_t field_idx = 0; field_idx < fields.Length(); field_idx++) {
field = Field::RawCast(fields.At(field_idx));
ASSERT(!field.IsNull());
field.DeoptimizeDependentCode();
}
}
DeoptimizeTypeTestingStubs();
// TODO(johnmccutchan): Also call LibraryPrefix::InvalidateDependentCode.
}
void IsolateReloadContext::CheckpointClasses() {
TIMELINE_SCOPE(CheckpointClasses);
TIR_Print("---- CHECKPOINTING CLASSES\n");
// Checkpoint classes before a reload. We need to copy the following:
// 1) The size of the class table.
// 2) The class table itself.
// For efficiency, we build a set of classes before the reload. This set
// is used to pair new classes with old classes.
ClassTable* class_table = I->class_table();
// Copy the size of the class table.
saved_num_cids_ = I->class_table()->NumCids();
// Copy of the class table.
ClassAndSize* local_saved_class_table = reinterpret_cast<ClassAndSize*>(
malloc(sizeof(ClassAndSize) * saved_num_cids_));
Class& cls = Class::Handle();
UnorderedHashSet<ClassMapTraits> old_classes_set(old_classes_set_storage_);
for (intptr_t i = 0; i < saved_num_cids_; i++) {
if (class_table->IsValidIndex(i) && class_table->HasValidClassAt(i)) {
// Copy the class into the saved class table and add it to the set.
local_saved_class_table[i] = class_table->PairAt(i);
if (i != kFreeListElement && i != kForwardingCorpse) {
cls = class_table->At(i);
bool already_present = old_classes_set.Insert(cls);
ASSERT(!already_present);
}
} else {
// No class at this index, mark it as NULL.
local_saved_class_table[i] = ClassAndSize(NULL);
}
}
old_classes_set_storage_ = old_classes_set.Release().raw();
// Assigning the field must be done after saving the class table.
saved_class_table_ = local_saved_class_table;
TIR_Print("---- System had %" Pd " classes\n", saved_num_cids_);
}
Dart_FileModifiedCallback IsolateReloadContext::file_modified_callback_ = NULL;
bool IsolateReloadContext::ScriptModifiedSince(const Script& script,
int64_t since) {
if (file_modified_callback_ == NULL) {
return true;
}
// We use the resolved url to determine if the script has been modified.
const String& url = String::Handle(script.resolved_url());
const char* url_chars = url.ToCString();
return (*file_modified_callback_)(url_chars, since);
}
static void PropagateLibraryModified(
const ZoneGrowableArray<ZoneGrowableArray<intptr_t>*>* imported_by,
intptr_t lib_index,
BitVector* modified_libs) {
ZoneGrowableArray<intptr_t>* dep_libs = (*imported_by)[lib_index];
for (intptr_t i = 0; i < dep_libs->length(); i++) {
intptr_t dep_lib_index = (*dep_libs)[i];
if (!modified_libs->Contains(dep_lib_index)) {
modified_libs->Add(dep_lib_index);
PropagateLibraryModified(imported_by, dep_lib_index, modified_libs);
}
}
}
static bool ContainsScriptUri(const GrowableArray<const char*>& seen_uris,
const char* uri) {
for (intptr_t i = 0; i < seen_uris.length(); i++) {
const char* seen_uri = seen_uris.At(i);
size_t seen_len = strlen(seen_uri);
if (seen_len != strlen(uri)) {
continue;
} else if (strncmp(seen_uri, uri, seen_len) == 0) {
return true;
}
}
return false;
}
void IsolateReloadContext::FindModifiedSources(
Thread* thread,
bool force_reload,
Dart_SourceFile** modified_sources,
intptr_t* count,
const char* packages_url) {
Zone* zone = thread->zone();
int64_t last_reload = I->last_reload_timestamp();
GrowableArray<const char*> modified_sources_uris;
const GrowableObjectArray& libs =
GrowableObjectArray::Handle(object_store()->libraries());
Library& lib = Library::Handle(zone);
Array& scripts = Array::Handle(zone);
Script& script = Script::Handle(zone);
String& uri = String::Handle(zone);
for (intptr_t lib_idx = 0; lib_idx < libs.Length(); lib_idx++) {
lib ^= libs.At(lib_idx);
if (lib.is_dart_scheme()) {
// We don't consider dart scheme libraries during reload.
continue;
}
scripts = lib.LoadedScripts();
for (intptr_t script_idx = 0; script_idx < scripts.Length(); script_idx++) {
script ^= scripts.At(script_idx);
uri ^= script.url();
if (ContainsScriptUri(modified_sources_uris, uri.ToCString())) {
// We've already accounted for this script in a prior library.
continue;
}
if (force_reload || ScriptModifiedSince(script, last_reload)) {
modified_sources_uris.Add(uri.ToCString());
}
}
}
// In addition to all sources, we need to check if the .packages file
// contents have been modified.
if (packages_url != NULL) {
if (file_modified_callback_ == NULL ||
(*file_modified_callback_)(packages_url, last_reload)) {
modified_sources_uris.Add(packages_url);
}
}
*count = modified_sources_uris.length();
if (*count == 0) {
return;
}
*modified_sources = zone_->Alloc<Dart_SourceFile>(*count);
for (intptr_t i = 0; i < *count; ++i) {
(*modified_sources)[i].uri = modified_sources_uris[i];
(*modified_sources)[i].source = NULL;
}
}
BitVector* IsolateReloadContext::FindModifiedLibraries(bool force_reload,
bool root_lib_modified) {
Thread* thread = Thread::Current();
int64_t last_reload = I->last_reload_timestamp();
const GrowableObjectArray& libs =
GrowableObjectArray::Handle(object_store()->libraries());
Library& lib = Library::Handle();
Array& scripts = Array::Handle();
Script& script = Script::Handle();
intptr_t num_libs = libs.Length();
// Construct the imported-by graph.
ZoneGrowableArray<ZoneGrowableArray<intptr_t>*>* imported_by = new (zone_)
ZoneGrowableArray<ZoneGrowableArray<intptr_t>*>(zone_, num_libs);
imported_by->SetLength(num_libs);
for (intptr_t i = 0; i < num_libs; i++) {
(*imported_by)[i] = new (zone_) ZoneGrowableArray<intptr_t>(zone_, 0);
}
Array& ports = Array::Handle();
Namespace& ns = Namespace::Handle();
Library& target = Library::Handle();
for (intptr_t lib_idx = 0; lib_idx < num_libs; lib_idx++) {
lib ^= libs.At(lib_idx);
ASSERT(lib_idx == lib.index());
if (lib.is_dart_scheme()) {
// We don't care about imports among dart scheme libraries.
continue;
}
// Add imports to the import-by graph.
ports = lib.imports();
for (intptr_t import_idx = 0; import_idx < ports.Length(); import_idx++) {
ns ^= ports.At(import_idx);
if (!ns.IsNull()) {
target = ns.library();
(*imported_by)[target.index()]->Add(lib.index());
}
}
// Add exports to the import-by graph.
ports = lib.exports();
for (intptr_t export_idx = 0; export_idx < ports.Length(); export_idx++) {
ns ^= ports.At(export_idx);
if (!ns.IsNull()) {
target = ns.library();
(*imported_by)[target.index()]->Add(lib.index());
}
}
// Add prefixed imports to the import-by graph.
DictionaryIterator entries(lib);
Object& entry = Object::Handle();
LibraryPrefix& prefix = LibraryPrefix::Handle();
while (entries.HasNext()) {
entry = entries.GetNext();
if (entry.IsLibraryPrefix()) {
prefix ^= entry.raw();
ports = prefix.imports();
for (intptr_t import_idx = 0; import_idx < ports.Length();
import_idx++) {
ns ^= ports.At(import_idx);
if (!ns.IsNull()) {
target = ns.library();
(*imported_by)[target.index()]->Add(lib.index());
}
}
}
}
}
BitVector* modified_libs = new (Z) BitVector(Z, num_libs);
if (root_lib_modified) {
// The root library was either moved or replaced. Mark it as modified to
// force a reload of the potential root library replacement.
lib ^= object_store()->root_library();
modified_libs->Add(lib.index());
}
for (intptr_t lib_idx = 0; lib_idx < num_libs; lib_idx++) {
lib ^= libs.At(lib_idx);
if (lib.is_dart_scheme() || modified_libs->Contains(lib_idx)) {
// We don't consider dart scheme libraries during reload. If
// the modified libs set already contains this library, then we
// have already visited it.
continue;
}
scripts = lib.LoadedScripts();
for (intptr_t script_idx = 0; script_idx < scripts.Length(); script_idx++) {
script ^= scripts.At(script_idx);
if (force_reload || ScriptModifiedSince(script, last_reload)) {
modified_libs->Add(lib_idx);
PropagateLibraryModified(imported_by, lib_idx, modified_libs);
break;
}
}
}
return modified_libs;
}
void IsolateReloadContext::CheckpointLibraries() {
TIMELINE_SCOPE(CheckpointLibraries);
TIR_Print("---- CHECKPOINTING LIBRARIES\n");
// Save the root library in case we abort the reload.
const Library& root_lib = Library::Handle(object_store()->root_library());
set_saved_root_library(root_lib);
// Save the old libraries array in case we abort the reload.
const GrowableObjectArray& libs =
GrowableObjectArray::Handle(object_store()->libraries());
set_saved_libraries(libs);
// Make a filtered copy of the old libraries array. Keep "clean" libraries
// that we will use instead of reloading.
const GrowableObjectArray& new_libs =
GrowableObjectArray::Handle(GrowableObjectArray::New(Heap::kOld));
Library& lib = Library::Handle();
UnorderedHashSet<LibraryMapTraits> old_libraries_set(
old_libraries_set_storage_);
num_saved_libs_ = 0;
for (intptr_t i = 0; i < libs.Length(); i++) {
lib ^= libs.At(i);
if (modified_libs_->Contains(i)) {
// We are going to reload this library. Clear the index.
lib.set_index(-1);
} else {
// We are preserving this library across the reload, assign its new index
lib.set_index(new_libs.Length());
new_libs.Add(lib, Heap::kOld);
num_saved_libs_++;
}
// Add old library to old libraries set.
bool already_present = old_libraries_set.Insert(lib);
ASSERT(!already_present);
}
modified_libs_ = NULL; // Renumbering the libraries has invalidated this.
old_libraries_set_storage_ = old_libraries_set.Release().raw();
// Reset the registered libraries to the filtered array.
Library::RegisterLibraries(Thread::Current(), new_libs);
// Reset the root library to null.
object_store()->set_root_library(Library::Handle());
}
// While reloading everything we do must be reversible so that we can abort
// safely if the reload fails. This function stashes things to the side and
// prepares the isolate for the reload attempt.
void IsolateReloadContext::Checkpoint() {
TIMELINE_SCOPE(Checkpoint);
CheckpointClasses();
CheckpointLibraries();
}
void IsolateReloadContext::RollbackClasses() {
TIR_Print("---- ROLLING BACK CLASS TABLE\n");
ASSERT(saved_num_cids_ > 0);
ASSERT(saved_class_table_ != NULL);
ClassTable* class_table = I->class_table();
class_table->SetNumCids(saved_num_cids_);
// Overwrite classes in class table with the saved classes.
for (intptr_t i = 0; i < saved_num_cids_; i++) {
if (class_table->IsValidIndex(i)) {
class_table->SetAt(i, saved_class_table_[i].get_raw_class());
}
}
ClassAndSize* local_saved_class_table = saved_class_table_;
saved_class_table_ = NULL;
// Can't free this table immediately as another thread (e.g., the sweeper) may
// be suspended between loading the table pointer and loading the table
// element. Table will be freed at the next major GC or isolate shutdown.
class_table->AddOldTable(local_saved_class_table);
}
void IsolateReloadContext::RollbackLibraries() {
TIR_Print("---- ROLLING BACK LIBRARY CHANGES\n");
Thread* thread = Thread::Current();
Library& lib = Library::Handle();
GrowableObjectArray& saved_libs =
GrowableObjectArray::Handle(Z, saved_libraries());
if (!saved_libs.IsNull()) {
for (intptr_t i = 0; i < saved_libs.Length(); i++) {
lib = Library::RawCast(saved_libs.At(i));
// Restore indexes that were modified in CheckpointLibraries.
lib.set_index(i);
}
// Reset the registered libraries to the filtered array.
Library::RegisterLibraries(thread, saved_libs);
}
Library& saved_root_lib = Library::Handle(Z, saved_root_library());
if (!saved_root_lib.IsNull()) {
object_store()->set_root_library(saved_root_lib);
}
set_saved_root_library(Library::Handle());
set_saved_libraries(GrowableObjectArray::Handle());
}
void IsolateReloadContext::Rollback() {
TIR_Print("---- ROLLING BACK");
RollbackClasses();
RollbackLibraries();
}
#ifdef DEBUG
void IsolateReloadContext::VerifyMaps() {
TIMELINE_SCOPE(VerifyMaps);
Class& cls = Class::Handle();
Class& new_cls = Class::Handle();
Class& cls2 = Class::Handle();
// Verify that two old classes aren't both mapped to the same new
// class. This could happen is the IsSameClass function is broken.
UnorderedHashMap<ClassMapTraits> class_map(class_map_storage_);
UnorderedHashMap<ClassMapTraits> reverse_class_map(
HashTables::New<UnorderedHashMap<ClassMapTraits> >(
class_map.NumOccupied()));
{
UnorderedHashMap<ClassMapTraits>::Iterator it(&class_map);
while (it.MoveNext()) {
const intptr_t entry = it.Current();
new_cls = Class::RawCast(class_map.GetKey(entry));
cls = Class::RawCast(class_map.GetPayload(entry, 0));
cls2 ^= reverse_class_map.GetOrNull(new_cls);
if (!cls2.IsNull()) {
OS::PrintErr(
"Classes '%s' and '%s' are distinct classes but both map "
" to class '%s'\n",
cls.ToCString(), cls2.ToCString(), new_cls.ToCString());
UNREACHABLE();
}
bool update = reverse_class_map.UpdateOrInsert(cls, new_cls);
ASSERT(!update);
}
}
class_map.Release();
reverse_class_map.Release();
}
#endif
static void RecordChanges(const GrowableObjectArray& changed_in_last_reload,
const Class& old_cls,
const Class& new_cls) {
// All members of enum classes are synthetic, so nothing to report here.
if (new_cls.is_enum_class()) {
return;
}
// Don't report synthetic classes like the superclass of
// `class MA extends S with M {}` or `class MA = S with M'. The relevant
// changes with be reported as changes in M.
if (new_cls.IsMixinApplication() || new_cls.is_mixin_app_alias()) {
return;
}
// Don't report `typedef bool Predicate(Object o)` as unused. There is nothing
// to execute.
if (new_cls.IsTypedefClass()) {
return;
}
if (new_cls.raw() == old_cls.raw()) {
// A new class maps to itself. All its functions, field initizers, and so
// on are new.
changed_in_last_reload.Add(new_cls);
return;
}
ASSERT(new_cls.is_finalized() == old_cls.is_finalized());
if (!new_cls.is_finalized()) {
if (new_cls.SourceFingerprint() == old_cls.SourceFingerprint()) {
return;
}
// We don't know the members. Register interest in the whole class. Creates
// false positives.
changed_in_last_reload.Add(new_cls);
return;
}
Zone* zone = Thread::Current()->zone();
const Array& functions = Array::Handle(zone, new_cls.functions());
const Array& fields = Array::Handle(zone, new_cls.fields());
Function& new_function = Function::Handle(zone);
Function& old_function = Function::Handle(zone);
Field& new_field = Field::Handle(zone);
Field& old_field = Field::Handle(zone);
String& selector = String::Handle(zone);
for (intptr_t i = 0; i < functions.Length(); i++) {
new_function ^= functions.At(i);
selector = new_function.name();
old_function = old_cls.LookupFunction(selector);
// If we made live changes with proper structed edits, this would just be
// old != new.
if (old_function.IsNull() || (new_function.SourceFingerprint() !=
old_function.SourceFingerprint())) {
ASSERT(!new_function.HasCode());
ASSERT(new_function.usage_counter() == 0);
changed_in_last_reload.Add(new_function);
}
}
for (intptr_t i = 0; i < fields.Length(); i++) {
new_field ^= fields.At(i);
if (!new_field.is_static()) continue;
selector = new_field.name();
old_field = old_cls.LookupField(selector);
if (old_field.IsNull() || !old_field.is_static()) {
// New field.
changed_in_last_reload.Add(new_field);
} else if (new_field.SourceFingerprint() != old_field.SourceFingerprint()) {
// Changed field.
changed_in_last_reload.Add(new_field);
if (!old_field.IsUninitialized()) {
new_field.set_initializer_changed_after_initialization(true);
}
}
}
}
void IsolateReloadContext::Commit() {
TIMELINE_SCOPE(Commit);
TIR_Print("---- COMMITTING RELOAD\n");
// Note that the object heap contains before and after instances
// used for morphing. It is therefore important that morphing takes
// place prior to any heap walking.
// So please keep this code at the top of Commit().
if (!MorphInstances()) {
free(saved_class_table_);
saved_class_table_ = NULL;
}
#ifdef DEBUG
VerifyMaps();
#endif
const GrowableObjectArray& changed_in_last_reload =
GrowableObjectArray::Handle(GrowableObjectArray::New());
{
TIMELINE_SCOPE(CopyStaticFieldsAndPatchFieldsAndFunctions);
// Copy static field values from the old classes to the new classes.
// Patch fields and functions in the old classes so that they retain
// the old script.
Class& old_cls = Class::Handle();
Class& new_cls = Class::Handle();
UnorderedHashMap<ClassMapTraits> class_map(class_map_storage_);
{
UnorderedHashMap<ClassMapTraits>::Iterator it(&class_map);
while (it.MoveNext()) {
const intptr_t entry = it.Current();
new_cls = Class::RawCast(class_map.GetKey(entry));
old_cls = Class::RawCast(class_map.GetPayload(entry, 0));
if (new_cls.raw() != old_cls.raw()) {
ASSERT(new_cls.is_enum_class() == old_cls.is_enum_class());
if (new_cls.is_enum_class() && new_cls.is_finalized()) {
new_cls.ReplaceEnum(old_cls);
} else {
new_cls.CopyStaticFieldValues(old_cls);
}
old_cls.PatchFieldsAndFunctions();
old_cls.MigrateImplicitStaticClosures(this, new_cls);
}
RecordChanges(changed_in_last_reload, old_cls, new_cls);
}
}
class_map.Release();
}
if (FLAG_identity_reload) {
Object& changed = Object::Handle();
for (intptr_t i = 0; i < changed_in_last_reload.Length(); i++) {
changed = changed_in_last_reload.At(i);
ASSERT(changed.IsClass()); // Only fuzzy from lazy finalization.
}
}
I->object_store()->set_changed_in_last_reload(changed_in_last_reload);
// Copy over certain properties of libraries, e.g. is the library
// debuggable?
{
TIMELINE_SCOPE(CopyLibraryBits);
Library& lib = Library::Handle();
Library& new_lib = Library::Handle();
UnorderedHashMap<LibraryMapTraits> lib_map(library_map_storage_);
{
// Reload existing libraries.
UnorderedHashMap<LibraryMapTraits>::Iterator it(&lib_map);
while (it.MoveNext()) {
const intptr_t entry = it.Current();
ASSERT(entry != -1);
new_lib = Library::RawCast(lib_map.GetKey(entry));
lib = Library::RawCast(lib_map.GetPayload(entry, 0));
new_lib.set_debuggable(lib.IsDebuggable());
// Native extension support.
new_lib.set_native_entry_resolver(lib.native_entry_resolver());
new_lib.set_native_entry_symbol_resolver(
lib.native_entry_symbol_resolver());
}
}
// Release the library map.
lib_map.Release();
}
{
TIMELINE_SCOPE(UpdateLibrariesArray);
// Update the libraries array.
Library& lib = Library::Handle();
const GrowableObjectArray& libs =
GrowableObjectArray::Handle(I->object_store()->libraries());
for (intptr_t i = 0; i < libs.Length(); i++) {
lib = Library::RawCast(libs.At(i));
VTIR_Print("Lib '%s' at index %" Pd "\n", lib.ToCString(), i);
lib.set_index(i);
}
// Initialize library side table.
library_infos_.SetLength(libs.Length());
for (intptr_t i = 0; i < libs.Length(); i++) {
lib = Library::RawCast(libs.At(i));
// Mark the library dirty if it comes after the libraries we saved.
library_infos_[i].dirty = i >= num_saved_libs_;
}
}
{
const GrowableObjectArray& become_enum_mappings =
GrowableObjectArray::Handle(become_enum_mappings_);
UnorderedHashMap<BecomeMapTraits> become_map(become_map_storage_);
intptr_t replacement_count =
become_map.NumOccupied() + become_enum_mappings.Length() / 2;
const Array& before =
Array::Handle(Array::New(replacement_count, Heap::kOld));
const Array& after =
Array::Handle(Array::New(replacement_count, Heap::kOld));
Object& obj = Object::Handle();
intptr_t replacement_index = 0;
UnorderedHashMap<BecomeMapTraits>::Iterator it(&become_map);
while (it.MoveNext()) {
const intptr_t entry = it.Current();
obj = become_map.GetKey(entry);
before.SetAt(replacement_index, obj);
obj = become_map.GetPayload(entry, 0);
after.SetAt(replacement_index, obj);
replacement_index++;
}
for (intptr_t i = 0; i < become_enum_mappings.Length(); i += 2) {
obj = become_enum_mappings.At(i);
before.SetAt(replacement_index, obj);
obj = become_enum_mappings.At(i + 1);
after.SetAt(replacement_index, obj);
replacement_index++;
}
ASSERT(replacement_index == replacement_count);
become_map.Release();
Become::ElementsForwardIdentity(before, after);
}
// Rehash constants map for all classes. Constants are hashed by content, and
// content may have changed from fields being added or removed.
{
TIMELINE_SCOPE(RehashConstants);
I->RehashConstants();
}
#ifdef DEBUG
I->ValidateConstants();
#endif
if (FLAG_identity_reload) {
if (saved_num_cids_ != I->class_table()->NumCids()) {
TIR_Print("Identity reload failed! B#C=%" Pd " A#C=%" Pd "\n",
saved_num_cids_, I->class_table()->NumCids());
}
const GrowableObjectArray& saved_libs =
GrowableObjectArray::Handle(saved_libraries());
const GrowableObjectArray& libs =
GrowableObjectArray::Handle(I->object_store()->libraries());
if (saved_libs.Length() != libs.Length()) {
TIR_Print("Identity reload failed! B#L=%" Pd " A#L=%" Pd "\n",
saved_libs.Length(), libs.Length());
}
}
// Run the initializers for new instance fields.
RunNewFieldInitializers();
}
bool IsolateReloadContext::IsDirty(const Library& lib) {
const intptr_t index = lib.index();
if (index == static_cast<classid_t>(-1)) {
// Treat deleted libraries as dirty.
return true;
}
ASSERT((index >= 0) && (index < library_infos_.length()));
return library_infos_[index].dirty;
}
void IsolateReloadContext::PostCommit() {
TIMELINE_SCOPE(PostCommit);
set_saved_root_library(Library::Handle());
set_saved_libraries(GrowableObjectArray::Handle());
InvalidateWorld();
TIR_Print("---- DONE COMMIT\n");
}
void IsolateReloadContext::AddReasonForCancelling(ReasonForCancelling* reason) {
reload_aborted_ = true;
reasons_to_cancel_reload_.Add(reason);
}
void IsolateReloadContext::AddInstanceMorpher(InstanceMorpher* morpher) {
instance_morphers_.Add(morpher);
cid_mapper_.Insert(morpher);
}
void IsolateReloadContext::ReportReasonsForCancelling() {
ASSERT(FLAG_reload_force_rollback || HasReasonsForCancelling());
for (int i = 0; i < reasons_to_cancel_reload_.length(); i++) {
reasons_to_cancel_reload_.At(i)->Report(this);
}
}
// The ObjectLocator is used for collecting instances that
// needs to be morphed.
class ObjectLocator : public ObjectVisitor {
public:
explicit ObjectLocator(IsolateReloadContext* context)
: context_(context), count_(0) {}
void VisitObject(RawObject* obj) {
InstanceMorpher* morpher =
context_->cid_mapper_.LookupValue(obj->GetClassId());
if (morpher != NULL) {
morpher->AddObject(obj);
count_++;
}
}
// Return the number of located objects for morphing.
intptr_t count() { return count_; }
private:
IsolateReloadContext* context_;
intptr_t count_;
};
bool IsolateReloadContext::MorphInstances() {
TIMELINE_SCOPE(MorphInstances);
if (!HasInstanceMorphers()) {
return false;
}
if (FLAG_trace_reload) {
LogBlock blocker;
TIR_Print("MorphInstance: \n");
for (intptr_t i = 0; i < instance_morphers_.length(); i++) {
instance_morphers_.At(i)->Dump();
}
}
// Find all objects that need to be morphed.
ObjectLocator locator(this);
{
HeapIterationScope iteration(Thread::Current());
iteration.IterateObjects(&locator);
}
// Return if no objects are located.
intptr_t count = locator.count();
if (count == 0) {
return false;
}
TIR_Print("Found %" Pd " object%s subject to morphing.\n", count,
(count > 1) ? "s" : "");
Array& before = Array::Handle();
Array& after = Array::Handle();
{ // Prevent GC to take place due object format confusion.
// Hint: More than one class share the same cid.
NoHeapGrowthControlScope scope;
for (intptr_t i = 0; i < instance_morphers_.length(); i++) {
instance_morphers_.At(i)->CreateMorphedCopies();
}
// Create the inputs for Become.
intptr_t index = 0;
before = Array::New(count);
after = Array::New(count);
for (intptr_t i = 0; i < instance_morphers_.length(); i++) {
InstanceMorpher* morpher = instance_morphers_.At(i);
for (intptr_t j = 0; j < morpher->before()->length(); j++) {
before.SetAt(index, *morpher->before()->At(j));
after.SetAt(index, *morpher->after()->At(j));
index++;
}
}
ASSERT(index == count);
}
// This is important: The saved class table (describing before objects)
// must be zapped to prevent the forwarding in GetClassSizeForHeapWalkAt.
// Instance will from now be described by the isolate's class table.
free(saved_class_table_);
saved_class_table_ = NULL;
Become::ElementsForwardIdentity(before, after);
return true;
}
void IsolateReloadContext::RunNewFieldInitializers() {
// Run new field initializers on all instances.
for (intptr_t i = 0; i < instance_morphers_.length(); i++) {
instance_morphers_.At(i)->RunNewFieldInitializers();
}
}
bool IsolateReloadContext::ValidateReload() {
TIMELINE_SCOPE(ValidateReload);
if (reload_aborted()) return false;
TIR_Print("---- VALIDATING RELOAD\n");
// Validate libraries.
{
ASSERT(library_map_storage_ != Array::null());
UnorderedHashMap<LibraryMapTraits> map(library_map_storage_);
UnorderedHashMap<LibraryMapTraits>::Iterator it(&map);
Library& lib = Library::Handle();
Library& new_lib = Library::Handle();
while (it.MoveNext()) {
const intptr_t entry = it.Current();
new_lib = Library::RawCast(map.GetKey(entry));
lib = Library::RawCast(map.GetPayload(entry, 0));
if (new_lib.raw() != lib.raw()) {
lib.CheckReload(new_lib, this);
}
}
map.Release();
}
// Validate classes.
{
ASSERT(class_map_storage_ != Array::null());
UnorderedHashMap<ClassMapTraits> map(class_map_storage_);
UnorderedHashMap<ClassMapTraits>::Iterator it(&map);
Class& cls = Class::Handle();
Class& new_cls = Class::Handle();
while (it.MoveNext()) {
const intptr_t entry = it.Current();
new_cls = Class::RawCast(map.GetKey(entry));
cls = Class::RawCast(map.GetPayload(entry, 0));
if (new_cls.raw() != cls.raw()) {
cls.CheckReload(new_cls, this);
}
}
map.Release();
}
return !FLAG_reload_force_rollback && !HasReasonsForCancelling();
}
RawClass* IsolateReloadContext::FindOriginalClass(const Class& cls) {
return MappedClass(cls);
}
RawClass* IsolateReloadContext::GetClassForHeapWalkAt(intptr_t cid) {
ClassAndSize* class_table =
AtomicOperations::LoadRelaxed(&saved_class_table_);
if (class_table != NULL) {
ASSERT(cid > 0);
ASSERT(cid < saved_num_cids_);
return class_table[cid].get_raw_class();
} else {
return isolate_->class_table()->At(cid);
}
}
intptr_t IsolateReloadContext::GetClassSizeForHeapWalkAt(intptr_t cid) {
ClassAndSize* class_table =
AtomicOperations::LoadRelaxed(&saved_class_table_);
if (class_table != NULL) {
ASSERT(cid > 0);
ASSERT(cid < saved_num_cids_);
return class_table[cid].size();
} else {
return isolate_->class_table()->SizeAt(cid);
}
}
RawLibrary* IsolateReloadContext::saved_root_library() const {
return saved_root_library_;
}
void IsolateReloadContext::set_saved_root_library(const Library& value) {
saved_root_library_ = value.raw();
}
RawGrowableObjectArray* IsolateReloadContext::saved_libraries() const {
return saved_libraries_;
}
void IsolateReloadContext::set_saved_libraries(
const GrowableObjectArray& value) {
saved_libraries_ = value.raw();
}
void IsolateReloadContext::VisitObjectPointers(ObjectPointerVisitor* visitor) {
visitor->VisitPointers(from(), to());
if (saved_class_table_ != NULL) {
visitor->VisitPointers(
reinterpret_cast<RawObject**>(&saved_class_table_[0]), saved_num_cids_);
}
}
ObjectStore* IsolateReloadContext::object_store() {
return isolate_->object_store();
}
void IsolateReloadContext::ResetUnoptimizedICsOnStack() {
Thread* thread = Thread::Current();
StackZone stack_zone(thread);
Zone* zone = stack_zone.GetZone();
Code& code = Code::Handle(zone);
Function& function = Function::Handle(zone);
DartFrameIterator iterator(thread,
StackFrameIterator::kNoCrossThreadIteration);
StackFrame* frame = iterator.NextFrame();
while (frame != NULL) {
code = frame->LookupDartCode();
if (code.is_optimized()) {
// If this code is optimized, we need to reset the ICs in the
// corresponding unoptimized code, which will be executed when the stack
// unwinds to the optimized code.
function = code.function();
code = function.unoptimized_code();
ASSERT(!code.IsNull());
code.ResetICDatas(zone);
} else {
code.ResetICDatas(zone);
}
frame = iterator.NextFrame();
}
}
void IsolateReloadContext::ResetMegamorphicCaches() {
object_store()->set_megamorphic_cache_table(GrowableObjectArray::Handle());
// Since any current optimized code will not make any more calls, it may be
// better to clear the table instead of clearing each of the caches, allow
// the current megamorphic caches get GC'd and any new optimized code allocate
// new ones.
}
class MarkFunctionsForRecompilation : public ObjectVisitor {
public:
MarkFunctionsForRecompilation(Isolate* isolate,
IsolateReloadContext* reload_context,
Zone* zone)
: ObjectVisitor(),
handle_(Object::Handle(zone)),
owning_class_(Class::Handle(zone)),
owning_lib_(Library::Handle(zone)),
code_(Code::Handle(zone)),
reload_context_(reload_context),
zone_(zone) {}
virtual void VisitObject(RawObject* obj) {
if (obj->IsPseudoObject()) {
// Cannot even be wrapped in handles.
return;
}
handle_ = obj;
if (handle_.IsFunction()) {
const Function& func = Function::Cast(handle_);
if (func.IsSignatureFunction()) {
return;
}
// Switch to unoptimized code or the lazy compilation stub.
func.SwitchToLazyCompiledUnoptimizedCode();
// Grab the current code.
code_ = func.CurrentCode();
ASSERT(!code_.IsNull());
const bool clear_code = IsFromDirtyLibrary(func);
const bool stub_code = code_.IsStubCode();
// Zero edge counters.
func.ZeroEdgeCounters();
if (!stub_code) {
if (clear_code) {
VTIR_Print("Marking %s for recompilation, clearning code\n",
func.ToCString());
ClearAllCode(func);
} else {
PreserveUnoptimizedCode();
}
}
// Clear counters.
func.set_usage_counter(0);
func.set_deoptimization_counter(0);
func.set_optimized_instruction_count(0);
func.set_optimized_call_site_count(0);
}
}
private:
void ClearAllCode(const Function& func) {
// Null out the ICData array and code.
func.ClearICDataArray();
func.ClearCode();
func.SetWasCompiled(false);
}
void PreserveUnoptimizedCode() {
ASSERT(!code_.IsNull());
// We are preserving the unoptimized code, fill all ICData arrays with
// the sentinel values so that we have no stale type feedback.
code_.ResetICDatas(zone_);
}
bool IsFromDirtyLibrary(const Function& func) {
owning_class_ = func.Owner();
owning_lib_ = owning_class_.library();
return reload_context_->IsDirty(owning_lib_);
}
Object& handle_;
Class& owning_class_;
Library& owning_lib_;
Code& code_;
IsolateReloadContext* reload_context_;
Zone* zone_;
};
typedef UnorderedHashMap<SmiTraits> IntHashMap;
class InvalidateKernelInfoCaches : public ObjectVisitor {
public:
explicit InvalidateKernelInfoCaches(Zone* zone)
: ObjectVisitor(),
handle_(Object::Handle(zone)),
data_(Array::Handle(zone)),
key_(Object::Handle(zone)),
value_(Smi::Handle(zone)) {}
virtual void VisitObject(RawObject* obj) {
if (obj->IsPseudoObject()) {
// Cannot even be wrapped in handles.
return;
}
handle_ = obj;
if (!handle_.IsKernelProgramInfo()) {
return;
}
const KernelProgramInfo& info = KernelProgramInfo::Cast(handle_);
// Clear the libraries cache.
{
data_ ^= info.libraries_cache();
ASSERT(!data_.IsNull());
IntHashMap table(&key_, &value_, &data_);
table.Clear();
info.set_libraries_cache(table.Release());
}
// Clear the classes cache.
{
data_ ^= info.classes_cache();
ASSERT(!data_.IsNull());
IntHashMap table(&key_, &value_, &data_);
table.Clear();
info.set_classes_cache(table.Release());
}
}
private:
Object& handle_;
Array& data_;
Object& key_;
Smi& value_;
};
void IsolateReloadContext::RunInvalidationVisitors() {
TIMELINE_SCOPE(MarkAllFunctionsForRecompilation);
TIR_Print("---- RUNNING INVALIDATION HEAP VISITORS\n");
Thread* thread = Thread::Current();
StackZone stack_zone(thread);
Zone* zone = stack_zone.GetZone();
HeapIterationScope iteration(thread);
GrowableArray<ObjectVisitor*> arr(zone, 2);
ExtensibleObjectVisitor visitor(&arr);
MarkFunctionsForRecompilation function_visitor(isolate_, this, zone);
InvalidateKernelInfoCaches kernel_info_visitor(zone);
visitor.Add(&function_visitor);
visitor.Add(&kernel_info_visitor);
iteration.IterateObjects(&visitor);
}
void IsolateReloadContext::InvalidateWorld() {
TIR_Print("---- INVALIDATING WORLD\n");
ResetMegamorphicCaches();
if (FLAG_trace_deoptimization) {
THR_Print("Deopt for reload\n");
}
DeoptimizeFunctionsOnStack();
ResetUnoptimizedICsOnStack();
RunInvalidationVisitors();
}
RawClass* IsolateReloadContext::MappedClass(const Class& replacement_or_new) {
UnorderedHashMap<ClassMapTraits> map(class_map_storage_);
Class& cls = Class::Handle();
cls ^= map.GetOrNull(replacement_or_new);
// No need to update storage address because no mutation occurred.
map.Release();
return cls.raw();
}
RawLibrary* IsolateReloadContext::MappedLibrary(
const Library& replacement_or_new) {
return Library::null();
}
RawClass* IsolateReloadContext::OldClassOrNull(
const Class& replacement_or_new) {
UnorderedHashSet<ClassMapTraits> old_classes_set(old_classes_set_storage_);
Class& cls = Class::Handle();
cls ^= old_classes_set.GetOrNull(replacement_or_new);
old_classes_set_storage_ = old_classes_set.Release().raw();
return cls.raw();
}
RawString* IsolateReloadContext::FindLibraryPrivateKey(
const Library& replacement_or_new) {
const Library& old = Library::Handle(OldLibraryOrNull(replacement_or_new));
if (old.IsNull()) {
return String::null();
}
#if defined(DEBUG)
VTIR_Print("`%s` is getting `%s`'s private key.\n",
String::Handle(replacement_or_new.url()).ToCString(),
String::Handle(old.url()).ToCString());
#endif
return old.private_key();
}
RawLibrary* IsolateReloadContext::OldLibraryOrNull(
const Library& replacement_or_new) {
UnorderedHashSet<LibraryMapTraits> old_libraries_set(
old_libraries_set_storage_);
Library& lib = Library::Handle();
lib ^= old_libraries_set.GetOrNull(replacement_or_new);
old_libraries_set.Release();
if (lib.IsNull() && (root_url_prefix_ != String::null()) &&
(old_root_url_prefix_ != String::null())) {
return OldLibraryOrNullBaseMoved(replacement_or_new);
}
return lib.raw();
}
// Attempt to find the pair to |replacement_or_new| with the knowledge that
// the base url prefix has moved.
RawLibrary* IsolateReloadContext::OldLibraryOrNullBaseMoved(
const Library& replacement_or_new) {
const String& url_prefix = String::Handle(root_url_prefix_);
const String& old_url_prefix = String::Handle(old_root_url_prefix_);
const intptr_t prefix_length = url_prefix.Length();
const intptr_t old_prefix_length = old_url_prefix.Length();
const String& new_url = String::Handle(replacement_or_new.url());
const String& suffix =
String::Handle(String::SubString(new_url, prefix_length));
if (!new_url.StartsWith(url_prefix)) {
return Library::null();
}
Library& old = Library::Handle();
String& old_url = String::Handle();
String& old_suffix = String::Handle();
GrowableObjectArray& saved_libs =
GrowableObjectArray::Handle(saved_libraries());
ASSERT(!saved_libs.IsNull());
for (intptr_t i = 0; i < saved_libs.Length(); i++) {
old = Library::RawCast(saved_libs.At(i));
old_url = old.url();
if (!old_url.StartsWith(old_url_prefix)) {
continue;
}
old_suffix ^= String::SubString(old_url, old_prefix_length);
if (old_suffix.IsNull()) {
continue;
}
if (old_suffix.Equals(suffix)) {
TIR_Print("`%s` is moving to `%s`\n", old_url.ToCString(),
new_url.ToCString());
return old.raw();
}
}
return Library::null();
}
void IsolateReloadContext::BuildLibraryMapping() {
const GrowableObjectArray& libs =
GrowableObjectArray::Handle(object_store()->libraries());
Library& replacement_or_new = Library::Handle();
Library& old = Library::Handle();
for (intptr_t i = num_saved_libs_; i < libs.Length(); i++) {
replacement_or_new = Library::RawCast(libs.At(i));
old ^= OldLibraryOrNull(replacement_or_new);
if (old.IsNull()) {
if (FLAG_identity_reload) {
TIR_Print("Could not find original library for %s\n",
replacement_or_new.ToCString());
UNREACHABLE();
}
// New library.
AddLibraryMapping(replacement_or_new, replacement_or_new);
} else {
ASSERT(!replacement_or_new.is_dart_scheme());
// Replaced class.
AddLibraryMapping(replacement_or_new, old);
AddBecomeMapping(old, replacement_or_new);
}
}
}
void IsolateReloadContext::AddClassMapping(const Class& replacement_or_new,
const Class& original) {
UnorderedHashMap<ClassMapTraits> map(class_map_storage_);
bool update = map.UpdateOrInsert(replacement_or_new, original);
ASSERT(!update);
// The storage given to the map may have been reallocated, remember the new
// address.
class_map_storage_ = map.Release().raw();
}
void IsolateReloadContext::AddLibraryMapping(const Library& replacement_or_new,
const Library& original) {
UnorderedHashMap<LibraryMapTraits> map(library_map_storage_);
bool update = map.UpdateOrInsert(replacement_or_new, original);
ASSERT(!update);
// The storage given to the map may have been reallocated, remember the new
// address.
library_map_storage_ = map.Release().raw();
}
void IsolateReloadContext::AddStaticFieldMapping(const Field& old_field,
const Field& new_field) {
ASSERT(old_field.is_static());
ASSERT(new_field.is_static());
AddBecomeMapping(old_field, new_field);
}
void IsolateReloadContext::AddBecomeMapping(const Object& old,
const Object& neu) {
ASSERT(become_map_storage_ != Array::null());
UnorderedHashMap<BecomeMapTraits> become_map(become_map_storage_);
bool update = become_map.UpdateOrInsert(old, neu);
ASSERT(!update);
become_map_storage_ = become_map.Release().raw();
}
void IsolateReloadContext::AddEnumBecomeMapping(const Object& old,
const Object& neu) {
const GrowableObjectArray& become_enum_mappings =
GrowableObjectArray::Handle(become_enum_mappings_);
become_enum_mappings.Add(old);
become_enum_mappings.Add(neu);
ASSERT((become_enum_mappings.Length() % 2) == 0);
}
void IsolateReloadContext::RebuildDirectSubclasses() {
ClassTable* class_table = I->class_table();
intptr_t num_cids = class_table->NumCids();
// Clear the direct subclasses for all classes.
Class& cls = Class::Handle();
GrowableObjectArray& subclasses = GrowableObjectArray::Handle();
for (intptr_t i = 1; i < num_cids; i++) {
if (class_table->HasValidClassAt(i)) {
cls = class_table->At(i);
subclasses = cls.direct_subclasses();
if (!subclasses.IsNull()) {
cls.ClearDirectSubclasses();
}
subclasses = cls.direct_implementors();
if (!subclasses.IsNull()) {
cls.ClearDirectImplementors();
}
}
}
// Recompute the direct subclasses / implementors.
AbstractType& super_type = AbstractType::Handle();
Class& super_cls = Class::Handle();
Array& interface_types = Array::Handle();
AbstractType& interface_type = AbstractType::Handle();
Class& interface_class = Class::Handle();
for (intptr_t i = 1; i < num_cids; i++) {
if (class_table->HasValidClassAt(i)) {
cls = class_table->At(i);
super_type = cls.super_type();
if (!super_type.IsNull() && !super_type.IsObjectType()) {
super_cls = cls.SuperClass();
ASSERT(!super_cls.IsNull());
super_cls.AddDirectSubclass(cls);
}
interface_types = cls.interfaces();
if (!interface_types.IsNull()) {
for (intptr_t j = 0; j < interface_types.Length(); ++j) {
interface_type ^= interface_types.At(j);
interface_class = interface_type.type_class();
interface_class.AddDirectImplementor(cls);
}
}
}
}
}
#endif // !defined(PRODUCT) && !defined(DART_PRECOMPILED_RUNTIME)
} // namespace dart