Files
sdk/runtime/vm/bootstrap.cc
T
Martin Kustermann ab6aeaa106 [vm/kernel] Use GC-tracked ExternalTypedData/TypedDataView for kernel buffers
Until now we often leaked kernel buffers (e.g. hot reload buffers) because various
objects were referencing ExternalTypedData objects pointing into the middle of
c-allocated memory. This made it impossible for the GC to determine when the last
reference is gone.

This CL ensures that the actual buffers are *always* made available via
ExternalTypedData and any inner pointers into it are created via TypedDataViews.

The embedder guarantees to the free kernel buffers it has provided to:
    - Dart_CreateIsolateFromKernel
    - Dart_LoadScriptFromKernel
    - Dart_LoadLibraryFromKernel
    - Dart_SetDartLibrarySourcesKernel
on isolate shutdown.

All other kernel buffers will get a finalizer attached, which ensures the
kernel buffers get freed by the GC once they are no longer referenced:
    - Kernel blobs for expression evaluation
    - Kernel blobs for Hot-Reload
    - Kernel blobs for cc tests

Fixes https://github.com/dart-lang/sdk/issues/33973
Fixes https://github.com/dart-lang/sdk/issues/36857
Issue https://github.com/dart-lang/sdk/issues/37030

Change-Id: I1cc410c94c0f4b229413e793728a261afcb10aaf
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/103130
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Commit-Queue: Martin Kustermann <kustermann@google.com>
2019-05-22 01:23:46 +00:00

177 lines
6.2 KiB
C++

// Copyright (c) 2012, 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/bootstrap.h"
#include "include/dart_api.h"
#include "vm/class_finalizer.h"
#include "vm/compiler/jit/compiler.h"
#include "vm/dart_api_impl.h"
#if !defined(DART_PRECOMPILED_RUNTIME)
#include "vm/kernel.h"
#include "vm/kernel_loader.h"
#endif
#include "vm/object.h"
#include "vm/object_store.h"
#include "vm/symbols.h"
namespace dart {
struct BootstrapLibProps {
ObjectStore::BootstrapLibraryId index;
const char* uri;
};
enum { kPathsUriOffset = 0, kPathsSourceOffset = 1, kPathsEntryLength = 2 };
#if !defined(DART_PRECOMPILED_RUNTIME)
#define MAKE_PROPERTIES(CamelName, name) \
{ObjectStore::k##CamelName, "dart:" #name},
static const BootstrapLibProps bootstrap_libraries[] = {
FOR_EACH_BOOTSTRAP_LIBRARY(MAKE_PROPERTIES)};
#undef MAKE_PROPERTIES
static const intptr_t kBootstrapLibraryCount = ARRAY_SIZE(bootstrap_libraries);
static void Finish(Thread* thread) {
Bootstrap::SetupNativeResolver();
if (!ClassFinalizer::ProcessPendingClasses()) {
FATAL("Error in class finalization during bootstrapping.");
}
// Eagerly compile the _Closure class as it is the class of all closure
// instances. This allows us to just finalize function types without going
// through the hoops of trying to compile their scope class.
ObjectStore* object_store = thread->isolate()->object_store();
Zone* zone = thread->zone();
Class& cls = Class::Handle(zone, object_store->closure_class());
ClassFinalizer::LoadClassMembers(cls);
#if defined(DEBUG)
// Verify that closure field offsets are identical in Dart and C++.
const Array& fields = Array::Handle(zone, cls.fields());
ASSERT(fields.Length() == 6);
Field& field = Field::Handle(zone);
field ^= fields.At(0);
ASSERT(field.Offset() == Closure::instantiator_type_arguments_offset());
field ^= fields.At(1);
ASSERT(field.Offset() == Closure::function_type_arguments_offset());
field ^= fields.At(2);
ASSERT(field.Offset() == Closure::delayed_type_arguments_offset());
field ^= fields.At(3);
ASSERT(field.Offset() == Closure::function_offset());
field ^= fields.At(4);
ASSERT(field.Offset() == Closure::context_offset());
field ^= fields.At(5);
ASSERT(field.Offset() == Closure::hash_offset());
#endif // defined(DEBUG)
// Eagerly compile Bool class, bool constants are used from within compiler.
cls = object_store->bool_class();
ClassFinalizer::LoadClassMembers(cls);
}
static RawError* BootstrapFromKernel(Thread* thread,
const uint8_t* kernel_buffer,
intptr_t kernel_buffer_size) {
Zone* zone = thread->zone();
const char* error = nullptr;
// NOTE: We do not attach a finalizer for this object, because the embedder
// will free it once the isolate has shutdown.
// (The embedder provides this buffer to [Dart_CreateIsolateFromKernel])
const auto& td = ExternalTypedData::Handle(ExternalTypedData::New(
kExternalTypedDataUint8ArrayCid, const_cast<uint8_t*>(kernel_buffer),
kernel_buffer_size, Heap::kOld));
kernel::Program* program = kernel::Program::ReadFromTypedData(td, &error);
if (program == nullptr) {
const intptr_t kMessageBufferSize = 512;
char message_buffer[kMessageBufferSize];
Utils::SNPrint(message_buffer, kMessageBufferSize,
"Can't load Kernel binary: %s.", error);
const String& msg = String::Handle(String::New(message_buffer, Heap::kOld));
return ApiError::New(msg, Heap::kOld);
}
kernel::KernelLoader loader(program, /*uri_to_source_table=*/nullptr);
Isolate* isolate = thread->isolate();
if (isolate->obfuscate()) {
loader.ReadObfuscationProhibitions();
}
// Load the bootstrap libraries in order (see object_store.h).
Library& library = Library::Handle(zone);
String& dart_name = String::Handle(zone);
for (intptr_t i = 0; i < kBootstrapLibraryCount; ++i) {
ObjectStore::BootstrapLibraryId id = bootstrap_libraries[i].index;
library = isolate->object_store()->bootstrap_library(id);
dart_name = library.url();
for (intptr_t j = 0; j < program->library_count(); ++j) {
const String& kernel_name = loader.LibraryUri(j);
if (kernel_name.Equals(dart_name)) {
loader.LoadLibrary(j);
break;
}
}
}
// Finish bootstrapping, including class finalization.
Finish(thread);
// The platform binary may contain other libraries (e.g., dart:_builtin or
// dart:io) that will not be bundled with application. Load them now.
const Object& result = Object::Handle(zone, loader.LoadProgram());
delete program;
if (result.IsError()) {
return Error::Cast(result).raw();
}
// The builtin library should be registered with the VM.
dart_name = String::New("dart:_builtin");
library = Library::LookupLibrary(thread, dart_name);
isolate->object_store()->set_builtin_library(library);
return Error::null();
}
RawError* Bootstrap::DoBootstrapping(const uint8_t* kernel_buffer,
intptr_t kernel_buffer_size) {
Thread* thread = Thread::Current();
Isolate* isolate = thread->isolate();
Zone* zone = thread->zone();
String& uri = String::Handle(zone);
Library& lib = Library::Handle(zone);
HANDLESCOPE(thread);
// Ensure there are library objects for all the bootstrap libraries.
for (intptr_t i = 0; i < kBootstrapLibraryCount; ++i) {
ObjectStore::BootstrapLibraryId id = bootstrap_libraries[i].index;
uri = Symbols::New(thread, bootstrap_libraries[i].uri);
lib = isolate->object_store()->bootstrap_library(id);
ASSERT(lib.raw() == Library::LookupLibrary(thread, uri));
if (lib.IsNull()) {
lib = Library::NewLibraryHelper(uri, false);
lib.SetLoadRequested();
lib.Register(thread);
isolate->object_store()->set_bootstrap_library(id, lib);
}
}
return BootstrapFromKernel(thread, kernel_buffer, kernel_buffer_size);
}
#else
RawError* Bootstrap::DoBootstrapping(const uint8_t* kernel_buffer,
intptr_t kernel_buffer_size) {
UNREACHABLE();
return Error::null();
}
#endif
} // namespace dart