Files
sdk/runtime/vm/service_isolate.cc
T
Ben Konyi 6ea62c02fe [ Service ] Run the service's main() via _runMainIsolate
Prior to this change, the VM service isolate was configured to execute
`main` directly. This resulted in unexpected behavior around exceptions
thrown after the first asynchronous gap, which were unhandled but caused
the service isolate to exit silently with no error.

This change updates how the service isolate starts execution by
invoking `main` via `dart:isolate`'s `_runMainIsolate` method, similar
to how user isolates and the DartDev isolate start execution. This
results in the message handler being triggered, meaning the microtask
queue will be processed correctly and unhandled exceptions in
asynchronous contexts being reported.

TEST=Local testing with exceptions explicitly thrown from within the VM
service

Change-Id: I69475a86d923489fa216bc8e939a2726cf3ff2e8
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/490220
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Commit-Queue: Ben Konyi <bkonyi@google.com>
2026-03-24 11:57:40 -07:00

684 lines
22 KiB
C++

// Copyright (c) 2015, 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/service_isolate.h"
#include "vm/compiler/jit/compiler.h"
#include "vm/dart_api_impl.h"
#include "vm/dart_api_message.h"
#include "vm/dart_entry.h"
#include "vm/isolate.h"
#include "vm/lockers.h"
#include "vm/message.h"
#include "vm/message_handler.h"
#include "vm/message_snapshot.h"
#include "vm/native_arguments.h"
#include "vm/native_entry.h"
#include "vm/object.h"
#include "vm/object_store.h"
#include "vm/port.h"
#include "vm/service.h"
#include "vm/symbols.h"
#include "vm/thread_pool.h"
#include "vm/timeline.h"
#if !defined(PRODUCT)
namespace dart {
#define Z (T->zone())
DEFINE_FLAG(bool, trace_service, false, "Trace VM service requests.");
DEFINE_FLAG(bool,
trace_service_pause_events,
false,
"Trace VM service isolate pause events.");
DEFINE_FLAG(bool,
trace_service_verbose,
false,
"Provide extra service tracing information.");
// These must be kept in sync with service/constants.dart
#define VM_SERVICE_ISOLATE_EXIT_MESSAGE_ID 0
#define VM_SERVICE_ISOLATE_STARTUP_MESSAGE_ID 1
#define VM_SERVICE_ISOLATE_SHUTDOWN_MESSAGE_ID 2
#define VM_SERVICE_WEB_SERVER_CONTROL_MESSAGE_ID 3
#define VM_SERVICE_SERVER_INFO_MESSAGE_ID 4
#define VM_SERVICE_METHOD_CALL_FROM_NATIVE 5
bool ServiceIsolate::SendServiceControlMessage(Thread* thread,
Dart_Port port_id,
intptr_t code,
const char* name) {
Dart_CObject ccode;
ccode.type = Dart_CObject_kInt32;
ccode.value.as_int32 = code;
Dart_CObject port_int;
port_int.type = Dart_CObject_kInt64;
port_int.value.as_int64 = port_id;
Dart_CObject send_port;
send_port.type = Dart_CObject_kSendPort;
send_port.value.as_send_port.id = port_id;
send_port.value.as_send_port.origin_id = port_id;
Dart_CObject cname;
cname.type = Dart_CObject_kString;
cname.value.as_string = const_cast<char*>(name);
Dart_CObject* values[4];
values[0] = &ccode;
values[1] = &port_int;
values[2] = &send_port;
values[3] = &cname;
Dart_CObject message;
message.type = Dart_CObject_kArray;
message.value.as_array.length = 4;
message.value.as_array.values = values;
return PortMap::PostMessage(WriteApiMessage(thread->zone(), &message, port_,
Message::kNormalPriority));
}
static ArrayPtr MakeServerControlMessage(const SendPort& sp,
intptr_t code,
bool enable,
const Bool& silenceOutput) {
const Array& list = Array::Handle(Array::New(4));
ASSERT(!list.IsNull());
list.SetAt(0, Integer::Handle(Integer::New(code)));
list.SetAt(1, sp);
list.SetAt(2, Bool::Get(enable));
list.SetAt(3, silenceOutput);
return list.ptr();
}
const char* ServiceIsolate::kName = DART_VM_SERVICE_ISOLATE_NAME;
Dart_IsolateGroupCreateCallback ServiceIsolate::create_group_callback_ =
nullptr;
Monitor* ServiceIsolate::monitor_ = new Monitor();
ServiceIsolate::State ServiceIsolate::state_ = ServiceIsolate::kStopped;
Isolate* ServiceIsolate::isolate_ = nullptr;
Dart_Port ServiceIsolate::port_ = ILLEGAL_PORT;
Dart_Port ServiceIsolate::origin_ = ILLEGAL_PORT;
char* ServiceIsolate::server_address_ = nullptr;
char* ServiceIsolate::startup_failure_reason_ = nullptr;
void ServiceIsolate::RequestServerInfo(const SendPort& sp) {
const Array& message = Array::Handle(MakeServerControlMessage(
sp, VM_SERVICE_SERVER_INFO_MESSAGE_ID, false /* ignored */,
Bool::Handle() /* ignored */));
ASSERT(!message.IsNull());
PortMap::PostMessage(WriteMessage(/* same_group */ false, message, port_,
Message::kNormalPriority));
}
void ServiceIsolate::ControlWebServer(const SendPort& sp,
bool enable,
const Bool& silenceOutput) {
const Array& message = Array::Handle(MakeServerControlMessage(
sp, VM_SERVICE_WEB_SERVER_CONTROL_MESSAGE_ID, enable, silenceOutput));
ASSERT(!message.IsNull());
PortMap::PostMessage(WriteMessage(/* same_group */ false, message, port_,
Message::kNormalPriority));
}
void ServiceIsolate::SetServerAddress(const char* address) {
if (server_address_ != nullptr) {
free(server_address_);
server_address_ = nullptr;
}
if (address == nullptr) {
return;
}
server_address_ = Utils::StrDup(address);
}
bool ServiceIsolate::Exists() {
MonitorLocker ml(monitor_);
return isolate_ != nullptr;
}
bool ServiceIsolate::IsRunning() {
MonitorLocker ml(monitor_);
return (port_ != ILLEGAL_PORT) && (isolate_ != nullptr);
}
bool ServiceIsolate::IsServiceIsolateDescendant(Isolate* isolate) {
MonitorLocker ml(monitor_);
return isolate->group()->id() == origin_;
}
Dart_Port ServiceIsolate::Port() {
MonitorLocker ml(monitor_);
return port_;
}
void ServiceIsolate::WaitForServiceIsolateStartup() {
MonitorLocker ml(monitor_);
while (state_ == kStarting) {
ml.Wait();
}
}
bool ServiceIsolate::SendServiceRpc(uint8_t* request_json,
intptr_t request_json_length,
Dart_Port reply_port,
char** error) {
// Keep in sync with "sdk/lib/vmservice/vmservice.dart:_handleNativeRpcCall".
Dart_CObject opcode;
opcode.type = Dart_CObject_kInt32;
opcode.value.as_int32 = VM_SERVICE_METHOD_CALL_FROM_NATIVE;
Dart_CObject message;
message.type = Dart_CObject_kTypedData;
message.value.as_typed_data.type = Dart_TypedData_kUint8;
message.value.as_typed_data.length = request_json_length;
message.value.as_typed_data.values = request_json;
Dart_CObject send_port;
send_port.type = Dart_CObject_kSendPort;
send_port.value.as_send_port.id = reply_port;
send_port.value.as_send_port.origin_id = ILLEGAL_PORT;
Dart_CObject* request_array[] = {
&opcode,
&message,
&send_port,
};
Dart_CObject request;
request.type = Dart_CObject_kArray;
request.value.as_array.values = request_array;
request.value.as_array.length = ARRAY_SIZE(request_array);
ServiceIsolate::WaitForServiceIsolateStartup();
Dart_Port service_port = ServiceIsolate::Port();
bool success = false;
if (service_port != ILLEGAL_PORT) {
success = Dart_PostCObject(service_port, &request);
if (!success && error != nullptr) {
*error = Utils::StrDup("Was unable to post message to service isolate.");
}
} else {
if (error != nullptr) {
if (startup_failure_reason_ != nullptr) {
*error = OS::SCreate(/*zone=*/nullptr,
"Service isolate failed to start up: %s.",
startup_failure_reason_);
} else {
*error = Utils::StrDup("No service isolate port was found.");
}
}
}
return success;
}
bool ServiceIsolate::SendIsolateStartupMessage() {
if (!IsRunning()) {
return false;
}
Thread* thread = Thread::Current();
Isolate* isolate = thread->isolate();
if (isolate->is_vm_isolate()) {
return false;
}
Dart_Port main_port = Dart_GetMainPortId();
if (FLAG_trace_service) {
OS::PrintErr(DART_VM_SERVICE_ISOLATE_NAME ": Isolate %s %" Pd64
" registered.\n",
isolate->name(), main_port);
}
bool result = SendServiceControlMessage(thread, main_port,
VM_SERVICE_ISOLATE_STARTUP_MESSAGE_ID,
isolate->name());
isolate->set_is_service_registered(true);
return result;
}
bool ServiceIsolate::SendIsolateShutdownMessage() {
if (!IsRunning()) {
return false;
}
Thread* thread = Thread::Current();
Isolate* isolate = thread->isolate();
if (isolate->is_vm_isolate()) {
return false;
}
Dart_Port main_port = isolate->main_port();
if (FLAG_trace_service) {
OS::PrintErr(DART_VM_SERVICE_ISOLATE_NAME ": Isolate %s %" Pd64
" deregistered.\n",
isolate->name(), main_port);
}
isolate->set_is_service_registered(false);
return SendServiceControlMessage(thread, main_port,
VM_SERVICE_ISOLATE_SHUTDOWN_MESSAGE_ID,
isolate->name());
}
void ServiceIsolate::SendServiceExitMessage() {
if (!IsRunning()) {
return;
}
if (FLAG_trace_service) {
OS::PrintErr(DART_VM_SERVICE_ISOLATE_NAME
": sending service exit message.\n");
}
Dart_CObject code;
code.type = Dart_CObject_kInt32;
code.value.as_int32 = VM_SERVICE_ISOLATE_EXIT_MESSAGE_ID;
Dart_CObject* values[1] = {&code};
Dart_CObject message;
message.type = Dart_CObject_kArray;
message.value.as_array.length = 1;
message.value.as_array.values = values;
AllocOnlyStackZone zone;
PortMap::PostMessage(WriteApiMessage(zone.GetZone(), &message, port_,
Message::kNormalPriority));
}
void ServiceIsolate::SetServicePort(Dart_Port port) {
MonitorLocker ml(monitor_);
port_ = port;
}
void ServiceIsolate::SetServiceIsolate(Isolate* isolate) {
MonitorLocker ml(monitor_);
isolate_ = isolate;
if (isolate_ != nullptr) {
ASSERT(isolate->is_service_isolate());
origin_ = isolate_->group()->id();
}
}
void ServiceIsolate::MaybeMakeServiceIsolate(Isolate* I) {
Thread* T = Thread::Current();
ASSERT(I == T->isolate());
ASSERT(I != nullptr);
ASSERT(I->name() != nullptr);
if (!I->is_service_isolate()) {
// Not service isolate.
return;
}
if (Exists()) {
// Service isolate already exists.
return;
}
SetServiceIsolate(I);
}
void ServiceIsolate::FinishedExiting() {
MonitorLocker ml(monitor_);
ASSERT(state_ == kStarted || state_ == kStopping);
state_ = kStopped;
port_ = ILLEGAL_PORT;
isolate_ = nullptr;
ml.NotifyAll();
}
void ServiceIsolate::FinishedInitializing() {
MonitorLocker ml(monitor_);
ASSERT(state_ == kStarting);
state_ = kStarted;
ml.NotifyAll();
}
void ServiceIsolate::InitializingFailed(char* error) {
MonitorLocker ml(monitor_);
ASSERT(state_ == kStarting);
state_ = kStopped;
port_ = ILLEGAL_PORT;
startup_failure_reason_ = error;
ml.NotifyAll();
}
class RunServiceTask : public ThreadPool::Task {
public:
virtual void Run() {
ASSERT(Isolate::Current() == nullptr);
#if defined(SUPPORT_TIMELINE)
TimelineBeginEndScope tbes(Timeline::GetVMStream(),
"ServiceIsolateStartup");
#endif // SUPPORT_TIMELINE
char* error = nullptr;
Isolate* isolate = nullptr;
const auto create_group_callback = ServiceIsolate::create_group_callback();
ASSERT(create_group_callback != nullptr);
Dart_IsolateFlags api_flags;
Isolate::FlagsInitialize(&api_flags);
api_flags.is_system_isolate = true;
api_flags.is_service_isolate = true;
isolate = reinterpret_cast<Isolate*>(
create_group_callback(ServiceIsolate::kName, ServiceIsolate::kName,
nullptr, nullptr, &api_flags, nullptr, &error));
if (isolate == nullptr) {
if (FLAG_trace_service) {
OS::PrintErr(DART_VM_SERVICE_ISOLATE_NAME
": Isolate creation error: %s\n",
error);
}
char* formatted_error = OS::SCreate(
/*zone=*/nullptr, "Invoking the 'create_group' failed with: '%s'",
error);
free(error);
error = nullptr;
ServiceIsolate::InitializingFailed(formatted_error);
return;
}
char* main_error = nullptr;
{
ASSERT(Isolate::Current() == nullptr);
StartIsolateScope start_scope(isolate);
main_error = RunMain(isolate);
}
// If we failed to run 'main' of the service isolate then there is
// reason to keep it running, it might be in an inconsistent state.
// e.g. it could have no port to communicate with it. Declare
// initialization failure and shut it down.
if (main_error != nullptr) {
if (FLAG_trace_service) {
OS::PrintErr("vm-service: encountered an error: %s\n", main_error);
}
ShutdownIsolate(reinterpret_cast<Dart_Isolate>(isolate));
ServiceIsolate::InitializingFailed(main_error);
return;
}
isolate->message_handler()->Run(
isolate->group()->thread_pool(), nullptr,
[](uword parameter) {
ShutdownIsolate(reinterpret_cast<Dart_Isolate>(parameter));
ServiceIsolate::FinishedExiting();
},
reinterpret_cast<uword>(isolate));
}
protected:
static void ShutdownIsolate(Dart_Isolate isolate) {
if (FLAG_trace_service) {
OS::PrintErr("vm-service: ShutdownIsolate\n");
}
Dart_EnterIsolate(isolate);
{
auto T = Thread::Current();
TransitionNativeToVM transition(T);
StackZone zone(T);
HandleScope handle_scope(T);
auto I = T->isolate();
ASSERT(I->is_service_isolate());
// Print the error if there is one. This may execute dart code to
// print the exception object, so we need to use a StartIsolateScope.
Error& error = Error::Handle(Z);
error = T->sticky_error();
if (!error.IsNull() && !error.IsUnwindError()) {
OS::PrintErr(DART_VM_SERVICE_ISOLATE_NAME ": Error: %s\n",
error.ToErrorCString());
}
error = I->sticky_error();
if (!error.IsNull() && !error.IsUnwindError()) {
OS::PrintErr(DART_VM_SERVICE_ISOLATE_NAME ": Error: %s\n",
error.ToErrorCString());
}
}
Dart_ShutdownIsolate();
if (FLAG_trace_service) {
OS::PrintErr(DART_VM_SERVICE_ISOLATE_NAME ": Shutdown.\n");
}
}
// Returns an error message if fails.
DART_WARN_UNUSED_RESULT char* RunMain(Isolate* I) {
Thread* T = Thread::Current();
ASSERT(I == T->isolate());
StackZone zone(T);
// Invoke main which will set up the service port.
const Library& root_library =
Library::Handle(Z, I->group()->object_store()->root_library());
if (root_library.IsNull()) {
if (FLAG_trace_service) {
OS::PrintErr(DART_VM_SERVICE_ISOLATE_NAME
": Embedder did not install a script.\n");
}
// Service isolate is not supported by embedder.
return Utils::StrDup("Service isolate is not supported by embedder.");
}
ASSERT(!root_library.IsNull());
const String& entry_name = Symbols::main();
ASSERT(!entry_name.IsNull());
const Object& main_closure = Object::Handle(
Z, root_library.InvokeGetter(entry_name, /*check_is_entrypoint=*/true,
/*respect_reflectable=*/false));
if (!main_closure.IsClosure()) {
if (FLAG_trace_service) {
OS::PrintErr(DART_VM_SERVICE_ISOLATE_NAME
": Embedder did not provide a main function.\n");
}
return Utils::StrDup(
"Embedder did not provide a main function for service isolate.");
}
const Library& isolate_library =
Library::Handle(Z, I->group()->object_store()->isolate_library());
const String& start_main_isolate_str =
String::Handle(Z, String::New("_startMainIsolate"));
const Function& start_main_isolate = Function::Handle(
Z, isolate_library.LookupFunctionAllowPrivate(start_main_isolate_str));
const Array& args = Array::Handle(Z, Array::New(3));
// First argument is the receiver, which is null for top-level functions.
const Object& receiver = Object::Handle(Z, Object::null());
args.SetAt(0, receiver);
// Second argument is the first argument passed to _startMainIsolate, which
// is a closure of the service's main method.
args.SetAt(1, main_closure);
// The last argument is the args to be passed to the service's main, which
// is an empty List<String>.
const Type& args_type = Type::Handle(Z, Type::StringType());
const Array& isolate_args = Array::Handle(Z, Array::New(0, args_type));
args.SetAt(2, isolate_args);
const Object& result =
Object::Handle(Z, DartEntry::InvokeFunction(start_main_isolate, args));
if (result.IsError()) {
// Service isolate did not initialize properly.
const char* error_cstr = Error::Cast(result).ToErrorCString();
if (FLAG_trace_service) {
OS::PrintErr(DART_VM_SERVICE_ISOLATE_NAME
": Calling main resulted in an error: %s\n",
error_cstr);
}
return OS::SCreate(/*zone=*/nullptr,
"Service isolate main resulted in error: %s",
error_cstr);
}
return nullptr; // No error.
}
};
void ServiceIsolate::Run() {
{
MonitorLocker ml(monitor_);
ASSERT(state_ == kStopped);
state_ = kStarting;
ml.NotifyAll();
}
// Grab the isolate create callback here to avoid race conditions with tests
// that change this after Dart_Initialize returns.
create_group_callback_ = Isolate::CreateGroupCallback();
if (create_group_callback_ == nullptr) {
ServiceIsolate::InitializingFailed(
Utils::StrDup("The 'create_group' callback was not provided"));
return;
}
bool task_started = Dart::thread_pool()->Run<RunServiceTask>();
ASSERT(task_started);
}
void ServiceIsolate::KillServiceIsolate() {
{
MonitorLocker ml(monitor_);
if (state_ == kStopped) {
return;
}
ASSERT(state_ == kStarted);
state_ = kStopping;
ml.NotifyAll();
}
Isolate::KillIfExists(isolate_, Isolate::kInternalKillMsg);
{
MonitorLocker ml(monitor_);
while (state_ == kStopping) {
ml.Wait();
}
ASSERT(state_ == kStopped);
}
}
void ServiceIsolate::Shutdown() {
{
MonitorLocker ml(monitor_);
while (state_ == kStarting) {
ml.Wait();
}
}
if (IsRunning()) {
{
MonitorLocker ml(monitor_);
ASSERT(state_ == kStarted);
state_ = kStopping;
ml.NotifyAll();
}
SendServiceExitMessage();
{
MonitorLocker ml(monitor_);
while (state_ == kStopping) {
ml.Wait();
}
ASSERT(state_ == kStopped);
}
} else {
if (isolate_ != nullptr) {
// TODO(johnmccutchan,turnidge) When it is possible to properly create
// the VMService object and set up its shutdown handler in the service
// isolate's main() function, this case will no longer be possible and
// can be removed.
KillServiceIsolate();
}
}
if (server_address_ != nullptr) {
free(server_address_);
server_address_ = nullptr;
}
if (startup_failure_reason_ != nullptr) {
free(startup_failure_reason_);
startup_failure_reason_ = nullptr;
}
}
void ServiceIsolate::BootVmServiceLibrary() {
Thread* thread = Thread::Current();
Library& lib =
Library::Handle(thread->isolate_group()->object_store()->root_library());
const String& boot_function_name = String::Handle(String::New("boot"));
Function& boot_function =
Function::Handle(lib.LookupFunctionAllowPrivate(boot_function_name));
if (boot_function.IsNull()) {
lib ^= Library::LookupLibrary(thread, Symbols::DartVMService());
ASSERT(!lib.IsNull());
boot_function ^= lib.LookupFunctionAllowPrivate(boot_function_name);
}
ASSERT(!boot_function.IsNull());
const Object& result = Object::Handle(
DartEntry::InvokeFunction(boot_function, Object::empty_array()));
ASSERT(!result.IsNull());
if (result.IsUnwindError() || result.IsUnhandledException()) {
Exceptions::PropagateError(Error::Cast(result));
}
Dart_Port port = ILLEGAL_PORT;
if (result.IsReceivePort()) {
port = ReceivePort::Cast(result).Id();
}
ASSERT(port != ILLEGAL_PORT);
ServiceIsolate::SetServicePort(port);
ServiceIsolate::FinishedInitializing();
}
void ServiceIsolate::RegisterRunningIsolates(
const GrowableArray<Dart_Port>& isolate_ports,
const GrowableArray<const String*>& isolate_names) {
auto thread = Thread::Current();
auto zone = thread->zone();
ASSERT(thread->isolate()->is_service_isolate());
// Obtain "_registerIsolate" function to call.
Library& lib =
Library::Handle(thread->isolate_group()->object_store()->root_library());
const String& function_name = String::Handle(String::New("_registerIsolate"));
Function& register_function_ =
Function::Handle(lib.LookupFunctionAllowPrivate(function_name));
if (register_function_.IsNull()) {
lib ^= Library::LookupLibrary(thread, Symbols::DartVMService());
ASSERT(!lib.IsNull());
register_function_ ^= lib.LookupFunctionAllowPrivate(function_name);
}
ASSERT(!register_function_.IsNull());
Integer& port_int = Integer::Handle(zone);
SendPort& send_port = SendPort::Handle(zone);
Array& args = Array::Handle(zone, Array::New(3));
Object& result = Object::Handle(zone);
ASSERT(isolate_ports.length() == isolate_names.length());
for (intptr_t i = 0; i < isolate_ports.length(); ++i) {
const Dart_Port port_id = isolate_ports[i];
const String& name = *isolate_names[i];
port_int = Integer::New(port_id);
send_port = SendPort::New(port_id);
args.SetAt(0, port_int);
args.SetAt(1, send_port);
args.SetAt(2, name);
result = DartEntry::InvokeFunction(register_function_, args);
if (FLAG_trace_service) {
OS::PrintErr("vm-service: Isolate %s %" Pd64 " registered.\n",
name.ToCString(), port_id);
}
ASSERT(!result.IsError());
}
}
void ServiceIsolate::VisitObjectPointers(ObjectPointerVisitor* visitor) {}
} // namespace dart
#endif // !defined(PRODUCT)