Flutter Engine
dart_vm_lifecycle.h
Go to the documentation of this file.
1 // Copyright 2013 The Flutter Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 #ifndef FLUTTER_RUNTIME_DART_VM_LIFECYCLE_H_
6 #define FLUTTER_RUNTIME_DART_VM_LIFECYCLE_H_
7 
8 #include <memory>
9 
10 #include "flutter/fml/macros.h"
11 #include "flutter/lib/ui/isolate_name_server/isolate_name_server.h"
12 #include "flutter/runtime/dart_vm.h"
13 #include "flutter/runtime/service_protocol.h"
14 
15 namespace flutter {
16 
17 // A strong reference to the Dart VM. There can only be one VM running in the
18 // process at any given time. A reference to the VM may only be obtained via the
19 // |Create| method. In case there is already a running instance of the VM in the
20 // process, a strong reference to that VM is obtained and the arguments to the
21 // |Create| call ignored. If there is no VM already running in the process, a VM
22 // is initialized in a thread safe manner and returned to the caller. The VM
23 // will shutdown only when all callers relinquish their references (by
24 // collecting their instances of this class).
25 //
26 // DartVMRef instances may be created on any thread.
27 class DartVMRef {
28  public:
29  [[nodiscard]] static DartVMRef Create(
30  Settings settings,
31  fml::RefPtr<DartSnapshot> vm_snapshot = nullptr,
32  fml::RefPtr<DartSnapshot> isolate_snapshot = nullptr);
33 
35 
36  ~DartVMRef();
37 
38  // This is an inherently racy way to check if a VM instance is running and
39  // should not be used outside of unit-tests where there is a known threading
40  // model.
41  static bool IsInstanceRunning();
42 
43  static std::shared_ptr<const DartVMData> GetVMData();
44 
45  static std::shared_ptr<ServiceProtocol> GetServiceProtocol();
46 
47  static std::shared_ptr<IsolateNameServer> GetIsolateNameServer();
48 
49  operator bool() const { return static_cast<bool>(vm_); }
50 
51  DartVM* get() {
52  FML_DCHECK(vm_);
53  return vm_.get();
54  }
55 
57  FML_DCHECK(vm_);
58  return vm_.get();
59  }
60 
62  FML_DCHECK(vm_);
63  return vm_.get();
64  }
65 
66  private:
67  friend class DartIsolate;
68 
69  std::shared_ptr<DartVM> vm_;
70 
71  DartVMRef(std::shared_ptr<DartVM> vm);
72 
73  // Only used by Dart Isolate to register itself with the VM.
74  static DartVM* GetRunningVM();
75 
77 };
78 
79 } // namespace flutter
80 
81 #endif // FLUTTER_RUNTIME_DART_VM_LIFECYCLE_H_
#define FML_DCHECK(condition)
Definition: logging.h:86
static std::shared_ptr< ServiceProtocol > GetServiceProtocol()
static std::shared_ptr< const DartVMData > GetVMData()
static bool IsInstanceRunning()
static DartVMRef Create(Settings settings, fml::RefPtr< DartSnapshot > vm_snapshot=nullptr, fml::RefPtr< DartSnapshot > isolate_snapshot=nullptr)
Represents an instance of a live isolate. An isolate is a separate Dart execution context...
Definition: dart_isolate.h:62
static std::shared_ptr< IsolateNameServer > GetIsolateNameServer()
DartVMRef(DartVMRef &&)
Describes a running instance of the Dart VM. There may only be one running instance of the Dart VM in...
Definition: dart_vm.h:61
#define FML_DISALLOW_COPY_AND_ASSIGN(TypeName)
Definition: macros.h:27