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dart_vm_lifecycle.h
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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 #include "third_party/dart/runtime/include/dart_tools_api.h"
15 
16 namespace flutter {
17 
18 // A strong reference to the Dart VM. There can only be one VM running in the
19 // process at any given time. A reference to the VM may only be obtained via the
20 // |Create| method. In case there is already a running instance of the VM in the
21 // process, a strong reference to that VM is obtained and the arguments to the
22 // |Create| call ignored. If there is no VM already running in the process, a VM
23 // is initialized in a thread safe manner and returned to the caller. The VM
24 // will shutdown only when all callers relinquish their references (by
25 // collecting their instances of this class).
26 //
27 // DartVMRef instances may be created on any thread.
28 class DartVMRef {
29  public:
30  [[nodiscard]] static DartVMRef Create(
31  Settings settings,
32  fml::RefPtr<const DartSnapshot> vm_snapshot = nullptr,
33  fml::RefPtr<const DartSnapshot> isolate_snapshot = nullptr);
34 
35  DartVMRef(const DartVMRef&) = default;
36 
38 
39  ~DartVMRef();
40 
41  // This is an inherently racy way to check if a VM instance is running and
42  // should not be used outside of unit-tests where there is a known threading
43  // model.
44  static bool IsInstanceRunning();
45 
46  static std::shared_ptr<const DartVMData> GetVMData();
47 
48  static std::shared_ptr<ServiceProtocol> GetServiceProtocol();
49 
50  static std::shared_ptr<IsolateNameServer> GetIsolateNameServer();
51 
52  operator bool() const { return static_cast<bool>(vm_); }
53 
54  DartVM* get() {
55  FML_DCHECK(vm_);
56  return vm_.get();
57  }
58 
59  const DartVM* get() const {
60  FML_DCHECK(vm_);
61  return vm_.get();
62  }
63 
65  FML_DCHECK(vm_);
66  return vm_.get();
67  }
68 
69  const DartVM* operator->() const {
70  FML_DCHECK(vm_);
71  return vm_.get();
72  }
73 
75  FML_DCHECK(vm_);
76  return vm_.get();
77  }
78 
79  private:
80  friend class DartIsolate;
81 
82  std::shared_ptr<DartVM> vm_;
83 
84  DartVMRef(std::shared_ptr<DartVM> vm);
85 
86  // Only used by Dart Isolate to register itself with the VM.
87  static DartVM* GetRunningVM();
88 };
89 
90 } // namespace flutter
91 
92 #endif // FLUTTER_RUNTIME_DART_VM_LIFECYCLE_H_
#define FML_DCHECK(condition)
Definition: logging.h:86
static std::shared_ptr< ServiceProtocol > GetServiceProtocol()
DartVMRef(const DartVMRef &)=default
static std::shared_ptr< const DartVMData > GetVMData()
static bool IsInstanceRunning()
static DartVMRef Create(Settings settings, fml::RefPtr< const DartSnapshot > vm_snapshot=nullptr, fml::RefPtr< const DartSnapshot > isolate_snapshot=nullptr)
const DartVM * operator->() const
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()
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