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 | |
34 | DartVMRef(DartVMRef&&); |
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 | |
56 | DartVM* operator->() { |
57 | FML_DCHECK(vm_); |
58 | return vm_.get(); |
59 | } |
60 | |
61 | DartVM* operator&() { |
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 | |
76 | FML_DISALLOW_COPY_AND_ASSIGN(DartVMRef); |
77 | }; |
78 | |
79 | } // namespace flutter |
80 | |
81 | #endif // FLUTTER_RUNTIME_DART_VM_LIFECYCLE_H_ |
82 | |