v8  6.8.275 (node 10.15.3)
V8 is Google's open source JavaScript engine
libplatform.h
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1 // Copyright 2014 the V8 project 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 V8_LIBPLATFORM_LIBPLATFORM_H_
6 #define V8_LIBPLATFORM_LIBPLATFORM_H_
7 
8 #include "libplatform/libplatform-export.h"
9 #include "libplatform/v8-tracing.h"
10 #include "v8-platform.h" // NOLINT(build/include)
11 #include "v8config.h" // NOLINT(build/include)
12 
13 namespace v8 {
14 namespace platform {
15 
18 
19 enum class MessageLoopBehavior : bool {
20  kDoNotWait = false,
21  kWaitForWork = true
22 };
23 
24 /**
25  * Returns a new instance of the default v8::Platform implementation.
26  *
27  * The caller will take ownership of the returned pointer. |thread_pool_size|
28  * is the number of worker threads to allocate for background jobs. If a value
29  * of zero is passed, a suitable default based on the current number of
30  * processors online will be chosen.
31  * If |idle_task_support| is enabled then the platform will accept idle
32  * tasks (IdleTasksEnabled will return true) and will rely on the embedder
33  * calling v8::platform::RunIdleTasks to process the idle tasks.
34  * If |tracing_controller| is nullptr, the default platform will create a
35  * v8::platform::TracingController instance and use it.
36  */
38  int thread_pool_size = 0,
39  IdleTaskSupport idle_task_support = IdleTaskSupport::kDisabled,
40  InProcessStackDumping in_process_stack_dumping =
42  std::unique_ptr<v8::TracingController> tracing_controller = {});
43 
45  "Use NewDefaultPlatform instead",
46  v8::Platform* CreateDefaultPlatform(
47  int thread_pool_size = 0,
48  IdleTaskSupport idle_task_support = IdleTaskSupport::kDisabled,
49  InProcessStackDumping in_process_stack_dumping =
51  v8::TracingController* tracing_controller = nullptr));
52 
53 /**
54  * Pumps the message loop for the given isolate.
55  *
56  * The caller has to make sure that this is called from the right thread.
57  * Returns true if a task was executed, and false otherwise. Unless requested
58  * through the |behavior| parameter, this call does not block if no task is
59  * pending. The |platform| has to be created using |NewDefaultPlatform|.
60  */
62  v8::Platform* platform, v8::Isolate* isolate,
64 
66  "This function has become obsolete and is essentially a nop",
67  void EnsureEventLoopInitialized(v8::Platform* platform,
68  v8::Isolate* isolate));
69 
70 /**
71  * Runs pending idle tasks for at most |idle_time_in_seconds| seconds.
72  *
73  * The caller has to make sure that this is called from the right thread.
74  * This call does not block if no task is pending. The |platform| has to be
75  * created using |NewDefaultPlatform|.
76  */
78  v8::Isolate* isolate,
79  double idle_time_in_seconds);
80 
81 /**
82  * Attempts to set the tracing controller for the given platform.
83  *
84  * The |platform| has to be created using |NewDefaultPlatform|.
85  *
86  */
88  "Access the DefaultPlatform directly",
89  void SetTracingController(
90  v8::Platform* platform,
91  v8::platform::tracing::TracingController* tracing_controller));
92 
93 } // namespace platform
94 } // namespace v8
95 
96 #endif // V8_LIBPLATFORM_LIBPLATFORM_H_