Flutter macOS Embedder
FlutterThreadSynchronizer.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_SHELL_PLATFORM_DARWIN_MACOS_FRAMEWORK_SOURCE_FLUTTERTHREADSYNCHRONIZER_H_
6 #define FLUTTER_SHELL_PLATFORM_DARWIN_MACOS_FRAMEWORK_SOURCE_FLUTTERTHREADSYNCHRONIZER_H_
7 
8 #import <Cocoa/Cocoa.h>
9 
10 /**
11  * Takes care of synchronization between raster and platform thread.
12  *
13  * All methods of this class must be called from the platform thread,
14  * except for performCommitForView:size:notify:.
15  */
16 @interface FlutterThreadSynchronizer : NSObject
17 
18 /**
19  * Creates a FlutterThreadSynchronizer that uses the OS main thread as the
20  * platform thread.
21  */
22 - (nullable instancetype)init;
23 
24 /**
25  * Blocks until all views have a commit with their given sizes (or empty) is requested.
26  */
27 - (void)beginResizeForView:(int64_t)viewId
28  size:(CGSize)size
29  notify:(nonnull dispatch_block_t)notify;
30 
31 /**
32  * Called from raster thread. Schedules the given block on platform thread
33  * and blocks until it is performed.
34  *
35  * If platform thread is blocked in `beginResize:` for given size (or size is empty),
36  * unblocks platform thread.
37  *
38  * The notify block is guaranteed to be called within a core animation transaction.
39  */
40 - (void)performCommitForView:(int64_t)viewId
41  size:(CGSize)size
42  notify:(nonnull dispatch_block_t)notify;
43 
44 /**
45  * Schedules the given block to be performed on the platform thread.
46  * The block will be performed even if the platform thread is blocked waiting
47  * for a commit.
48  */
49 - (void)performOnPlatformThread:(nonnull dispatch_block_t)block;
50 
51 /**
52  * Requests the synchronizer to track another view.
53  *
54  * A view must be registered before calling begineResizeForView: or
55  * performCommitForView:. It is typically done when the view controller is
56  * created.
57  */
58 - (void)registerView:(int64_t)viewId;
59 
60 /**
61  * Requests the synchronizer to no longer track a view.
62  *
63  * It is typically done when the view controller is destroyed.
64  */
65 - (void)deregisterView:(int64_t)viewId;
66 
67 /**
68  * Called when the engine shuts down.
69  *
70  * Prevents any further synchronization and no longer blocks any threads.
71  */
72 - (void)shutdown;
73 
74 @end
75 
77 
78 /**
79  * Creates a FlutterThreadSynchronizer that uses the specified queue as the
80  * platform thread.
81  */
82 - (nullable instancetype)initWithMainQueue:(nonnull dispatch_queue_t)queue;
83 
84 /**
85  * Blocks current thread until the mutex is available, then return whether the
86  * synchronizer is waiting for a correct commit during resizing.
87  *
88  * After calling an operation of the thread synchronizer, call this method,
89  * and when it returns, the thread synchronizer can be at one of the following 3
90  * states:
91  *
92  * 1. The operation has not started at all (with a return value FALSE.)
93  * 2. The operation has ended (with a return value FALSE.)
94  * 3. beginResizeForView: is in progress, waiting (with a return value TRUE.)
95  *
96  * By eliminating the 1st case (such as using the notify callback), we can use
97  * this return value to decide whether the synchronizer is in case 2 or case 3,
98  * that is whether the resizing is blocked by a mismatching commit.
99  */
100 - (BOOL)isWaitingWhenMutexIsAvailable;
101 
102 /**
103  * Blocks current thread until there is frame available.
104  * Used in FlutterEngineTest.
105  */
106 - (void)blockUntilFrameAvailable;
107 
108 @end
109 
110 #endif // FLUTTER_SHELL_PLATFORM_DARWIN_MACOS_FRAMEWORK_SOURCE_FLUTTERTHREADSYNCHRONIZER_H_
-[FlutterThreadSynchronizer init]
nullable instancetype init()
Definition: FlutterThreadSynchronizer.mm:47
FlutterThreadSynchronizer(TestUtils)
Definition: FlutterThreadSynchronizer.h:76
FlutterThreadSynchronizer
Definition: FlutterThreadSynchronizer.h:16
-[FlutterThreadSynchronizer shutdown]
void shutdown()
Definition: FlutterThreadSynchronizer.mm:192