Documentation
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Overview ¶
A synchronization semaphore that can be used to synchronize multiple [graphics.gd/classdb/Thread]s. Initialized to zero on creation. For a binary version, see graphics.gd/classdb/Mutex.
Warning: Semaphores must be used carefully to avoid deadlocks.
Warning: To guarantee that the operating system is able to perform proper cleanup (no crashes, no deadlocks), these conditions must be met:
- When a graphics.gd/classdb/Semaphore's reference count reaches zero and it is therefore destroyed, no threads must be waiting on it.
- When a graphics.gd/classdb/Thread's reference count reaches zero and it is therefore destroyed, it must not be waiting on any semaphore.
Index ¶
- type Advanced
- type Any
- type Expanded
- type Extension
- type ID
- type Instance
- func (self Instance) AsObject() [1]gd.Object
- func (self Instance) AsRefCounted() [1]gd.RefCounted
- func (self Instance) AsSemaphore() Instance
- func (self Instance) ID() ID
- func (self Instance) Post()
- func (self *Instance) SetObject(obj [1]gd.Object) bool
- func (self Instance) TryWait() bool
- func (self Instance) Virtual(name string) reflect.Value
- func (self Instance) Wait()
Constants ¶
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Variables ¶
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Functions ¶
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Types ¶
type Advanced ¶
type Advanced = class
Advanced exposes a 1:1 low-level instance of the class, undocumented, for those who know what they are doing.
type Expanded ¶
func (Expanded) Post ¶
Lowers the graphics.gd/classdb/Semaphore, allowing one thread in, or more if 'count' is specified.
type Extension ¶
Extension can be embedded in a new struct to create an extension of this class. T should be the type that is embedding this Extension
func (*Extension[T]) AsRefCounted ¶
func (self *Extension[T]) AsRefCounted() [1]gd.RefCounted
func (*Extension[T]) AsSemaphore ¶
type ID ¶
ID is a typed object ID (reference) to an instance of this class, use it to store references to objects with unknown lifetimes, as an ID will not panic on use if the underlying object has been destroyed.
type Instance ¶
Instance of the class with convieniently typed arguments and results.
var Nil Instance
Nil is a nil/null instance of the class. Equivalent to the zero value.
func (Instance) AsRefCounted ¶
func (self Instance) AsRefCounted() [1]gd.RefCounted
func (Instance) AsSemaphore ¶
func (Instance) Post ¶
func (self Instance) Post()
Lowers the graphics.gd/classdb/Semaphore, allowing one thread in, or more if 'count' is specified.
func (Instance) TryWait ¶
Like Instance.Wait, but won't block, so if the value is zero, fails immediately and returns false. If non-zero, it returns true to report success.
func (Instance) Wait ¶
func (self Instance) Wait()
Waits for the graphics.gd/classdb/Semaphore, if its value is zero, blocks until non-zero.
Source Files