<?xml version="1.0" encoding="UTF-8" ?> <class name="Mutex" inherits="RefCounted" version="4.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="../class.xsd"> <brief_description> A synchronization mutex (mutual exclusion). </brief_description> <description> A synchronization mutex (mutual exclusion). This is used to synchronize multiple [Thread]s, and is equivalent to a binary [Semaphore]. It guarantees that only one thread can ever acquire the lock at a time. A mutex can be used to protect a critical section; however, be careful to avoid deadlocks. </description> <tutorials> <link title="Using multiple threads">$DOCS_URL/tutorials/performance/using_multiple_threads.html</link> </tutorials> <methods> <method name="lock"> <return type="void" /> <description> Locks this [Mutex], blocks until it is unlocked by the current owner. [b]Note:[/b] This function returns without blocking if the thread already has ownership of the mutex. </description> </method> <method name="try_lock"> <return type="int" enum="Error" /> <description> Tries locking this [Mutex], but does not block. Returns [constant OK] on success, [constant ERR_BUSY] otherwise. [b]Note:[/b] This function returns [constant OK] if the thread already has ownership of the mutex. </description> </method> <method name="unlock"> <return type="void" /> <description> Unlocks this [Mutex], leaving it to other threads. [b]Note:[/b] If a thread called [method lock] or [method try_lock] multiple times while already having ownership of the mutex, it must also call [method unlock] the same number of times in order to unlock it correctly. </description> </method> </methods> </class>