<?xml version="1.0" encoding="UTF-8" ?> <class name="Semaphore" inherits="Reference" version="3.11"> <brief_description> A synchronization semaphore. </brief_description> <description> A synchronization semaphore which can be used to synchronize multiple [Thread]s. Initialized to zero on creation. Be careful to avoid deadlocks. For a binary version, see [Mutex]. </description> <tutorials> <link>$DOCS_URL/tutorials/performance/threads/using_multiple_threads.html</link> </tutorials> <methods> <method name="post"> <return type="int" enum="Error" /> <description> Lowers the [Semaphore], allowing one more thread in. [b]Note:[/b] This method internals' can't possibly fail, but an error code is returned for backwards compatibility, which will always be [constant OK]. </description> </method> <method name="try_wait"> <return type="int" enum="Error" /> <description> Like [method wait], but won't block, so if the value is zero, fails immediately and returns [constant ERR_BUSY]. If non-zero, it returns [constant OK] to report success. </description> </method> <method name="wait"> <return type="int" enum="Error" /> <description> Waits for the [Semaphore], if its value is zero, blocks until non-zero. [b]Note:[/b] This method internals' can't possibly fail, but an error code is returned for backwards compatibility, which will always be [constant OK]. </description> </method> </methods> <constants> </constants> </class>