6311ee5bd5
Co-authored-by: RandomShaper <RandomShaper@users.noreply.github.com> Co-authored-by: A Thousand Ships (she/her) <96648715+AThousandShips@users.noreply.github.com> Co-authored-by: Mickeon <Mickeon@users.noreply.github.com>
39 lines
1.9 KiB
XML
39 lines
1.9 KiB
XML
<?xml version="1.0" encoding="UTF-8" ?>
|
|
<class name="Semaphore" inherits="RefCounted" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="../class.xsd">
|
|
<brief_description>
|
|
A synchronization mechanism used to control access to a shared resource by [Thread]s.
|
|
</brief_description>
|
|
<description>
|
|
A synchronization semaphore that can be used to synchronize multiple [Thread]s. Initialized to zero on creation. For a binary version, see [Mutex].
|
|
[b]Warning:[/b] Semaphores must be used carefully to avoid deadlocks.
|
|
[b]Warning:[/b] To guarantee that the operating system is able to perform proper cleanup (no crashes, no deadlocks), these conditions must be met:
|
|
- When a [Semaphore]'s reference count reaches zero and it is therefore destroyed, no threads must be waiting on it.
|
|
- When a [Thread]'s reference count reaches zero and it is therefore destroyed, it must not be waiting on any semaphore.
|
|
</description>
|
|
<tutorials>
|
|
<link title="Using multiple threads">$DOCS_URL/tutorials/performance/using_multiple_threads.html</link>
|
|
<link title="Thread-safe APIs">$DOCS_URL/tutorials/performance/thread_safe_apis.html</link>
|
|
</tutorials>
|
|
<methods>
|
|
<method name="post">
|
|
<return type="void" />
|
|
<param index="0" name="count" type="int" default="1" />
|
|
<description>
|
|
Lowers the [Semaphore], allowing one thread in, or more if [param count] is specified.
|
|
</description>
|
|
</method>
|
|
<method name="try_wait">
|
|
<return type="bool" />
|
|
<description>
|
|
Like [method wait], but won't block, so if the value is zero, fails immediately and returns [code]false[/code]. If non-zero, it returns [code]true[/code] to report success.
|
|
</description>
|
|
</method>
|
|
<method name="wait">
|
|
<return type="void" />
|
|
<description>
|
|
Waits for the [Semaphore], if its value is zero, blocks until non-zero.
|
|
</description>
|
|
</method>
|
|
</methods>
|
|
</class>
|