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https://github.com/godotengine/godot.git
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32ddd4f4e0
We don't use that info for anything, and it generates unnecessary diffs
every time we bump the minor version (and CI failures if we forget to
sync some files from opt-in modules (mono, text_server_fb).
(cherry picked from commit 81064cc239)
44 lines
2.5 KiB
XML
44 lines
2.5 KiB
XML
<?xml version="1.0" encoding="UTF-8" ?>
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<class name="Mutex" inherits="Reference" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="../class.xsd">
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<brief_description>
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A synchronization mutex (mutual exclusion).
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</brief_description>
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<description>
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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.
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It's of the recursive kind, so it can be locked multiple times by one thread, provided it also unlocks it as many times.
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[b]Warning:[/b]
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To guarantee that the operating system is able to perform proper cleanup (no crashes, no deadlocks), these conditions must be met:
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- By the time a [Mutex]'s reference count reaches zero and therefore it is destroyed, no threads (including the one on which the destruction will happen) must have it locked.
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- By the time a [Thread]'s reference count reaches zero and therefore it is destroyed, it must not have any mutex locked.
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</description>
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<tutorials>
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<link>$DOCS_URL/tutorials/performance/threads/using_multiple_threads.html</link>
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</tutorials>
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<methods>
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<method name="lock">
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<return type="void" />
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<description>
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Locks this [Mutex], blocks until it is unlocked by the current owner.
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[b]Note:[/b] This function returns without blocking if the thread already has ownership of the mutex.
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</description>
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</method>
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<method name="try_lock">
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<return type="int" enum="Error" />
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<description>
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Tries locking this [Mutex], but does not block. Returns [constant OK] on success, [constant ERR_BUSY] otherwise.
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[b]Note:[/b] This function returns [constant OK] if the thread already has ownership of the mutex.
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</description>
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</method>
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<method name="unlock">
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<return type="void" />
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<description>
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Unlocks this [Mutex], leaving it to other threads.
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[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.
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[b]Warning:[/b] Calling [method unlock] more times that [method lock] on a given thread, thus ending up trying to unlock a non-locked mutex, is wrong and may causes crashes or deadlocks.
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</description>
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</method>
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</methods>
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<constants>
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</constants>
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</class>
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