SDL::RWLock Struct Reference

Handle to an owned rWLock. More...

Inheritance diagram for SDL::RWLock:

Public Member Functions
void	Destroy ()
	Destroy a read/write lock created with RWLock.Create().
RWLockShared	share ()
	Move this rWLock into a RWLockShared.
constexpr	ResourceUnique (std::nullptr_t=nullptr)
	Default constructor.
constexpr	ResourceUnique (base::value_type value, DELETER deleter={})
	Constructs from raw type.
constexpr	ResourceUnique (ResourceUnique &&other)
	Move constructor.
	ResourceUnique (const ResourceUnique &other)=delete
Public Member Functions inherited from SDL::ResourceUnique< RWLockRef >
constexpr	ResourceUnique (std::nullptr_t=nullptr)
	Default constructor.
constexpr	ResourceUnique (base::value_type value, DefaultDeleter< RWLockRef > deleter={})
	Constructs from raw type.
constexpr	ResourceUnique (ResourceUnique &&other)
	Move constructor.
	ResourceUnique (const ResourceUnique &other)=delete
	~ResourceUnique ()
	Destructor.
constexpr ResourceUnique &	operator= (ResourceUnique other)
	Assignment operator.
void	reset ()
	Resets the value, destroying the resource if not nullptr.
Public Member Functions inherited from SDL::ResourceOwnerBase< RESOURCE, DELETER >
RESOURCE	release ()
	Returns reference and reset this.
Public Member Functions inherited from SDL::ResourcePtrBase< RESOURCE >
constexpr	operator bool () const
	Check if not null.
constexpr bool	operator== (const ResourcePtrBase &other) const
	Comparison.
constexpr bool	operator== (std::nullptr_t) const
	Comparison.
constexpr bool	operator== (std::nullopt_t) const
	Comparison.
constexpr reference	operator* () const
	Gets reference.
constexpr const reference *	operator-> () const
	Gets addressable reference.
constexpr reference *	operator-> ()
	Gets addressable reference.
reference	get () const
	Get reference.

Static Public Member Functions
static RWLock	Create ()
	Create a new read/write lock.

Additional Inherited Members
Public Types inherited from SDL::ResourceOwnerBase< RESOURCE, DELETER >
using	deleter = DELETER
	The deleter type.
Public Types inherited from SDL::ResourcePtrBase< RESOURCE >
using	reference = RESOURCE
	The reference resource type.
using	value_type = typename reference::value_type
	The raw resource type.
Protected Member Functions inherited from SDL::ResourceOwnerBase< RESOURCE, DELETER >
constexpr	ResourceOwnerBase (base::value_type value={}, DELETER deleter={})
	Constructs from raw type.
void	free ()
	Frees resource.
Protected Member Functions inherited from SDL::ResourcePtrBase< RESOURCE >
constexpr	ResourcePtrBase (value_type value={})
	Constructs from raw type.
reference &	get ()
	Get reference.

Detailed Description

Category:

Resource

See also

RWLockRef

Member Function Documentation

Create()

static RWLock SDL::RWLock::Create ( )

inlinestatic

A read/write lock is useful for situations where you have multiple threads trying to access a resource that is rarely updated. All threads requesting a read-only lock will be allowed to run in parallel; if a thread requests a write lock, it will be provided exclusive access. This makes it safe for multiple threads to use a resource at the same time if they promise not to change it, and when it has to be changed, the rwlock will serve as a gateway to make sure those changes can be made safely.

In the right situation, a rwlock can be more efficient than a mutex, which only lets a single thread proceed at a time, even if it won't be modifying the data.

All newly-created read/write locks begin in the unlocked state.

Calls to RWLockRef.LockForReading() and RWLockRef.LockForWriting will not return while the rwlock is locked for writing by another thread. See RWLockRef.TryLockForReading() and RWLockRef.TryLockForWriting() to attempt to lock without blocking.

SDL read/write locks are only recursive for read-only locks! They are not guaranteed to be fair, or provide access in a FIFO manner! They are not guaranteed to favor writers. You may not lock a rwlock for both read-only and write access at the same time from the same thread (so you can't promote your read-only lock to a write lock without unlocking first).

Returns

the initialized and unlocked read/write lock or nullptr on failure; call GetError() for more information.

Since

This function is available since SDL 3.2.0.

See also

RWLock.Destroy

RWLockRef.LockForReading

RWLockRef.LockForWriting

RWLockRef.TryLockForReading

RWLockRef.TryLockForWriting

RWLockRef.Unlock

Destroy()

void SDL::RWLock::Destroy ( )

inline

This function must be called on any read/write lock that is no longer needed. Failure to destroy a rwlock will result in a system memory or resource leak. While it is safe to destroy a rwlock that is unlocked, it is not safe to attempt to destroy a locked rwlock, and may result in undefined behavior depending on the platform.

Since

This function is available since SDL 3.2.0.

See also

RWLock.Create

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The documentation for this struct was generated from the following file:

• SDL3pp/SDL3pp_mutex.h