SDL::RWLockRef Struct Reference

Handle to a non owned rWLock. More...

Inheritance diagram for SDL::RWLockRef:

Public Member Functions
constexpr	RWLockRef (const RWLockRef &other)
	Copy constructor.
constexpr	RWLockRef (RWLockRef &&other)
	Move constructor.
constexpr	~RWLockRef ()=default
	Default constructor.
RWLockRef &	operator= (RWLockRef other)
	Assignment operator.
void	reset (SDL_RWLock *newResource={})
	Destroy a read/write lock created with RWLockBase.RWLockBase().
	RWLockBase ()
	Create a new read/write lock.
Public Member Functions inherited from SDL::RWLockBase
	RWLockBase ()
	Create a new read/write lock.
void	LockForReading ()
	Lock the read/write lock for read only operations.
void	LockForWriting ()
	Lock the read/write lock for write operations.
void	TryLockForReading ()
	Try to lock a read/write lock for reading without blocking.
void	TryLockForWriting ()
	Try to lock a read/write lock for writing without blocking.
void	Unlock ()
	Unlock the read/write lock.
constexpr	Resource (T resource={})
	Constructs the underlying resource.
constexpr	Resource (std::nullptr_t)
	Equivalent to default ctor.
constexpr	Resource (std::nullopt_t)
	Equivalent to default ctor.
	Resource (const Resource &other)=delete
	Resource (Resource &&other)=delete
Public Member Functions inherited from SDL::Resource< SDL_RWLock * >
constexpr	Resource (SDL_RWLock * resource={})
	Constructs the underlying resource.
constexpr	Resource (std::nullptr_t)
	Equivalent to default ctor.
constexpr	Resource (std::nullopt_t)
	Equivalent to default ctor.
	Resource (const Resource &other)=delete
	Resource (Resource &&other)=delete
Resource &	operator= (const Resource &other)=delete
Resource &	operator= (Resource &&other)=delete
constexpr	operator bool () const
	True if contains a valid resource.
constexpr bool	operator== (const Resource &other) const=default
	Comparison.
constexpr bool	operator== (std::nullopt_t) const
	Comparison.
constexpr bool	operator== (std::nullptr_t) const
	Comparison.
constexpr SDL_RWLock *	get () const
	Return contained resource;.
constexpr SDL_RWLock *	release (SDL_RWLock * newResource={})
	Return contained resource and empties or replace value.
constexpr const SDL_RWLock *	operator-> () const
	Access to fields.
constexpr SDL_RWLock *	operator-> ()
	Access to fields.

Detailed Description

Category:

Resource

See also

RWLockBase

RWLock

Member Function Documentation

reset()

void SDL::RWLockRef::reset ( SDL_RWLock *  newResource = {} )

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

RWLockBase.RWLockBase

RWLockBase()

SDL::RWLockBase::RWLockBase ( )

inline

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 RWLockBase.LockForReading() and RWLockBase.LockForWriting will not return while the rwlock is locked for writing by another thread. See RWLockBase.TryLockForReading() and RWLockBase.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).

Postcondition

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

RWLockBase.LockForReading

RWLockBase.LockForWriting

RWLockBase.TryLockForReading

RWLockBase.TryLockForWriting

RWLockBase.Unlock

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

• SDL3pp/SDL3pp_mutex.h