SDL::ConditionRef Struct Reference

A means to block multiple threads until a condition is satisfied. More...

Inheritance diagram for SDL::ConditionRef:

Public Member Functions
void	Signal ()
	Restart one of the threads that are waiting on the condition variable.
void	Broadcast ()
	Restart all threads that are waiting on the condition variable.
void	Wait (MutexRef mutex)
	Wait until a condition variable is signaled.
bool	WaitTimeout (MutexRef mutex, std::chrono::milliseconds timeout)
	Wait until a condition variable is signaled or a certain time has passed.
constexpr	Resource (T resource={})
	Constructs from the underlying resource.
constexpr	Resource (const ResourceHandle< Resource< T > > auto &resource)
	Constructs from pointer like.
constexpr	Resource (std::nullptr_t)
	Equivalent to default ctor.
constexpr	Resource (std::nullopt_t)
	Equivalent to default ctor.
Public Member Functions inherited from SDL::Resource< SDL_Condition * >
constexpr	Resource (SDL_Condition * resource={})
	Constructs from the underlying resource.
constexpr	Resource (const ResourceHandle< Resource< SDL_Condition * > > auto &resource)
	Constructs from pointer like.
constexpr	Resource (std::nullptr_t)
	Equivalent to default ctor.
constexpr	Resource (std::nullopt_t)
	Equivalent to default ctor.
constexpr	operator bool () const
	True if contains a valid resource.
constexpr	operator value_type () const
	Converts back to underlying type.
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_Condition *	get () const
	Return contained resource;.
constexpr const SDL_Condition *	operator-> () const
	Access to fields.
constexpr SDL_Condition *	operator-> ()
	Access to fields.

Static Public Member Functions
static void	reset (SDL_Condition *resource)
	Destroy a condition variable.

Additional Inherited Members
Public Types inherited from SDL::Resource< SDL_Condition * >
using	value_type = SDL_Condition *
	The raw resource type.

Detailed Description

Condition variables, paired with an Mutex, let an app halt multiple threads until a condition has occurred, at which time the app can release one or all waiting threads.

Wikipedia has a thorough explanation of the concept:

https://en.wikipedia.org/wiki/Condition_variable

Since

This struct is available since SDL 3.2.0.

Category:

Resource

See also

Condition

Member Function Documentation

Broadcast()

void SDL::ConditionRef::Broadcast ( )

inline

Thread safety:

It is safe to call this function from any thread.

Since

This function is available since SDL 3.2.0.

See also

ConditionRef.Signal

ConditionRef.Wait

ConditionRef.WaitTimeout

reset()

static void SDL::ConditionRef::reset ( SDL_Condition *  resource )

inlinestatic

Parameters

resource

the condition variable to destroy.

Since

This function is available since SDL 3.2.0.

See also

Condition.Create

Signal()

void SDL::ConditionRef::Signal ( )

inline

Thread safety:

It is safe to call this function from any thread.

Since

This function is available since SDL 3.2.0.

See also

ConditionRef.Broadcast

ConditionRef.Wait

ConditionRef.WaitTimeout

Wait()

void SDL::ConditionRef::Wait ( MutexRef  mutex )

inline

This function unlocks the specified mutex and waits for another thread to call ConditionRef.Signal() or ConditionRef.Broadcast() on the condition variable cond. Once the condition variable is signaled, the mutex is re-locked and the function returns.

The mutex must be locked before calling this function. Locking the mutex recursively (more than once) is not supported and leads to undefined behavior.

This function is the equivalent of calling ConditionRef.WaitTimeout() with a time length of -1.

Parameters

mutex

the mutex used to coordinate thread access.

Thread safety:

It is safe to call this function from any thread.

Since

This function is available since SDL 3.2.0.

See also

ConditionRef.Broadcast

ConditionRef.Signal

ConditionRef.WaitTimeout

WaitTimeout()

bool SDL::ConditionRef::WaitTimeout ( MutexRef  mutex, std::chrono::milliseconds  timeout  )

inline

This function unlocks the specified mutex and waits for another thread to call ConditionRef.Signal() or ConditionRef.Broadcast() on the condition variable cond, or for the specified time to elapse. Once the condition variable is signaled or the time elapsed, the mutex is re-locked and the function returns.

The mutex must be locked before calling this function. Locking the mutex recursively (more than once) is not supported and leads to undefined behavior.

Parameters

mutex	the mutex used to coordinate thread access.
timeout	the maximum time to wait, in milliseconds, or -1 to wait indefinitely.

Returns

true if the condition variable is signaled, false if the condition is not signaled in the allotted time.

Thread safety:

It is safe to call this function from any thread.

Since

This function is available since SDL 3.2.0.

See also

ConditionRef.Broadcast

ConditionRef.Signal

ConditionRef.Wait

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

• SDL3pp/SDL3pp_mutex.h