SDL::InitState Struct Reference

A structure used for thread-safe initialization and shutdown. More...

Inheritance diagram for SDL::InitState:

Public Member Functions
constexpr	InitState ()
	Constructor.
bool	ShouldInit ()
	Return whether initialization should be done.
bool	ShouldQuit ()
	Return whether cleanup should be done.
void	SetInitialized (bool initialized)
	Finish an initialization state transition.

Detailed Description

Here is an example of using this:

   static SDL::InitState init;
 
   bool InitSystem(void)
   {
       if (!InitState.ShouldInit(&init)) {
           // The system is initialized
           return true;
       }
 
       // At this point, you should not leave this function without calling
InitState.SetInitialized()
 
       bool initialized = DoInitTasks();
       InitState.SetInitialized(&init, initialized);
       return initialized;
   }
 
   bool UseSubsystem(void)
   {
       if (InitState.ShouldInit(&init)) {
           // Error, the subsystem isn't initialized
           InitState.SetInitialized(&init, false);
           return false;
       }
 
       // Do work using the initialized subsystem
 
       return true;
   }
 
   void QuitSystem(void)
   {
       if (!InitState.ShouldQuit(&init)) {
           // The system is not initialized
           return;
       }
 
       // At this point, you should not leave this function without calling
InitState.SetInitialized()
 
       DoQuitTasks();
       InitState.SetInitialized(&init, false);
   }

Note that this doesn't protect any resources created during initialization, or guarantee that nobody is using those resources during cleanup. You should use other mechanisms to protect those, if that's a concern for your code.

Since

This struct is available since SDL 3.2.0.

Member Function Documentation

SetInitialized()

void SDL::InitState::SetInitialized ( bool  initialized )

inline

This function sets the status of the passed in state to INIT_STATUS_INITIALIZED or INIT_STATUS_UNINITIALIZED and allows any threads waiting for the status to proceed.

Parameters

initialized

the new initialization state.

Thread safety:

It is safe to call this function from any thread.

Since

This function is available since SDL 3.2.0.

See also

InitState.ShouldInit

InitState.ShouldQuit

ShouldInit()

bool SDL::InitState::ShouldInit ( )

inline

This function checks the passed in state and if initialization should be done, sets the status to INIT_STATUS_INITIALIZING and returns true. If another thread is already modifying this state, it will wait until that's done before returning.

If this function returns true, the calling code must call InitState.SetInitialized() to complete the initialization.

Returns

true if initialization needs to be done, false otherwise.

Thread safety:

It is safe to call this function from any thread.

Since

This function is available since SDL 3.2.0.

See also

InitState.SetInitialized

InitState.ShouldQuit

ShouldQuit()

bool SDL::InitState::ShouldQuit ( )

inline

This function checks the passed in state and if cleanup should be done, sets the status to INIT_STATUS_UNINITIALIZING and returns true.

If this function returns true, the calling code must call InitState.SetInitialized() to complete the cleanup.

Returns

true if cleanup needs to be done, false otherwise.

Thread safety:

It is safe to call this function from any thread.

Since

This function is available since SDL 3.2.0.

See also

InitState.SetInitialized

InitState.ShouldInit

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

• SDL3pp/SDL3pp_mutex.h