devela::_dep::sdl3::sys::asyncio

Function SDL_CloseAsyncIO

pub unsafe extern "C" fn SDL_CloseAsyncIO(
    asyncio: *mut SDL_AsyncIO,
    flush: bool,
    queue: *mut SDL_AsyncIOQueue,
    userdata: *mut c_void,
) -> bool
Available on crate feature dep_sdl3 only.
Expand description

Close and free any allocated resources for an async I/O object.

Closing a file is also an asynchronous task! If a write failure were to happen during the closing process, for example, the task results will report it as usual.

Closing a file that has been written to does not guarantee the data has made it to physical media; it may remain in the operating system’s file cache, for later writing to disk. This means that a successfully-closed file can be lost if the system crashes or loses power in this small window. To prevent this, call this function with the flush parameter set to true. This will make the operation take longer, and perhaps increase system load in general, but a successful result guarantees that the data has made it to physical storage. Don’t use this for temporary files, caches, and unimportant data, and definitely use it for crucial irreplaceable files, like game saves.

This function guarantees that the close will happen after any other pending tasks to asyncio, so it’s safe to open a file, start several operations, close the file immediately, then check for all results later. This function will not block until the tasks have completed.

Once this function returns true, asyncio is no longer valid, regardless of any future outcomes. Any completed tasks might still contain this pointer in their SDL_AsyncIOOutcome data, in case the app was using this value to track information, but it should not be used again.

If this function returns false, the close wasn’t started at all, and it’s safe to attempt to close again later.

An SDL_AsyncIOQueue must be specified. The newly-created task will be added to it when it completes its work.

§Parameters

  • asyncio: a pointer to an SDL_AsyncIO structure to close.
  • flush: true if data should sync to disk before the task completes.
  • queue: a queue to add the new SDL_AsyncIO to.
  • userdata: an app-defined pointer that will be provided with the task results.

§Return value

Returns true on success or false on failure; call [SDL_GetError()] for more information.

§Thread safety

It is safe to call this function from any thread, but two threads should not attempt to close the same object.

§Availability

This function is available since SDL 3.2.0.