Struct spa_loop_control_methods

#[repr(C)]
pub struct spa_loop_control_methods {
    pub version: u32,
    pub get_fd: Option<unsafe extern "C" fn(object: *mut c_void) -> c_int>,
    pub add_hook: Option<unsafe extern "C" fn(object: *mut c_void, hook: *mut spa_hook, hooks: *const spa_loop_control_hooks, data: *mut c_void)>,
    pub enter: Option<unsafe extern "C" fn(object: *mut c_void)>,
    pub leave: Option<unsafe extern "C" fn(object: *mut c_void)>,
    pub iterate: Option<unsafe extern "C" fn(object: *mut c_void, timeout: c_int) -> c_int>,
    pub check: Option<unsafe extern "C" fn(object: *mut c_void) -> c_int>,
}

Control an event loop

The event loop control function provide API to run the event loop.

The below (pseudo)code is a minimal example outlining the use of the loop control: \code{.c} spa_loop_control_enter(loop); while (running) { spa_loop_control_iterate(loop, -1); } spa_loop_control_leave(loop); \endcode

It is also possible to add the loop to an existing event loop by using the spa_loop_control_get_fd() call. This fd will become readable when activity has been detected on the sources in the loop. spa_loop_control_iterate() with a 0 timeout should be called to process the pending sources.

spa_loop_control_enter() and spa_loop_control_leave() should be called once from the thread that will run the iterate() function.

Fields

version: u32

get_fd: Option<unsafe extern "C" fn(object: *mut c_void) -> c_int>

get the loop fd \param object the control to query

Get the fd of this loop control. This fd will be readable when a source in the loop has activity. The user should call iterate() with a 0 timeout to schedule one iteration of the loop and dispatch the sources. \return the fd of the loop

add_hook: Option<unsafe extern "C" fn(object: *mut c_void, hook: *mut spa_hook, hooks: *const spa_loop_control_hooks, data: *mut c_void)>

Add a hook \param object the control to change \param hooks the hooks to add

Adds hooks to the loop controlled by \a ctrl.

enter: Option<unsafe extern "C" fn(object: *mut c_void)>

Enter a loop \param object the control

This function should be called before calling iterate and is typically used to capture the thread that this loop will run in. It should ideally be called once from the thread that will run the loop.

leave: Option<unsafe extern "C" fn(object: *mut c_void)>

Leave a loop \param object the control

It should ideally be called once after calling iterate when the loop will no longer be iterated from the thread that called enter().

iterate: Option<unsafe extern "C" fn(object: *mut c_void, timeout: c_int) -> c_int>

Perform one iteration of the loop. \param ctrl the control \param timeout an optional timeout in milliseconds. 0 for no timeout, -1 for infinite timeout.

This function will block up to \a timeout milliseconds and then dispatch the fds with activity. The number of dispatched fds is returned.

check: Option<unsafe extern "C" fn(object: *mut c_void) -> c_int>

Check context of the loop \param ctrl the control

This function will check if the current thread is currently the one that did the enter call. Since version 1:1.

returns 1 on success, 0 or negative errno value on error.

Trait Implementations

impl Clone for spa_loop_control_methods

fn clone(&self) -> spa_loop_control_methods

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for spa_loop_control_methods

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl PartialEq for spa_loop_control_methods

fn eq(&self, other: &spa_loop_control_methods) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for spa_loop_control_methods

impl Eq for spa_loop_control_methods

impl StructuralPartialEq for spa_loop_control_methods