pub struct Reactor { /* private fields */ }Expand description
The core reactor, or event loop.
The event loop is the main source of blocking in an application which drives all other I/O events and notifications happening. Each event loop can have multiple handles pointing to it, each of which can then be used to create various I/O objects to interact with the event loop in interesting ways.
Implementations§
Source§impl Reactor
impl Reactor
Sourcepub fn new() -> Result<Reactor>
pub fn new() -> Result<Reactor>
Creates a new event loop, returning any error that happened during the creation.
Sourcepub fn handle(&self) -> Handle
pub fn handle(&self) -> Handle
Returns a handle to this event loop which can be sent across threads and can be used as a proxy to the event loop itself.
Handles are cloneable and clones always refer to the same event loop. This handle is typically passed into functions that create I/O objects to bind them to this event loop.
Sourcepub fn set_fallback(&self) -> Result<(), SetFallbackError>
pub fn set_fallback(&self) -> Result<(), SetFallbackError>
Configures the fallback handle to be returned from Handle::default.
The Handle::default() function will by default lazily spin up a global
thread and run a reactor on this global thread. This behavior is not
always desirable in all applications, however, and sometimes a different
fallback reactor is desired.
This function will attempt to globally alter the return value of
Handle::default() to return the handle specified rather than a
lazily initialized global thread. If successful then all future calls to
Handle::default() which would otherwise fall back to the global thread
will instead return a clone of the handle specified.
§Errors
This function may not always succeed in configuring the fallback handle. If this function was previously called (or perhaps concurrently called on many threads) only the first invocation of this function will succeed. All other invocations will return an error.
Additionally if the global reactor thread has already been initialized
then this function will also return an error. (aka if Handle::default
has been called previously in this program).
Sourcepub fn turn(&mut self, max_wait: Option<Duration>) -> Result<Turn>
pub fn turn(&mut self, max_wait: Option<Duration>) -> Result<Turn>
Performs one iteration of the event loop, blocking on waiting for events
for at most max_wait (forever if None).
This method is the primary method of running this reactor and processing I/O events that occur. This method executes one iteration of an event loop, blocking at most once waiting for events to happen.
If a max_wait is specified then the method should block no longer than
the duration specified, but this shouldn’t be used as a super-precise
timer but rather a “ballpark approximation”
§Return value
This function returns an instance of Turn
Turn as of today has no extra information with it and can be safely
discarded. In the future Turn may contain information about what
happened while this reactor blocked.
§Errors
This function may also return any I/O error which occurs when polling
for readiness of I/O objects with the OS. This is quite unlikely to
arise and typically mean that things have gone horribly wrong at that
point. Currently this is primarily only known to happen for internal
bugs to tokio itself.
Sourcepub fn is_idle(&self) -> bool
pub fn is_idle(&self) -> bool
Returns true if the reactor is currently idle.
Idle is defined as all tasks that have been spawned have completed, either successfully or with an error.
Sourcepub fn background(self) -> Result<Background>
pub fn background(self) -> Result<Background>
Run this reactor on a background thread.
This function takes ownership, spawns a new thread, and moves the
reactor to this new thread. It then runs the reactor, driving all
associated I/O resources, until the Background handle is dropped or
explicitly shutdown.