#[repr(transparent)]pub struct Event { /* private fields */ }Expand description
A readiness event.
Event is a readiness state paired with a Token. It is returned by
Poll::poll.
For more documentation on polling and events, see Poll.
Implementations§
source§impl Event
impl Event
sourcepub fn is_readable(&self) -> bool
pub fn is_readable(&self) -> bool
Returns true if the event contains readable readiness.
Notes
Out-of-band (OOB) data also triggers readable events. But must application don’t actually read OOB data, this could leave an application open to a Denial-of-Service (Dos) attack, see https://github.com/sandstorm-io/sandstorm-website/blob/58f93346028c0576e8147627667328eaaf4be9fa/_posts/2015-04-08-osx-security-bug.md. However because Mio uses edge-triggers it will not result in an infinite loop as described in the article above.
sourcepub fn is_writable(&self) -> bool
pub fn is_writable(&self) -> bool
Returns true if the event contains writable readiness.
sourcepub fn is_error(&self) -> bool
pub fn is_error(&self) -> bool
Returns true if the event contains error readiness.
Error events occur when the socket enters an error state. In this case, the socket will also receive a readable or writable event. Reading or writing to the socket will result in an error.
Notes
Method is available on all platforms, but not all platforms trigger the error event.
The table below shows what flags are checked on what OS.
| OS selector | Flag(s) checked |
|---|---|
| epoll | EPOLLERR |
| kqueue | EV_ERROR and EV_EOF with fflags set to 0. |
sourcepub fn is_read_closed(&self) -> bool
pub fn is_read_closed(&self) -> bool
Returns true if the event contains read closed readiness.
Notes
Read closed readiness can be expected after any of the following have occurred:
- The local stream has shutdown the read half of its socket
- The local stream has shutdown both the read half and the write half of its socket
- The peer stream has shutdown the write half its socket; this sends a
FINpacket that has been received by the local stream
Method is a best effort implementation. While some platforms may not return readiness when read half is closed, it is guaranteed that false-positives will not occur.
The table below shows what flags are checked on what OS.
| OS selector | Flag(s) checked |
|---|---|
| epoll | EPOLLHUP, or |
EPOLLIN and EPOLLRDHUP | |
| kqueue | EV_EOF |
sourcepub fn is_write_closed(&self) -> bool
pub fn is_write_closed(&self) -> bool
Returns true if the event contains write closed readiness.
Notes
On epoll this is essentially a check for EPOLLHUP flag as the
local stream shutting down its write half does not trigger this event.
On kqueue the local stream shutting down the write half of its socket will trigger this event.
Method is a best effort implementation. While some platforms may not return readiness when write half is closed, it is guaranteed that false-positives will not occur.
The table below shows what flags are checked on what OS.
| OS selector | Flag(s) checked |
|---|---|
| epoll | EPOLLHUP, or |
only EPOLLERR, or | |
EPOLLOUT and EPOLLERR | |
| kqueue | EV_EOF |
sourcepub fn is_priority(&self) -> bool
pub fn is_priority(&self) -> bool
Returns true if the event contains priority readiness.
Notes
Method is available on all platforms, but not all platforms trigger the priority event.
The table below shows what flags are checked on what OS.
| OS selector | Flag(s) checked |
|---|---|
| epoll | EPOLLPRI |
| kqueue | Not supported |
sourcepub fn is_aio(&self) -> bool
pub fn is_aio(&self) -> bool
Returns true if the event contains AIO readiness.
Notes
Method is available on all platforms, but not all platforms support AIO.
The table below shows what flags are checked on what OS.
| OS selector | Flag(s) checked |
|---|---|
| epoll | Not supported |
| kqueue1 | EVFILT_AIO |
1: Only supported on DragonFly BSD, FreeBSD, iOS and macOS.