Ev (class)
The Ev class
Introduction
(PECL ev >= 0.2.0)
Ev is a static class providing access to the default loop and to some common operations.
Class synopsis
final Ev
{
/* Constants */
const integer FLAG_AUTO = 0 ;
const integer FLAG_NOENV = 16777216 ;
const integer FLAG_FORKCHECK = 33554432 ;
const integer FLAG_NOINOTIFY = 1048576 ;
const integer FLAG_SIGNALFD = 2097152 ;
const integer FLAG_NOSIGMASK = 4194304 ;
const integer RUN_NOWAIT = 1 ;
const integer RUN_ONCE = 2 ;
const integer BREAK_CANCEL = 0 ;
const integer BREAK_ONE = 1 ;
const integer BREAK_ALL = 2 ;
const integer MINPRI = -2 ;
const integer MAXPRI = 2 ;
const integer READ = 1 ;
const integer WRITE = 2 ;
const integer TIMER = 256 ;
const integer PERIODIC = 512 ;
const integer SIGNAL = 1024 ;
const integer CHILD = 2048 ;
const integer STAT = 4096 ;
const integer IDLE = 8192 ;
const integer PREPARE = 16384 ;
const integer CHECK = 32768 ;
const integer EMBED = 65536 ;
const integer CUSTOM = 16777216 ;
const integer ERROR = 2147483648 ;
const integer BACKEND_SELECT = 1 ;
const integer BACKEND_POLL = 2 ;
const integer BACKEND_EPOLL = 4 ;
const integer BACKEND_KQUEUE = 8 ;
const integer BACKEND_DEVPOLL = 16 ;
const integer BACKEND_PORT = 32 ;
const integer BACKEND_ALL = 63 ;
const integer BACKEND_MASK = 65535 ;
/* Methods */
final public static int backend ( void )
final public static int depth ( void )
final public static void embeddableBackends ( void )
final public static void feedSignal ( int $signum )
final public static void feedSignalEvent ( int $signum )
final public static int iteration ( void )
final public static double now ( void )
final public static void nowUpdate ( void )
final public static void recommendedBackends ( void )
final public static void resume ( void )
final public static void run ([ int $flags ] )
final public static void sleep ( double $seconds )
final public static void stop ([ int $how ] )
final public static void supportedBackends ( void )
final public static void suspend ( void )
final public static double time ( void )
final public static void verify ( void )
}
Predefined Constants
Flags passed to create a loop:
Ev::FLAG_AUTO
The default flags value
Ev::FLAG_NOENV
If this flag used(or the program runs setuid or setgid), libev
won't look at the environment variable LIBEV_FLAGS . Otherwise(by default), LIBEV_FLAGS will override the flags completely if it is found. Useful for performance tests and searching for bugs.
Ev::FLAG_FORKCHECK
Makes libev check for a fork in each iteration, instead of calling EvLoop::fork() manually. This works by calling getpid()
on every iteration of the loop, and thus this might slow down the event loop with lots of loop iterations, but usually is not noticeable. This flag setting cannot be overridden or specified in the LIBEV_FLAGS environment variable.
Ev::FLAG_NOINOTIFY
When this flag is specified, libev
won't attempt to use the inotify
API for its » ev
_
stat
watchers. The flag can be useful to conserve inotify
file descriptors, as otherwise each loop using ev
_
stat
watchers consumes one inotify
handle.
Ev::FLAG_SIGNALFD
When this flag is specified, libev
will attempt to use the signalfd
API for its » ev_signal (and » ev_child ) watchers. This API delivers signals synchronously, which makes it both faster and might make it possible to get the queued signal data. It can also simplify signal handling with threads, as long as signals are properly blocked in threads. Signalfd
will not be used by default.
Ev::FLAG_NOSIGMASK
When this flag is specified, libev
will avoid to modify the signal mask. Specifically, this means having to make sure signals are unblocked before receiving them.
This behaviour is useful for custom signal handling, or handling signals only in specific threads.
Flags passed to Ev::run() , or EvLoop::run()
Ev::RUN_NOWAIT
Means that event loop will look for new events, will handle those events and any already outstanding ones, but will not wait and block the process in case there are no events and will return after one iteration of the loop. This is sometimes useful to poll and handle new events while doing lengthy calculations, to keep the program responsive.
Ev::RUN_ONCE
Means that event loop will look for new events (waiting if necessary) and will handle those and any already outstanding ones. It will block the process until at least one new event arrives (which could be an event internal to libev itself, so there is no guarantee that a user-registered callback will be called), and will return after one iteration of the loop.
Flags passed to Ev::stop() , or EvLoop::stop()
Ev::BREAK_CANCEL
Cancel the break operation.
Ev::BREAK_ONE
Makes the innermost Ev::run() (or EvLoop::run() ) call return.
Ev::BREAK_ALL
Makes all nested Ev::run() (or EvLoop::run() ) calls return.
Watcher priorities:
Ev::MINPRI
Minimum allowed watcher priority.
Ev::MAXPRI
Maximum allowed watcher priority.
Bit masks of (received) events:
Ev::READ
The file descriptor in the EvIo watcher has become readable.
Ev::WRITE
The file descriptor in the EvIo watcher has become writable.
Ev::TIMER
EvTimer watcher has been timed out.
Ev::PERIODIC
EvPeriodic watcher has been timed out.
Ev::SIGNAL
A signal specified in EvSignal::__construct() has been received.
Ev::CHILD
The pid
specified in EvChild::__construct() has received a status change.
Ev::STAT
The path specified in EvStat watcher changed its attributes.
Ev::IDLE
EvIdle watcher works when there is nothing to do with other watchers.
Ev::PREPARE
All EvPrepare watchers are invoked just before Ev::run() starts. Thus, EvPrepare watchers are the last watchers invoked before the event loop sleeps or polls for new events.
Ev::CHECK
All EvCheck watchers are queued just after Ev::run() has gathered the new events, but before it queues any callbacks for any received events. Thus, EvCheck watchers will be invoked before any other watchers of the same or lower priority within an event loop iteration.
Ev::EMBED
The embedded event loop specified in the EvEmbed watcher needs attention.
Ev::CUSTOM
Not ever sent(or otherwise used) by libev
itself, but can be freely used by libev
users to signal watchers (e.g. via EvWatcher::feed() ).
Ev::ERROR
An unspecified error has occurred, the watcher has been stopped. This might happen because the watcher could not be properly started because libev
ran out of memory, a file descriptor was found to be closed or any other problem. Libev
considers these application bugs. See also » ANATOMY OF A WATCHER
Backend flags:
Ev::BACKEND_SELECT
select(2) backend
Ev::BACKEND_POLL
poll(2) backend
Ev::BACKEND_EPOLL
Linux-specific epoll(7)
backend for both pre- and post-2.6.9 kernels
Ev::BACKEND_KQUEUE
kqueue
backend used on most BSD systems. EvEmbed watcher could be used to embed one loop(with kqueue
backend) into another. For instance, one can try to create an event loop with kqueue
backend and use it for sockets only.
Ev::BACKEND_DEVPOLL
Solaris 8 backend. This is not implemented yet.
Ev::BACKEND_PORT
Solaris 10 event port mechanism with a good scaling.
Ev::BACKEND_ALL
Try all backends(even currupted ones). It's not recommended to use it explicitly. Bitwise operators should be applied here(e.g. Ev::BACKEND_ALL
& ~ Ev::BACKEND_KQUEUE
) Use Ev::recommendedBackends() , or don't specify any backends at all.
Ev::BACKEND_MASK
Not a backend, but a mask to select all backend bits from flags
value to mask out any backends(e.g. when modifying the LIBEV_FLAGS environment variable).
Note
: For the default loop during module initialization phaseEv
registers » ev_
loop_
fork call by means ofpthread
_
atfork
(if available).Note
: There are methods providing access to thedefault event loop
inEv
class(e.g.Ev
::iteration() ,Ev
::depth() etc.) Forcustom loops
(created withEv
Loop::_
_
construct() ) these values may be accessed via corresponding properties and methods of theEv
Loop class. The instance of thedefault event loop
itself can be fetched by means ofEv
Loop::defaultLoop() method.
Table of Contents
- Ev::backend — Returns an integer describing the backend used by libev.
- Ev::depth — Returns recursion depth
- Ev::embeddableBackends — Returns the set of backends that are embeddable in other event loops.
- Ev::feedSignal — Feed a signal event info Ev
- Ev::feedSignalEvent — Feed signal event into the default loop
- Ev::iteration — Return the number of times the default event loop has polled for new events.
- Ev::now — Returns the time when the last iteration of the default event loop has started.
- Ev::nowUpdate — Establishes the current time by querying the kernel, updating the time returned by Ev::now in the progress.
- Ev::recommendedBackends — Returns a bit mask of recommended backends for current platform.
- Ev::resume — Resume previously suspended default event loop
- Ev::run — Begin checking for events and calling callbacks for the default loop
- Ev::sleep — Block the process for the given number of seconds.
- Ev::stop — Stops the default event loop
- Ev::supportedBackends — Returns the set of backends supported by current libev configuration.
- Ev::suspend — Suspend the default event loop
- Ev::time — Returns the current time in fractional seconds since the epoch.
- Ev::verify — Performs internal consistency checks(for debugging)
← Periodic watcher operation modes
Ev::backend →
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