The Ev class
(PECL ev >= 0.2.0)
簡介
Ev is a static class providing access to the default loop and to some common operations.
類摘要
預定義常量
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),
libevwon'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,
libevwon't attempt to use theinotifyAPI for its » ev_stat watchers. The flag can be useful to conserve inotify file descriptors, as otherwise each loop usingev_statwatchers consumes oneinotifyhandle.-
Ev::FLAG_SIGNALFD When this flag is specified,
libevwill attempt to use thesignalfdAPI 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.Signalfdwill not be used by default.-
Ev::FLAG_NOSIGMASK When this flag is specified,
libevwill 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
pidspecified 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
libevitself, but can be freely used bylibevusers 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
libevran out of memory, a file descriptor was found to be closed or any other problem.Libevconsiders 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 kqueuebackend 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 withkqueuebackend 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
flagsvalue to mask out any backends(e.g. when modifying the LIBEV_FLAGS environment variable).
注意:
For the default loop during module initialization phase
Evregisters » ev_loop_fork call by means ofpthread_atfork(if available).
注意:
There are methods providing access to the default event loop in Ev class(e.g. Ev::iteration() , Ev::depth() etc.) For custom loops (created with EvLoop::__construct() ) these values may be accessed via corresponding properties and methods of the EvLoop class.
The instance of the default event loop itself can be fetched by means of EvLoop::defaultLoop() method.
目錄
- 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)