Unlike ev_timer's, they are not based on real time (or relative time) but on wallclock time (absolute time). You can tell a periodic watcher to trigger "at" some specific point in time. For example, if you tell a -periodic watcher to trigger in 10 seconds (by specifiying e.g. c<ev_now () -+ 10.>) and then reset your system clock to the last year, then it will +periodic watcher to trigger in 10 seconds (by specifiying e.g.

ev_now ()
++ 10.

) and then reset your system clock to the last year, then it will take a year to trigger the event (unlike an ev_timer, which would trigger roughly 10 seconds later and of course not if you reset your system time again).

C++ SUPPORT

TBD.

Libev comes with some simplistic wrapper classes for C++ that mainly allow +you to use some convinience methods to start/stop watchers and also change +the callback model to a model using method callbacks on objects.

To use it,

  #include <ev++.h>
+
+

(it is not installed by default). This automatically includes ev.h +and puts all of its definitions (many of them macros) into the global +namespace. All C++ specific things are put into the ev namespace.

It should support all the same embedding options as ev.h, most notably +EV_MULTIPLICITY.

Here is a list of things available in the ev namespace:

ev::READ, ev::WRITE etc.

These are just enum values with the same values as the EV_READ etc. +macros from ev.h.

ev::tstamp, ev::now

Aliases to the same types/functions as with the ev_ prefix.

ev::io, ev::timer, ev::periodic, ev::idle, ev::sig etc.

For each ev_TYPE watcher in ev.h there is a corresponding class of +the same name in the ev namespace, with the exception of ev_signal +which is called ev::sig to avoid clashes with the signal macro +defines by many implementations.

All of those classes have these methods:

ev::TYPE::TYPE (object *, object::method *)

ev::TYPE::TYPE (object *, object::method *, struct ev_loop *)

ev::TYPE::~TYPE

The constructor takes a pointer to an object and a method pointer to +the event handler callback to call in this class. The constructor calls +ev_init for you, which means you have to call the set method +before starting it. If you do not specify a loop then the constructor +automatically associates the default loop with this watcher.

The destructor automatically stops the watcher if it is active.

w->set (struct ev_loop *)

Associates a different struct ev_loop with this watcher. You can only +do this when the watcher is inactive (and not pending either).

w->set ([args])

Basically the same as ev_TYPE_set, with the same args. Must be +called at least once. Unlike the C counterpart, an active watcher gets +automatically stopped and restarted.

w->start ()

Starts the watcher. Note that there is no loop argument as the +constructor already takes the loop.

w->stop ()

Stops the watcher if it is active. Again, no loop argument.

w->again () ev::timer, ev::periodic only

For ev::timer and ev::periodic, this invokes the corresponding +ev_TYPE_again function.

w->sweep () ev::embed only

Invokes ev_embed_sweep.

Example: Define a class with an IO and idle watcher, start one of them in +the constructor.

  class myclass
+  {
+    ev_io   io;   void io_cb   (ev::io   &w, int revents);
+    ev_idle idle  void idle_cb (ev::idle &w, int revents);
+
+    myclass ();
+  }
+
+  myclass::myclass (int fd)
+  : io   (this, &myclass::io_cb),
+    idle (this, &myclass::idle_cb)
+  {
+    io.start (fd, ev::READ);
+  }
+
+

AUTHOR

's, they are not based on real time (or relative time) but on wallclock time (absolute time). You can tell a periodic watcher to trigger "at" some specific point in time. For example, if you tell a -periodic watcher to trigger in 10 seconds (by specifiying e.g. c) and then reset your system clock to the last year, then it will take a year to trigger the event (unlike an C, which would trigger roughly 10 seconds later and of course not if you reset your system time @@ -1312,7 +1312,109 @@ to use the libev header file and library. =head1 C++ SUPPORT -TBD. +Libev comes with some simplistic wrapper classes for C++ that mainly allow +you to use some convinience methods to start/stop watchers and also change +the callback model to a model using method callbacks on objects. + +To use it, + + #include + +(it is not installed by default). This automatically includes F +and puts all of its definitions (many of them macros) into the global +namespace. All C++ specific things are put into the C namespace. + +It should support all the same embedding options as F, most notably +C. + +Here is a list of things available in the C namespace: + +=over 4 + +=item C, C etc. + +These are just enum values with the same values as the C etc. +macros from F. + +=item C, C + +Aliases to the same types/functions as with the C prefix. + +=item C, C, C, C, C etc. + +For each C watcher in F there is a corresponding class of +the same name in the C namespace, with the exception of C +which is called C to avoid clashes with the C macro +defines by many implementations. + +All of those classes have these methods: + +=over 4 + +=item ev::TYPE::TYPE (object *, object::method *) + +=item ev::TYPE::TYPE (object *, object::method *, struct ev_loop *) + +=item ev::TYPE::~TYPE + +The constructor takes a pointer to an object and a method pointer to +the event handler callback to call in this class. The constructor calls +C for you, which means you have to call the C method +before starting it. If you do not specify a loop then the constructor +automatically associates the default loop with this watcher. + +The destructor automatically stops the watcher if it is active. + +=item w->set (struct ev_loop *) + +Associates a different C with this watcher. You can only +do this when the watcher is inactive (and not pending either). + +=item w->set ([args]) + +Basically the same as C, with the same args. Must be +called at least once. Unlike the C counterpart, an active watcher gets +automatically stopped and restarted. + +=item w->start () + +Starts the watcher. Note that there is no C argument as the +constructor already takes the loop. + +=item w->stop () + +Stops the watcher if it is active. Again, no C argument. + +=item w->again () C, C only + +For C and C, this invokes the corresponding +C function. + +=item w->sweep () C only + +Invokes C. + +=back + +=back + +Example: Define a class with an IO and idle watcher, start one of them in +the constructor. + + class myclass + { + ev_io io; void io_cb (ev::io &w, int revents); + ev_idle idle void idle_cb (ev::idle &w, int revents); + + myclass (); + } + + myclass::myclass (int fd) + : io (this, &myclass::io_cb), + idle (this, &myclass::idle_cb) + { + io.start (fd, ev::READ); + } =head1 AUTHOR -- cgit v1.2.3