diff options
Diffstat (limited to 'ev.3')
| -rw-r--r-- | ev.3 | 109 |
1 files changed, 106 insertions, 3 deletions
@@ -997,8 +997,8 @@ Periodic watchers are also timers of a kind, but they are very versatile Unlike \f(CW\*(C`ev_timer\*(C'\fR'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 \*(L"at\*(R" 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. \f(CW\*(C`ev_now () ++ 10.\*(C'\fR) and then reset your system clock to the last year, then it will take a year to trigger the event (unlike an \f(CW\*(C`ev_timer\*(C'\fR, which would trigger roughly 10 seconds later and of course not if you reset your system time again). @@ -1434,7 +1434,110 @@ emulate the internals of libevent, so here are some usage hints: .PD .SH "\*(C+ SUPPORT" .IX Header " SUPPORT" -\&\s-1TBD\s0. +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. +.PP +To use it, +.PP +.Vb 1 +\& #include <ev++.h> +.Ve +.PP +(it is not installed by default). This automatically includes \fIev.h\fR +and puts all of its definitions (many of them macros) into the global +namespace. All \*(C+ specific things are put into the \f(CW\*(C`ev\*(C'\fR namespace. +.PP +It should support all the same embedding options as \fIev.h\fR, most notably +\&\f(CW\*(C`EV_MULTIPLICITY\*(C'\fR. +.PP +Here is a list of things available in the \f(CW\*(C`ev\*(C'\fR namespace: +.ie n .IP """ev::READ""\fR, \f(CW""ev::WRITE"" etc." 4 +.el .IP "\f(CWev::READ\fR, \f(CWev::WRITE\fR etc." 4 +.IX Item "ev::READ, ev::WRITE etc." +These are just enum values with the same values as the \f(CW\*(C`EV_READ\*(C'\fR etc. +macros from \fIev.h\fR. +.ie n .IP """ev::tstamp""\fR, \f(CW""ev::now""" 4 +.el .IP "\f(CWev::tstamp\fR, \f(CWev::now\fR" 4 +.IX Item "ev::tstamp, ev::now" +Aliases to the same types/functions as with the \f(CW\*(C`ev_\*(C'\fR prefix. +.ie n .IP """ev::io""\fR, \f(CW""ev::timer""\fR, \f(CW""ev::periodic""\fR, \f(CW""ev::idle""\fR, \f(CW""ev::sig"" etc." 4 +.el .IP "\f(CWev::io\fR, \f(CWev::timer\fR, \f(CWev::periodic\fR, \f(CWev::idle\fR, \f(CWev::sig\fR etc." 4 +.IX Item "ev::io, ev::timer, ev::periodic, ev::idle, ev::sig etc." +For each \f(CW\*(C`ev_TYPE\*(C'\fR watcher in \fIev.h\fR there is a corresponding class of +the same name in the \f(CW\*(C`ev\*(C'\fR namespace, with the exception of \f(CW\*(C`ev_signal\*(C'\fR +which is called \f(CW\*(C`ev::sig\*(C'\fR to avoid clashes with the \f(CW\*(C`signal\*(C'\fR macro +defines by many implementations. +.Sp +All of those classes have these methods: +.RS 4 +.IP "ev::TYPE::TYPE (object *, object::method *)" 4 +.IX Item "ev::TYPE::TYPE (object *, object::method *)" +.PD 0 +.IP "ev::TYPE::TYPE (object *, object::method *, struct ev_loop *)" 4 +.IX Item "ev::TYPE::TYPE (object *, object::method *, struct ev_loop *)" +.IP "ev::TYPE::~TYPE" 4 +.IX Item "ev::TYPE::~TYPE" +.PD +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 +\&\f(CW\*(C`ev_init\*(C'\fR for you, which means you have to call the \f(CW\*(C`set\*(C'\fR method +before starting it. If you do not specify a loop then the constructor +automatically associates the default loop with this watcher. +.Sp +The destructor automatically stops the watcher if it is active. +.IP "w\->set (struct ev_loop *)" 4 +.IX Item "w->set (struct ev_loop *)" +Associates a different \f(CW\*(C`struct ev_loop\*(C'\fR with this watcher. You can only +do this when the watcher is inactive (and not pending either). +.IP "w\->set ([args])" 4 +.IX Item "w->set ([args])" +Basically the same as \f(CW\*(C`ev_TYPE_set\*(C'\fR, with the same args. Must be +called at least once. Unlike the C counterpart, an active watcher gets +automatically stopped and restarted. +.IP "w\->start ()" 4 +.IX Item "w->start ()" +Starts the watcher. Note that there is no \f(CW\*(C`loop\*(C'\fR argument as the +constructor already takes the loop. +.IP "w\->stop ()" 4 +.IX Item "w->stop ()" +Stops the watcher if it is active. Again, no \f(CW\*(C`loop\*(C'\fR argument. +.ie n .IP "w\->again () ""ev::timer""\fR, \f(CW""ev::periodic"" only" 4 +.el .IP "w\->again () \f(CWev::timer\fR, \f(CWev::periodic\fR only" 4 +.IX Item "w->again () ev::timer, ev::periodic only" +For \f(CW\*(C`ev::timer\*(C'\fR and \f(CW\*(C`ev::periodic\*(C'\fR, this invokes the corresponding +\&\f(CW\*(C`ev_TYPE_again\*(C'\fR function. +.ie n .IP "w\->sweep () ""ev::embed"" only" 4 +.el .IP "w\->sweep () \f(CWev::embed\fR only" 4 +.IX Item "w->sweep () ev::embed only" +Invokes \f(CW\*(C`ev_embed_sweep\*(C'\fR. +.RE +.RS 4 +.RE +.PP +Example: Define a class with an \s-1IO\s0 and idle watcher, start one of them in +the constructor. +.PP +.Vb 4 +\& class myclass +\& { +\& ev_io io; void io_cb (ev::io &w, int revents); +\& ev_idle idle void idle_cb (ev::idle &w, int revents); +.Ve +.PP +.Vb 2 +\& myclass (); +\& } +.Ve +.PP +.Vb 6 +\& myclass::myclass (int fd) +\& : io (this, &myclass::io_cb), +\& idle (this, &myclass::idle_cb) +\& { +\& io.start (fd, ev::READ); +\& } +.Ve .SH "AUTHOR" .IX Header "AUTHOR" Marc Lehmann <libev@schmorp.de>. |