diff options
| author | root <root> | 2007-12-07 20:13:08 +0000 |
|---|---|---|
| committer | root <root> | 2007-12-07 20:13:08 +0000 |
| commit | 7f61bc3d979ef53b867172664694f8fcf9e5bdd0 (patch) | |
| tree | f6b6f43698f245e91cb76ba3a1244cb0ce440035 /ev.html | |
| parent | 39ca7b64db757c30ab6f0dc5dad63206f1d5a375 (diff) | |
document c++ callbacks!
Diffstat (limited to 'ev.html')
| -rw-r--r-- | ev.html | 81 |
1 files changed, 62 insertions, 19 deletions
@@ -6,7 +6,7 @@ <meta name="description" content="Pod documentation for libev" /> <meta name="inputfile" content="<standard input>" /> <meta name="outputfile" content="<standard output>" /> - <meta name="created" content="Fri Dec 7 20:23:46 2007" /> + <meta name="created" content="Fri Dec 7 21:13:07 2007" /> <meta name="generator" content="Pod::Xhtml 1.57" /> <link rel="stylesheet" href="http://res.tst.eu/pod.css"/></head> <body> @@ -1738,11 +1738,19 @@ the callback model to a model using method callbacks on objects.</p> <pre> #include <ev++.h> </pre> -<p>(it is not installed by default). This automatically includes <cite>ev.h</cite> -and puts all of its definitions (many of them macros) into the global -namespace. All C++ specific things are put into the <code>ev</code> namespace.</p> -<p>It should support all the same embedding options as <cite>ev.h</cite>, most notably -<code>EV_MULTIPLICITY</code>.</p> +<p>This automatically includes <cite>ev.h</cite> and puts all of its definitions (many +of them macros) into the global namespace. All C++ specific things are +put into the <code>ev</code> namespace. It should support all the same embedding +options as <cite>ev.h</cite>, most notably <code>EV_MULTIPLICITY</code>.</p> +<p>Care has been taken to keep the overhead low. The only data member added +to the C-style watchers is the event loop the watcher is associated with +(or no additional members at all if you disable <code>EV_MULTIPLICITY</code> when +embedding libev).</p> +<p>Currently, functions and static and non-static member functions can be +used as callbacks. Other types should be easy to add as long as they only +need one additional pointer for context. If you need support for other +types of functors please contact the author (preferably after implementing +it).</p> <p>Here is a list of things available in the <code>ev</code> namespace:</p> <dl> <dt><code>ev::READ</code>, <code>ev::WRITE</code> etc.</dt> @@ -1763,17 +1771,50 @@ defines by many implementations.</p> <p>All of those classes have these methods:</p> <p> <dl> - <dt>ev::TYPE::TYPE (object *, object::method *)</dt> - <dt>ev::TYPE::TYPE (object *, object::method *, struct ev_loop *)</dt> + <dt>ev::TYPE::TYPE ()</dt> + <dt>ev::TYPE::TYPE (struct ev_loop *)</dt> <dt>ev::TYPE::~TYPE</dt> <dd> - <p>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 -<code>ev_init</code> for you, which means you have to call the <code>set</code> method -before starting it. If you do not specify a loop then the constructor -automatically associates the default loop with this watcher.</p> + <p>The constructor (optionally) takes an event loop to associate the watcher +with. If it is omitted, it will use <code>EV_DEFAULT</code>.</p> + <p>The constructor calls <code>ev_init</code> for you, which means you have to call the +<code>set</code> method before starting it.</p> + <p>It will not set a callback, however: You have to call the templated <code>set</code> +method to set a callback before you can start the watcher.</p> + <p>(The reason why you have to use a method is a limitation in C++ which does +not allow explicit template arguments for constructors).</p> <p>The destructor automatically stops the watcher if it is active.</p> </dd> + <dt>w->set<class, &class::method> (object *)</dt> + <dd> + <p>This method sets the callback method to call. The method has to have a +signature of <code>void (*)(ev_TYPE &, int)</code>, it receives the watcher as +first argument and the <code>revents</code> as second. The object must be given as +parameter and is stored in the <code>data</code> member of the watcher.</p> + <p>This method synthesizes efficient thunking code to call your method from +the C callback that libev requires. If your compiler can inline your +callback (i.e. it is visible to it at the place of the <code>set</code> call and +your compiler is good :), then the method will be fully inlined into the +thunking function, making it as fast as a direct C callback.</p> + <p>Example: simple class declaration and watcher initialisation</p> +<pre> struct myclass + { + void io_cb (ev::io &w, int revents) { } + } + + myclass obj; + ev::io iow; + iow.set <myclass, &myclass::io_cb> (&obj); + +</pre> + </dd> + <dt>w->set (void (*function)(watcher &w, int), void *data = 0)</dt> + <dd> + <p>Also sets a callback, but uses a static method or plain function as +callback. The optional <code>data</code> argument will be stored in the watcher's +<code>data</code> member and is free for you to use.</p> + <p>See the method-<code>set</code> above for more details.</p> + </dd> <dt>w->set (struct ev_loop *)</dt> <dd> <p>Associates a different <code>struct ev_loop</code> with this watcher. You can only @@ -1782,13 +1823,14 @@ do this when the watcher is inactive (and not pending either).</p> <dt>w->set ([args])</dt> <dd> <p>Basically the same as <code>ev_TYPE_set</code>, with the same args. Must be -called at least once. Unlike the C counterpart, an active watcher gets -automatically stopped and restarted.</p> +called at least once. Unlike the C counterpart, an active watcher gets +automatically stopped and restarted when reconfiguring it with this +method.</p> </dd> <dt>w->start ()</dt> <dd> - <p>Starts the watcher. Note that there is no <code>loop</code> argument as the -constructor already takes the loop.</p> + <p>Starts the watcher. Note that there is no <code>loop</code> argument, as the +constructor already stores the event loop.</p> </dd> <dt>w->stop ()</dt> <dd> @@ -1822,9 +1864,10 @@ the constructor.</p> } myclass::myclass (int fd) - : io (this, &myclass::io_cb), - idle (this, &myclass::idle_cb) { + io .set <myclass, &myclass::io_cb > (this); + idle.set <myclass, &myclass::idle_cb> (this); + io.start (fd, ev::READ); } |