<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <link rel="stylesheet" href="style.css" type="text/css"> <meta content="text/html; charset=iso-8859-1" http-equiv="Content-Type"> <link rel="Start" href="index.html"> <link rel="previous" href="Dynlink.html"> <link rel="next" href="Filename.html"> <link rel="Up" href="index.html"> <link title="Index of types" rel=Appendix href="index_types.html"> <link title="Index of exceptions" rel=Appendix href="index_exceptions.html"> <link title="Index of values" rel=Appendix href="index_values.html"> <link title="Index of modules" rel=Appendix href="index_modules.html"> <link title="Index of module types" rel=Appendix href="index_module_types.html"> <link title="Arg" rel="Chapter" href="Arg.html"> <link title="Arith_status" rel="Chapter" href="Arith_status.html"> <link title="Array" rel="Chapter" href="Array.html"> <link title="ArrayLabels" rel="Chapter" href="ArrayLabels.html"> <link title="Big_int" rel="Chapter" href="Big_int.html"> <link title="Bigarray" rel="Chapter" href="Bigarray.html"> <link title="Buffer" rel="Chapter" href="Buffer.html"> <link title="Callback" rel="Chapter" href="Callback.html"> <link title="CamlinternalLazy" rel="Chapter" href="CamlinternalLazy.html"> <link title="CamlinternalMod" rel="Chapter" href="CamlinternalMod.html"> <link title="CamlinternalOO" rel="Chapter" href="CamlinternalOO.html"> <link title="Char" rel="Chapter" href="Char.html"> <link title="Complex" rel="Chapter" href="Complex.html"> <link title="Condition" rel="Chapter" href="Condition.html"> <link title="Digest" rel="Chapter" href="Digest.html"> <link title="Dynlink" rel="Chapter" href="Dynlink.html"> <link title="Event" rel="Chapter" href="Event.html"> <link title="Filename" rel="Chapter" href="Filename.html"> <link title="Format" rel="Chapter" href="Format.html"> <link title="Gc" rel="Chapter" href="Gc.html"> <link title="Genlex" rel="Chapter" href="Genlex.html"> <link title="Graphics" rel="Chapter" href="Graphics.html"> <link title="GraphicsX11" rel="Chapter" href="GraphicsX11.html"> <link title="Hashtbl" rel="Chapter" href="Hashtbl.html"> <link title="Int32" rel="Chapter" href="Int32.html"> <link title="Int64" rel="Chapter" href="Int64.html"> <link title="Lazy" rel="Chapter" href="Lazy.html"> <link title="Lexing" rel="Chapter" href="Lexing.html"> <link title="List" rel="Chapter" href="List.html"> <link title="ListLabels" rel="Chapter" href="ListLabels.html"> <link title="Map" rel="Chapter" href="Map.html"> <link title="Marshal" rel="Chapter" href="Marshal.html"> <link title="MoreLabels" rel="Chapter" href="MoreLabels.html"> <link title="Mutex" rel="Chapter" href="Mutex.html"> <link title="Nativeint" rel="Chapter" href="Nativeint.html"> <link title="Num" rel="Chapter" href="Num.html"> <link title="Obj" rel="Chapter" href="Obj.html"> <link title="Oo" rel="Chapter" href="Oo.html"> <link title="Parsing" rel="Chapter" href="Parsing.html"> <link title="Pervasives" rel="Chapter" href="Pervasives.html"> <link title="Printexc" rel="Chapter" href="Printexc.html"> <link title="Printf" rel="Chapter" href="Printf.html"> <link title="Queue" rel="Chapter" href="Queue.html"> <link title="Random" rel="Chapter" href="Random.html"> <link title="Ratio" rel="Chapter" href="Ratio.html"> <link title="Scanf" rel="Chapter" href="Scanf.html"> <link title="Set" rel="Chapter" href="Set.html"> <link title="Sort" rel="Chapter" href="Sort.html"> <link title="Stack" rel="Chapter" href="Stack.html"> <link title="StdLabels" rel="Chapter" href="StdLabels.html"> <link title="Str" rel="Chapter" href="Str.html"> <link title="Stream" rel="Chapter" href="Stream.html"> <link title="String" rel="Chapter" href="String.html"> <link title="StringLabels" rel="Chapter" href="StringLabels.html"> <link title="Sys" rel="Chapter" href="Sys.html"> <link title="Thread" rel="Chapter" href="Thread.html"> <link title="ThreadUnix" rel="Chapter" href="ThreadUnix.html"> <link title="Tk" rel="Chapter" href="Tk.html"> <link title="Unix" rel="Chapter" href="Unix.html"> <link title="UnixLabels" rel="Chapter" href="UnixLabels.html"> <link title="Weak" rel="Chapter" href="Weak.html"><title>Event</title> </head> <body> <div class="navbar"><a class="pre" href="Dynlink.html" title="Dynlink">Previous</a> <a class="up" href="index.html" title="Index">Up</a> <a class="post" href="Filename.html" title="Filename">Next</a> </div> <h1>Module <a href="type_Event.html">Event</a></h1> <pre><span class="keyword">module</span> Event: <code class="code"><span class="keyword">sig</span></code> <a href="Event.html">..</a> <code class="code"><span class="keyword">end</span></code></pre><div class="info module top"> First-class synchronous communication. <p> This module implements synchronous inter-thread communications over channels. As in John Reppy's Concurrent ML system, the communication events are first-class values: they can be built and combined independently before being offered for communication.<br> </div> <hr width="100%"> <pre><span id="TYPEchannel"><span class="keyword">type</span> <code class="type">'a</code> channel</span> </pre> <div class="info "> The type of communication channels carrying values of type <code class="code"><span class="keywordsign">'</span>a</code>.<br> </div> <pre><span id="VALnew_channel"><span class="keyword">val</span> new_channel</span> : <code class="type">unit -> 'a <a href="Event.html#TYPEchannel">channel</a></code></pre><div class="info "> Return a new channel.<br> </div> <pre><span id="TYPEevent"><span class="keyword">type</span> <code class="type">+'a</code> event</span> </pre> <div class="info "> The type of communication events returning a result of type <code class="code"><span class="keywordsign">'</span>a</code>.<br> </div> <pre><span id="VALsend"><span class="keyword">val</span> send</span> : <code class="type">'a <a href="Event.html#TYPEchannel">channel</a> -> 'a -> unit <a href="Event.html#TYPEevent">event</a></code></pre><div class="info "> <code class="code">send ch v</code> returns the event consisting in sending the value <code class="code">v</code> over the channel <code class="code">ch</code>. The result value of this event is <code class="code">()</code>.<br> </div> <pre><span id="VALreceive"><span class="keyword">val</span> receive</span> : <code class="type">'a <a href="Event.html#TYPEchannel">channel</a> -> 'a <a href="Event.html#TYPEevent">event</a></code></pre><div class="info "> <code class="code">receive ch</code> returns the event consisting in receiving a value from the channel <code class="code">ch</code>. The result value of this event is the value received.<br> </div> <pre><span id="VALalways"><span class="keyword">val</span> always</span> : <code class="type">'a -> 'a <a href="Event.html#TYPEevent">event</a></code></pre><div class="info "> <code class="code">always v</code> returns an event that is always ready for synchronization. The result value of this event is <code class="code">v</code>.<br> </div> <pre><span id="VALchoose"><span class="keyword">val</span> choose</span> : <code class="type">'a <a href="Event.html#TYPEevent">event</a> list -> 'a <a href="Event.html#TYPEevent">event</a></code></pre><div class="info "> <code class="code">choose evl</code> returns the event that is the alternative of all the events in the list <code class="code">evl</code>.<br> </div> <pre><span id="VALwrap"><span class="keyword">val</span> wrap</span> : <code class="type">'a <a href="Event.html#TYPEevent">event</a> -> ('a -> 'b) -> 'b <a href="Event.html#TYPEevent">event</a></code></pre><div class="info "> <code class="code">wrap ev fn</code> returns the event that performs the same communications as <code class="code">ev</code>, then applies the post-processing function <code class="code">fn</code> on the return value.<br> </div> <pre><span id="VALwrap_abort"><span class="keyword">val</span> wrap_abort</span> : <code class="type">'a <a href="Event.html#TYPEevent">event</a> -> (unit -> unit) -> 'a <a href="Event.html#TYPEevent">event</a></code></pre><div class="info "> <code class="code">wrap_abort ev fn</code> returns the event that performs the same communications as <code class="code">ev</code>, but if it is not selected the function <code class="code">fn</code> is called after the synchronization.<br> </div> <pre><span id="VALguard"><span class="keyword">val</span> guard</span> : <code class="type">(unit -> 'a <a href="Event.html#TYPEevent">event</a>) -> 'a <a href="Event.html#TYPEevent">event</a></code></pre><div class="info "> <code class="code">guard fn</code> returns the event that, when synchronized, computes <code class="code">fn()</code> and behaves as the resulting event. This allows to compute events with side-effects at the time of the synchronization operation.<br> </div> <pre><span id="VALsync"><span class="keyword">val</span> sync</span> : <code class="type">'a <a href="Event.html#TYPEevent">event</a> -> 'a</code></pre><div class="info "> 'Synchronize' on an event: offer all the communication possibilities specified in the event to the outside world, and block until one of the communications succeed. The result value of that communication is returned.<br> </div> <pre><span id="VALselect"><span class="keyword">val</span> select</span> : <code class="type">'a <a href="Event.html#TYPEevent">event</a> list -> 'a</code></pre><div class="info "> 'Synchronize' on an alternative of events. <code class="code">select evl</code> is shorthand for <code class="code">sync(choose evl)</code>.<br> </div> <pre><span id="VALpoll"><span class="keyword">val</span> poll</span> : <code class="type">'a <a href="Event.html#TYPEevent">event</a> -> 'a option</code></pre><div class="info "> Non-blocking version of <a href="Event.html#VALsync"><code class="code"><span class="constructor">Event</span>.sync</code></a>: offer all the communication possibilities specified in the event to the outside world, and if one can take place immediately, perform it and return <code class="code"><span class="constructor">Some</span> r</code> where <code class="code">r</code> is the result value of that communication. Otherwise, return <code class="code"><span class="constructor">None</span></code> without blocking.<br> </div> </body></html>