49 lines
52 KiB
HTML
49 lines
52 KiB
HTML
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
|
|
<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"/><title>4 Drivers</title><link rel="stylesheet" type="text/css" href="scribble.css" title="default"/><link rel="stylesheet" type="text/css" href="racket.css" title="default"/><link rel="stylesheet" type="text/css" href="manual-style.css" title="default"/><link rel="stylesheet" type="text/css" href="manual-racket.css" title="default"/><script type="text/javascript" src="scribble-common.js"></script><!--[if IE 6]><style type="text/css">.SIEHidden { overflow: hidden; }</style><![endif]--></head><body id="scribble-racket-lang-org"><div class="tocset"><div class="tocview"><div class="tocviewlist tocviewlisttopspace"><div class="tocviewtitle"><table cellspacing="0" cellpadding="0"><tr><td style="width: 1em;"><a href="javascript:void(0);" title="Expand/Collapse" class="tocviewtoggle" onclick="TocviewToggle(this,"tocview_0");">▼</a></td><td></td><td><a href="index.html" class="tocviewlink" data-pltdoc="x">Marketplace:<span class="mywbr"> </span> Network-<wbr></wbr>Aware Programming</a></td></tr></table></div><div class="tocviewsublisttop" style="display: block;" id="tocview_0"><table cellspacing="0" cellpadding="0"><tr><td align="right">1 </td><td><a href="Concepts.html" class="tocviewlink" data-pltdoc="x">Concepts</a></td></tr><tr><td align="right">2 </td><td><a href="high-level-interface.html" class="tocviewlink" data-pltdoc="x">High-<wbr></wbr>level interface</a></td></tr><tr><td align="right">3 </td><td><a href="low-level-interface.html" class="tocviewlink" data-pltdoc="x">Low-<wbr></wbr>level interface</a></td></tr><tr><td align="right">4 </td><td><a href="Drivers.html" class="tocviewselflink" data-pltdoc="x">Drivers</a></td></tr><tr><td align="right">5 </td><td><a href="Management_and_Monitoring.html" class="tocviewlink" data-pltdoc="x">Management and Monitoring</a></td></tr><tr><td align="right">6 </td><td><a href="Examples.html" class="tocviewlink" data-pltdoc="x">Examples</a></td></tr></table></div></div><div class="tocviewlist"><table cellspacing="0" cellpadding="0"><tr><td style="width: 1em;"><a href="javascript:void(0);" title="Expand/Collapse" class="tocviewtoggle" onclick="TocviewToggle(this,"tocview_1");">►</a></td><td>4 </td><td><a href="Drivers.html" class="tocviewselflink" data-pltdoc="x">Drivers</a></td></tr></table><div class="tocviewsublistbottom" style="display: none;" id="tocview_1"><table cellspacing="0" cellpadding="0"><tr><td align="right">4.1 </td><td><a href="Drivers.html#%28part._event-relay%29" class="tocviewlink" data-pltdoc="x">event-<wbr></wbr>relay</a></td></tr><tr><td align="right">4.2 </td><td><a href="Drivers.html#%28part._tcp-bare%29" class="tocviewlink" data-pltdoc="x">tcp-<wbr></wbr>bare</a></td></tr><tr><td align="right">4.3 </td><td><a href="Drivers.html#%28part._timer__typed_and_untyped_%29" class="tocviewlink" data-pltdoc="x">timer (typed and untyped)</a></td></tr><tr><td align="right">4.4 </td><td><a href="Drivers.html#%28part._udp__typed_and_untyped_%29" class="tocviewlink" data-pltdoc="x">udp (typed and untyped)</a></td></tr></table></div></div></div><div class="tocsub"><div class="tocsubtitle">On this page:</div><table class="tocsublist" cellspacing="0"><tr><td><span class="tocsublinknumber">4.1<tt> </tt></span><a href="#%28part._event-relay%29" class="tocsubseclink" data-pltdoc="x">event-<wbr></wbr>relay</a></td></tr><tr><td><a href="#%28def._%28%28lib._marketplace%2Fdrivers%2Fevent-relay..rkt%29._event-relay%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">event-<wbr></wbr>relay</span></span></a></td></tr><tr><td><span class="tocsublinknumber">4.2<tt> </tt></span><a href="#%28part._tcp-bare%29" class="tocsubseclink" data-pltdoc="x">tcp-<wbr></wbr>bare</a></td></tr><tr><td><a href="#%28def._%28%28lib._marketplace%2Fdrivers%2Ftcp-bare..rkt%29._tcp-driver%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">tcp-<wbr></wbr>driver</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._marketplace%2Fdrivers%2Ftcp-bare..rkt%29._tcp%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">tcp</span></span></a></td></tr><tr><td><span class="tocsublinknumber">4.2.1<tt> </tt></span><a href="#%28part._.T.C.P_channels%29" class="tocsubseclink" data-pltdoc="x">TCP channels</a></td></tr><tr><td><a href="#%28def._%28%28lib._marketplace%2Fdrivers%2Ftcp-bare..rkt%29._tcp-channel%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">tcp-<wbr></wbr>channel</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._marketplace%2Fdrivers%2Ftcp-bare..rkt%29._.Tcp.Sub.Packet%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym">Tcp<span class="mywbr"> </span>Sub<span class="mywbr"> </span>Packet</span></a></td></tr><tr><td><span class="tocsublinknumber">4.2.2<tt> </tt></span><a href="#%28part._.T.C.P_addresses%29" class="tocsubseclink" data-pltdoc="x">TCP addresses</a></td></tr><tr><td><a href="#%28def._%28%28lib._marketplace%2Fdrivers%2Ftcp-bare..rkt%29._.Tcp.Address%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym">Tcp<span class="mywbr"> </span>Address</span></a></td></tr><tr><td><a href="#%28def._%28%28lib._marketplace%2Fdrivers%2Ftcp-bare..rkt%29._tcp-address%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">tcp-<wbr></wbr>address</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._marketplace%2Fdrivers%2Ftcp-bare..rkt%29._tcp-handle%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">tcp-<wbr></wbr>handle</span></span></a></td></tr><tr><td><a href="#%28def._%28%28lib._marketplace%2Fdrivers%2Ftcp-bare..rkt%29._tcp-listener%29%29" class="tocsubnonseclink" data-pltdoc="x"><span class="RktSym"><span class="RktValLink">tcp-<wbr></wbr>listener</span></span></a></td></tr><tr><td><span class="tocsublinknumber">4.2.3<tt> </tt></span><a href="#%28part._.Opening_an_outbound_connection%29" class="tocsubseclink" data-pltdoc="x">Opening an outbound connection</a></td></tr><tr><td><span class="tocsublinknumber">4.2.4<tt> </tt></span><a href="#%28part._.Accepting_inbound_connections%29" class="tocsubseclink" data-pltdoc="x">Accepting inbound connections</a></td></tr><tr><td><span class="tocsublinknumber">4.2.5<tt> </tt></span><a href="#%28part._.Receiving_data%29" class="tocsubseclink" data-pltdoc="x">Receiving data</a></td></tr><tr><td><span class="tocsublinknumber">4.2.6<tt> </tt></span><a href="#%28part._.Sending_data%29" class="tocsubseclink" data-pltdoc="x">Sending data</a></td></tr><tr><td><span class="tocsublinknumber">4.3<tt> </tt></span><a href="#%28part._timer__typed_and_untyped_%29" class="tocsubseclink" data-pltdoc="x">timer (typed and untyped)</a></td></tr><tr><td><span class="tocsublinknumber">4.4<tt> </tt></span><a href="#%28part._udp__typed_and_untyped_%29" class="tocsubseclink" data-pltdoc="x">udp (typed and untyped)</a></td></tr></table></div></div><div class="maincolumn"><div class="main"><div class="versionbox"><span class="version">6.0.0.1</span></div><div class="navsettop"><span class="navleft"> </span><span class="navright"> <a href="low-level-interface.html" title="backward to "3 Low-level interface"" data-pltdoc="x">← prev</a> <a href="index.html" title="up to "Marketplace: Network-Aware Programming"" data-pltdoc="x">up</a> <a href="Management_and_Monitoring.html" title="forward to "5 Management and Monitoring"" data-pltdoc="x">next →</a></span> </div><h3>4<tt> </tt><a name="(part._.Drivers)"></a>Drivers</h3><h4>4.1<tt> </tt><a name="(part._event-relay)"></a><a name="(mod-path._marketplace/drivers/event-relay)"></a>event-relay</h4><p><div class="SIntrapara"><table cellspacing="0" class="defmodule"><tr><td align="left" colspan="2"><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="http://docs.racket-lang.org/reference/require.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._require%29%29" class="RktStxLink" data-pltdoc="x">require</a></span><span class="stt"> </span><a href="Drivers.html#%28mod-path._marketplace%2Fdrivers%2Fevent-relay%29" class="RktModLink" data-pltdoc="x"><span class="RktSym">marketplace/drivers/event-relay</span></a><span class="RktPn">)</span></td></tr><tr><td align="left"> </td><td align="right"><span class="RpackageSpec"><span class="Smaller"> package:</span> <span class="stt">marketplace</span></span></td></tr></table></div><div class="SIntrapara"><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>procedure</p></div></div><p class="RForeground"><span class="RktPn">(</span><a name="(def._((lib._marketplace/drivers/event-relay..rkt)._event-relay))"></a><span title="Provided from: marketplace/drivers/event-relay"><span class="RktSym"><a href="Drivers.html#%28def._%28%28lib._marketplace%2Fdrivers%2Fevent-relay..rkt%29._event-relay%29%29" class="RktValDef RktValLink" data-pltdoc="x">event-relay</a></span></span><span class="hspace"> </span><span class="RktVar">self-id</span><span class="RktPn">)</span><span class="hspace"> </span>→<span class="hspace"> </span><span class="RktSym"><a href="low-level-interface.html#%28def._%28%28lib._marketplace%2Fmain..rkt%29._.Spawn%29%29" class="RktValLink" data-pltdoc="x">Spawn</a></span></p></blockquote></td></tr><tr><td><span class="hspace"> </span><span class="RktVar">self-id</span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktSym"><a href="http://docs.racket-lang.org/ts-reference/type-ref.html#%28form._%28%28lib._typed-racket%2Fbase-env%2Fbase-types..rkt%29._.Symbol%29%29" class="RktStxLink" data-pltdoc="x">Symbol</a></span></td></tr></table></blockquote></div><div class="SIntrapara">Lets processes in some nested VM interact with the outside
|
|
world using <span class="RktSym"><a href="high-level-interface.html#%28form._%28%28lib._marketplace%2Fsugar-untyped..rkt%29._ground-vm%29%29" class="RktStxLink" data-pltdoc="x">ground-vm</a></span>-level event-based subscriptions.</div></p></div><div class="SIntrapara">Returns a <span class="RktSym"><a href="high-level-interface.html#%28form._%28%28lib._marketplace%2Fsugar-untyped..rkt%29._spawn%29%29" class="RktStxLink" data-pltdoc="x">spawn</a></span> which starts an event-relay process with
|
|
debug-name <span class="RktVal">`</span><span class="RktVal">(</span><span class="RktVal">event-relay</span><span class="stt"> </span><span class="RktRdr">,</span><span class="RktVar">self-id</span><span class="RktVal">)</span>.</div><div class="SIntrapara">The relay process observes subscriptions matching the topic-pattern
|
|
<span class="RktPn">(</span><span class="RktSym"><a href="http://docs.racket-lang.org/reference/pairs.html#%28def._%28%28quote._~23~25kernel%29._cons%29%29" class="RktValLink" data-pltdoc="x">cons</a></span><span class="stt"> </span><span class="RktPn">(</span><span class="RktSym"><a href="low-level-interface.html#%28def._%28%28lib._marketplace%2Fsugar-untyped..rkt%29._~3f%29%29" class="RktValLink" data-pltdoc="x">?</a></span><span class="stt"> </span><span class="RktSym"><a href="http://docs.racket-lang.org/reference/sync.html#%28def._%28%28quote._~23~25kernel%29._evt~3f%29%29" class="RktValLink" data-pltdoc="x">evt?</a></span><span class="RktPn">)</span><span class="stt"> </span><span class="RktSym"><a href="http://docs.racket-lang.org/reference/stx-patterns.html#%28form._%28%28lib._racket%2Fprivate%2Fstxcase-scheme..rkt%29.__%29%29" class="RktStxLink" data-pltdoc="x">_</a></span><span class="RktPn">)</span>, and when one appears, constructs an
|
|
analogous one using <span class="RktSym"><a href="high-level-interface.html#%28def._%28%28lib._marketplace%2Fsugar-untyped..rkt%29._at-meta-level%29%29" class="RktValLink" data-pltdoc="x">at-meta-level</a></span> to connect to the next VM
|
|
down the stack. Messages from the meta-level will be relayed up to the
|
|
current level. When the subscription disappears, the relay withdraws
|
|
the subscription at the meta-level as well.</div></p><h4>4.2<tt> </tt><a name="(part._tcp-bare)"></a><a name="(mod-path._marketplace/drivers/tcp-bare)"></a>tcp-bare</h4><p><div class="SIntrapara"><table cellspacing="0" class="defmodule"><tr><td align="left" colspan="2"><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="http://docs.racket-lang.org/reference/require.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._require%29%29" class="RktStxLink" data-pltdoc="x">require</a></span><span class="stt"> </span><a href="Drivers.html#%28mod-path._marketplace%2Fdrivers%2Ftcp-bare%29" class="RktModLink" data-pltdoc="x"><span class="RktSym">marketplace/drivers/tcp-bare</span></a><span class="RktPn">)</span></td></tr><tr><td align="left"> </td><td align="right"><span class="RpackageSpec"><span class="Smaller"> package:</span> <span class="stt">marketplace</span></span></td></tr></table></div><div class="SIntrapara">This module is only available for use by untyped Racket processes. It
|
|
is included by default in programs using <span class="stt">#lang marketplace</span>; see
|
|
<a href="high-level-interface.html#%28part._hashlang-variations%29" data-pltdoc="x">Using <span class="stt">#lang marketplace</span> and friends</a> for information on other language
|
|
variants.</div><div class="SIntrapara"><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>procedure</p></div></div><p class="RForeground"><span class="RktPn">(</span><a name="(def._((lib._marketplace/drivers/tcp-bare..rkt)._tcp-driver))"></a><span title="Provided from: marketplace/drivers/tcp-bare"><span class="RktSym"><a href="Drivers.html#%28def._%28%28lib._marketplace%2Fdrivers%2Ftcp-bare..rkt%29._tcp-driver%29%29" class="RktValDef RktValLink" data-pltdoc="x">tcp-driver</a></span></span><span class="RktPn"></span><span class="RktPn">)</span><span class="hspace"> </span>→<span class="hspace"> </span><span class="RktSym"><a href="low-level-interface.html#%28def._%28%28lib._marketplace%2Fmain..rkt%29._.Spawn%29%29" class="RktValLink" data-pltdoc="x">Spawn</a></span></p></blockquote></td></tr></table></blockquote></div><div class="SIntrapara">Returns a <span class="RktSym"><a href="high-level-interface.html#%28form._%28%28lib._marketplace%2Fsugar-untyped..rkt%29._spawn%29%29" class="RktStxLink" data-pltdoc="x">spawn</a></span> action which starts a TCP driver. The TCP
|
|
driver should run either directly in a ground VM, or in a nested VM
|
|
with a running <span class="RktSym"><a href="Drivers.html#%28def._%28%28lib._marketplace%2Fdrivers%2Fevent-relay..rkt%29._event-relay%29%29" class="RktValLink" data-pltdoc="x">event-relay</a></span>.</div></p></div><div class="SIntrapara"><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>value</p></div></div><p class="RForeground"><a name="(def._((lib._marketplace/drivers/tcp-bare..rkt)._tcp))"></a><span title="Provided from: marketplace/drivers/tcp-bare"><span class="RktSym"><a href="Drivers.html#%28def._%28%28lib._marketplace%2Fdrivers%2Ftcp-bare..rkt%29._tcp%29%29" class="RktValDef RktValLink" data-pltdoc="x">tcp</a></span></span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktSym"><a href="low-level-interface.html#%28def._%28%28lib._marketplace%2Fmain..rkt%29._.Spawn%29%29" class="RktValLink" data-pltdoc="x">Spawn</a></span></p></blockquote></td></tr></table></blockquote></div><div class="SIntrapara">A pre-made <span class="RktSym"><a href="high-level-interface.html#%28form._%28%28lib._marketplace%2Fsugar-untyped..rkt%29._spawn%29%29" class="RktStxLink" data-pltdoc="x">spawn</a></span> action equivalent to <span class="RktPn">(</span><span class="RktSym"><a href="Drivers.html#%28def._%28%28lib._marketplace%2Fdrivers%2Ftcp-bare..rkt%29._tcp-driver%29%29" class="RktValLink" data-pltdoc="x">tcp-driver</a></span><span class="RktPn">)</span>.</div></p></div></p><h5>4.2.1<tt> </tt><a name="(part._.T.C.P_channels)"></a>TCP channels</h5><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>struct</p></div></div><table cellspacing="0" class="RForeground"><tr><td><span class="RktPn">(</span><span class="RktSym"><a href="http://docs.racket-lang.org/reference/define-struct.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._struct%29%29" class="RktStxLink" data-pltdoc="x">struct</a></span></td><td><span class="hspace"> </span></td><td><a name="(def._((lib._marketplace/drivers/tcp-bare..rkt)._tcp-channel-subpacket))"></a><a name="(def._((lib._marketplace/drivers/tcp-bare..rkt)._tcp-channel-destination))"></a><a name="(def._((lib._marketplace/drivers/tcp-bare..rkt)._tcp-channel-source))"></a><a name="(def._((lib._marketplace/drivers/tcp-bare..rkt)._tcp-channel~3f))"></a><a name="(def._((lib._marketplace/drivers/tcp-bare..rkt)._struct~3atcp-channel))"></a><a name="(def._((lib._marketplace/drivers/tcp-bare..rkt)._tcp-channel))"></a><span title="Provided from: marketplace/drivers/tcp-bare"><span class="RktSym"><a href="Drivers.html#%28def._%28%28lib._marketplace%2Fdrivers%2Ftcp-bare..rkt%29._tcp-channel%29%29" class="RktValDef RktValLink" data-pltdoc="x">tcp-channel</a></span></span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym">source</span><span class="stt"> </span><span class="RktSym">destination</span><span class="stt"> </span><span class="RktSym">subpacket</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace"> </span></td><td><span class="hspace"> </span></td><td><span class="RktPn">#:prefab</span><span class="RktPn">)</span></td></tr></table></blockquote></td></tr><tr><td><span class="hspace"> </span><span class="RktSym">source</span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktSym">TcpAddress</span></td></tr><tr><td><span class="hspace"> </span><span class="RktSym">destination</span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktSym">TcpAddress</span></td></tr><tr><td><span class="hspace"> </span><span class="RktSym">subpacket</span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktSym">TcpSubPacket</span></td></tr></table></blockquote></div><div class="SIntrapara">A TCP channel represents a section of a unidirectional TCP flow
|
|
appearing on our local "subnet" of the full TCP network, complete with
|
|
source, destination and subpacket. Each TCP connection has two such
|
|
flows: one inbound (remote-to-local) bytestream, and one outbound
|
|
(local-to-remote) bytestream.</div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>type</p></div></div><p class="RForeground"><a name="(def._((lib._marketplace/drivers/tcp-bare..rkt)._.Tcp.Sub.Packet))"></a><span title="Provided from: marketplace/drivers/tcp-bare"><span class="RktSym"><span class="RktSymDef RktSym">TcpSubPacket</span></span></span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym">or/c</span><span class="hspace"> </span><span class="RktSym"><a href="http://docs.racket-lang.org/reference/port-ops.html#%28def._%28%28quote._~23~25kernel%29._eof-object~3f%29%29" class="RktValLink" data-pltdoc="x">eof-object?</a></span><span class="hspace"> </span><span class="RktSym"><a href="http://docs.racket-lang.org/reference/bytestrings.html#%28def._%28%28quote._~23~25kernel%29._bytes~3f%29%29" class="RktValLink" data-pltdoc="x">bytes?</a></span><span class="RktPn">)</span></p></blockquote></td></tr></table></blockquote></div><div class="SIntrapara">Packets carried by <span class="RktSym"><a href="Drivers.html#%28def._%28%28lib._marketplace%2Fdrivers%2Ftcp-bare..rkt%29._tcp-channel%29%29" class="RktValLink" data-pltdoc="x">tcp-channel</a></span> structures are either
|
|
end-of-file objects or raw binary data represented as Racket byte
|
|
vectors.</div></p><h5>4.2.2<tt> </tt><a name="(part._.T.C.P_addresses)"></a>TCP addresses</h5><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>type</p></div></div><p class="RForeground"><a name="(def._((lib._marketplace/drivers/tcp-bare..rkt)._.Tcp.Address))"></a><span title="Provided from: marketplace/drivers/tcp-bare"><span class="RktSym"><span class="RktSymDef RktSym">TcpAddress</span></span></span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym">or/c</span><span class="hspace"> </span><span class="RktSym"><a href="Drivers.html#%28def._%28%28lib._marketplace%2Fdrivers%2Ftcp-bare..rkt%29._tcp-address~3f%29%29" class="RktValLink" data-pltdoc="x">tcp-address?</a></span><span class="hspace"> </span><span class="RktSym"><a href="Drivers.html#%28def._%28%28lib._marketplace%2Fdrivers%2Ftcp-bare..rkt%29._tcp-handle~3f%29%29" class="RktValLink" data-pltdoc="x">tcp-handle?</a></span><span class="hspace"> </span><span class="RktSym"><a href="Drivers.html#%28def._%28%28lib._marketplace%2Fdrivers%2Ftcp-bare..rkt%29._tcp-listener~3f%29%29" class="RktValLink" data-pltdoc="x">tcp-listener?</a></span><span class="RktPn">)</span></p></blockquote></td></tr></table></blockquote></div><div class="SIntrapara">A TCP address describes one end of a TCP connection. It can be either</div></p><ul><li><p>a <span class="RktSym"><a href="Drivers.html#%28def._%28%28lib._marketplace%2Fdrivers%2Ftcp-bare..rkt%29._tcp-address%29%29" class="RktValLink" data-pltdoc="x">tcp-address</a></span>, representing a remote socket;</p></li><li><p>a <span class="RktSym"><a href="Drivers.html#%28def._%28%28lib._marketplace%2Fdrivers%2Ftcp-bare..rkt%29._tcp-handle%29%29" class="RktValLink" data-pltdoc="x">tcp-handle</a></span>, representing a local socket on a kernel-assigned port; or</p></li><li><p>a <span class="RktSym"><a href="Drivers.html#%28def._%28%28lib._marketplace%2Fdrivers%2Ftcp-bare..rkt%29._tcp-listener%29%29" class="RktValLink" data-pltdoc="x">tcp-listener</a></span>, representing a local socket on a user-assigned port.</p></li></ul><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>struct</p></div></div><table cellspacing="0" class="RForeground"><tr><td><span class="RktPn">(</span><span class="RktSym"><a href="http://docs.racket-lang.org/reference/define-struct.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._struct%29%29" class="RktStxLink" data-pltdoc="x">struct</a></span></td><td><span class="hspace"> </span></td><td><a name="(def._((lib._marketplace/drivers/tcp-bare..rkt)._tcp-address-port))"></a><a name="(def._((lib._marketplace/drivers/tcp-bare..rkt)._tcp-address-host))"></a><a name="(def._((lib._marketplace/drivers/tcp-bare..rkt)._tcp-address~3f))"></a><a name="(def._((lib._marketplace/drivers/tcp-bare..rkt)._struct~3atcp-address))"></a><a name="(def._((lib._marketplace/drivers/tcp-bare..rkt)._tcp-address))"></a><span title="Provided from: marketplace/drivers/tcp-bare"><span class="RktSym"><a href="Drivers.html#%28def._%28%28lib._marketplace%2Fdrivers%2Ftcp-bare..rkt%29._tcp-address%29%29" class="RktValDef RktValLink" data-pltdoc="x">tcp-address</a></span></span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym">host</span><span class="stt"> </span><span class="RktSym">port</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace"> </span></td><td><span class="hspace"> </span></td><td><span class="RktPn">#:prefab</span><span class="RktPn">)</span></td></tr></table></blockquote></td></tr><tr><td><span class="hspace"> </span><span class="RktSym">host</span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktSym"><a href="http://docs.racket-lang.org/reference/strings.html#%28def._%28%28quote._~23~25kernel%29._string~3f%29%29" class="RktValLink" data-pltdoc="x">string?</a></span></td></tr><tr><td><span class="hspace"> </span><span class="RktSym">port</span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym">integer-in</span><span class="hspace"> </span><span class="RktVal">0</span><span class="hspace"> </span><span class="RktVal">65535</span><span class="RktPn">)</span></td></tr></table></blockquote></div><div class="SIntrapara">Describes a remote half-connection. The <span class="RktSym">host</span> part is to be a
|
|
string containing either a hostname (e.g. <span class="RktVal">"localhost"</span>) or an
|
|
ASCII representation of an IP address (e.g. <span class="RktVal">"127.0.0.1"</span>).</div></p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>struct</p></div></div><table cellspacing="0" class="RForeground"><tr><td><span class="RktPn">(</span><span class="RktSym"><a href="http://docs.racket-lang.org/reference/define-struct.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._struct%29%29" class="RktStxLink" data-pltdoc="x">struct</a></span></td><td><span class="hspace"> </span></td><td><a name="(def._((lib._marketplace/drivers/tcp-bare..rkt)._tcp-handle-id))"></a><a name="(def._((lib._marketplace/drivers/tcp-bare..rkt)._tcp-handle~3f))"></a><a name="(def._((lib._marketplace/drivers/tcp-bare..rkt)._struct~3atcp-handle))"></a><a name="(def._((lib._marketplace/drivers/tcp-bare..rkt)._tcp-handle))"></a><span title="Provided from: marketplace/drivers/tcp-bare"><span class="RktSym"><a href="Drivers.html#%28def._%28%28lib._marketplace%2Fdrivers%2Ftcp-bare..rkt%29._tcp-handle%29%29" class="RktValDef RktValLink" data-pltdoc="x">tcp-handle</a></span></span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym">id</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace"> </span></td><td><span class="hspace"> </span></td><td><span class="RktPn">#:prefab</span><span class="RktPn">)</span></td></tr></table></blockquote></td></tr><tr><td><span class="hspace"> </span><span class="RktSym">id</span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktSym">any/c</span></td></tr></table></blockquote></div><div class="SIntrapara">Describes a local half-connection with a kernel-assigned port number.
|
|
The port number is not directly accessible; the <span class="RktSym">id</span> is used as
|
|
a local name for whichever underlying port number ends up being used.</div></p><p>The <span class="RktSym">id</span> must be chosen carefully: it is scoped to the local
|
|
VM, i.e. shared between processes in that VM, so processes must make
|
|
sure not to accidentally clash in handle ID selection. They are also
|
|
used in TcpChannel to mean a specific <span style="font-style: italic">instance</span> of a TCP
|
|
connection, so if you are likely to want to reconnect individual
|
|
flows, use different values for <span class="RktSym">id</span>.</p><p><div class="SIntrapara"><blockquote class="SVInsetFlow"><table cellspacing="0" class="boxed RBoxed"><tr><td><blockquote class="SubFlow"><div class="RBackgroundLabel SIEHidden"><div class="RBackgroundLabelInner"><p>struct</p></div></div><table cellspacing="0" class="RForeground"><tr><td><span class="RktPn">(</span><span class="RktSym"><a href="http://docs.racket-lang.org/reference/define-struct.html#%28form._%28%28lib._racket%2Fprivate%2Fbase..rkt%29._struct%29%29" class="RktStxLink" data-pltdoc="x">struct</a></span></td><td><span class="hspace"> </span></td><td><a name="(def._((lib._marketplace/drivers/tcp-bare..rkt)._tcp-listener-port))"></a><a name="(def._((lib._marketplace/drivers/tcp-bare..rkt)._tcp-listener~3f))"></a><a name="(def._((lib._marketplace/drivers/tcp-bare..rkt)._struct~3atcp-listener))"></a><a name="(def._((lib._marketplace/drivers/tcp-bare..rkt)._tcp-listener))"></a><span title="Provided from: marketplace/drivers/tcp-bare"><span class="RktSym"><a href="Drivers.html#%28def._%28%28lib._marketplace%2Fdrivers%2Ftcp-bare..rkt%29._tcp-listener%29%29" class="RktValDef RktValLink" data-pltdoc="x">tcp-listener</a></span></span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym">port</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace"> </span></td><td><span class="hspace"> </span></td><td><span class="RktPn">#:prefab</span><span class="RktPn">)</span></td></tr></table></blockquote></td></tr><tr><td><span class="hspace"> </span><span class="RktSym">port</span><span class="hspace"> </span>:<span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym">integer-in</span><span class="hspace"> </span><span class="RktVal">0</span><span class="hspace"> </span><span class="RktVal">65535</span><span class="RktPn">)</span></td></tr></table></blockquote></div><div class="SIntrapara">Describes a local half-connection with a user-assigned port number.
|
|
Use this to describe server sockets.</div></p><h5>4.2.3<tt> </tt><a name="(part._.Opening_an_outbound_connection)"></a>Opening an outbound connection</h5><p>Choose a <span class="RktSym"><a href="Drivers.html#%28def._%28%28lib._marketplace%2Fdrivers%2Ftcp-bare..rkt%29._tcp-handle%29%29" class="RktValLink" data-pltdoc="x">tcp-handle</a></span>, and then create endpoints as follows:</p><blockquote class="SCodeFlow"><table cellspacing="0" class="RktBlk"><tr><td><span class="RktPn">(</span><span class="RktSym"><a href="http://docs.racket-lang.org/reference/let.html#%28form._%28%28lib._racket%2Fprivate%2Fletstx-scheme..rkt%29._let%29%29" class="RktStxLink" data-pltdoc="x">let</a></span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktPn">(</span><span class="RktSym">local</span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="Drivers.html#%28def._%28%28lib._marketplace%2Fdrivers%2Ftcp-bare..rkt%29._tcp-handle%29%29" class="RktValLink" data-pltdoc="x">tcp-handle</a></span><span class="hspace"> </span><span class="RktVal">'</span><span class="RktVal">some-unique-value</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym">remote</span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="Drivers.html#%28def._%28%28lib._marketplace%2Fdrivers%2Ftcp-bare..rkt%29._tcp-address%29%29" class="RktValLink" data-pltdoc="x">tcp-address</a></span><span class="hspace"> </span><span class="RktVal">"the.remote.host.example.com"</span><span class="hspace"> </span><span class="RktVal">5999</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="high-level-interface.html#%28form._%28%28lib._marketplace%2Fsugar-typed..rkt%29._transition%2Fno-state%29%29" class="RktStxLink" data-pltdoc="x">transition/no-state</a></span></td></tr><tr><td><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="high-level-interface.html#%28form._%28%28lib._marketplace%2Fsugar-untyped..rkt%29._publisher%29%29" class="RktStxLink" data-pltdoc="x">publisher</a></span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="Drivers.html#%28def._%28%28lib._marketplace%2Fdrivers%2Ftcp-bare..rkt%29._tcp-channel%29%29" class="RktValLink" data-pltdoc="x">tcp-channel</a></span><span class="hspace"> </span><span class="RktSym">local</span><span class="hspace"> </span><span class="RktSym">remote</span><span class="hspace"> </span><span class="RktSym"><a href="low-level-interface.html#%28def._%28%28lib._marketplace%2Fsugar-untyped..rkt%29._~3f%29%29" class="RktValLink" data-pltdoc="x">?</a></span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="high-level-interface.html#%28form._%28%28lib._marketplace%2Fsugar-untyped..rkt%29._subscriber%29%29" class="RktStxLink" data-pltdoc="x">subscriber</a></span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="Drivers.html#%28def._%28%28lib._marketplace%2Fdrivers%2Ftcp-bare..rkt%29._tcp-channel%29%29" class="RktValLink" data-pltdoc="x">tcp-channel</a></span><span class="hspace"> </span><span class="RktSym">remote</span><span class="hspace"> </span><span class="RktSym">local</span><span class="hspace"> </span><span class="RktSym"><a href="low-level-interface.html#%28def._%28%28lib._marketplace%2Fsugar-untyped..rkt%29._~3f%29%29" class="RktValLink" data-pltdoc="x">?</a></span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="high-level-interface.html#%28form._%28%28lib._marketplace%2Fsugar-untyped..rkt%29._on-message%29%29" class="RktStxLink" data-pltdoc="x">on-message</a></span></td></tr><tr><td><span class="hspace"> </span><span class="RktPn">[</span><span class="RktPn">(</span><span class="RktSym"><a href="Drivers.html#%28def._%28%28lib._marketplace%2Fdrivers%2Ftcp-bare..rkt%29._tcp-channel%29%29" class="RktValLink" data-pltdoc="x">tcp-channel</a></span><span class="hspace"> </span><span class="RktSym"><a href="http://docs.racket-lang.org/reference/stx-patterns.html#%28form._%28%28lib._racket%2Fprivate%2Fstxcase-scheme..rkt%29.__%29%29" class="RktStxLink" data-pltdoc="x">_</a></span><span class="hspace"> </span><span class="RktSym"><a href="http://docs.racket-lang.org/reference/stx-patterns.html#%28form._%28%28lib._racket%2Fprivate%2Fstxcase-scheme..rkt%29.__%29%29" class="RktStxLink" data-pltdoc="x">_</a></span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="low-level-interface.html#%28def._%28%28lib._marketplace%2Fsugar-untyped..rkt%29._~3f%29%29" class="RktValLink" data-pltdoc="x">?</a></span><span class="hspace"> </span><span class="RktSym"><a href="http://docs.racket-lang.org/reference/port-ops.html#%28def._%28%28quote._~23~25kernel%29._eof-object~3f%29%29" class="RktValLink" data-pltdoc="x">eof-object?</a></span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace"> </span><span class="RktCmt">;</span><span class="RktCmt"> </span><span class="RktCmt">Handle a received end-of-file object</span></td></tr><tr><td><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="high-level-interface.html#%28form._%28%28lib._marketplace%2Fsugar-values..rkt%29._transition%29%29" class="RktStxLink" data-pltdoc="x">transition</a></span><span class="hspace"> </span><span class="RktSym"><a href="http://docs.racket-lang.org/reference/stx-patterns.html#%28form._%28%28lib._racket%2Fprivate%2Fstxcase-scheme..rkt%29._......%29%29" class="RktStxLink" data-pltdoc="x">...</a></span><span class="RktPn">)</span><span class="RktPn">]</span></td></tr><tr><td><span class="hspace"> </span><span class="RktPn">[</span><span class="RktPn">(</span><span class="RktSym"><a href="Drivers.html#%28def._%28%28lib._marketplace%2Fdrivers%2Ftcp-bare..rkt%29._tcp-channel%29%29" class="RktValLink" data-pltdoc="x">tcp-channel</a></span><span class="hspace"> </span><span class="RktSym"><a href="http://docs.racket-lang.org/reference/stx-patterns.html#%28form._%28%28lib._racket%2Fprivate%2Fstxcase-scheme..rkt%29.__%29%29" class="RktStxLink" data-pltdoc="x">_</a></span><span class="hspace"> </span><span class="RktSym"><a href="http://docs.racket-lang.org/reference/stx-patterns.html#%28form._%28%28lib._racket%2Fprivate%2Fstxcase-scheme..rkt%29.__%29%29" class="RktStxLink" data-pltdoc="x">_</a></span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="low-level-interface.html#%28def._%28%28lib._marketplace%2Fsugar-untyped..rkt%29._~3f%29%29" class="RktValLink" data-pltdoc="x">?</a></span><span class="hspace"> </span><span class="RktSym"><a href="http://docs.racket-lang.org/reference/bytestrings.html#%28def._%28%28quote._~23~25kernel%29._bytes~3f%29%29" class="RktValLink" data-pltdoc="x">bytes?</a></span><span class="hspace"> </span><span class="RktSym">data</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace"> </span><span class="RktCmt">;</span><span class="RktCmt"> </span><span class="RktCmt">Handle received data</span></td></tr><tr><td><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="high-level-interface.html#%28form._%28%28lib._marketplace%2Fsugar-values..rkt%29._transition%29%29" class="RktStxLink" data-pltdoc="x">transition</a></span><span class="hspace"> </span><span class="RktSym"><a href="http://docs.racket-lang.org/reference/stx-patterns.html#%28form._%28%28lib._racket%2Fprivate%2Fstxcase-scheme..rkt%29._......%29%29" class="RktStxLink" data-pltdoc="x">...</a></span><span class="RktPn">)</span><span class="RktPn">]</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr></table></blockquote><p>The TCP driver will automatically create an outbound connection in
|
|
response to the presence of the endpoints. When the endpoints are
|
|
deleted (or the process exits), the TCP driver will notice the absence
|
|
and will close the underlying TCP socket.</p><p>For a complete example, see <a href="Examples.html#%28part._chat-client-example%29" data-pltdoc="x">TCP chat client</a>.</p><h5>4.2.4<tt> </tt><a name="(part._.Accepting_inbound_connections)"></a>Accepting inbound connections</h5><p>Choose a port number, and then create an <span style="font-style: italic">observer</span> endpoint as
|
|
follows:</p><blockquote class="SCodeFlow"><table cellspacing="0" class="RktBlk"><tr><td><span class="RktPn">(</span><span class="RktSym"><a href="high-level-interface.html#%28form._%28%28lib._marketplace%2Fsugar-untyped..rkt%29._observe-publishers%29%29" class="RktStxLink" data-pltdoc="x">observe-publishers</a></span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="Drivers.html#%28def._%28%28lib._marketplace%2Fdrivers%2Ftcp-bare..rkt%29._tcp-channel%29%29" class="RktValLink" data-pltdoc="x">tcp-channel</a></span><span class="hspace"> </span><span class="RktSym"><a href="low-level-interface.html#%28def._%28%28lib._marketplace%2Fsugar-untyped..rkt%29._~3f%29%29" class="RktValLink" data-pltdoc="x">?</a></span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="Drivers.html#%28def._%28%28lib._marketplace%2Fdrivers%2Ftcp-bare..rkt%29._tcp-listener%29%29" class="RktValLink" data-pltdoc="x">tcp-listener</a></span><span class="hspace"> </span><span class="RktVal">5999</span><span class="RktPn">)</span><span class="hspace"> </span><span class="RktSym"><a href="low-level-interface.html#%28def._%28%28lib._marketplace%2Fsugar-untyped..rkt%29._~3f%29%29" class="RktValLink" data-pltdoc="x">?</a></span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="high-level-interface.html#%28form._%28%28lib._marketplace%2Fsugar-untyped..rkt%29._match-conversation%29%29" class="RktStxLink" data-pltdoc="x">match-conversation</a></span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="Drivers.html#%28def._%28%28lib._marketplace%2Fdrivers%2Ftcp-bare..rkt%29._tcp-channel%29%29" class="RktValLink" data-pltdoc="x">tcp-channel</a></span><span class="hspace"> </span><span class="RktSym">them</span><span class="hspace"> </span><span class="RktSym">us</span><span class="hspace"> </span><span class="RktSym"><a href="http://docs.racket-lang.org/reference/stx-patterns.html#%28form._%28%28lib._racket%2Fprivate%2Fstxcase-scheme..rkt%29.__%29%29" class="RktStxLink" data-pltdoc="x">_</a></span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="high-level-interface.html#%28form._%28%28lib._marketplace%2Fsugar-untyped..rkt%29._on-presence%29%29" class="RktStxLink" data-pltdoc="x">on-presence</a></span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="high-level-interface.html#%28form._%28%28lib._marketplace%2Fsugar-untyped..rkt%29._spawn%29%29" class="RktStxLink" data-pltdoc="x">spawn</a></span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym">chat-session</span><span class="hspace"> </span><span class="RktSym">them</span><span class="hspace"> </span><span class="RktSym">us</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr></table></blockquote><p>The use of <span class="RktSym"><a href="high-level-interface.html#%28form._%28%28lib._marketplace%2Fsugar-untyped..rkt%29._observe-publishers%29%29" class="RktStxLink" data-pltdoc="x">observe-publishers</a></span> here indicates that this endpoint isn’t
|
|
actually interested in exchanging any TCP data; instead, it is
|
|
monitoring demand for such exchanges. The TCP driver uses the unusual
|
|
<span class="RktVal">'</span><span class="RktVal">everything</span> <span class="RktSym"><a href="low-level-interface.html#%28def._%28%28lib._marketplace%2Fmain..rkt%29._.Interest.Type%29%29" class="RktValLink" data-pltdoc="x">InterestType</a></span> to monitor the presence of
|
|
<span class="RktVal">'</span><span class="RktVal">observer</span>s, and creates listening TCP server sockets in
|
|
response. When a connection comes in, the TCP driver spawns a manager
|
|
process which offers regular <span class="RktVal">'</span><span class="RktVal">participant</span> endpoints for
|
|
communicating on the newly-arrived socket.</p><p>To illustrate the code for handling a newly-arrived connection,</p><blockquote class="SCodeFlow"><table cellspacing="0" class="RktBlk"><tr><td><span class="RktPn">(</span><span class="RktSym"><a href="http://docs.racket-lang.org/ts-reference/special-forms.html#%28form._%28%28lib._typed-racket%2Fbase-env%2Fprims..rkt%29._define%29%29" class="RktStxLink" data-pltdoc="x">define</a></span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym">chat-session</span><span class="hspace"> </span><span class="RktSym">them</span><span class="hspace"> </span><span class="RktSym">us</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="high-level-interface.html#%28form._%28%28lib._marketplace%2Fsugar-typed..rkt%29._transition%2Fno-state%29%29" class="RktStxLink" data-pltdoc="x">transition/no-state</a></span></td></tr><tr><td><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="high-level-interface.html#%28form._%28%28lib._marketplace%2Fsugar-untyped..rkt%29._subscriber%29%29" class="RktStxLink" data-pltdoc="x">subscriber</a></span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="Drivers.html#%28def._%28%28lib._marketplace%2Fdrivers%2Ftcp-bare..rkt%29._tcp-channel%29%29" class="RktValLink" data-pltdoc="x">tcp-channel</a></span><span class="hspace"> </span><span class="RktSym">them</span><span class="hspace"> </span><span class="RktSym">us</span><span class="hspace"> </span><span class="RktSym"><a href="low-level-interface.html#%28def._%28%28lib._marketplace%2Fsugar-untyped..rkt%29._~3f%29%29" class="RktValLink" data-pltdoc="x">?</a></span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="high-level-interface.html#%28form._%28%28lib._marketplace%2Fsugar-untyped..rkt%29._on-absence%29%29" class="RktStxLink" data-pltdoc="x">on-absence</a></span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="high-level-interface.html#%28def._%28%28lib._marketplace%2Fsugar-values..rkt%29._quit%29%29" class="RktValLink" data-pltdoc="x">quit</a></span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="high-level-interface.html#%28form._%28%28lib._marketplace%2Fsugar-untyped..rkt%29._on-message%29%29" class="RktStxLink" data-pltdoc="x">on-message</a></span><span class="hspace"> </span><span class="RktPn">[</span><span class="RktPn">(</span><span class="RktSym"><a href="Drivers.html#%28def._%28%28lib._marketplace%2Fdrivers%2Ftcp-bare..rkt%29._tcp-channel%29%29" class="RktValLink" data-pltdoc="x">tcp-channel</a></span><span class="hspace"> </span><span class="RktSym"><a href="http://docs.racket-lang.org/reference/stx-patterns.html#%28form._%28%28lib._racket%2Fprivate%2Fstxcase-scheme..rkt%29.__%29%29" class="RktStxLink" data-pltdoc="x">_</a></span><span class="hspace"> </span><span class="RktSym"><a href="http://docs.racket-lang.org/reference/stx-patterns.html#%28form._%28%28lib._racket%2Fprivate%2Fstxcase-scheme..rkt%29.__%29%29" class="RktStxLink" data-pltdoc="x">_</a></span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="low-level-interface.html#%28def._%28%28lib._marketplace%2Fsugar-untyped..rkt%29._~3f%29%29" class="RktValLink" data-pltdoc="x">?</a></span><span class="hspace"> </span><span class="RktSym"><a href="http://docs.racket-lang.org/reference/bytestrings.html#%28def._%28%28quote._~23~25kernel%29._bytes~3f%29%29" class="RktValLink" data-pltdoc="x">bytes?</a></span><span class="hspace"> </span><span class="RktSym">data</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr><tr><td><span class="hspace"> </span><span class="RktCmt">;</span><span class="RktCmt"> </span><span class="RktCmt">Handle incoming data</span></td></tr><tr><td><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="high-level-interface.html#%28form._%28%28lib._marketplace%2Fsugar-values..rkt%29._transition%29%29" class="RktStxLink" data-pltdoc="x">transition</a></span><span class="hspace"> </span><span class="RktSym"><a href="http://docs.racket-lang.org/reference/stx-patterns.html#%28form._%28%28lib._racket%2Fprivate%2Fstxcase-scheme..rkt%29._......%29%29" class="RktStxLink" data-pltdoc="x">...</a></span><span class="RktPn">)</span><span class="RktPn">]</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span><span class="RktPn">)</span></td></tr></table></blockquote><h5>4.2.5<tt> </tt><a name="(part._.Receiving_data)"></a>Receiving data</h5><p>TCP-related messages will be of the form</p><blockquote class="SCodeFlow"><p><span class="RktPn">(</span><span class="RktSym"><a href="Drivers.html#%28def._%28%28lib._marketplace%2Fdrivers%2Ftcp-bare..rkt%29._tcp-channel%29%29" class="RktValLink" data-pltdoc="x">tcp-channel</a></span><span class="hspace"> </span><span class="RktSym">remote-address</span><span class="hspace"> </span><span class="RktSym">local-address</span><span class="hspace"> </span><span class="RktSym">subpacket</span><span class="RktPn">)</span></p></blockquote><p>where the <span class="RktSym">subpacket</span> is either <span class="RktSym"><a href="http://docs.racket-lang.org/reference/port-ops.html#%28def._%28%28quote._~23~25kernel%29._eof%29%29" class="RktValLink" data-pltdoc="x">eof</a></span> or a
|
|
<span class="RktSym"><a href="http://docs.racket-lang.org/reference/bytestrings.html#%28def._%28%28quote._~23~25kernel%29._bytes~3f%29%29" class="RktValLink" data-pltdoc="x">bytes?</a></span>.</p><h5>4.2.6<tt> </tt><a name="(part._.Sending_data)"></a>Sending data</h5><p>Send data with</p><blockquote class="SCodeFlow"><p><span class="RktPn">(</span><span class="RktSym"><a href="high-level-interface.html#%28def._%28%28lib._marketplace%2Fsugar-values..rkt%29._send-message%29%29" class="RktValLink" data-pltdoc="x">send-message</a></span><span class="hspace"> </span><span class="RktPn">(</span><span class="RktSym"><a href="Drivers.html#%28def._%28%28lib._marketplace%2Fdrivers%2Ftcp-bare..rkt%29._tcp-channel%29%29" class="RktValLink" data-pltdoc="x">tcp-channel</a></span><span class="hspace"> </span><span class="RktSym">local-address</span><span class="hspace"> </span><span class="RktSym">remote-address</span><span class="hspace"> </span><span class="RktSym">subpacket</span><span class="RktPn">)</span><span class="RktPn">)</span></p></blockquote><p>where, as for receiving data, the <span class="RktSym">subpacket</span> is either
|
|
<span class="RktSym"><a href="http://docs.racket-lang.org/reference/port-ops.html#%28def._%28%28quote._~23~25kernel%29._eof%29%29" class="RktValLink" data-pltdoc="x">eof</a></span> or a <span class="RktSym"><a href="http://docs.racket-lang.org/reference/bytestrings.html#%28def._%28%28quote._~23~25kernel%29._bytes~3f%29%29" class="RktValLink" data-pltdoc="x">bytes?</a></span>.</p><h4>4.3<tt> </tt><a name="(part._timer__typed_and_untyped_)"></a>timer (typed and untyped)</h4><p>For examples of the use of the timer driver, see uses of
|
|
<span class="RktSym">set-timer</span> and <span class="RktSym">timer-expired</span> in
|
|
<a href="https://github.com/tonyg/marketplace-dns/blob/master/network-query.rkt">the
|
|
Marketplace-based DNS resolver</a>.</p><h4>4.4<tt> </tt><a name="(part._udp__typed_and_untyped_)"></a>udp (typed and untyped)</h4><p>For examples of the use of the UDP driver, see uses of
|
|
<span class="RktSym">udp-packet</span> etc. in
|
|
<a href="https://github.com/tonyg/marketplace-dns/blob/master/tk-dns.rkt">the
|
|
Marketplace-based DNS resolver</a>.</p><div class="navsetbottom"><span class="navleft"> </span><span class="navright"> <a href="low-level-interface.html" title="backward to "3 Low-level interface"" data-pltdoc="x">← prev</a> <a href="index.html" title="up to "Marketplace: Network-Aware Programming"" data-pltdoc="x">up</a> <a href="Management_and_Monitoring.html" title="forward to "5 Management and Monitoring"" data-pltdoc="x">next →</a></span> </div></div></div><div id="contextindicator"> </div></body></html> |