82 lines
2.4 KiB
HTML
82 lines
2.4 KiB
HTML
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<head>
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<meta http-equiv="content-type" content="text/html; charset=iso-8859-1" />
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<title>PvaClientChannelStateChangeRequester</title>
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</head>
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<body>
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<h1>PvaClientChannelStateChangeRequester</h1>
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<p>This class has the single method <b>channelStateChange</b>.
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It is called each time the channel connection status changes.
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</p>
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<p>
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<b>NOTE:</b>
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The implementation must not call a method that blocks waiting for a response from the server.
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It it does the client may be blocked forever.
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</p>
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<p>
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An example of illegal code is:
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</p>
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<pre>
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virtual void channelStateChange(PvaClientChannelPtr const & channel, bool isConnected)
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{
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if(isConnected&&!pvaClientPut)
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{
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pvaClientPut = pvaClientChannel->createPut(request);
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pvaClientPut->connect();
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}
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}
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</pre>
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<p>
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This is illegal because the call to <b>connect</b> blocks.
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</p>
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<p>The following is an example of legal code:
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</p>
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<pre>
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virtual void channelStateChange(PvaClientChannelPtr const & channel, bool isConnected)
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{
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if(isConnected&&!pvaClientPut)
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{
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pvaClientPut = pvaClientChannel->createPut(request);
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pvaClientPut->issueConnect();
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}
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}
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</pre>
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<p>This is legal code because neither <b>createPut</b> or <b>issueConnect</b>
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blocks.
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</p>
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</body>
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</html>
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