TAO/docs/rtcorba/status.html

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  12 <h3><a name="intro">Real-Time CORBA Support in TAO</a> </h3>
  13 <a name="status">
  14
  15 <p>Support for <a href="http://www.omg.org">OMG</a> <a
  16 href="http://www.omg.org/cgi-bin/doc?ptc/99-05-03">Real-Time CORBA 1.0
  17 specification</a> has been added to TAO.  For an overview of Real-time
  18 CORBA features, please see the <A
  19 HREF="http://www.dre.vanderbilt.edu/~schmidt/report-doc.html#rt">C/C++ Users
  20 Journal columns</A> written by <A
  21 HREF="http://www.dre.vanderbilt.edu/~schmidt/">Douglas Schmidt</A> and <A
  22 HREF="http://www.iona.com/hyplan/vinoski/">Steve Vinoski</a>.  For a
  23 detailed design discussions and results of empirical performance
  24 analyzes of TAO's Real-time CORBA implementation, please see the <A
  25 HREF="http://www.dre.vanderbilt.edu/">DOC group's</a>
  26 <A
  27 HREF="http://www.dre.vanderbilt.edu/~schmidt/corba-research-realtime.html">Real-time
  28 CORBA research page</A>.
  29
  30 <p>As usual, questions, comments, and contributions should be posted
  31 to  <a
  32 href="https://github.com/DOCGroup/ACE_TAO/issues">github issues</a> (best) or by filling out the <A
  33 HREF="../../PROBLEM-REPORT-FORM">TAO_ROOT/PROBLEM-REPORT-FORM</A>
  34 and posting it to the newsgroup. Please indicate &quot;RTCORBA&quot;
  35 in the component field when submitting a bug report. </p>
  36
  37 <p>Points of contact for the project are:
  38
  39 <ul>
  40   <li><a href="mailto:corsaro@cs.wustl.edu">Angelo Corsaro</a> - collocation and policy
  41     encoding into ior</li>
  42   <li><a href="mailto:irfan@cs.wustl.edu">Irfan Pyarali</a> - POA threadpools and RT POA</li>
  43   <li><a href="mailto:marina@cs.wustl.edu">Marina Spivak</a> - all other features and online
  44     documentation </li>
  45   <li><a href="mailto:yamuna@oomworks.com">Yamuna Krishnamurthy</a> - Diffserv support in RTCORBA </li>
  46 </ul>
  47
  48 <h3><a name="supported">Supported Features</a></h3>
  49
  50 <p>Following is the complete list of features from the Real-Time CORBA 1.0 specification
  51 that are currently supported in TAO. (These do not include <a href="#in progress">work
  52 in progress</a>).
  53
  54 <ul>
  55   <li>Real-Time ORB</li>
  56   <li>Real-Time POA</li>
  57   <li>Real-Time Current</li>
  58   <li>Priority Mappings</li>
  59   <li>Client_Propagated Priority Model</li>
  60   <li>Server_Declared Priority Model</li>
  61   <li>Server Protocol Policy</li>
  62   <li>Client Protocol Policy</li>
  63   <li>Priority Banded Connections</li>
  64   <li>Explicit Binding</li>
  65   <li>Private Connections</li>
  66   <li>Invocation Timeout</li>
  67   <li>RT Mutex</li>
  68   <li>POA Threadpools</li>
  69 </ul>
  70
  71 <h3><a name="unsupported">Unsupported Features</a></h3>
  72
  73 <p>The following features are not currently supported, and there are no immediate plans
  74 for their implementation:
  75
  76 <ul>
  77   <li>POA Threadpool request buffering</li>
  78   <li>POA Threadpool thread borrowing </li>
  79   <li>Priority Transforms</li>
  80   <li>ORBinit command-line option</li>
  81 </ul>
  82
  83 <h3><a name="future">Future Work</a></h3>
  84
  85 <ol>
  86
  87   <li>Currently, persistent objects are not supported for RT POAs.  We
  88     need to add this feature.</li>
  89
  90   <li>Currently, purging of connection only happens for the lane of
  91     the thread that runs out of connection.  We need to change this
  92     such that we allow system wide purging.</li>
  93
  94   <li>Currently, all user-created threads are part of the default
  95     thread pool.  There is nothing done to separate out these threads
  96     into different (implicit) lanes based on their priorities.  We may
  97     need to add this separation to get better/predictable behavior
  98     with respect to sharing of resources across threads of different
  99     priorities.</li>
 100
 101   <li>Currently, some CDR memory pools are global.  We should
 102     reevaluate them to see which of them can be made a per-lane
 103     resource.</li>
 104
 105   <li>Improve current RT CORBA implementation through benchmarking and
 106     optimizations, resolving known bugs and issues, adding examples,
 107     and other enhancements.</li>
 108
 109   <li>Implement an alternative real-time orb architecture using a
 110     <em>queue-per-lane</em> approach, as described in the <a
 111     href="architecture.html">TAO Real-Time Architecture</a>
 112     section. In this approach, each threadpool lane owns a queue,
 113     while I/O resources are being shared among all the threadpool
 114     lanes of the same priority within a server.  Strategize TAO to use
 115     either <em>queue-per-lane</em> or <em>reactor-per-lane</em>
 116     implementation, and compare the two.</li>
 117
 118   <li>As both real-time and fault tolerance implementations mature
 119     separately, explore issues in combining them, and, ultimately,
 120     enable TAO to provide applications with both real-time and fault
 121     tolerance support at the same time. </li> </ol>
 122
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