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  <header>
    <copyright>
      <year>1997</year><year>2010</year>
      <holder>Ericsson AB. All Rights Reserved.</holder>
    </copyright>
    <legalnotice>
      The contents of this file are subject to the Erlang Public License,
      Version 1.1, (the "License"); you may not use this file except in
      compliance with the License. You should have received a copy of the
      Erlang Public License along with this software. If not, it can be
      retrieved online at http://www.erlang.org/.

      Software distributed under the License is distributed on an "AS IS"
      basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
      the License for the specific language governing rights and limitations
      under the License.

    </legalnotice>

    <title>CosEventChannelAdmin</title>
    <prepared></prepared>
    <responsible></responsible>
    <docno></docno>
    <approved></approved>
    <checked></checked>
    <date>1997-11-13</date>
    <rev>PA1</rev>
    <file>CosEventChannelAdmin.xml</file>
  </header>
  <module>CosEventChannelAdmin</module>
  <modulesummary>The CosEventChannelAdmin defines a set if event service interfaces that  enables decoupled asynchronous communication between objects and implements generic (untyped) version of the OMG COSS standard event service.</modulesummary>
  <description>
    <p>The event service defines two roles for objects: the supplier role and 
      the consumer role. Suppliers supply event data to the event channel and 
      consumers receive event data from the channel. Suppliers do not need to 
      know the identity of the consumers, and vice versa. Consumers and 
      suppliers are connected to the event channel via proxies, which are managed
      by ConsumerAdmin and SupplierAdmin objects.</p>
    <p>There are four general models of communication.  These are:    </p>
    <list type="bulleted">
      <item>The canonical push model. It allows the suppliers of events to initiate the
       transfer of event data to consumers. Event channels play the role of 
      <c><![CDATA[Notifier]]></c>. Active suppliers use event channel to push data to 
       passive consumers registered with the event channel.</item>
      <item>The canonical pull model. It allows consumers to request events from 
       suppliers. Event channels play the role of <c><![CDATA[Procure]]></c> since they 
       procure events on behalf of consumers. Active consumers can explicitly 
       pull data from passive suppliers via the event channels.</item>
      <item>The hybrid push/pull model. It allows consumers request events queued at
       a channel by suppliers. Event channels play the role of <c><![CDATA[Queue]]></c>.
       Active consumers explicitly pull data deposited by active suppliers via 
       the event channels.</item>
      <item>The hybrid pull/push model. It allows the channel to pull events from 
       suppliers and push them to consumers. Event channels play the role of 
      <c><![CDATA[Intelligent agent]]></c>. Active event channels can pull data from 
       passive suppliers to push it to passive consumers.</item>
    </list>
    <p>To get access to all definitions, e.g., exceptions,
      include necessary <c><![CDATA[hrl]]></c> files by using:<br></br><c><![CDATA[-include_lib("cosEvent/include/*.hrl").]]></c></p>
    <p>There are seven different interfaces supported in the service:</p>
    <list type="bulleted">
      <item>ProxyPushConsumer</item>
      <item>ProxyPullSupplier</item>
      <item>ProxyPullConsumer</item>
      <item>ProxyPushSupplier</item>
      <item>ConsumerAdmin</item>
      <item>SupplierAdmin</item>
      <item>EventChannel</item>
    </list>
  </description>
  
</erlref>

