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added para on ca client library context

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Jeff Hill
2003-04-15 18:42:06 +00:00
parent ef8fb769a1
commit 338d438830
1 changed files with 26 additions and 0 deletions
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@@ -96,6 +96,8 @@ height="31" width="88"></a></p>
<li><a href="#Connection">Connection Management</a></li>
<li><a href="#Thread">Thread Safety and Preemptive Callback to User
Code</a></li>
<li><a href="#Client2">CA Client Contexts and Application Specific
Auxillary Threads</a></li>
<li><a href="#Polling">Polling the CA Client Library From Single Threaded
Applications</a></li>
<li><a href="#Avoid">Avoid Emulating Bad Practices that May Still be
@@ -1246,6 +1248,30 @@ library. When the CA client library invokes a user's&nbsp;call back function
it will always wait for the current callback to complete prior to executing
another call back function.</p>
<h3><a name="Client2">CA Client Contexts and Application Specific Auxillary
Threads</a></h3>
<p>It may be necessary for several CA client side tools running in the same
address space (process) to be independent of each other. For example, the
database CA links and the sequencer are designed to not use the same CA
client library threads, network circuits, and data structures. Each thread
that calls <a href="#ca_context_create">ca_context_create()</a> for the first
time either directly, or implicitly when calling a CA routine for the first
time, creates a CA client library context. A CA client libray context
contains all of the threads, network circuits, and data structures required
to connect and communicate with the channels that a CA cllient application
has created. The priority of auxillary threads spawned by the CA client
library are at fixed offsets from the priority of the thread that called <a
href="#ca_context_create">ca_context_create()</a>. An application specific
auxillary thread can join a CA context by calling <a
href="#ca_attach_context">ca_attach_context()</a> using the CA context
identifier that was retuned from <a
href="#ca_current_context">ca_current_context()</a> when it was called by the
thread that called <a href="#ca_context_create">ca_context_create()</a>. A CA
client library context can be shut down and cleaned up, after destroying any
channels or application specific threads that are attached to it, by calling
<a href="#ca_context_destroy">ca_context_destroy()</a>.</p>
<h3><a name="Polling">Polling the CA Client Library From Single Threaded
Applications</a></h3>