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Fix EPICS_CA_AUTO_ARRAY_BYTES doc'n in CAref.html

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This commit is contained in:
Andrew Johnson
2017-05-09 14:58:40 -05:00
parent ac590e671e
commit 020f09e83a
1 changed files with 8 additions and 11 deletions
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19
src/ca/client/CAref.html
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@@ -316,7 +316,7 @@ is used.</p>
</tr>
<tr>
<td>EPICS_CA_AUTO_ARRAY_BYTES</td>
<td>i &gt;= YES</td>
<td>{YES, NO}</td>
<td>YES</td>
</tr>
<tr>
@@ -756,6 +756,12 @@ in the variable EPICS_TS_MIN_WEST.</p>
<h3><a name="Configurin1">Configuring the Maximum Array Size</a></h3>
<p>From version R3.16.1, the default setting of EPICS_CA_AUTO_ARRAY_BYTES=YES
will cause the software to ignore EPICS_CA_MAX_ARRAY_BYTES and attempt to
allocate network buffer space as needed by the particular client connection
using malloc. Setting EPICS_CA_AUTO_ARRAY_BYTES=NO will configure the software
to respect the EPICS_CA_MAX_ARRAY_BYTES setting as described below instead.</p>
<p>Starting with version R3.14 the environment variable
EPICS_CA_MAX_ARRAY_BYTES determines the size of the largest array that may pass
through CA. Prior to this version only arrays smaller than 16k bytes could be
@@ -764,11 +770,6 @@ buffers that are used for ordinary communication. If EPICS_CA_MAX_ARRAY_BYTES
is larger than 16384 then a second free list of larger data buffers is
established and used only after a client send its first large array request.</p>
<p>Beginning with R3.16.1, EPICS_CA_AUTO_ARRAY_BYTES=YES (the default) will ignore
EPICS_CA_MAX_ARRAY_BYTES and attempt to allocate sufficient buffer space
as needed. Setting EPICS_CA_AUTO_ARRAY_BYTES=NO will continue to respect
EPICS_CA_MAX_ARRAY_BYTES.</p>
<p>The CA client library uses EPICS_CA_MAX_ARRAY_BYTES to determines the
maximum array that it will send or receive. Likewise, the CA server uses
EPICS_CA_MAX_ARRAY_BYTES to determine the maximum array that it may send or
@@ -783,11 +784,7 @@ array larger than EPICS_CA_MAX_ARRAY_BYTES it will return ECA_TOLARGE.</p>
by multiplying the number of elements by the size of a single element, but
neglect to add additional bytes for the compound data types (for example
DBR_GR_DOUBLE) commonly used by the more sophisticated client side
applications. <em>Based on this confusion, one could arrive at the conclusion
that EPICS_CA_MAX_ARRAY_BYTES might have been better named
EPICS_CA_MAX_DATUM_BYTES, or that the software should be changed internally to
round the users request up by the size of the maximum scalar datum (nothing has
been done to address this issue so far).</em></p>
applications.</p>
<h3><a name="Configurin2">Configuring a CA Server</a></h3>