Merged parallel-cbthreads-3 branch

2014-10-02 15:07:07 -05:00
parent 565f0e3725 c0a4ebebff
commit 70feb515c3
20 changed files with 1357 additions and 161 deletions
@@ -7,7 +7,7 @@
 </head>

 <body lang="en">
-<h1 align="center">EPICS Base Release 3.15.0.1</h1>
+<h1 align="center">EPICS Base Release 3.15.0.2</h1>

 <p>
 EPICS Base 3.15.0.x releases are not intended for use in production systems.</p>
@@ -15,6 +15,23 @@ EPICS Base 3.15.0.x releases are not intended for use in production systems.</p>
 <h2 align="center">Changes between 3.15.0.1 and 3.15.0.2</h2>
 <!-- Insert new items immediately below here ... -->

+<h3>Parallel callback threads</h3>
+
+<p>The general purpose callback facility can run multiple parallel callback
+threads per priority level. This makes better use of SMP architectures (e.g.
+processors with multiple cores), as callback work - which includes second
+stage processing of records with asynchronuous device support and I/O
+scanned processing - can be distributed over the available CPUs.</p>
+
+<p>Note that by using parallel callback threads the order of scan callback
+requests in the queue is not retained. If a device support needs to be
+informed when scanIoRequest processing has finished, it should use the new
+scanIoSetComplete() feature to add a user function that will be called after
+the scanIoRequest record processing has finished.</p>
+
+<p>Parallel callback threads have to be explicitly configured, by default
+the IOC keeps the old behavior of running one callback thread per priority.</p>
+
 <h3>Merge MMIO API from devLib2</h3>

 <p>Added calls to handle 8, 16, and 32 bit Memory Mapped I/O reads and writes.
@@ -108,8 +125,7 @@ backwards compatibility reasons. Only the alarm.h header needs to be included
 now to declare the epicsAlarmSeverityStrings and epicsAlarmConditionStrings
 arrays.</p>

-<h3>
-General purpose thread pool</h3>
+<h3>General purpose thread pool</h3>

 <p>
 A general purpose threaded work queue API epicsThreadPool is added.