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<a name="Ravenscar-Profile"></a>
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<a name="Tasking-Support-when-using-the-Ravenscar-Profile"></a>
<h4 class="subsubsection">15.4.10.9 Tasking Support when using the Ravenscar Profile</h4>
<a name="index-Ravenscar-Profile"></a>

<p>The <em>Ravenscar Profile</em> is a subset of the Ada tasking features,
specifically designed for systems with safety-critical real-time
requirements.
</p>
<dl compact="compact">
<dd><a name="index-set-ravenscar-task_002dswitching-on"></a>
<a name="index-task-switching-with-program-using-Ravenscar-Profile"></a>
</dd>
<dt><code>set ravenscar task-switching on</code></dt>
<dd><p>Allows task switching when debugging a program that uses the Ravenscar
Profile.  This is the default.
</p>
<a name="index-set-ravenscar-task_002dswitching-off"></a>
</dd>
<dt><code>set ravenscar task-switching off</code></dt>
<dd><p>Turn off task switching when debugging a program that uses the Ravenscar
Profile.  This is mostly intended to disable the code that adds support
for the Ravenscar Profile, in case a bug in either <small>GDB</small> or in
the Ravenscar runtime is preventing <small>GDB</small> from working properly.
To be effective, this command should be run before the program is started.
</p>
<a name="index-show-ravenscar-task_002dswitching"></a>
</dd>
<dt><code>show ravenscar task-switching</code></dt>
<dd><p>Show whether it is possible to switch from task to task in a program
using the Ravenscar Profile.
</p>
</dd>
</dl>

<a name="index-Ravenscar-thread"></a>
<p>When Ravenscar task-switching is enabled, Ravenscar tasks are
announced by <small>GDB</small> as if they were threads:
</p>
<div class="smallexample">
<pre class="smallexample">(gdb) continue
[New Ravenscar Thread 0x2b8f0]
</pre></div>

<p>Both Ravenscar tasks and the underlying CPU threads will show up in
the output of <code>info threads</code>:
</p>
<div class="smallexample">
<pre class="smallexample">(gdb) info threads
  Id   Target Id                  Frame
  1    Thread 1 (CPU#0 [running]) simple () at simple.adb:10
  2    Thread 2 (CPU#1 [running]) 0x0000000000003d34 in __gnat_initialize_cpu_devices ()
  3    Thread 3 (CPU#2 [running]) 0x0000000000003d28 in __gnat_initialize_cpu_devices ()
  4    Thread 4 (CPU#3 [halted ]) 0x000000000000c6ec in system.task_primitives.operations.idle ()
* 5    Ravenscar Thread 0x2b8f0   simple () at simple.adb:10
  6    Ravenscar Thread 0x2f150   0x000000000000c6ec in system.task_primitives.operations.idle ()
</pre></div>

<p>One known limitation of the Ravenscar support in <small>GDB</small> is that
it isn&rsquo;t currently possible to single-step through the runtime
initialization sequence.  If you need to debug this code, you should
use <code>set ravenscar task-switching off</code>.
</p>
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