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<div id="projectname">Jack2
 <span id="projectnumber">1.9.9</span>
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<a href="#func-members">Functions</a> </div>
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<div class="title">Controlling & querying JACK server operation</div> </div>
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Functions</h2></td></tr>
<tr class="memitem:gad65c741a1d1d2fb09efacf51437b841a"><td class="memItemLeft" align="right" valign="top">int </td><td class="memItemRight" valign="bottom"><a class="el" href="group__ServerClientControl.html#gad65c741a1d1d2fb09efacf51437b841a">jack_set_freewheel</a> (jack_client_t *client, int onoff) JACK_OPTIONAL_WEAK_EXPORT</td></tr>
<tr class="memitem:gad96bda0901b924f5996e02e41a979685"><td class="memItemLeft" align="right" valign="top">int </td><td class="memItemRight" valign="bottom"><a class="el" href="group__ServerClientControl.html#gad96bda0901b924f5996e02e41a979685">jack_set_buffer_size</a> (jack_client_t *client, jack_nframes_t nframes) JACK_OPTIONAL_WEAK_EXPORT</td></tr>
<tr class="memitem:ga62022d4f2fbfba065f0874a497afd3b4"><td class="memItemLeft" align="right" valign="top">jack_nframes_t </td><td class="memItemRight" valign="bottom"><a class="el" href="group__ServerClientControl.html#ga62022d4f2fbfba065f0874a497afd3b4">jack_get_sample_rate</a> (jack_client_t *) JACK_OPTIONAL_WEAK_EXPORT</td></tr>
<tr class="memitem:gad1f5972836af7e72e6d79ed6bc53916f"><td class="memItemLeft" align="right" valign="top">jack_nframes_t </td><td class="memItemRight" valign="bottom"><a class="el" href="group__ServerClientControl.html#gad1f5972836af7e72e6d79ed6bc53916f">jack_get_buffer_size</a> (jack_client_t *) JACK_OPTIONAL_WEAK_EXPORT</td></tr>
<tr class="memitem:ga2db0a4e9ab7b6d9984e91abba27ab71d"><td class="memItemLeft" align="right" valign="top">int </td><td class="memItemRight" valign="bottom"><a class="el" href="group__ServerClientControl.html#ga2db0a4e9ab7b6d9984e91abba27ab71d">jack_engine_takeover_timebase</a> (jack_client_t *) JACK_OPTIONAL_WEAK_DEPRECATED_EXPORT</td></tr>
<tr class="memitem:ga9136d56397ad4f394a8b169462f5683b"><td class="memItemLeft" align="right" valign="top">float </td><td class="memItemRight" valign="bottom"><a class="el" href="group__ServerClientControl.html#ga9136d56397ad4f394a8b169462f5683b">jack_cpu_load</a> (jack_client_t *client) JACK_OPTIONAL_WEAK_EXPORT</td></tr>
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<hr/><a name="details" id="details"></a><h2>Detailed Description</h2>
<hr/><h2>Function Documentation</h2>
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<td class="memname">int jack_set_freewheel </td>
<td>(</td>
<td class="paramtype">jack_client_t * </td>
<td class="paramname"><em>client</em>, </td>
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<td class="paramkey"></td>
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<td class="paramtype">int </td>
<td class="paramname"><em>onoff</em> </td>
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<p>Start/Stop JACK's "freewheel" mode.</p>
<p>When in "freewheel" mode, JACK no longer waits for any external event to begin the start of the next process cycle.</p>
<p>As a result, freewheel mode causes "faster than realtime" execution of a JACK graph. If possessed, real-time scheduling is dropped when entering freewheel mode, and if appropriate it is reacquired when stopping.</p>
<p>IMPORTANT: on systems using capabilities to provide real-time scheduling (i.e. Linux kernel 2.4), if onoff is zero, this function must be called from the thread that originally called <a class="el" href="group__ClientFunctions.html#ga9800d5b29bd7670d9944a15f6ea0ecf8">jack_activate()</a>. This restriction does not apply to other systems (e.g. Linux kernel 2.6 or OS X).</p>
<dl class="params"><dt>Parameters:</dt><dd>
<table class="params">
<tr><td class="paramname">client</td><td>pointer to JACK client structure </td></tr>
<tr><td class="paramname">onoff</td><td>if non-zero, freewheel mode starts. Otherwise freewheel mode ends.</td></tr>
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</dd>
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<dl class="section return"><dt>Returns:</dt><dd>0 on success, otherwise a non-zero error code. </dd></dl>
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<td class="memname">int jack_set_buffer_size </td>
<td>(</td>
<td class="paramtype">jack_client_t * </td>
<td class="paramname"><em>client</em>, </td>
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<td class="paramkey"></td>
<td></td>
<td class="paramtype">jack_nframes_t </td>
<td class="paramname"><em>nframes</em> </td>
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<td>)</td>
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<p>Change the buffer size passed to the <em>process_callback</em>.</p>
<p>This operation stops the JACK engine process cycle, then calls all registered <em>bufsize_callback</em> functions before restarting the process cycle. This will cause a gap in the audio flow, so it should only be done at appropriate stopping points.</p>
<dl class="section see"><dt>See also:</dt><dd><a class="el" href="group__ClientCallbacks.html#ga030cc371acb19abe52861492acb960ad">jack_set_buffer_size_callback()</a></dd></dl>
<dl class="params"><dt>Parameters:</dt><dd>
<table class="params">
<tr><td class="paramname">client</td><td>pointer to JACK client structure. </td></tr>
<tr><td class="paramname">nframes</td><td>new buffer size. Must be a power of two.</td></tr>
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</dd>
</dl>
<dl class="section return"><dt>Returns:</dt><dd>0 on success, otherwise a non-zero error code </dd></dl>
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<td class="memname">jack_nframes_t jack_get_sample_rate </td>
<td>(</td>
<td class="paramtype">jack_client_t * </td>
<td class="paramname"></td><td>)</td>
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<dl class="section return"><dt>Returns:</dt><dd>the sample rate of the jack system, as set by the user when jackd was started. </dd></dl>
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<td class="memname">jack_nframes_t jack_get_buffer_size </td>
<td>(</td>
<td class="paramtype">jack_client_t * </td>
<td class="paramname"></td><td>)</td>
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<dl class="section return"><dt>Returns:</dt><dd>the current maximum size that will ever be passed to the <em>process_callback</em>. It should only be used <em>before</em> the client has been activated. This size may change, clients that depend on it must register a <em>bufsize_callback</em> so they will be notified if it does.</dd></dl>
<dl class="section see"><dt>See also:</dt><dd><a class="el" href="group__ClientCallbacks.html#ga030cc371acb19abe52861492acb960ad">jack_set_buffer_size_callback()</a> </dd></dl>
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<td class="memname">int jack_engine_takeover_timebase </td>
<td>(</td>
<td class="paramtype">jack_client_t * </td>
<td class="paramname"></td><td>)</td>
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<p>Old-style interface to become the timebase for the entire JACK subsystem.</p>
<dl class="deprecated"><dt><b><a class="el" href="deprecated.html#_deprecated000005">Deprecated:</a></b></dt><dd>This function still exists for compatibility with the earlier transport interface, but it does nothing. Instead, see <a class="el" href="transport_8h_source.html">transport.h</a> and use <a class="el" href="group__TransportControl.html#ga0c2f2f464f6ba1c0b2aa45e6507b7aa9">jack_set_timebase_callback()</a>.</dd></dl>
<dl class="section return"><dt>Returns:</dt><dd>ENOSYS, function not implemented. </dd></dl>
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<td class="memname">float jack_cpu_load </td>
<td>(</td>
<td class="paramtype">jack_client_t * </td>
<td class="paramname"><em>client</em></td><td>)</td>
<td></td>
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<dl class="section return"><dt>Returns:</dt><dd>the current CPU load estimated by JACK. This is a running average of the time it takes to execute a full process cycle for all clients as a percentage of the real time available per cycle determined by the buffer size and sample rate. </dd></dl>
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