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<h1><a class="anchor" name="timer">Timer interface</a></h1>Timer interface is designed to use internal timers in sound hardware, but it can be driven with any timer.<h2><a class="anchor" name="timer_general_overview">
General overview</a></h2>
The timer implementation uses ring buffer to store information about timing events. In this buffer is recorded count of ticks and current tick resolution in nanoseconds.<h2><a class="anchor" name="timer_open">
Opening</a></h2>
Timer devices can be opened in two ways. When <a class="el" href="group___timer.html#g19279d167469082d1efd10f6ed4289ab">SND_TIMER_OPEN_NONBLOCK</a> flag is used, then the open functions return immediately with -EBUSY error code when resources are occupied with another application. When <a class="el" href="group___timer.html#g19279d167469082d1efd10f6ed4289ab">SND_TIMER_OPEN_NONBLOCK</a> is not used (by default) the open functions block the application requesting device until resources are not free.<h2><a class="anchor" name="timer_events">
Events</a></h2>
Events are read via <a class="el" href="group___timer.html#g09307fbc086367b5d0dda0aca1ce38b9">snd_timer_read()</a> function.<h2><a class="anchor" name="timer_examples">
Examples</a></h2>
The full featured examples with cross-links:<p>
<dl compact><dt><b>Simple timer test program</b></dt><dd><a class="el" href="/builddir/build/BUILD/alsa-lib-1.0.17a/src/timer/timer.c.html#example_test_timer">example code</a> </dd></dl>
<dl compact><dt><b></b></dt><dd>This example shows opening a timer device and reading of timer events. </dd></dl>
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