Move coreaudio_set_realtime_policy into libpbd

libs/backends/coreaudio/coreaudio_backend.cc

@@ -333,10 +333,10 @@ CoreAudioBackend::set_buffer_size (uint32_t bs)
 	_samples_per_period = bs;
 	_pcmio->set_samples_per_period(bs);
 	if (_run) {
-		coreaudio_set_realtime_policy (_main_thread);
+		pbd_mach_set_realtime_policy (_main_thread, 1e9 * _samples_per_period / _samplerate);
 	}
 	for (std::vector<pthread_t>::const_iterator i = _threads.begin (); i != _threads.end (); ++i) {
-		coreaudio_set_realtime_policy (*i);
+		pbd_mach_set_realtime_policy (*i, 1e9 * _samples_per_period / _samplerate);
 	}
 	//engine.buffer_size_change (bs);
 	return 0;
@@ -822,34 +822,6 @@ CoreAudioBackend::coreaudio_process_thread (void *arg)
 	return 0;
 }
 
-bool
-CoreAudioBackend::coreaudio_set_realtime_policy (pthread_t thread_id) const
-{
-	thread_time_constraint_policy_data_t policy;
-#ifndef NDEBUG
-	mach_msg_type_number_t msgt = 4;
-	boolean_t dflt = false;
-	kern_return_t rv = thread_policy_get (pthread_mach_thread_np (_main_thread),
-			THREAD_TIME_CONSTRAINT_POLICY, (thread_policy_t) &policy,
-			&msgt, &dflt);
-	printf ("Coreaudio Main Thread(%p) %d %d %d %d DFLT %d OK: %d\n", _main_thread, policy.period, policy.computation, policy.constraint, policy.preemptible, dflt, rv == KERN_SUCCESS);
-#endif
-
-	double period_ns = 1e9 * _samples_per_period / _samplerate;
-	policy.period = AudioConvertNanosToHostTime (period_ns);
-	policy.computation = AudioConvertNanosToHostTime (period_ns * .9);
-	policy.constraint = AudioConvertNanosToHostTime (period_ns * .95);
-	policy.preemptible = true;
-	kern_return_t res = thread_policy_set (pthread_mach_thread_np (thread_id),
-			THREAD_TIME_CONSTRAINT_POLICY, (thread_policy_t) &policy,
-			THREAD_TIME_CONSTRAINT_POLICY_COUNT);
-
-#ifndef NDEBUG
-	printf ("Coreaudio Proc Thread(%p) %d %d %d %d OK: %d\n", thread_id, policy.period, policy.computation, policy.constraint, policy.preemptible, res == KERN_SUCCESS);
-#endif
-	return res != KERN_SUCCESS;
-}
-
 int
 CoreAudioBackend::create_process_thread (boost::function<void()> func)
 {
@@ -872,7 +844,7 @@ CoreAudioBackend::create_process_thread (boost::function<void()> func)
 		pthread_attr_destroy (&attr);
 	}
 
-	if (coreaudio_set_realtime_policy (thread_id)) {
+	if (pbd_mach_set_realtime_policy (thread_id, 1e9 * _samples_per_period / _samplerate)) {
 		PBD::warning << _("AudioEngine: process thread failed to set mach realtime policy.") << endmsg;
 	}
 
@@ -1733,7 +1705,7 @@ CoreAudioBackend::freewheel_thread ()
 			AudioEngine::thread_init_callback (this);
 			_midiio->set_enabled(false);
 			reset_midi_parsers ();
-			coreaudio_set_realtime_policy (_main_thread);
+			pbd_mach_set_realtime_policy (_main_thread, 1e9 * _samples_per_period / _samplerate);
 		}
 
 		// process port updates first in every cycle.
@@ -1799,7 +1771,7 @@ CoreAudioBackend::process_callback (const uint32_t n_samples, const uint64_t hos
 		_reinit_thread_callback = false;
 		_main_thread = pthread_self();
 		AudioEngine::thread_init_callback (this);
-		coreaudio_set_realtime_policy (_main_thread);
+		pbd_mach_set_realtime_policy (_main_thread, 1e9 * _samples_per_period / _samplerate);
 	}
 
 	if (pthread_mutex_trylock (&_process_callback_mutex)) {

libs/backends/coreaudio/coreaudio_backend.h

@@ -439,7 +439,6 @@ class CoreAudioBackend : public AudioBackend {
 
 	/* process threads */
 	static void* coreaudio_process_thread (void *);
-	bool coreaudio_set_realtime_policy (pthread_t) const;
 	std::vector<pthread_t> _threads;
 
 	struct ThreadData {

libs/pbd/pbd/pthread_utils.h

@@ -61,6 +61,7 @@ LIBPBD_API int pbd_realtime_pthread_create (
 		void *arg);
 
 LIBPBD_API int  pbd_set_thread_priority (pthread_t, const int policy, int priority);
+LIBPBD_API bool pbd_mach_set_realtime_policy (pthread_t thread_id, double period_ns);
 
 namespace PBD {
 	LIBPBD_API extern void notify_event_loops_about_thread_creation (pthread_t, const std::string&, int requests = 256);

libs/pbd/pthread_utils.cc

@@ -266,3 +266,37 @@ pbd_set_thread_priority (pthread_t thread, const int policy, int priority)
 
 	return pthread_setschedparam (thread, SCHED_FIFO, &param);
 }
+
+bool
+pbd_mach_set_realtime_policy (pthread_t thread_id, double period_ns)
+{
+#ifdef _APPLE_
+	thread_time_constraint_policy_data_t policy;
+#ifndef NDEBUG
+	mach_msg_type_number_t msgt = 4;
+	boolean_t dflt = false;
+	kern_return_t rv = thread_policy_get (pthread_mach_thread_np (_main_thread),
+			THREAD_TIME_CONSTRAINT_POLICY, (thread_policy_t) &policy,
+			&msgt, &dflt);
+	printf ("Mach Thread(%p) %d %d %d %d DFLT %d OK: %d\n", _main_thread, policy.period, policy.computation, policy.constraint, policy.preemptible, dflt, rv == KERN_SUCCESS);
+#endif
+
+	mach_timebase_info_data_t timebase_info;
+	mach_timebase_info(&timebase_info);
+	const double period_clk = period_ns * (double)timebase_info.denom / (double)timebase_info.numer;
+
+	policy.period = period_clk;
+	policy.computation = period_clk * .9;
+	policy.constraint = period_clk * .95;
+	policy.preemptible = true;
+	kern_return_t res = thread_policy_set (pthread_mach_thread_np (thread_id),
+			THREAD_TIME_CONSTRAINT_POLICY, (thread_policy_t) &policy,
+			THREAD_TIME_CONSTRAINT_POLICY_COUNT);
+
+#ifndef NDEBUG
+	printf ("Mach Thread(%p) %d %d %d %d OK: %d\n", thread_id, policy.period, policy.computation, policy.constraint, policy.preemptible, res == KERN_SUCCESS);
+#endif
+	return res != KERN_SUCCESS;
+#endif
+	return false; // OK
+}