gearmulator

commit a56446c5f01ffcc15ac784f8a12d583f6b29de48
parent 309cd8685fc443afd408a57c771ba3417f063052
Author: dsp56300 <dsp56300@users.noreply.github.com>
Date:   Mon, 29 Jul 2024 17:07:17 +0200

add rate limiting to fix DSPs running too fast

Diffstat:
M
source/nord/n2x/n2xLib/n2xhardware.cpp
 | 
21
+++++++++++++++++++++
M
source/nord/n2x/n2xLib/n2xhardware.h
 | 
8
++++++++

2 files changed, 29 insertions(+), 0 deletions(-)
diff --git a/source/nord/n2x/n2xLib/n2xhardware.cpp b/source/nord/n2x/n2xLib/n2xhardware.cpp
@@ -73,6 +73,8 @@ namespace n2x
 			const auto processCount = std::min(_frames, static_cast<uint32_t>(64));
 			_frames -= processCount;
 
+			advanceSamples(processCount, _latency);
+
 			const auto requiredSize = processCount > 8 ? processCount - 8 : 0;
 
 			if(esaiB.getAudioOutputs().size() < requiredSize)
@@ -167,6 +169,15 @@ namespace n2x
 		{
 			m_requestedFramesAvailableMutex.unlock();
 		}
+
+		if(m_esaiFrameIndex >= m_maxEsaiCallbacks + m_esaiLatency)
+		{
+			std::unique_lock uLock(m_haltDSPmutex);
+			m_haltDSPcv.wait(uLock, [&]
+			{
+				return (m_maxEsaiCallbacks + m_esaiLatency) > m_esaiFrameIndex;
+			});
+		}
 	}
 
 	void Hardware::syncUCtoDSP()
@@ -227,6 +238,16 @@ namespace n2x
 		}
 	}
 
+	void Hardware::advanceSamples(const uint32_t _samples, const uint32_t _latency)
+	{
+		{
+			std::lock_guard uLockHalt(m_haltDSPmutex);
+			m_maxEsaiCallbacks += _samples;
+			m_esaiLatency = _latency;
+		}
+		m_haltDSPcv.notify_one();
+	}
+
 	void Hardware::haltDSPs()
 	{
 		if(m_dspHalted)
diff --git a/source/nord/n2x/n2xLib/n2xhardware.h b/source/nord/n2x/n2xLib/n2xhardware.h
@@ -3,6 +3,7 @@
 #include "n2xdsp.h"
 #include "n2xmc.h"
 #include "n2xrom.h"
+
 #include "synthLib/audioTypes.h"
 
 namespace n2x
@@ -40,6 +41,7 @@ namespace n2x
 		void onEsaiCallbackB();
 		void syncUCtoDSP();
 		void ucThreadFunc();
+		void advanceSamples(uint32_t _samples, uint32_t _latency);
 
 		Rom m_rom;
 		Microcontroller m_uc;
@@ -67,5 +69,11 @@ namespace n2x
 		dsp56k::SpscSemaphore m_semDspAtoB;
 		dsp56k::RingBuffer<dsp56k::Audio::RxFrame, 4, true> m_dspAtoBbuf;
 		std::unique_ptr<std::thread> m_ucThread;
+
+		// DSP slowdown
+		uint32_t m_maxEsaiCallbacks = 0;
+		uint32_t m_esaiLatency = 0;
+		std::mutex m_haltDSPmutex;
+		std::condition_variable m_haltDSPcv;
 	};
 }