From 8e14d2f4e8224c21fde4c9f1c2a20297cdead87c Mon Sep 17 00:00:00 2001
From: Jared Boone <jboone@earfeast.com>
Date: Sun, 27 Mar 2016 22:49:30 -0700
Subject: [PATCH] Signal SD card write thread from M4 event.

---
 firmware/application/audio_thread.hpp | 16 +++++++++++++---
 firmware/application/event_m0.cpp     |  4 ++++
 firmware/application/event_m0.hpp     |  2 ++
 3 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/firmware/application/audio_thread.hpp b/firmware/application/audio_thread.hpp
index 5155fc4f..9752d018 100644
--- a/firmware/application/audio_thread.hpp
+++ b/firmware/application/audio_thread.hpp
@@ -67,11 +67,23 @@ public:
 
 	~AudioThread() {
 		chThdTerminate(thread);
+		chEvtSignal(thread, EVT_FIFO_HIGHWATER);
 		chThdWait(thread);
 	}
 
+	static void check_fifo_isr() {
+		if( (shared_memory.FIFO_HACK != nullptr) && (thread != nullptr) ) {
+			auto fifo = reinterpret_cast<FIFO<uint8_t>*>(shared_memory.FIFO_HACK);
+			if( fifo->len() >= write_size ) {
+				chEvtSignalI(thread, EVT_FIFO_HIGHWATER);
+			}
+		}
+	}
+
 private:
 	static constexpr size_t write_size = 4096;
+	static constexpr eventmask_t EVT_FIFO_HIGHWATER = 1;
+
 	const std::string file_path;
 
 	File file;
@@ -95,7 +107,7 @@ private:
 		}
 
 		while( !chThdShouldTerminate() ) {
-			// SUCH A HACK!!!
+			chEvtWaitAny(EVT_FIFO_HIGHWATER);
 
 			auto fifo = reinterpret_cast<FIFO<uint8_t>*>(shared_memory.FIFO_HACK);
 			if( !fifo ) {
@@ -117,8 +129,6 @@ private:
 				}
 				led_usb.off();
 			}
-
-			chThdSleepMilliseconds(25);
 		}
 
 		file.close();
diff --git a/firmware/application/event_m0.cpp b/firmware/application/event_m0.cpp
index 06890318..af12bee1 100644
--- a/firmware/application/event_m0.cpp
+++ b/firmware/application/event_m0.cpp
@@ -31,6 +31,8 @@
 
 #include "irq_controls.hpp"
 
+#include "audio_thread.hpp"
+
 #include "ch.h"
 
 #include "lpc43xx_cpp.hpp"
@@ -44,6 +46,7 @@ CH_IRQ_HANDLER(M4Core_IRQHandler) {
 	CH_IRQ_PROLOGUE();
 
 	chSysLockFromIsr();
+	AudioThread::check_fifo_isr();
 	EventDispatcher::events_flag_isr(EVT_MASK_APPLICATION);
 	chSysUnlockFromIsr();
 
@@ -56,6 +59,7 @@ CH_IRQ_HANDLER(M4Core_IRQHandler) {
 
 MessageHandlerMap EventDispatcher::message_map_;
 Thread* EventDispatcher::thread_event_loop = nullptr;
+Thread* EventDispatcher::thread_record = nullptr;
 
 EventDispatcher::EventDispatcher(
 	ui::Widget* const top_widget,
diff --git a/firmware/application/event_m0.hpp b/firmware/application/event_m0.hpp
index 414a3a62..69dcede2 100644
--- a/firmware/application/event_m0.hpp
+++ b/firmware/application/event_m0.hpp
@@ -73,6 +73,8 @@ public:
 		return message_map_;
 	}
 
+	static Thread* thread_record;
+	
 private:
 	static MessageHandlerMap message_map_;
 	static Thread* thread_event_loop;