Extract BufferExchange, simplify threading.

firmware/application/CMakeLists.txt

@@ -174,6 +174,7 @@ set(CPPSRC
 	file.cpp
 	log_file.cpp
 	${COMMON}/png_writer.cpp
+	${COMMON}/buffer_exchange.cpp
 	capture_thread.cpp
 	io_file.cpp
 	io_wave.cpp

firmware/application/capture_thread.cpp

@@ -22,67 +22,20 @@
 #include "capture_thread.hpp"
 
 #include "baseband_api.hpp"
+#include "buffer_exchange.hpp"
 
-// BufferExchange ///////////////////////////////////////////////////////////
+struct BasebandCapture {
-
+	BasebandCapture(CaptureConfig* const config) {
-class BufferExchange {
+		baseband::capture_start(config);
-public:
-	BufferExchange(CaptureConfig* const config);
-	~BufferExchange();
-
-#if defined(LPC43XX_M0)
-	StreamBuffer* get() {
-		StreamBuffer* p { nullptr };
-		fifo_buffers_for_application->out(p);
-		return p;
 	}
 
-	bool put(StreamBuffer* const p) {
+	~BasebandCapture() {
-		return fifo_buffers_for_baseband->in(p);
+		baseband::capture_stop();
 	}
-#endif
-
-#if defined(LPC43XX_M4)
-	StreamBuffer* get() {
-		StreamBuffer* p { nullptr };
-		fifo_buffers_for_baseband->out(p);
-		return p;
-	}
-
-	bool put(StreamBuffer* const p) {
-		return fifo_buffers_for_application->in(p);
-	}
-#endif
-
-	static FIFO<StreamBuffer*>* fifo_buffers_for_baseband;
-	static FIFO<StreamBuffer*>* fifo_buffers_for_application;
-
-private:
-	CaptureConfig* const config;
 };
 
-FIFO<StreamBuffer*>* BufferExchange::fifo_buffers_for_baseband = nullptr;
-FIFO<StreamBuffer*>* BufferExchange::fifo_buffers_for_application = nullptr;
-
-BufferExchange::BufferExchange(
-	CaptureConfig* const config
-) : config { config }
-{
-	baseband::capture_start(config);
-	fifo_buffers_for_baseband = config->fifo_buffers_empty;
-	fifo_buffers_for_application = config->fifo_buffers_full;
-}
-
-BufferExchange::~BufferExchange() {
-	fifo_buffers_for_baseband = nullptr;
-	fifo_buffers_for_application = nullptr;
-	baseband::capture_stop();
-}
-
 // CaptureThread //////////////////////////////////////////////////////////
 
-Thread* CaptureThread::thread = nullptr;
-
 CaptureThread::CaptureThread(
 	std::unique_ptr<stream::Writer> writer,
 	size_t write_size,
@@ -101,23 +54,11 @@ CaptureThread::CaptureThread(
 CaptureThread::~CaptureThread() {
 	if( thread ) {
 		chThdTerminate(thread);
-		chEvtSignal(thread, event_mask_loop_wake);
 		chThdWait(thread);
 		thread = nullptr;
 	}
 }
 
-void CaptureThread::check_fifo_isr() {
-	// TODO: Prevent over-signalling by transmitting a set of 
-	// flags from the baseband core.
-	const auto fifo = BufferExchange::fifo_buffers_for_application;
-	if( fifo ) {
-		if( !fifo->is_empty() ) {
-			chEvtSignalI(thread, event_mask_loop_wake);
-		}
-	}
-}
-
 msg_t CaptureThread::static_fn(void* arg) {
 	auto obj = static_cast<CaptureThread*>(arg);
 	const auto error = obj->run();
@@ -132,20 +73,17 @@ msg_t CaptureThread::static_fn(void* arg) {
 }
 
 Optional<File::Error> CaptureThread::run() {
+	BasebandCapture capture { &config };
 	BufferExchange buffers { &config };
 
 	while( !chThdShouldTerminate() ) {
 		auto buffer = buffers.get();
-		if( buffer ) {
+		auto write_result = writer->write(buffer->data(), buffer->size());
-			auto write_result = writer->write(buffer->data(), buffer->size());
+		if( write_result.is_error() ) {
-			if( write_result.is_error() ) {
+			return write_result.error();
-				return write_result.error();
-			}
-			buffer->empty();
-			buffers.put(buffer);
-		} else {
-			chEvtWaitAny(event_mask_loop_wake);
 		}
+		buffer->empty();
+		buffers.put(buffer);
 	}
 
 	return { };

firmware/application/capture_thread.hpp

@@ -48,16 +48,12 @@ public:
 		return config;
 	}
 
-	static void check_fifo_isr();
-
 private:
-	static constexpr auto event_mask_loop_wake = EVENT_MASK(0);
-
 	CaptureConfig config;
 	std::unique_ptr<stream::Writer> writer;
 	std::function<void()> success_callback;
 	std::function<void(File::Error)> error_callback;
-	static Thread* thread;
+	Thread* thread;
 
 	static msg_t static_fn(void* arg);
 

firmware/application/event_m0.cpp

@@ -31,7 +31,7 @@
 
 #include "irq_controls.hpp"
 
-#include "capture_thread.hpp"
+#include "buffer_exchange.hpp"
 
 #include "ch.h"
 
@@ -48,7 +48,7 @@ CH_IRQ_HANDLER(M4Core_IRQHandler) {
 	CH_IRQ_PROLOGUE();
 
 	chSysLockFromIsr();
-	CaptureThread::check_fifo_isr();
+	BufferExchange::handle_isr();
 	EventDispatcher::check_fifo_isr();
 	chSysUnlockFromIsr();
 

firmware/common/buffer_exchange.cpp

@@ -0,0 +1,54 @@
+/*
+ * Copyright (C) 2016 Jared Boone, ShareBrained Technology, Inc.
+ *
+ * This file is part of PortaPack.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#include "buffer_exchange.hpp"
+
+BufferExchange* BufferExchange::obj { nullptr };
+
+BufferExchange::BufferExchange(
+	CaptureConfig* const config
+) : config { config }
+{
+	obj = this;
+	fifo_buffers_for_baseband = config->fifo_buffers_empty;
+	fifo_buffers_for_application = config->fifo_buffers_full;
+}
+
+BufferExchange::~BufferExchange() {
+	obj = nullptr;
+	fifo_buffers_for_baseband = nullptr;
+	fifo_buffers_for_application = nullptr;
+}
+
+StreamBuffer* BufferExchange::get(FIFO<StreamBuffer*>* fifo) {
+	while(true) {
+		StreamBuffer* p { nullptr };
+		fifo->out(p);
+		if( p ) {
+			return p;
+		}
+
+		chSysLock();
+		thread = chThdSelf();
+		chSchGoSleepS(THD_STATE_SUSPENDED);
+		chSysUnlock();
+	}
+}

firmware/common/buffer_exchange.hpp

@@ -0,0 +1,91 @@
+/*
+ * Copyright (C) 2016 Jared Boone, ShareBrained Technology, Inc.
+ *
+ * This file is part of PortaPack.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2, or (at your option)
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; see the file COPYING.  If not, write to
+ * the Free Software Foundation, Inc., 51 Franklin Street,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#pragma once
+
+#include "ch.h"
+
+#include "message.hpp"
+#include "fifo.hpp"
+#include "io.hpp"
+
+class BufferExchange {
+public:
+	BufferExchange(CaptureConfig* const config);
+	~BufferExchange();
+
+#if defined(LPC43XX_M0)
+	bool empty() const {
+		return fifo_buffers_for_application->is_empty();
+	}
+
+	StreamBuffer* get() {
+		return get(fifo_buffers_for_application);
+	}
+
+	bool put(StreamBuffer* const p) {
+		return fifo_buffers_for_baseband->in(p);
+	}
+#endif
+
+#if defined(LPC43XX_M4)
+	bool empty() const {
+		return fifo_buffers_for_baseband->is_empty();
+	}
+
+	StreamBuffer* get() {
+		return get(fifo_buffers_for_baseband);
+	}
+
+	bool put(StreamBuffer* const p) {
+		return fifo_buffers_for_application->in(p);
+	}
+#endif
+
+	static void handle_isr() {
+		if( obj ) {
+			obj->check_fifo_isr();
+		}
+	}
+
+private:
+	CaptureConfig* const config;
+	FIFO<StreamBuffer*>* fifo_buffers_for_baseband;
+	FIFO<StreamBuffer*>* fifo_buffers_for_application;
+	Thread* thread;
+	static BufferExchange* obj;
+
+	void check_fifo_isr() {
+		if( !empty() ) {
+			wakeup_isr();
+		}
+	}
+
+	void wakeup_isr() {
+		auto thread_tmp = thread;
+		if( thread_tmp ) {
+			thread = nullptr;
+			chSchReadyI(thread_tmp);
+		}
+	}
+
+	StreamBuffer* get(FIFO<StreamBuffer*>* fifo);
+};