Refactor of capture buffer management between cores.

Instead of copying data into and out of FIFO, passing buffer pointers between cores that are sized to match preferred/ideal SD card write size.

firmware/application/analog_audio_app.hpp

@@ -143,7 +143,7 @@ private:
 
 	RecordView record_view {
 		{ 0 * 8, 2 * 16, 30 * 8, 1 * 16 },
-		"AUD_????", RecordView::FileType::WAV, 12, 2,
+		"AUD_????", RecordView::FileType::WAV, 4096, 4
 	};
 
 	spectrum::WaterfallWidget waterfall;

firmware/application/capture_app.hpp

@@ -78,7 +78,7 @@ private:
 
 	RecordView record_view {
 		{ 0 * 8, 2 * 16, 30 * 8, 1 * 16 },
-		"BBD_????", RecordView::FileType::RawS16, 14, 1,
+		"BBD_????", RecordView::FileType::RawS16, 16384, 3
 	};
 
 	spectrum::WaterfallWidget waterfall;

firmware/application/capture_thread.cpp

@@ -31,20 +31,29 @@ public:
 	~StreamOutput();
 
 	size_t available() {
-		return fifo->len();
+		return fifo_buffers_full->len();
 	}
 
-	size_t read(void* const data, const size_t length) {
-		return fifo->out(reinterpret_cast<uint8_t*>(data), length);
+	StreamBuffer* get_buffer() {
+		StreamBuffer* p { nullptr };
+		fifo_buffers_full->out(p);
+		return p;
 	}
 
-	static FIFO<uint8_t>* fifo;
+	bool release_buffer(StreamBuffer* const p) {
+		p->empty();
+		return fifo_buffers_empty->in(p);
+	}
+
+	static FIFO<StreamBuffer*>* fifo_buffers_empty;
+	static FIFO<StreamBuffer*>* fifo_buffers_full;
 
 private:
 	CaptureConfig* const config;
 };
 
-FIFO<uint8_t>* StreamOutput::fifo = nullptr;
+FIFO<StreamBuffer*>* StreamOutput::fifo_buffers_empty = nullptr;
+FIFO<StreamBuffer*>* StreamOutput::fifo_buffers_full = nullptr;
 
 StreamOutput::StreamOutput(
 	CaptureConfig* const config
@@ -53,11 +62,13 @@ StreamOutput::StreamOutput(
 	shared_memory.baseband_queue.push_and_wait(
 		CaptureConfigMessage { config }
 	);
-	fifo = config->fifo;
+	fifo_buffers_empty = config->fifo_buffers_empty;
+	fifo_buffers_full = config->fifo_buffers_full;
 }
 
 StreamOutput::~StreamOutput() {
-	fifo = nullptr;
+	fifo_buffers_full = nullptr;
+	fifo_buffers_empty = nullptr;
 	shared_memory.baseband_queue.push_and_wait(
 		CaptureConfigMessage { nullptr }
 	);
@@ -69,9 +80,9 @@ Thread* CaptureThread::thread = nullptr;
 
 CaptureThread::CaptureThread(
 	std::unique_ptr<Writer> writer,
-	size_t write_size_log2,
-	size_t buffer_count_log2
-) : config { write_size_log2, buffer_count_log2 },
+	size_t write_size,
+	size_t buffer_count
+) : config { write_size, buffer_count },
 	writer { std::move(writer) }
 {
 	// Need significant stack for FATFS
@@ -90,29 +101,22 @@ CaptureThread::~CaptureThread() {
 void CaptureThread::check_fifo_isr() {
 	// TODO: Prevent over-signalling by transmitting a set of 
 	// flags from the baseband core.
-	const auto fifo = StreamOutput::fifo;
+	const auto fifo = StreamOutput::fifo_buffers_full;
 	if( fifo ) {
 		chEvtSignalI(thread, EVT_MASK_CAPTURE_THREAD);
 	}
 }
 
 msg_t CaptureThread::run() {
-	const size_t write_size = 1U << config.write_size_log2;
-	const auto write_buffer = std::make_unique<uint8_t[]>(write_size);
-	if( !write_buffer ) {
-		return false;
-	}
-
 	StreamOutput stream { &config };
 
 	while( !chThdShouldTerminate() ) {
-		if( stream.available() >= write_size ) {
-			if( stream.read(write_buffer.get(), write_size) != write_size ) {
-				return false;
-			}
-			if( !writer->write(write_buffer.get(), write_size) ) {
+		if( stream.available() ) {
+			auto buffer = stream.get_buffer();
+			if( !writer->write(buffer->data(), buffer->size()) ) {
 				return false;
 			}
+			stream.release_buffer(buffer);
 		} else {
 			chEvtWaitAny(EVT_MASK_CAPTURE_THREAD);
 		}

firmware/application/capture_thread.hpp

@@ -40,8 +40,8 @@ class CaptureThread {
 public:
 	CaptureThread(
 		std::unique_ptr<Writer> writer,
-		size_t write_size_log2,
-		size_t buffer_count_log2
+		size_t write_size,
+		size_t buffer_count
 	);
 	~CaptureThread();
 

firmware/application/ui_record_view.cpp

@@ -139,13 +139,13 @@ RecordView::RecordView(
 	const Rect parent_rect,
 	std::string filename_stem_pattern,
 	const FileType file_type,
-	const size_t buffer_size_k,
-	const size_t buffer_count_k
+	const size_t write_size,
+	const size_t buffer_count
 ) : View { parent_rect },
 	filename_stem_pattern { filename_stem_pattern },
 	file_type { file_type },
-	buffer_size_k { buffer_size_k },
-	buffer_count_k { buffer_count_k }
+	write_size { write_size },
+	buffer_count { buffer_count }
 {
 	add_children({ {
 		&button_record,
@@ -222,7 +222,7 @@ void RecordView::start() {
 		button_record.set_bitmap(&bitmap_stop);
 		capture_thread = std::make_unique<CaptureThread>(
 			std::move(writer),
-			buffer_size_k, buffer_count_k
+			write_size, buffer_count
 		);
 	}
 }

firmware/application/ui_record_view.hpp

@@ -46,8 +46,8 @@ public:
 		const Rect parent_rect,
 		std::string filename_stem_pattern,
 		FileType file_type,
-		const size_t buffer_size_k,
-		const size_t buffer_count_k
+		const size_t write_size,
+		const size_t buffer_count
 	);
 	~RecordView();
 
@@ -73,8 +73,8 @@ private:
 
 	const std::string filename_stem_pattern;
 	const FileType file_type;
-	const size_t buffer_size_k;
-	const size_t buffer_count_k;
+	const size_t write_size;
+	const size_t buffer_count;
 	size_t sampling_rate { 0 };
 	SignalToken signal_token_tick_second;
 

firmware/baseband/Makefile

@@ -146,6 +146,7 @@ CPPSRC = main.cpp \
          proc_tpms.cpp \
          proc_ert.cpp \
          proc_capture.cpp \
+         stream_input.cpp \
          dsp_squelch.cpp \
          clock_recovery.cpp \
          packet_builder.cpp \

firmware/baseband/stream_input.cpp

@@ -0,0 +1,76 @@
+/*
+ * 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 "stream_input.hpp"
+
+#include "lpc43xx_cpp.hpp"
+using namespace lpc43xx;
+
+StreamInput::StreamInput(CaptureConfig* const config) :
+	fifo_buffers_empty { buffers_empty.data(), buffer_count_max_log2 },
+	fifo_buffers_full { buffers_full.data(), buffer_count_max_log2 },
+	config { config },
+	data { std::make_unique<uint8_t[]>(config->write_size * config->buffer_count) }
+{
+	config->fifo_buffers_empty = &fifo_buffers_empty;
+	config->fifo_buffers_full = &fifo_buffers_full;
+
+	for(size_t i=0; i<config->buffer_count; i++) {
+		buffers[i] = { &(data.get()[i * config->write_size]), config->write_size };
+		fifo_buffers_empty.in(&buffers[i]);
+	}
+}
+
+size_t StreamInput::write(const void* const data, const size_t length) {
+	const uint8_t* p = static_cast<const uint8_t*>(data);
+	size_t written = 0;
+
+	while( written < length ) {
+		if( !active_buffer ) {
+			// We need an empty buffer...
+			if( !fifo_buffers_empty.out(active_buffer) ) {
+				// ...but none are available. Samples were dropped.
+				break;
+			}
+		}
+		
+		const auto remaining = length - written;
+		written += active_buffer->write(&p[written], remaining);
+
+		if( active_buffer->is_full() ) {
+			if( !fifo_buffers_full.in(active_buffer) ) {
+				// FIFO is fuil of buffers, there's no place for this one.
+				// Bail out of the loop, and try submitting the buffer in the
+				// next pass.
+				// This should never happen if the number of buffers is less
+				// than the capacity of the FIFO.
+				break;
+			}
+			active_buffer = nullptr;
+			creg::m4txevent::assert();
+		}
+	}
+
+	config->baseband_bytes_received += length;
+	config->baseband_bytes_dropped += (length - written);
+
+	return written;
+}

firmware/baseband/stream_input.hpp

@@ -25,46 +25,29 @@
 #include "message.hpp"
 #include "fifo.hpp"
 
-#include "lpc43xx_cpp.hpp"
-using namespace lpc43xx;
-
 #include <cstdint>
 #include <cstddef>
+#include <array>
 #include <memory>
 
 class StreamInput {
 public:
-	StreamInput(CaptureConfig* const config) :
-		config { config },
-		K { config->write_size_log2 + config->buffer_count_log2 },
-		event_bytes_mask { (1UL << config->write_size_log2) - 1 },
-		data { std::make_unique<uint8_t[]>(1UL << K) },
-		fifo { data.get(), K }
-	{
-		config->fifo = &fifo;
-	}
+	StreamInput(CaptureConfig* const config);
 
-	size_t write(const void* const data, const size_t length) {
-		const auto written = fifo.in(reinterpret_cast<const uint8_t*>(data), length);
-
-		const auto last_bytes_written = bytes_written;
-		bytes_written += written;
-		if( (bytes_written & event_bytes_mask) < (last_bytes_written & event_bytes_mask) ) {
-			creg::m4txevent::assert();
-		}
-		config->baseband_bytes_received += length;
-		config->baseband_bytes_dropped = config->baseband_bytes_received - bytes_written;
-
-		return written;
-	}
+	size_t write(const void* const data, const size_t length);
 
 private:
-	CaptureConfig* const config;
-	const size_t K;
-	const uint64_t event_bytes_mask;
-	uint64_t bytes_written = 0;
+	static constexpr size_t buffer_count_max_log2 = 3;
+	static constexpr size_t buffer_count_max = 1U << buffer_count_max_log2;
+	
+	FIFO<StreamBuffer*> fifo_buffers_empty;
+	FIFO<StreamBuffer*> fifo_buffers_full;
+	std::array<StreamBuffer, buffer_count_max> buffers;
+	std::array<StreamBuffer*, buffer_count_max> buffers_empty;
+	std::array<StreamBuffer*, buffer_count_max> buffers_full;
+	StreamBuffer* active_buffer { nullptr };
+	CaptureConfig* const config { nullptr };
 	std::unique_ptr<uint8_t[]> data;
-	FIFO<uint8_t> fifo;
 };
 
 #endif/*__STREAM_INPUT_H__*/

firmware/common/message.hpp

@@ -24,6 +24,7 @@
 
 #include <cstdint>
 #include <cstddef>
+#include <cstring>
 #include <array>
 #include <functional>
 #include <algorithm>
@@ -411,21 +412,63 @@ public:
 	const iir_biquad_config_t audio_hpf_config;
 };
 
+// TODO: Put this somewhere else, or at least the implementation part.
+class StreamBuffer {
+	uint8_t* data_;
+	size_t used_;
+	size_t capacity_;
+
+public:
+	constexpr StreamBuffer(
+		void* const data = nullptr,
+		const size_t capacity = 0
+	) : data_ { static_cast<uint8_t*>(data) },
+		used_ { 0 },
+		capacity_ { capacity }
+	{
+	}
+
+	size_t write(const void* p, const size_t count) {
+		const auto copy_size = std::min(capacity_ - used_, count);
+		memcpy(&data_[used_], p, copy_size);
+		used_ += copy_size;
+		return copy_size;
+	}
+
+	bool is_full() const {
+		return used_ >= capacity_;
+	}
+
+	const void* data() const {
+		return data_;
+	}
+
+	size_t size() const {
+		return used_;
+	}
+
+	void empty() {
+		used_ = 0;
+	}
+};
+
 struct CaptureConfig {
-	const size_t write_size_log2;
-	const size_t buffer_count_log2;
+	const size_t write_size;
+	const size_t buffer_count;
 	uint64_t baseband_bytes_received;
 	uint64_t baseband_bytes_dropped;
-	FIFO<uint8_t>* fifo;
+	FIFO<StreamBuffer*>* fifo_buffers_empty;
+	FIFO<StreamBuffer*>* fifo_buffers_full;
 
 	constexpr CaptureConfig(
-		const size_t write_size_log2,
-		const size_t buffer_count_log2
-	) : write_size_log2 { write_size_log2 },
-		buffer_count_log2 { buffer_count_log2 },
+		const size_t write_size,
+		const size_t buffer_count
+	) : write_size { write_size },
+		buffer_count { buffer_count },
 		baseband_bytes_received { 0 },
 		baseband_bytes_dropped { 0 },
-		fifo { nullptr }
+		fifo_buffers_empty { nullptr },
+		fifo_buffers_full { nullptr }
 	{
 	}