Replace concurrentqueue with ringbuffer

platform/posix/cdcacm.cpp

@@ -140,9 +140,8 @@ bool CDCACM::close() {
 	int ret = ::close(fd);
 	fd = -1;
 
-	uint8_t flush;
 	WriteOperation flushop;
-	while (readQueue.try_dequeue(flush)) {}
+	readBuffer.clear();
 	while (writeQueue.try_dequeue(flushop)) {}
 
 	if(modeChanging) {
@@ -191,8 +190,7 @@ void CDCACM::readTask() {
 			}
 			std::cout << std::dec << std::endl;
 #endif
-		
-			readQueue.enqueue_bulk(readbuf, bytesRead);
+			readBuffer.write(readbuf, bytesRead);
 		} else {
 			if(modeChanging) {
 				// We were expecting a disconnect for reenumeration

platform/posix/firmio.cpp

@@ -16,6 +16,7 @@
 #include <errno.h>
 #include <sys/select.h>
 #include <sys/mman.h>
+#include <sys/resource.h>
 
 using namespace icsneo;
 
@@ -44,13 +45,13 @@ void FirmIO::Find(std::vector<FoundDevice>& found) {
 	const auto start = steady_clock::now();
 	// Get an absolute wall clock to compare to
 	const auto overallTimeout = start + milliseconds(500);
-	while(temp.readWait(payload, milliseconds(50))) {
+	while(!temp.readAvailable()) {
 		if(steady_clock::now() > overallTimeout) {
 			// failed to read out a serial number reponse in time
 			break;
 		}
 
-		if(!packetizer.input(payload))
+		if(!packetizer.input(temp.getReadBuffer()))
 			continue; // A full packet has not yet been read out
 
 		for(const auto& packet : packetizer.output()) {
@@ -182,9 +183,6 @@ bool FirmIO::close() {
 	ret |= ::close(fd);
 	fd = -1;
 
-	uint8_t flush;
-	while (readQueue.try_dequeue(flush)) {}
-
 	if(ret == 0) {
 		return true;
 	} else {
@@ -198,6 +196,12 @@ void FirmIO::readTask() {
 	Msg msg;
 	std::vector<Msg> toFree;
 
+	// attempt to elevate the thread priority. PRIO_MIN is actually the highest priority but the lowest value.
+	int err = setpriority(PRIO_PROCESS, 0, -1);
+	if (err != 0) {
+		std::cerr << "FirmIO::readTask setpriority failed : " << strerror(errno)  << std::endl;
+	}
+
 	while(!closing && !isDisconnected()) {
 		fd_set rfds = {0};
 		struct timeval tv = {0};
@@ -219,10 +223,7 @@ void FirmIO::readTask() {
 
 		toFree.clear();
 		int i = 0;
-		while(!in->isEmpty() && i++ < 1000) {
-			if(!in->read(&msg))
-				break;
-
+		while(in->read(&msg) && i++ < 1000) {
 			switch(msg.command) {
 			case Msg::Command::ComData: {
 				if(toFree.empty() || toFree.back().payload.free.refCount == 6) {
@@ -241,9 +242,14 @@ void FirmIO::readTask() {
 
 				// Translate the physical address back to our virtual address space
 				uint8_t* addr = reinterpret_cast<uint8_t*>(msg.payload.data.addr - PHY_ADDR_BASE + vbase);
-				readQueue.enqueue_bulk(addr, msg.payload.data.len);
-				break;
+				while (!readBuffer.write(addr, msg.payload.data.len)) {
+					std::this_thread::sleep_for(std::chrono::milliseconds(1)); // back-off so reading thread can empty the buffer
+					if (closing || isDisconnected()) {
+						break;
+					}
+				}
 			}
+			break;
 			case Msg::Command::ComFree: {
 				std::lock_guard<std::mutex> lk(outMutex);
 				// std::cout << "Got some free " << std::hex << msg.payload.free.ref[0] << std::endl;

platform/posix/ftdi.cpp

@@ -109,9 +109,8 @@ bool FTDI::close() {
 			report(APIEvent::Type::DriverFailedToClose, APIEvent::Severity::Error);
 	}
 	
-	uint8_t flush;
 	WriteOperation flushop;
-	while(readQueue.try_dequeue(flush)) {}
+	readBuffer.clear();
 	while(writeQueue.try_dequeue(flushop)) {}
 
 	closing = false;
@@ -214,7 +213,7 @@ void FTDI::readTask() {
 			} else
 				report(APIEvent::Type::FailedToRead, APIEvent::Severity::EventWarning);
 		} else
-			readQueue.enqueue_bulk(readbuf, readBytes);
+			readBuffer.write(readbuf, readBytes);
 	}
 }
 

platform/posix/pcap.cpp

@@ -136,6 +136,8 @@ void PCAP::Find(std::vector<FoundDevice>& found) {
 		pcap_sendpacket(iface.fp, bs.data(), (int)bs.size());
 
 		auto timeout = std::chrono::high_resolution_clock::now() + std::chrono::milliseconds(50);
+		constexpr const size_t TempBufferSize = 4096;
+		RingBuffer tempBuffer(TempBufferSize);
 		while(std::chrono::high_resolution_clock::now() <= timeout) { // Wait up to 50ms for the response
 			struct pcap_pkthdr* header;
 			const uint8_t* data;
@@ -158,7 +160,8 @@ void PCAP::Find(std::vector<FoundDevice>& found) {
 				continue; // This packet is not for us
 
 			Packetizer packetizer([](APIEvent::Type, APIEvent::Severity) {});
-			if(!packetizer.input(ethPacketizer.outputUp()))
+			tempBuffer.write(ethPacketizer.outputUp());
+			if(!packetizer.input(tempBuffer))
 				continue; // This packet was not well formed
 
 			EthernetPacketizer::EthernetPacket decoded(data, header->caplen);
@@ -267,9 +270,8 @@ bool PCAP::close() {
 	pcap_close(iface.fp);
 	iface.fp = nullptr;
 
-	uint8_t flush;
 	WriteOperation flushop;
-	while(readQueue.try_dequeue(flush)) {}
+	readBuffer.clear();
 	while(writeQueue.try_dequeue(flushop)) {}
 
 	return true;
@@ -282,7 +284,7 @@ void PCAP::readTask() {
 			PCAP* driver = reinterpret_cast<PCAP*>(obj);
 			if(driver->ethPacketizer.inputUp({data, data + header->caplen})) {
 				const auto bytes = driver->ethPacketizer.outputUp();
-				driver->readQueue.enqueue_bulk(bytes.data(), bytes.size());
+				driver->readBuffer.write(bytes.data(), bytes.size());
 			}
 		}, (uint8_t*)this);
 	}