From 6860aed85bf9cb91e11c3730c33388d38df98f71 Mon Sep 17 00:00:00 2001
From: Jonathan Naylor <jonathan.naylor@igence.com>
Date: Wed, 15 Nov 2017 11:10:12 +0000
Subject: [PATCH] Fixes for OSX serial writing.

---
 Modem.cpp            |  4 +++
 SerialController.cpp | 68 ++++++++++++++++++++++++++++++++++++++++----
 SerialController.h   |  6 ++++
 3 files changed, 73 insertions(+), 5 deletions(-)

diff --git a/Modem.cpp b/Modem.cpp
index 7f87c33..9265879 100644
--- a/Modem.cpp
+++ b/Modem.cpp
@@ -906,6 +906,10 @@ bool CModem::readVersion()
 		if (ret != 3)
 			return false;
 
+#if defined(__APPLE__)
+		m_serial.setNonblock(true);
+#endif
+
 		for (unsigned int count = 0U; count < MAX_RESPONSES; count++) {
 			CThread::sleep(10U);
 			RESP_TYPE_MMDVM resp = getResponse();
diff --git a/SerialController.cpp b/SerialController.cpp
index 67310c8..7856c24 100644
--- a/SerialController.cpp
+++ b/SerialController.cpp
@@ -237,8 +237,11 @@ CSerialController::~CSerialController()
 bool CSerialController::open()
 {
 	assert(m_fd == -1);
-
+#if defined(__APPLE__)
+	m_fd = ::open(m_device.c_str(), O_RDWR | O_NOCTTY | O_NONBLOCK); /*open in block mode under OSX*/
+#else
 	m_fd = ::open(m_device.c_str(), O_RDWR | O_NOCTTY | O_NDELAY, 0);
+#endif
 	if (m_fd < 0) {
 		LogError("Cannot open device - %s", m_device.c_str());
 		return false;
@@ -257,6 +260,23 @@ bool CSerialController::open()
 		return false;
 	}
 
+	#if defined(__APPLE__)
+	termios.c_cflag |= (CLOCAL | CREAD);    /* ignore modem controls */
+	termios.c_cflag &= ~CSIZE;
+	termios.c_cflag |= CS8;         /* 8-bit characters */
+	termios.c_cflag &= ~PARENB;     /* no parity bit */
+	termios.c_cflag &= ~CSTOPB;     /* only need 1 stop bit */
+	termios.c_cflag &= ~CRTSCTS;    /* no hardware flowcontrol */
+
+    /* setup for non-canonical mode */
+	termios.c_iflag &= ~(IGNBRK | BRKINT | PARMRK | ISTRIP | INLCR | IGNCR | ICRNL | IXON);
+	termios.c_lflag &= ~(ECHO | ECHONL | ICANON | ISIG | IEXTEN);
+	termios.c_oflag &= ~OPOST;
+
+    /* fetch bytes as they become available */
+	termios.c_cc[VMIN] = 1;
+	termios.c_cc[VTIME] = 1;
+#else
 	termios.c_lflag    &= ~(ECHO | ECHOE | ICANON | IEXTEN | ISIG);
 	termios.c_iflag    &= ~(BRKINT | ICRNL | INPCK | ISTRIP | IXON | IXOFF | IXANY);
 	termios.c_cflag    &= ~(CSIZE | CSTOPB | PARENB | CRTSCTS);
@@ -264,6 +284,7 @@ bool CSerialController::open()
 	termios.c_oflag    &= ~(OPOST);
 	termios.c_cc[VMIN]  = 0;
 	termios.c_cc[VTIME] = 10;
+#endif
 
 	switch (m_speed) {
 		case SERIAL_1200:
@@ -327,9 +348,27 @@ bool CSerialController::open()
 		}
 	}
 
+#if defined(__APPLE__)
+	setNonblock(false);
+#endif
+
 	return true;
 }
 
+#if defined(__APPLE__)
+int CSerialController::setNonblock(bool nonblock)
+{
+	int flag = ::fcntl(m_fd, F_GETFD, 0);
+
+	if (nonblock)
+		flag |= O_NONBLOCK;
+	else
+		flag &= ~O_NONBLOCK;
+
+	return ::fcntl(m_fd, F_SETFL, flag);
+}
+#endif
+
 int CSerialController::read(unsigned char* buffer, unsigned int length)
 {
 	assert(buffer != NULL);
@@ -344,13 +383,11 @@ int CSerialController::read(unsigned char* buffer, unsigned int length)
 		fd_set fds;
 		FD_ZERO(&fds);
 		FD_SET(m_fd, &fds);
-
 		int n;
 		if (offset == 0U) {
 			struct timeval tv;
 			tv.tv_sec  = 0;
 			tv.tv_usec = 0;
-
 			n = ::select(m_fd + 1, &fds, NULL, NULL, &tv);
 			if (n == 0)
 				return 0;
@@ -380,6 +417,26 @@ int CSerialController::read(unsigned char* buffer, unsigned int length)
 	return length;
 }
 
+bool CSerialController::canWrite(){
+#if defined(__APPLE__)
+	fd_set wset;
+	FD_ZERO(&wset);
+	FD_SET(m_fd, &wset);
+
+	struct timeval timeo;
+	timeo.tv_sec  = 0;
+	timeo.tv_usec = 0;
+
+	int rc = select(m_fd + 1, NULL, &wset, NULL, &timeo);
+	if (rc >0 && FD_ISSET(m_fd, &wset))
+		return true;
+
+	return false;
+#else
+	return true;
+#endif
+}
+
 int CSerialController::write(const unsigned char* buffer, unsigned int length)
 {
 	assert(buffer != NULL);
@@ -389,9 +446,10 @@ int CSerialController::write(const unsigned char* buffer, unsigned int length)
 		return 0;
 
 	unsigned int ptr = 0U;
-
 	while (ptr < length) {
-		ssize_t n = ::write(m_fd, buffer + ptr, length - ptr);
+		ssize_t n = 0U;
+		if (canWrite())
+			n = ::write(m_fd, buffer + ptr, length - ptr);
 		if (n < 0) {
 			if (errno != EAGAIN) {
 				LogError("Error returned from write(), errno=%d", errno);
diff --git a/SerialController.h b/SerialController.h
index edb8e2b..63bd8be 100644
--- a/SerialController.h
+++ b/SerialController.h
@@ -53,6 +53,10 @@ public:
 
 	virtual void close();
 
+#if defined(__APPLE__)
+	virtual int setNonblock(bool nonblock);
+#endif
+
 private:
 	std::string    m_device;
 	SERIAL_SPEED   m_speed;
@@ -65,6 +69,8 @@ private:
 
 #if defined(_WIN32) || defined(_WIN64)
 	int readNonblock(unsigned char* buffer, unsigned int length);
+#else
+	bool canWrite();
 #endif
 };