Cellular: Replace CellularSocket.rx_avail with pending_bytes

CellularSocket::rx_avail can be refactored away as
it is a duplicate to CellularSocket::pending_bytes.

Author: Ari Parkkila

features/cellular/framework/AT/AT_CellularStack.cpp

@@ -274,7 +274,7 @@ nsapi_size_or_error_t AT_CellularStack::socket_sendto(nsapi_socket_t handle, con
         return NSAPI_ERROR_NO_SOCKET;
     }
 
-    if (socket->closed && !socket->rx_avail) {
+    if (socket->closed && !socket->pending_bytes) {
         tr_info("sendto socket %d closed", socket->id);
         return NSAPI_ERROR_NO_CONNECTION;
     }

features/cellular/framework/AT/AT_CellularStack.h

@@ -112,7 +112,6 @@ class AT_CellularStack : public NetworkStack, public AT_CellularBase {
             closed(false),
             started(false),
             tx_ready(false),
-            rx_avail(false),
             tls_socket(false),
             pending_bytes(0)
         {
@@ -130,7 +129,6 @@ class AT_CellularStack : public NetworkStack, public AT_CellularBase {
         bool closed; // socket has been closed by a peer
         bool started; // socket has been opened on modem stack
         bool tx_ready; // socket is ready for sending on modem stack
-        bool rx_avail; // socket has data for reading on modem stack
         bool tls_socket; // socket uses modem's internal TLS socket functionality
         nsapi_size_t pending_bytes; // The number of received bytes pending
     };

features/cellular/framework/targets/GEMALTO/CINTERION/GEMALTO_CINTERION_CellularStack.cpp

@@ -99,7 +99,7 @@ void GEMALTO_CINTERION_CellularStack::sisr_urc_handler(int sock_id, int urc_code
     if (sock) {
         if (urc_code == 1) { // data available
             if (sock->_cb) {
-                sock->rx_avail = true;
+                sock->pending_bytes = 1;
                 sock->_cb(sock->_data);
             }
         }
@@ -387,9 +387,9 @@ nsapi_size_or_error_t GEMALTO_CINTERION_CellularStack::socket_recvfrom_impl(Cell
 
     // we must use this flag, otherwise ^SISR URC can come while we are reading response and there is
     // no way to detect if that is really an URC or response
-    if (!socket->rx_avail) {
+    if (!socket->pending_bytes) {
         _at.process_oob(); // check for ^SISR URC
-        if (!socket->rx_avail) {
+        if (!socket->pending_bytes) {
             tr_debug("Socekt %d recv would block", socket->id);
             return NSAPI_ERROR_WOULD_BLOCK;
         }
@@ -430,12 +430,12 @@ nsapi_size_or_error_t GEMALTO_CINTERION_CellularStack::socket_recvfrom_impl(Cell
         tr_error("Socket %d recvfrom failed!", socket->id);
         return NSAPI_ERROR_DEVICE_ERROR;
     }
-    socket->rx_avail = false;
+    socket->pending_bytes = 0;
     if (len >= (nsapi_size_or_error_t)size) {
         len = (nsapi_size_or_error_t)size;
         int remain_len = _at.read_int();
         if (remain_len > 0) {
-            socket->rx_avail = true;
+            socket->pending_bytes = 1;
         }
     }
 

features/cellular/framework/targets/UBLOX/AT/UBLOX_AT_CellularStack.cpp

@@ -55,7 +55,6 @@ void UBLOX_AT_CellularStack::UUSORD_URC()
 
     socket = find_socket(a);
     if (socket != NULL) {
-        socket->rx_avail = true;
         socket->pending_bytes = b;
         // No debug prints here as they can affect timing
         // and cause data loss in UARTSerial
@@ -76,7 +75,6 @@ void UBLOX_AT_CellularStack::UUSORF_URC()
 
     socket = find_socket(a);
     if (socket != NULL) {
-        socket->rx_avail = true;
         socket->pending_bytes = b;
         // No debug prints here as they can affect timing
         // and cause data loss in UARTSerial
@@ -353,7 +351,6 @@ nsapi_size_or_error_t UBLOX_AT_CellularStack::socket_recvfrom_impl(CellularSocke
     }
     timer.stop();
 
-    socket->rx_avail = false;
     socket->pending_bytes = 0;
     if (!count || (_at.get_last_error() != NSAPI_ERROR_OK)) {
         return NSAPI_ERROR_WOULD_BLOCK;
@@ -398,7 +395,6 @@ void UBLOX_AT_CellularStack::clear_socket(CellularSocket *socket)
     if (socket != NULL) {
         socket->id = SOCKET_UNUSED;
         socket->started = false;
-        socket->rx_avail = false;
         socket->pending_bytes = 0;
         socket->closed = true;
         if (socket->_cb) {

features/cellular/framework/targets/UBLOX/N2XX/UBLOX_N2XX_CellularStack.cpp

@@ -54,7 +54,6 @@ void UBLOX_N2XX_CellularStack::NSONMI_URC()
 
     socket = find_socket(a);
     if (socket != NULL) {
-        socket->rx_avail = true;
         socket->pending_bytes = b;
         // No debug prints here as they can affect timing
         // and cause data loss in UARTSerial
@@ -209,7 +208,6 @@ nsapi_size_or_error_t UBLOX_N2XX_CellularStack::socket_recvfrom_impl(CellularSoc
     }
     timer.stop();
 
-    socket->rx_avail = false;
     socket->pending_bytes = 0;
     if (!count || (_at.get_last_error() != NSAPI_ERROR_OK)) {
         return NSAPI_ERROR_WOULD_BLOCK;