Update udp test cases to verify network socket statistics

Cases Updated are:
1. UDPSOCKET_ECHOTEST_NONBLOCK
2. UDPSOCKET_OPEN_CLOSE_REPEAT
3. UDPSOCKET_OPEN_LIMIT

TESTS/netsocket/udp/main.cpp

@@ -37,6 +37,10 @@ namespace {
 NetworkInterface *net;
 }
 
+#if defined(MBED_NW_STATS_ENABLED)
+mbed_stats_socket_t udp_stats[MBED_CONF_NSAPI_SOCKET_STATS_MAX_COUNT] = {0};
+#endif
+
 NetworkInterface *get_interface()
 {
     return net;
@@ -76,6 +80,15 @@ void fill_tx_buffer_ascii(char *buff, size_t len)
     }
 }
 
+int fetch_stats()
+{
+#if defined(MBED_NW_STATS_ENABLED)
+    return SocketStats::mbed_stats_socket_get_each(&udp_stats[0], MBED_CONF_NSAPI_SOCKET_STATS_MAX_COUNT);
+#else
+    return 0;
+#endif
+}
+
 // Test setup
 utest::v1::status_t greentea_setup(const size_t number_of_cases)
 {

TESTS/netsocket/udp/udp_tests.h

@@ -21,6 +21,11 @@
 NetworkInterface *get_interface();
 void drop_bad_packets(UDPSocket &sock, int orig_timeout);
 void fill_tx_buffer_ascii(char *buff, size_t len);
+int fetch_stats(void);
+
+#if defined(MBED_NW_STATS_ENABLED)
+extern mbed_stats_socket_t udp_stats[MBED_CONF_NSAPI_SOCKET_STATS_MAX_COUNT];
+#endif
 
 /*
  * Test cases

TESTS/netsocket/udp/udpsocket_echotest.cpp

@@ -121,6 +121,14 @@ void udpsocket_echotest_nonblock_receiver(void *receive_bytes)
 
 void UDPSOCKET_ECHOTEST_NONBLOCK()
 {
+#if defined(MBED_NW_STATS_ENABLED)
+    int j = 0;
+    int count = fetch_stats();
+    for (; j < count; j++) {
+        TEST_ASSERT_EQUAL(SOCK_CLOSED, udp_stats[j].state);
+    }
+#endif
+
     SocketAddress udp_addr;
     get_interface()->gethostbyname(MBED_CONF_APP_ECHO_SERVER_ADDR, &udp_addr);
     udp_addr.set_port(MBED_CONF_APP_ECHO_SERVER_PORT);
@@ -174,6 +182,14 @@ void UDPSOCKET_ECHOTEST_NONBLOCK()
         }
     }
     free(stack_mem);
+
+#if defined(MBED_NW_STATS_ENABLED)
+    TEST_ASSERT_EQUAL(1, fetch_stats());
+    TEST_ASSERT_EQUAL(NSAPI_UDP, udp_stats[0].proto);
+    TEST_ASSERT(udp_stats[0].sent_bytes != 0);
+    TEST_ASSERT(udp_stats[0].recv_bytes != 0);
+#endif
+
     // Packet loss up to 30% tolerated
     if (packets_sent > 0) {
         double loss_ratio = 1 - ((double)packets_recv / (double)packets_sent);

TESTS/netsocket/udp/udpsocket_open_close_repeat.cpp

@@ -26,6 +26,11 @@ using namespace utest::v1;
 
 void UDPSOCKET_OPEN_CLOSE_REPEAT()
 {
+    int count = fetch_stats();
+    for (int j = 0; j < count; j++) {
+        TEST_ASSERT_EQUAL(SOCK_CLOSED,  udp_stats[j].state);
+    }
+
     UDPSocket *sock = new UDPSocket;
     if (!sock) {
         TEST_FAIL();
@@ -36,4 +41,9 @@ void UDPSOCKET_OPEN_CLOSE_REPEAT()
         TEST_ASSERT_EQUAL(NSAPI_ERROR_OK, sock->close());
     }
     delete sock;
+
+    count = fetch_stats();
+    for (int j = 0; j < count; j++) {
+        TEST_ASSERT_EQUAL(SOCK_CLOSED, udp_stats[j].state);
+    }
 }

TESTS/netsocket/udp/udpsocket_open_limit.cpp

@@ -21,6 +21,7 @@
 #include "UDPSocket.h"
 #include "unity/unity.h"
 #include "utest.h"
+#include "SocketStats.h"
 
 using namespace utest::v1;
 
@@ -70,6 +71,15 @@ void UDPSOCKET_OPEN_LIMIT()
             break;
         }
 
+        int count = fetch_stats();
+        int open_count = 0;
+        for (int j = 0; j < count; j++) {
+            if ((udp_stats[j].state == SOCK_OPEN) && (udp_stats[j].proto == NSAPI_UDP)) {
+                open_count++;
+            }
+        }
+        TEST_ASSERT(open_count >= 3);
+
         UDPSocketItem *tmp;
         for (UDPSocketItem *it = socket_list_head; it;) {
             ++open_sockets[i];