InternetSocket: Use atomics, not volatile

Use a better tool for the job.

Author: kjbracey

UNITTESTS/features/netsocket/DTLSSocketWrapper/unittest.cmake

@@ -21,6 +21,7 @@ set(unittest-test-sources
   features/netsocket/DTLSSocketWrapper/test_DTLSSocketWrapper.cpp
   stubs/Mutex_stub.cpp
   stubs/mbed_assert_stub.c
+  stubs/mbed_critical_stub.c
   stubs/equeue_stub.c
   ../features/nanostack/coap-service/test/coap-service/unittest/stub/mbedtls_stub.c
   stubs/EventQueue_stub.cpp

UNITTESTS/features/netsocket/InternetSocket/test_InternetSocket.cpp

@@ -79,14 +79,6 @@ class stubInternetSocket : public InternetSocket {
     {
         _writers--;
     }
-    void add_pending(void)
-    {
-        _pending++;
-    }
-    void rem_pending(void)
-    {
-        _pending--;
-    }
 
 protected:
     virtual nsapi_protocol_t get_proto()

UNITTESTS/features/netsocket/InternetSocket/unittest.cmake

@@ -18,6 +18,7 @@ set(unittest-test-sources
   features/netsocket/InternetSocket/test_InternetSocket.cpp
   stubs/Mutex_stub.cpp
   stubs/mbed_assert_stub.c
+  stubs/mbed_critical_stub.c
   stubs/equeue_stub.c
   stubs/EventQueue_stub.cpp
   stubs/mbed_shared_queues_stub.cpp

UNITTESTS/features/netsocket/TCPServer/unittest.cmake

@@ -22,6 +22,7 @@ set(unittest-sources
 set(unittest-test-sources
   stubs/Mutex_stub.cpp
   stubs/mbed_assert_stub.c
+  stubs/mbed_critical_stub.c
   stubs/equeue_stub.c
   stubs/EventQueue_stub.cpp
   stubs/mbed_shared_queues_stub.cpp

UNITTESTS/features/netsocket/TCPSocket/unittest.cmake

@@ -19,6 +19,7 @@ set(unittest-test-sources
   features/netsocket/TCPSocket/test_TCPSocket.cpp
   stubs/Mutex_stub.cpp
   stubs/mbed_assert_stub.c
+  stubs/mbed_critical_stub.c
   stubs/equeue_stub.c
   stubs/EventQueue_stub.cpp
   stubs/mbed_shared_queues_stub.cpp

UNITTESTS/features/netsocket/TLSSocketWrapper/unittest.cmake

@@ -20,6 +20,7 @@ set(unittest-test-sources
   features/netsocket/TLSSocketWrapper/test_TLSSocketWrapper.cpp
   stubs/Mutex_stub.cpp
   stubs/mbed_assert_stub.c
+  stubs/mbed_critical_stub.c
   stubs/equeue_stub.c
   ../features/nanostack/coap-service/test/coap-service/unittest/stub/mbedtls_stub.c
   stubs/EventQueue_stub.cpp

UNITTESTS/features/netsocket/UDPSocket/unittest.cmake

@@ -19,6 +19,7 @@ set(unittest-test-sources
   features/netsocket/UDPSocket/test_UDPSocket.cpp
   stubs/Mutex_stub.cpp
   stubs/mbed_assert_stub.c
+  stubs/mbed_critical_stub.c
   stubs/equeue_stub.c
   stubs/EventQueue_stub.cpp
   stubs/mbed_shared_queues_stub.cpp

features/netsocket/InternetSocket.cpp

@@ -21,9 +21,10 @@ using namespace mbed;
 
 InternetSocket::InternetSocket()
     : _stack(0), _socket(0), _timeout(osWaitForever),
-      _readers(0), _writers(0), _pending(0),
+      _readers(0), _writers(0),
       _factory_allocated(false)
 {
+    core_util_atomic_flag_clear(&_pending);
     _socket_stats.stats_new_socket_entry(this);
 }
 
@@ -199,8 +200,7 @@ void InternetSocket::event()
 {
     _event_flag.set(READ_FLAG | WRITE_FLAG);
 
-    _pending += 1;
-    if (_callback && _pending == 1) {
+    if (_callback && !core_util_atomic_flag_test_and_set(&_pending)) {
         _callback();
     }
 }

features/netsocket/InternetSocket.h

@@ -25,6 +25,7 @@
 #include "rtos/Mutex.h"
 #include "rtos/EventFlags.h"
 #include "Callback.h"
+#include "mbed_critical.h"
 #include "mbed_toolchain.h"
 #include "SocketStats.h"
 
@@ -168,7 +169,7 @@ class InternetSocket : public Socket {
     SocketAddress _remote_peer;
     uint8_t _readers;
     uint8_t _writers;
-    volatile unsigned _pending;
+    core_util_atomic_flag _pending;
     bool _factory_allocated;
 
     // Event flags

features/netsocket/TCPServer.cpp

@@ -38,7 +38,7 @@ nsapi_error_t TCPServer::accept(TCPSocket *connection, SocketAddress *address)
             break;
         }
 
-        _pending = 0;
+        core_util_atomic_flag_clear(&_pending);
         void *socket;
         ret = _stack->socket_accept(_socket, &socket, address);