- Fixed a memory leak in s1ap_paging. The static instance was not getting freed.

- Rewrite the singleton to self manage its lifetime.

srsepc/hdr/mme/s1ap_paging.h

@@ -33,19 +33,18 @@ class mme;
 
 class s1ap_paging
 {
+  s1ap_paging() = default;
+
 public:
-  static s1ap_paging* m_instance;
-  static s1ap_paging* get_instance(void);
-  static void         cleanup(void);
-  void                init(void);
+  virtual ~s1ap_paging() = default;
+
+  static s1ap_paging* get_instance();
+  void                init();
 
   // Packing/unpacking helper functions
   bool send_paging(uint64_t imsi, uint16_t erab_to_setup);
 
 private:
-  s1ap_paging();
-  virtual ~s1ap_paging();
-
   mme*                m_mme;
   s1ap*               m_s1ap;
   srslte::log_filter* m_s1ap_log;

srsepc/src/mme/s1ap_paging.cc

@@ -27,40 +27,13 @@
 
 namespace srsepc {
 
-s1ap_paging*    s1ap_paging::m_instance    = NULL;
-pthread_mutex_t s1ap_paging_instance_mutex = PTHREAD_MUTEX_INITIALIZER;
-
-s1ap_paging::s1ap_paging()
-{
-  return;
-}
-
-s1ap_paging::~s1ap_paging()
-{
-  return;
-}
-
-s1ap_paging* s1ap_paging::get_instance(void)
-{
-  pthread_mutex_lock(&s1ap_paging_instance_mutex);
-  if (NULL == m_instance) {
-    m_instance = new s1ap_paging();
-  }
-  pthread_mutex_unlock(&s1ap_paging_instance_mutex);
-  return (m_instance);
-}
-
-void s1ap_paging::cleanup(void)
+s1ap_paging* s1ap_paging::get_instance()
 {
-  pthread_mutex_lock(&s1ap_paging_instance_mutex);
-  if (NULL != m_instance) {
-    delete m_instance;
-    m_instance = NULL;
-  }
-  pthread_mutex_unlock(&s1ap_paging_instance_mutex);
+  static std::unique_ptr<s1ap_paging> m_instance = std::unique_ptr<s1ap_paging>(new s1ap_paging);
+  return m_instance.get();
 }
 
-void s1ap_paging::init(void)
+void s1ap_paging::init()
 {
   m_s1ap      = s1ap::get_instance();
   m_mme       = mme::get_instance();
@@ -80,7 +53,7 @@ bool s1ap_paging::send_paging(uint64_t imsi, uint16_t erab_to_setup)
 
   // Getting UE NAS Context
   nas* nas_ctx = m_s1ap->find_nas_ctx_from_imsi(imsi);
-  if (nas_ctx == NULL) {
+  if (nas_ctx == nullptr) {
     m_s1ap_log->error("Could not find UE to page NAS context\n");
     return false;
   }