- IEC 61850 client: IedConnection - list of client control objects is protected by a lock

src/iec61850/client/ied_connection.c

@@ -473,8 +473,12 @@ handleLastApplErrorMessage(IedConnection self, MmsValue* lastApplError)
     self->lastApplError.ctlNum = MmsValue_toUint32(ctlNum);
     self->lastApplError.addCause = (ControlAddCause) MmsValue_toInt32(addCause);
     self->lastApplError.error = (ControlLastApplError) MmsValue_toInt32(error);
+
+    Semaphore_wait(self->clientControlsLock);
+
     LinkedList control = LinkedList_getNext(self->clientControls);
-    while (control != NULL) {
+
+    while (control) {
         ControlObjectClient object = (ControlObjectClient) control->data;
 
         const char* objectRef = ControlObjectClient_getObjectReference(object);
@@ -485,6 +489,8 @@ handleLastApplErrorMessage(IedConnection self, MmsValue* lastApplError)
 
         control = LinkedList_getNext(control);
     }
+
+    Semaphore_post(self->clientControlsLock);
 }
 
 static void
@@ -515,9 +521,11 @@ informationReportHandler(void* parameter, char* domainName,
             if (DEBUG_IED_CLIENT)
                 printf("IED_CLIENT: RCVD CommandTermination for %s/%s\n", domainName, variableListName);
 
+            Semaphore_wait(self->clientControlsLock);
+
             LinkedList control = LinkedList_getNext(self->clientControls);
 
-            while (control != NULL) {
+            while (control) {
                ControlObjectClient object = (ControlObjectClient) control->data;
 
                const char* objectRef = ControlObjectClient_getObjectReference(object);
@@ -527,6 +535,8 @@ informationReportHandler(void* parameter, char* domainName,
 
                control = LinkedList_getNext(control);
             }
+
+            Semaphore_post(self->clientControlsLock);
         }
 
         MmsValue_delete(value);
@@ -585,6 +595,7 @@ createNewConnectionObject(TLSConfiguration tlsConfig, bool useThreads)
     if (self) {
         self->enabledReports = LinkedList_create();
         self->logicalDevices = NULL;
+        self->clientControlsLock = Semaphore_create(1);
         self->clientControls = LinkedList_create();
 
 
@@ -810,6 +821,7 @@ IedConnection_destroy(IedConnection self)
 
     LinkedList_destroyStatic(self->clientControls);
 
+    Semaphore_destroy(self->clientControlsLock);
     Semaphore_destroy(self->outstandingCallsLock);
     Semaphore_destroy(self->stateMutex);
     Semaphore_destroy(self->reportHandlerMutex);
@@ -3796,13 +3808,21 @@ IedConnection_getLastApplError(IedConnection self)
 void
 iedConnection_addControlClient(IedConnection self, ControlObjectClient control)
 {
+    Semaphore_wait(self->clientControlsLock);
+
     LinkedList_add(self->clientControls, control);
+
+    Semaphore_post(self->clientControlsLock);
 }
 
 void
 iedConnection_removeControlClient(IedConnection self, ControlObjectClient control)
 {
+    Semaphore_wait(self->clientControlsLock);
+
     LinkedList_remove(self->clientControls, control);
+
+    Semaphore_post(self->clientControlsLock);
 }
 
 FileDirectoryEntry

src/iec61850/inc/iec61850_client.h

@@ -1957,14 +1957,32 @@ ControlObjectClient_createEx(const char* objectReference, IedConnection connecti
 LIB61850_API void
 ControlObjectClient_destroy(ControlObjectClient self);
 
+/**
+ * Cause of the \ref ControlObjectClient_ControlActionHandler invocation
+ */
 typedef enum
 {
-    CONTROL_ACTION_TYPE_SELECT = 0,
-    CONTROL_ACTION_TYPE_OPERATE = 1,
-    CONTROL_ACTION_TYPE_CANCEL = 2
+    CONTROL_ACTION_TYPE_SELECT = 0, /** < callback was invoked because of a select command */
+    CONTROL_ACTION_TYPE_OPERATE = 1,  /** < callback was invoked because of an operate command */
+    CONTROL_ACTION_TYPE_CANCEL = 2 /** < callback was invoked because of a cancel command */
 } ControlActionType;
 
-
+/**
+ * \brief A callback handler that is invoked when a command termination message is received.
+ *
+ * This callback is invoked whenever a CommandTermination+ or CommandTermination- message is received.
+ * To distinguish between a CommandTermination+ and CommandTermination- please use the
+ * ControlObjectClient_getLastApplError function.
+ *
+ * NOTE: Do not call \ref ControlObjectClient_destroy inside of this callback! Doing so will cause a dead-lock.
+ *
+ * \param invokeId invoke ID of the command sent by the client
+ * \param parameter the user parameter that is passed to the callback function
+ * \param err the error code when an error occurred, or IED_ERROR_OK
+ * \param type control action type that caused the callback
+ * \param success true, when the command was successful, false otherwise
+ *
+ */
 typedef void
 (*ControlObjectClient_ControlActionHandler) (uint32_t invokeId, void* parameter, IedClientError err, ControlActionType type, bool success);
 
@@ -2196,7 +2214,7 @@ ControlObjectClient_setOrigin(ControlObjectClient self, const char* orIdent, int
  * NOTE: Some non-standard compliant servers may require this to accept oper/cancel requests
  *
  * \param self the ControlObjectClient instance
- * \param useContantT enable this behaviour with true, disable with false
+ * \param useContantT enable this behavior with true, disable with false
  */
 LIB61850_API void
 ControlObjectClient_useConstantT(ControlObjectClient self, bool useConstantT);
@@ -2233,13 +2251,15 @@ ControlObjectClient_setSynchroCheck(ControlObjectClient self, bool value);
 
 
 /**
- * \brief Private a callback handler that is invoked when a command termination message is received.
+ * \brief A callback handler that is invoked when a command termination message is received.
  *
  * This callback is invoked whenever a CommandTermination+ or CommandTermination- message is received.
  * To distinguish between a CommandTermination+ and CommandTermination- please use the
  * ControlObjectClient_getLastApplError function.
  *
- * \param parameter the user paramter that is passed to the callback function
+ * NOTE: Do not call \ref ControlObjectClient_destroy inside of this callback! Doing so will cause a dead-lock.
+ *
+ * \param parameter the user parameter that is passed to the callback function
  * \param controlClient the ControlObjectClient instance
  */
 typedef void (*CommandTerminationHandler) (void* parameter, ControlObjectClient controlClient);

src/iec61850/inc_private/ied_connection_private.h

@@ -56,7 +56,10 @@ struct sIedConnection
     IedConnectionState state;
     LinkedList enabledReports;
     LinkedList logicalDevices;
+
+    Semaphore clientControlsLock;
     LinkedList clientControls;
+
     LastApplError lastApplError;
 
     Semaphore stateMutex;