/* Sleeper thread: sleeps 60 seconds and then triggers the WaitSet. */
void *
delayedEscape(
void *arg)
{
DDS_ReturnCode_t status;
sleep(60); /* wait for 60 sec. */
status = DDS_GuardCondition_set_trigger_value(escape, TRUE);
checkStatus(status, "DDS_GuardCondition_set_trigger_value");
return NULL;
}
int OSPL_MAIN (int argc, char *argv[])
{
DDS_sequence_ListenerData_Msg* message_seq = DDS_sequence_ListenerData_Msg__alloc();
DDS_SampleInfoSeq* message_infoSeq = DDS_SampleInfoSeq__alloc();
DDS_Subscriber message_Subscriber;
DDS_DataReader message_DataReader;
DDS_WaitSet waitSet;
DDS_ConditionSeq* guardList = NULL;
struct DDS_DataReaderListener *message_Listener;
DDS_Duration_t timeout = { 0, 200000000 };
struct Listener_data* Listener_data;
DDS_GuardCondition guardCondition = DDS_GuardCondition__alloc();
int count = 0;
DDS_StatusMask mask;
// Create DDS DomainParticipant
createParticipant("Listener example");
// Register the Topic's type in the DDS Domain.
g_MessageTypeSupport = ListenerData_MsgTypeSupport__alloc();
checkHandle(g_MessageTypeSupport, "ListenerData_MsgTypeSupport__alloc");
registerMessageType(g_MessageTypeSupport);
// Create the Topic's in the DDS Domain.
g_MessageTypeName = ListenerData_MsgTypeSupport_get_type_name(g_MessageTypeSupport);
g_MessageTopic = createTopic("ListenerData_Msg", g_MessageTypeName);
DDS_free(g_MessageTypeName);
DDS_free(g_MessageTypeSupport);
// Create the Subscriber's in the DDS Domain.
message_Subscriber = createSubscriber();
// Request a Reader from the the Subscriber.
message_DataReader = createDataReader(message_Subscriber, g_MessageTopic);
/* Allocate the DataReaderListener interface. */
message_Listener = DDS_DataReaderListener__alloc();
checkHandle(message_Listener, "DDS_DataReaderListener__alloc");
Listener_data = malloc(sizeof(struct Listener_data));
checkHandle(Listener_data, "malloc");
Listener_data->guardCondition = &guardCondition;
Listener_data->message_DataReader = &message_DataReader;
Listener_data->isClosed = &isClosed;
message_Listener->listener_data = Listener_data;
message_Listener->on_data_available = on_data_available;
message_Listener->on_requested_deadline_missed = on_requested_deadline_missed;
mask =
DDS_DATA_AVAILABLE_STATUS | DDS_REQUESTED_DEADLINE_MISSED_STATUS;
g_status = DDS_DataReader_set_listener(message_DataReader, message_Listener, mask);
checkStatus(g_status, "DDS_DataReader_set_listener");
// WaitSet is used to avoid spinning in the loop below.
waitSet = DDS_WaitSet__alloc();
checkHandle(waitSet, "DDS_WaitSet__alloc");
g_status = DDS_WaitSet_attach_condition(waitSet, guardCondition);
checkStatus(g_status, "DDS_WaitSet_attach_condition (readCondition)");
// Initialize and pre-allocate the GuardList used to obtain the triggered Conditions.
guardList = DDS_ConditionSeq__alloc();
checkHandle(guardList, "DDS_ConditionSeq__alloc");
guardList->_maximum = 1;
guardList->_length = 0;
guardList->_buffer = DDS_ConditionSeq_allocbuf(1);
checkHandle(guardList->_buffer, "DDS_ConditionSeq_allocbuf");
printf("\n=== [ListenerDataSubscriber] Ready...");
isClosed = FALSE;
do
{
g_status = DDS_WaitSet_wait(waitSet, guardList, &timeout);
if(g_status != DDS_RETCODE_TIMEOUT)
{
checkStatus(g_status, "DDS_WaitSet_wait");
}
else
{
printf("\n=== [ListenerDataSubscriber] (timeout)");
}
g_status = DDS_GuardCondition_set_trigger_value(guardCondition, FALSE);
checkStatus(g_status, "DDS_GuardCondition_set_trigger_value");
++ count;
}
while( isClosed == FALSE && count < 1500 );
printf("\n\n=== [ListenerDataSubscriber] isClosed");
// Cleanup DDS from the created Entities.
deleteDataReader(message_Subscriber, message_DataReader);
deleteSubscriber(message_Subscriber);
deleteTopic(g_MessageTopic);
deleteParticipant();
// Cleanup C allocations
// Recursively free the instances sequence using the OpenSplice API.
DDS_free(message_seq);
DDS_free(message_infoSeq);
free(Listener_data);
// Print out an empty line, just to avoid the shell writing on the same line as our last output.
printf("\n");
return 0;
}
int OSPL_MAIN (int argc, char *argv[])
{
DDS_sequence_WaitSetData_Msg* message_seq = DDS_sequence_WaitSetData_Msg__alloc();
DDS_SampleInfoSeq* message_infoSeq = DDS_SampleInfoSeq__alloc();
DDS_Subscriber message_Subscriber;
DDS_DataReader message_DataReader;
DDS_char* query_parameter = "Hello again";
DDS_char *query_string = "message=%0";
DDS_ReadCondition readCondition;
DDS_QueryCondition queryCondition;
DDS_StatusCondition statusCondition;
DDS_WaitSet waitSet;
DDS_GuardCondition escape;
DDS_LivelinessChangedStatus livelinessChangedStatus;
DDS_ConditionSeq *guardList = NULL;
DDS_Duration_t timeout = { 20, 0 };
int count = 0;
DDS_long previousLivelinessCount;
c_bool isClosed = FALSE;
c_bool isEscaped = FALSE;
c_bool writerLeft = FALSE;
unsigned long i, j;
// Create DDS DomainParticipant
createParticipant("WaitSet example");
// Register the Topic's type in the DDS Domain.
g_MessageTypeSupport = WaitSetData_MsgTypeSupport__alloc();
checkHandle(g_MessageTypeSupport, "WaitSetData_MsgTypeSupport__alloc");
registerMessageType(g_MessageTypeSupport);
// Create the Topic's in the DDS Domain.
g_MessageTypeName = WaitSetData_MsgTypeSupport_get_type_name(g_MessageTypeSupport);
g_MessageTopic = createTopic("WaitSetData_Msg", g_MessageTypeName);
DDS_free(g_MessageTypeName);
DDS_free(g_MessageTypeSupport);
// Create the Subscriber's in the DDS Domain.
message_Subscriber = createSubscriber();
// Request a Reader from the the Subscriber.
message_DataReader = createDataReader(message_Subscriber, g_MessageTopic);
// 1- Create a ReadCondition that will contain new Msg only.
readCondition = DDS_DataReader_create_readcondition(message_DataReader, DDS_NOT_READ_SAMPLE_STATE, DDS_NEW_VIEW_STATE, DDS_ALIVE_INSTANCE_STATE);
checkHandle(readCondition, "DDS_DataReader_create_readcondition (newUser)");
// 2- Create QueryCondition.
queryCondition = createQueryCondition(message_DataReader, query_string, (DDS_char*) query_parameter);
printf("=== [WaitSetDataSubscriber] Query : message = \"%s\"", query_parameter);
// 3- Obtain a StatusCondition associated to a Writer
// and that triggers only when the Writer changes Liveliness.
statusCondition = DDS_DataReader_get_statuscondition(message_DataReader);
checkHandle(statusCondition, "DDS_DataReader_get_statuscondition");
g_status = DDS_StatusCondition_set_enabled_statuses(statusCondition, DDS_LIVELINESS_CHANGED_STATUS);
checkStatus(g_status, "DDS_StatusCondition_set_enabled_statuses");
// 4- Create a GuardCondition which will be used to close the subscriber.
escape = DDS_GuardCondition__alloc();
checkHandle(escape, "DDS_GuardCondition__alloc");
// Create a waitset and add the 4 Conditions created above :
// ReadCondition, QueryCondition, StatusCondition, GuardCondition.
waitSet = DDS_WaitSet__alloc();
checkHandle(waitSet, "DDS_WaitSet__alloc");
g_status = DDS_WaitSet_attach_condition(waitSet, readCondition);
checkStatus(g_status, "DDS_WaitSet_attach_condition (readCondition)");
g_status = DDS_WaitSet_attach_condition(waitSet, queryCondition);
checkStatus(g_status, "DDS_WaitSet_attach_condition (queryCondition)");
g_status = DDS_WaitSet_attach_condition(waitSet, statusCondition);
checkStatus(g_status, "DDS_WaitSet_attach_condition (statusCondition)");
g_status = DDS_WaitSet_attach_condition(waitSet, escape);
checkStatus(g_status, "DDS_WaitSet_attach_condition (escape)");
// Initialize and pre-allocate the GuardList used to obtain the triggered Conditions.
guardList = DDS_ConditionSeq__alloc();
checkHandle(guardList, "DDS_ConditionSeq__alloc");
guardList->_maximum = 4;
guardList->_length = 0;
guardList->_buffer = DDS_ConditionSeq_allocbuf(4);
checkHandle(guardList->_buffer, "DDS_ConditionSeq_allocbuf");
printf("\n=== [WaitSetDataSubscriber] Ready ...");
// Used to store the livelinessChangedStatus.alive_count value (StatusCondition).
previousLivelinessCount = 0;
do
{
// Wait until at least one of the Conditions in the waitset triggers.
g_status = DDS_WaitSet_wait(waitSet, guardList, &timeout);
if (g_status == DDS_RETCODE_OK) {
i = 0;
do
{
if( guardList->_buffer[i] == statusCondition )
{
// StatusCondition triggered.
// Some liveliness has changed (either a DataWriter joined or a DataWriter left).
// Check whether a new Writer appeared.
g_status = DDS_DataReader_get_liveliness_changed_status(message_DataReader, &livelinessChangedStatus);
checkStatus(g_status, "DDS_DataReader_get_liveliness_changed_status");
if( livelinessChangedStatus.alive_count > previousLivelinessCount )
{
// a DataWriter joined.
printf("\n\n!!! a MsgWriter joined");
g_status = DDS_StatusCondition_set_enabled_statuses(statusCondition, DDS_LIVELINESS_CHANGED_STATUS);
checkStatus(g_status, "DDS_StatusCondition_set_enabled_statuses");
}
else if( livelinessChangedStatus.alive_count < previousLivelinessCount )
{
// A MsgWriter lost its liveliness.
printf("\n\n!!! a MsgWriter lost its liveliness");
g_status = DDS_StatusCondition_set_enabled_statuses(statusCondition, DDS_LIVELINESS_CHANGED_STATUS);
checkStatus(g_status, "DDS_StatusCondition_set_enabled_statuses");
writerLeft = TRUE;
printf("\n === Triggering escape condition");
g_status = DDS_GuardCondition_set_trigger_value(escape, TRUE);
checkStatus(g_status, "DDS_GuardCondition_set_trigger_value");
}
else if ( livelinessChangedStatus.alive_count == previousLivelinessCount )
{
// The status has changed, though alive_count is still zero,
// this implies that both events have occurred,
// and that the value is back to zero already.
printf("\n\n!!! a MsgWriter joined\n");
printf("\n\n!!! a MsgWriter lost its liveliness\n");
writerLeft = TRUE;
printf("\n === Triggering escape condition");
g_status = DDS_GuardCondition_set_trigger_value(escape, TRUE);
checkStatus(g_status, "DDS_GuardCondition_set_trigger_value");
// NB: we do not need to activate this Condition anymore;
// both events occurred.
}
// NB: Here we record the count a in order to compare it next time this condition triggers (?).
previousLivelinessCount = livelinessChangedStatus.alive_count;
}
else if( guardList->_buffer[i] == readCondition )
{
/* The newMsg ReadCondition contains data */
g_status = WaitSetData_MsgDataReader_read_w_condition(message_DataReader, message_seq, message_infoSeq, DDS_LENGTH_UNLIMITED, readCondition);
checkStatus(g_status, "WaitSetData_MsgDataReader_read_w_condition");
for( j = 0; j < message_seq->_length ; j++ )
{
printf("\n --- New message received ---");
if( message_infoSeq->_buffer[j].valid_data == TRUE )
{
printf("\n userID : %d", message_seq->_buffer[j].userID);
printf("\n Message : \"%s\"", message_seq->_buffer[j].message);
}
else
{
printf("\n Data is invalid!");
}
}
fflush(stdout);
g_status = WaitSetData_MsgDataReader_return_loan(message_DataReader, message_seq, message_infoSeq);
checkStatus(g_status, "WaitSetData_MsgDataReader_return_loan");
}
else if( guardList->_buffer[i] == queryCondition )
{
/* The queryCond QueryCondition contains data */
g_status = WaitSetData_MsgDataReader_take_w_condition(message_DataReader, message_seq, message_infoSeq, DDS_LENGTH_UNLIMITED, queryCondition);
checkStatus(g_status, "WaitSetData_MsgDataReader_take_w_condition");
for( j = 0; j < message_seq->_length ; j++ )
{
printf("\n\n --- message received (with QueryCOndition on message field) ---");
if( message_infoSeq->_buffer[j].valid_data == TRUE )
{
printf("\n userID : %d", message_seq->_buffer[j].userID);
printf("\n Message : \"%s\"", message_seq->_buffer[j].message);
}
else
{
printf("\n Data is invalid!");
}
}
fflush(stdout);
g_status = WaitSetData_MsgDataReader_return_loan(message_DataReader, message_seq, message_infoSeq);
checkStatus(g_status, "WaitSetData_MsgDataReader_return_loan");
}
// This checks whether the Timeout Thread has resumed waiting.
else if( guardList->_buffer[i] == escape )
{
printf("\n escape condition triggered! - count = %d\n ", count);
isEscaped = TRUE;
g_status = DDS_GuardCondition_set_trigger_value(escape, FALSE);
checkStatus(g_status, "DDS_GuardCondition_set_trigger_value");
}
}
while( ++i < guardList->_length );
}
else if (g_status != DDS_RETCODE_TIMEOUT) {
// DDS_RETCODE_TIMEOUT is considered as an error
// only after it has occurred count times
checkStatus(g_status, "DDS_WaitSet_wait");
} else {
printf("!!! [INFO] WaitSet timedout - count = %d\n ", count);
}
++count;
isClosed = isEscaped && writerLeft;
} while( isClosed == FALSE && count < 20);
if (count >= 20) {
printf( "*** Error : Timed out - count = %d ***\n", count);
}
/* Remove all Conditions from the WaitSet. */
g_status = DDS_WaitSet_detach_condition(waitSet, escape);
checkStatus(g_status, "DDS_WaitSet_detach_condition (escape)");
g_status = DDS_WaitSet_detach_condition(waitSet, statusCondition);
checkStatus(g_status, "DDS_WaitSet_detach_condition (statusCondition)");
g_status = DDS_WaitSet_detach_condition(waitSet, queryCondition);
checkStatus(g_status, "DDS_WaitSet_detach_condition (queryCondition)");
g_status = DDS_WaitSet_detach_condition(waitSet, readCondition);
checkStatus(g_status, "DDS_WaitSet_detach_condition (readCondition)");
// Cleanup DDS from the created Entities.
deleteQueryCondition(message_DataReader, readCondition);
deleteQueryCondition(message_DataReader, queryCondition);
deleteDataReader(message_Subscriber, message_DataReader);
deleteSubscriber(message_Subscriber);
deleteTopic(g_MessageTopic);
deleteParticipant();
// Cleanup C allocations
// Recursively free the instances sequence using the OpenSplice API.
DDS_free(guardList);
DDS_free(message_seq);
DDS_free(message_infoSeq);
DDS_free(waitSet);
DDS_free(escape);
printf("\n");
return 0;
}