/**
* Respond to a sent message.
* This will create a node representing the recipient for this process and free the node.
*/
void respond_to_message(Message* response, const char* recipient_name, Node* sender){
assert(sender->status == RECIEVED_MESSAGE);
Node* recipient = create_node(recipient_name, sizeof(Message), READ | WRITE);
assert(recipient->status == WAITING_FOR_RESPONSE);
if (response){
transfer_message(response, recipient);
}
else{
strcpy(recipient->buffer, "");
}
//recipient->status = HANDLING_RESPONSE;
recipient->status = AVAILABLE;
detatch_node(recipient);
sender->status = AVAILABLE;
}
/**
* Send a message and receive a response.
* This will create a node representing the recipient for this process and free the node.
*/
Message* send_message(Message* message, const char* recipient, Node* sender){
Node* recipient_node = create_node(recipient, sizeof(Message), READ | WRITE);
// Copy bytes
transfer_message(message, recipient_node);
sender->status = WAITING_FOR_RESPONSE;
// Wait for response
recipient_node->status = RECIEVED_MESSAGE;
detatch_node(recipient_node);
//while (sender->status != HANDLING_RESPONSE){
while (sender->status != AVAILABLE){
sleep(1);
}
// Return the response
//sender->status = AVAILABLE;
return (Message*)(&(sender->buffer));
}
static WriterResult
ParallelWriterClose(ParallelWriter *self, bool onError)
{
WriterResult ret = { 0 };
if (!self->base.rel)
self->writer->close(self->writer, onError);
/* wait for reader */
if (self->conn)
{
if (self->queue && !onError)
{
PGresult *res;
int sock;
fd_set input_mask;
/* terminate with zero */
write_queue(self, NULL, 0);
do
{
sock = PQsocket(self->conn);
FD_ZERO(&input_mask);
FD_SET(sock, &input_mask);
while (select(sock + 1, &input_mask, NULL, NULL, NULL) < 0)
{
if (errno == EINTR)
{
CHECK_FOR_INTERRUPTS();
continue;
}
ereport(ERROR,
(errcode(ERRCODE_INTERNAL_ERROR),
errmsg("select() failed"),
errdetail("%s", finish_and_get_message(self))));
}
PQconsumeInput(self->conn);
} while (PQisBusy(self->conn));
res = PQgetResult(self->conn);
if (PQresultStatus(res) != PGRES_TUPLES_OK)
{
PQfinish(self->conn);
self->conn = NULL;
transfer_message(NULL, res);
}
else
{
self->base.count = ParseInt64(PQgetvalue(res, 0, 1), 0);
ret.num_dup_new = ParseInt64(PQgetvalue(res, 0, 3), 0);
ret.num_dup_old = ParseInt64(PQgetvalue(res, 0, 4), 0);
PQclear(res);
/* commit transaction */
res = PQexec(self->conn, "COMMIT");
if (PQresultStatus(res) != PGRES_COMMAND_OK)
{
ereport(ERROR,
(errcode(ERRCODE_SQLCLIENT_UNABLE_TO_ESTABLISH_SQLCONNECTION),
errmsg("could not commit transaction"),
errdetail("%s", finish_and_get_message(self))));
}
}
PQclear(res);
}
else if (PQisBusy(self->conn))
{
char errbuf[256];
PGcancel *cancel = PQgetCancel(self->conn);
if (cancel)
PQcancel(cancel, errbuf, lengthof(errbuf));
}
if (self->conn)
PQfinish(self->conn);
self->conn = NULL;
}
/*
* Close self after wait for reader because reader hasn't opened the self
* yet. If we close self too early, the reader cannot open the self.
*/
if (self->queue)
QueueClose(self->queue);
self->queue = NULL;
if (!onError)
{
MemoryContextDelete(self->base.context);
if (self->base.rel)
heap_close(self->base.rel, NoLock);
}
return ret;
}