Function PQgetCancel

src/interfaces/libpq/fe-connect.c:4516–4536

* PQgetCancel: get a PGcancel structure corresponding to a connection. * * A copy is needed to be able to cancel a running query from a different * thread. If the same structure is used all structure members would have * to be individually locked (if the entire structure was locked, it would * be impossible to cancel a synchronous query because the structure would * have to stay locked for t

 * have to stay locked for the duration of the query).
 */
PGcancel *
PQgetCancel(PGconn *conn)
{
	PGcancel   *cancel;

	if (!conn)
		return NULL;

	if (conn->sock == PGINVALID_SOCKET)
		return NULL;

	cancel = malloc(sizeof(PGcancel));
	if (cancel == NULL)
		return NULL;

	memcpy(&cancel->raddr, &conn->raddr, sizeof(SockAddr));
	cancel->be_pid = conn->be_pid;
	cancel->be_key = conn->be_key;

	return cancel;
}

/* PQfreeCancel: free a cancel structure */
void