/// <summary>
/// Releases all references to the server.
/// </summary>
protected virtual void ReleaseServer()
{
lock (m_lock)
{
ComUtils.ReleaseServer(m_unknown);
m_unknown = null;
}
}
/// <summary>
/// An overrideable version of the Dispose.
/// </summary>
protected virtual void Dispose(bool disposing)
{
if (m_server != null)
{
ComUtils.ReleaseServer(m_server);
m_server = null;
}
}
/// <summary>
/// An overrideable version of the Dispose.
/// </summary>
protected virtual void Dispose(bool disposing)
{
object enumerator = System.Threading.Interlocked.Exchange(ref m_enumerator, null);
if (enumerator != null)
{
ComUtils.ReleaseServer(enumerator);
}
}
/// <summary>
/// Must be called in the finally block after making a COM call.
/// </summary>
/// <param name="methodName">Name of the method.</param>
protected void EndComCall(string methodName)
{
Utils.Trace(Utils.TraceMasks.ExternalSystem, "{0} completed.", methodName);
lock (m_lock)
{
m_outstandingCalls--;
if (m_disposed && m_outstandingCalls <= 0)
{
ComUtils.ReleaseServer(m_unknown);
}
}
}
/// <summary>
/// Releases the active server.
/// </summary>
public void Disconnect()
{
try
{
if (m_server != null)
{
ComUtils.ReleaseServer(m_server);
m_server = null;
}
}
catch (Exception e)
{
throw ServiceResultException.Create(StatusCodes.BadCommunicationError, e, "Could not release OPCEnum server.");
}
}
public List <Guid> GetClsIds()
{
var categories = new[]
{
new Guid("63D5F432-CFE4-11d1-B2C8-0060083BA1FB"), // DA 2.xxx
new Guid("CC603642-66D7-48f1-B69A-B625E73652D7"), // DA 3.0
};
IOPCEnumGUID enumerator = null;
_server.EnumClassesOfCategories(2, categories, 0, null, out enumerator);
var guids = new List <Guid>();
try
{
var buffer = new Uri[10];
var guidSize = Marshal.SizeOf <Guid>();
int fetched = 0;
do
{
var ptr = Marshal.AllocCoTaskMem(guidSize * buffer.Length);
try
{
enumerator.Next(buffer.Length, ptr, out fetched);
if (fetched > 0)
{
var p = ptr;
for (int i = 0; i < fetched; i++, p += guidSize)
{
var v = Marshal.PtrToStructure <Guid>(p);
Marshal.DestroyStructure <Guid>(p);
guids.Add(v);
}
}
}
finally
{
Marshal.FreeCoTaskMem(ptr);
}
}while (fetched > 0);
}
catch { }
finally
{
ComUtils.ReleaseServer(enumerator);
}
return(guids);
}
/// <summary>
/// Returns a list of servers that support the specified specification.
/// </summary>
public Uri[] GetAvailableServers(params Specification[] specifications)
{
// enumerate servers on specified machine.
try
{
// convert the interface version to a guid.
Guid[] catids = new Guid[specifications.Length];
for (int ii = 0; ii < catids.Length; ii++)
{
catids[ii] = new Guid(specifications[ii].Id);
}
// get list of servers in the specified specification.
IOPCEnumGUID enumerator = null;
m_server.EnumClassesOfCategories(
catids.Length,
catids,
0,
null,
out enumerator);
// read clsids.
List <Guid> clsids = ReadClasses(enumerator);
// release enumerator object.
ComUtils.ReleaseServer(enumerator);
enumerator = null;
// fetch class descriptions.
Uri[] uris = new Uri[clsids.Count];
for (int ii = 0; ii < uris.Length; ii++)
{
uris[ii] = CreateUri(clsids[ii]);
}
return(uris);
}
catch (Exception e)
{
throw ServiceResultException.Create(StatusCodes.BadCommunicationError, e, "Could not enumerate COM servers.");
}
}
/// <summary>
/// An overrideable version of the Dispose.
/// </summary>
protected virtual void Dispose(bool disposing)
{
UnregisterInterface(typeof(OpcRcw.Ae.IOPCEventSink).GUID);
// Remove monitored items added for this subscription
if (m_AreaVector.Count > 0)
{
m_server.RemoveMonitoredItems(m_AreaVector);
}
if (m_server != null)
{
m_server.SubscriptionListRemove(this);
}
if (m_server != null)
{
ComUtils.ReleaseServer(m_server);
m_server = null;
}
}
/// <summary>
/// Connects to OPCEnum on the specified machine.
/// </summary>
public void Connect(string host, UserIdentity identity)
{
// disconnect from current server.
Disconnect();
// create in the instance.
object unknown = null;
try
{
unknown = ComUtils.CreateInstance(OPCEnumCLSID, host, identity);
}
catch (Exception e)
{
throw ServiceResultException.Create(StatusCodes.BadCommunicationError, e, "Could not connect to OPCEnum server.");
}
m_server = unknown as IOPCServerList2;
if (m_server == null)
{
ComUtils.ReleaseServer(unknown);
StringBuilder error = new StringBuilder();
error.Append("Server does not support IOPCServerList2. ");
error.Append("The OPC proxy/stubs may not be installed properly or the client or server machine. ");
error.Append("The also could be a problem with DCOM security configuration.");
throw ServiceResultException.Create(StatusCodes.BadCommunicationError, error.ToString());
}
m_host = host;
if (String.IsNullOrEmpty(m_host))
{
m_host = "localhost";
}
}
