internal static bool Start(string connectionString, string queue, bool useDefaults)
{
if (string.IsNullOrEmpty(connectionString))
{
if (null == connectionString)
{
throw ADP.ArgumentNull(nameof(connectionString));
}
else
{
throw ADP.Argument(nameof(connectionString));
}
}
if (!useDefaults && string.IsNullOrEmpty(queue))
{ // If specified but null or empty, use defaults.
useDefaults = true;
queue = null; // Force to null - for proper hashtable comparison for default case.
}
// End duplicate Start/Stop logic.
bool errorOccurred = false;
bool result = false;
lock (s_startStopLock)
{
try
{
if (null == s_processDispatcher)
{ // Ensure _processDispatcher reference is present - inside lock.
s_processDispatcher = SqlDependencyProcessDispatcher.SingletonProcessDispatcher;
}
if (useDefaults)
{ // Default listener.
string server = null;
DbConnectionPoolIdentity identity = null;
string user = null;
string database = null;
string service = null;
bool appDomainStart = false;
RuntimeHelpers.PrepareConstrainedRegions();
try
{ // CER to ensure that if Start succeeds we add to hash completing setup.
// Start using process wide default service/queue & database from connection string.
result = s_processDispatcher.StartWithDefault(
connectionString,
out server,
out identity,
out user,
out database,
ref service,
s_appDomainKey,
SqlDependencyPerAppDomainDispatcher.SingletonInstance,
out errorOccurred,
out appDomainStart);
}
finally
{
if (appDomainStart && !errorOccurred)
{ // If success, add to hashtable.
IdentityUserNamePair identityUser = new IdentityUserNamePair(identity, user);
DatabaseServicePair databaseService = new DatabaseServicePair(database, service);
if (!AddToServerUserHash(server, identityUser, databaseService))
{
try
{
Stop(connectionString, queue, useDefaults, true);
}
catch (Exception e)
{ // Discard stop failure!
if (!ADP.IsCatchableExceptionType(e))
{
throw;
}
ADP.TraceExceptionWithoutRethrow(e); // Discard failure, but trace for now.
}
throw SQL.SqlDependencyDuplicateStart();
}
}
}
}
else
{ // Start with specified service/queue & database.
result = s_processDispatcher.Start(
connectionString,
queue,
s_appDomainKey,
SqlDependencyPerAppDomainDispatcher.SingletonInstance);
// No need to call AddToServerDatabaseHash since if not using default queue user is required
// to provide options themselves.
}
}
catch (Exception e)
{
if (!ADP.IsCatchableExceptionType(e))
{
throw;
}
ADP.TraceExceptionWithoutRethrow(e); // Discard failure, but trace for now.
throw;
}
}
return(result);
}
