public virtual void ReleaseItemExclusive(IAspEnvironmentContext context, string id, object lockID)
{
///We are using current context items to hold some values. So we have to delete them before
///current request completes or is forced to complete.
context.RemoveItem(SESSION_LOCK_COUNT);
if (_lockSessions)
{
ReleaseSessionItemLock(context, id, lockID);
}
}
private object getSessionStoreItem(bool acquireLock, IAspEnvironmentContext context, string id, out bool locked, out TimeSpan lockAge, out object lockID, out SessionInitializationActions action)
{
//lock age is set to zero, so SessionStateModule will,
//after 0.5 sec, calls this GetItemExclusive function until a value or
//null reference is returned. If no data was found, 'locked' is set to false and
//null reference is returned which tells SessionStateModule to call CreateDataStore
//function to create new data store
locked = false;
lockAge = TimeSpan.Zero;
lockID = null;
action = SessionInitializationActions.InitializeItem;
DateTime lockDate = DateTime.UtcNow;
LockHandle lockHandle = new LockHandle(null, lockDate);
object items = null;
Hashtable table = null;
bool lockTimedOut = false;
string locationID = GetLocationID(context, id);
if (_cache == null)
{
LogError(new OperationFailedException("The specified cache is not running. "), id);
return(null);
}
try
{
_cache.IsSessionCookieless = IsSessionCookieless(context);
byte[] buffer = null;
lock (s_dataLock)
{
if (s_cacheNeedInit)
{
InitializeCache();
}
}
if (_lockSessions)
{
try
{
buffer = (byte[])_cache.Get(locationID, GetUniqueSessionId(id), ref lockHandle, acquireLock, true);
}
catch (Exception)
{
buffer = (byte[])_cache.Get(locationID, GetUniqueSessionId(id), ref lockHandle, acquireLock, false);
}
lockID = lockHandle.LockId == null ? null : lockHandle;
lockDate = lockHandle == null ? DateTime.UtcNow : lockHandle.LockDate;
}
else
{
try
{
buffer = (byte[])_cache.Get(locationID, GetUniqueSessionId(id), true);
}
catch (Exception)
{
buffer = (byte[])_cache.Get(locationID, GetUniqueSessionId(id), false);
}
}
if (buffer != null)
{
using (MemoryStream stream = new MemoryStream(buffer))
{
BinaryFormatter formatter = new BinaryFormatter();
table = formatter.Deserialize(stream) as Hashtable;
stream.Close();
}
}
if (_lockSessions && !String.IsNullOrEmpty(lockHandle.LockId))
{
DateTime now = DateTime.UtcNow;
if ((0L < lockDate.Ticks) && (lockDate.Ticks < now.Ticks))
{
lockAge = (TimeSpan)(now - lockDate);
}
else
{
lockAge = TimeSpan.Zero;
}
/// Following 'if' block is executed if item is locked.
/// i.e NCache API returns null and out variables are populated with lockId and lockDate
/// Note: Item exists in cache but is locked.
if (table == null)
{
if (this._sessionLockingRetries >= 0)
{
if (!context.ContainsItem(SESSION_LOCK_COUNT))
{
context[SESSION_LOCK_COUNT] = 0;
}
int retriesCompleted = (int)context[SESSION_LOCK_COUNT];
if (retriesCompleted < this._sessionLockingRetries)
{
context[SESSION_LOCK_COUNT] = retriesCompleted + 1;
}
else ///this will construct and send a dummy session to application
{
if (this._emptySessionWhenLocked)
{
locked = false;///a dummy session is going to be returned
lockID = null;
lockTimedOut = true;
return(CreateEmptySession(context, _defaultTimeout));
}
else
{
throw new ProviderException("Cannot acquire session lock. Session is already locked.");
}
}
}
locked = true;
return(null);
}
}
/// If item exists in cahce and lock acqusition was successfull or locking was disabled.
if (table != null)
{
items = GetContents(context, table, ref action);
if (action == SessionInitializationActions.InitializeItem)
{
int timeout = (int)table[TIMEOUT_KEY];
items = CreateNewStoreData(context, timeout);
}
}
else
{
if (NCacheLog != null && NCacheLog.IsInfoEnabled)
{
NCacheLog.Warn("SessionStoreBase.GetSessionItem", "Session not found in cache. " + id);
}
}
}
catch (Exception exc)
{
/// If item is not found in Remote cache.
/// Update cookies to do any further operations for this session request on current primary cache;
/// and do not raise exception.
LogError(exc, id);
}
finally
{
if ((lockTimedOut || table != null) && context.ContainsItem(SESSION_LOCK_COUNT))
{
context.RemoveItem(SESSION_LOCK_COUNT);
}
// throw new ProviderException("Cannot acquire session lock. Session is already locked.");
}
return(items);
}
