private void CleanUpMessages(object state)
{
var directory = (DirectoryInfo)state;
bool createdNew;
var mutexName = string.Concat(MutexCleanUpKey, ".", directory.Name);
var accessControl = new MutexSecurity();
var sid = new SecurityIdentifier(WellKnownSidType.AuthenticatedUserSid, null);
accessControl.SetAccessRule(new MutexAccessRule(sid, MutexRights.FullControl, AccessControlType.Allow));
using (var mutex = new Mutex(true, mutexName, out createdNew, accessControl))
{
if (createdNew)
{
try
{
Thread.Sleep(fileTimeoutMilliseconds);
}
catch (ThreadInterruptedException)
{
}
CleanUpMessages(directory);
mutex.ReleaseMutex();
}
}
if (createdNew)
{
ThreadPool.QueueUserWorkItem(CleanUpMessages, directory);
}
}
public static void Main()
{
// Create a string representing the current user.
string user = Environment.UserDomainName + "\\" +
Environment.UserName;
// Create a security object that grants no access.
MutexSecurity mSec = new MutexSecurity();
// Add a rule that grants the current user the
// right to enter or release the mutex and read the
// permissions on the mutex.
MutexAccessRule rule = new MutexAccessRule(user,
MutexRights.Synchronize | MutexRights.Modify
| MutexRights.ReadPermissions,
AccessControlType.Allow);
mSec.AddAccessRule(rule);
// Add a rule that denies the current user the
// right to change permissions on the mutex.
rule = new MutexAccessRule(user,
MutexRights.ChangePermissions,
AccessControlType.Deny);
mSec.AddAccessRule(rule);
// Display the rules in the security object.
ShowSecurity(mSec);
// Create a rule that grants the current user
// the full control over the mutex. Use the
// SetAccessRule method to replace the
// existing Allow rule with the new rule.
rule = new MutexAccessRule(user,
MutexRights.FullControl,
AccessControlType.Allow);
mSec.SetAccessRule(rule);
ShowSecurity(mSec);
}
/// <summary>
/// This method is called within a seperate thread and deletes messages that are older than
/// the pre-defined expiry time.
/// </summary>
/// <param name = "state"></param>
private static void CleanUpMessages(object state)
{
var directory = (DirectoryInfo)state;
// use a mutex to ensure only one listener system wide is running
bool createdNew;
string mutexName = string.Concat(mutexCleanUpKey, ".", directory.Name);
var accessControl = new MutexSecurity();
var sid = new SecurityIdentifier(WellKnownSidType.AuthenticatedUserSid, null);
accessControl.SetAccessRule(new MutexAccessRule(sid, MutexRights.FullControl, AccessControlType.Allow));
using (var mutex = new Mutex(true, mutexName, out createdNew, accessControl))
{
// we this thread owns the Mutex then clean up otherwise exit.
if (createdNew)
{
// wait for the specified timeout before attempting to clean directory
try
{
Thread.Sleep(fileTimeoutMilliseconds);
}
catch (ThreadInterruptedException)
{
}
CleanUpMessages(directory);
// release the mutex
mutex.ReleaseMutex();
}
}
if (createdNew)
{
// after mutex release add an additional thread for cleanup in case we're the last out
// and there are now additional files to clean
ThreadPool.QueueUserWorkItem(CleanUpMessages, directory);
}
}
