/// <summary>
/// Monitor changes in the registry.
/// Note: This operation is the main Run() loop for the Registry Monitor Thread.
/// </summary>
private void MonitorChanges()
{
//use a hashtable to keep track of bulk changes to the registry so that we only fire one event each
//if multiple changes are made to the registry at once (like when a key is renamed)
Hashtable regChangeList = new Hashtable();
while (true)
{
SafeHandle[] monitorHandles;
RegistryKeyMonitor[] monitors;
lock (this) //lock here so that we don't encounter race conditions if registry listeners are being added/removed
{
monitorHandles = MonitorHandles;
monitors = (RegistryKeyMonitor[])ArrayHelper.CollectionToArray(keyMonitors.Values, (typeof(RegistryKeyMonitor)));
}
using (SafeHandleArrayHelper safeHandleArrayHelper = new SafeHandleArrayHelper(monitorHandles))
{
uint result =
Kernel32.WaitForMultipleObjects((uint)monitorHandles.Length, safeHandleArrayHelper.IntPtrs, false,
Kernel32.INFINITE);
if (result >= 0 && result < FIXED_MONITOR_EVENTS.Length)
{
//a FIXED_MONITOR_EVENT occured, so handle it.
if (result == MONITOR_HANDLES_UPDATED_INDEX)
{
//the monitorHandlesUpdatedEvent was signalled, so reset it and re-loop
//so that we get the latest list of events to monitor.
monitorHandlesUpdatedEvent.Reset();
}
else if (result == MONITOR_ABORT_INDEX)
{
//the monitorAbortEvent was signaled, so exit the method.
//Debug.WriteLine("registry monitor stopped", "RegistryMonitor");
monitorAbortEvent.Reset();
return;
}
else
{
Debug.Fail("unknown FIXED_MONITOR_EVENT detected!");
}
}
else if (result >= WAIT.OBJECT_0 && result <= (WAIT.OBJECT_0 + monitorHandles.Length - 1))
{
//one or more registry keys have changed, so loop to gather up all of the signaled events
uint nextResult = result;
while ((result >= WAIT.OBJECT_0 && result <= (WAIT.OBJECT_0 + monitorHandles.Length - 1))
&& !(result >= 0 && result < FIXED_MONITOR_EVENTS.Length))
{
//a registry change event occured, so add the monitor to the notification list.
RegistryKeyMonitor keyMonitor = monitors[result - FIXED_MONITOR_EVENTS.Length];
regChangeList[keyMonitor.FullKey] = keyMonitor;
//re-register the monitor for change events from the OS
RegisterForRegistryKeyChanged(keyMonitor);
//get the next pending event from the kernel (without blocking)
result =
Kernel32.WaitForMultipleObjects((uint)monitorHandles.Length, safeHandleArrayHelper.IntPtrs, false, 0);
}
//notify the listeners the keys have changed (use the backgroundWorkerQueue so that this thread can't get hosed!)
RegistryKeyMonitor[] changedMonitors =
(RegistryKeyMonitor[])
ArrayHelper.CollectionToArray(regChangeList.Values, typeof(RegistryKeyMonitor));
workerQueue.AddWorker(new WaitCallback(backgroundWorker_HandleRegistryKeyChanged),
changedMonitors);
//clear the change list.
regChangeList.Clear();
}
else if (result == WAIT.FAILED)
{
Debug.Fail("Wait failed: " + Marshal.GetLastWin32Error());
}
else if (result == WAIT.TIMEOUT)
{
//just re-loop so that we have the latest list of events to monitor.
}
else
{
Debug.Fail("unexpected WaitForMultipleObjects() return code!: " + result);
}
}
}
}
/// <summary>
/// Monitor changes in the registry.
/// Note: This operation is the main Run() loop for the Registry Monitor Thread.
/// </summary>
private void MonitorChanges()
{
//use a hashtable to keep track of bulk changes to the registry so that we only fire one event each
//if multiple changes are made to the registry at once (like when a key is renamed)
Hashtable regChangeList = new Hashtable();
while (true)
{
SafeHandle[] monitorHandles;
RegistryKeyMonitor[] monitors;
lock (this) //lock here so that we don't encounter race conditions if registry listeners are being added/removed
{
monitorHandles = MonitorHandles;
monitors = (RegistryKeyMonitor[])ArrayHelper.CollectionToArray(keyMonitors.Values, (typeof(RegistryKeyMonitor)));
}
using (SafeHandleArrayHelper safeHandleArrayHelper = new SafeHandleArrayHelper(monitorHandles))
{
uint result =
Kernel32.WaitForMultipleObjects((uint)monitorHandles.Length, safeHandleArrayHelper.IntPtrs, false,
Kernel32.INFINITE);
if (result >= 0 && result < FIXED_MONITOR_EVENTS.Length)
{
//a FIXED_MONITOR_EVENT occured, so handle it.
if (result == MONITOR_HANDLES_UPDATED_INDEX)
{
//the monitorHandlesUpdatedEvent was signalled, so reset it and re-loop
//so that we get the latest list of events to monitor.
monitorHandlesUpdatedEvent.Reset();
}
else if (result == MONITOR_ABORT_INDEX)
{
//the monitorAbortEvent was signaled, so exit the method.
//Debug.WriteLine("registry monitor stopped", "RegistryMonitor");
monitorAbortEvent.Reset();
return;
}
else
{
Debug.Fail("unknown FIXED_MONITOR_EVENT detected!");
}
}
else if (result >= WAIT.OBJECT_0 && result <= (WAIT.OBJECT_0 + monitorHandles.Length - 1))
{
//one or more registry keys have changed, so loop to gather up all of the signaled events
uint nextResult = result;
while ((result >= WAIT.OBJECT_0 && result <= (WAIT.OBJECT_0 + monitorHandles.Length - 1)) &&
!(result >= 0 && result < FIXED_MONITOR_EVENTS.Length))
{
//a registry change event occured, so add the monitor to the notification list.
RegistryKeyMonitor keyMonitor = monitors[result - FIXED_MONITOR_EVENTS.Length];
regChangeList[keyMonitor.FullKey] = keyMonitor;
//re-register the monitor for change events from the OS
RegisterForRegistryKeyChanged(keyMonitor);
//get the next pending event from the kernel (without blocking)
result =
Kernel32.WaitForMultipleObjects((uint)monitorHandles.Length, safeHandleArrayHelper.IntPtrs, false, 0);
}
//notify the listeners the keys have changed (use the backgroundWorkerQueue so that this thread can't get hosed!)
RegistryKeyMonitor[] changedMonitors =
(RegistryKeyMonitor[])
ArrayHelper.CollectionToArray(regChangeList.Values, typeof(RegistryKeyMonitor));
workerQueue.AddWorker(new WaitCallback(backgroundWorker_HandleRegistryKeyChanged),
changedMonitors);
//clear the change list.
regChangeList.Clear();
}
else if (result == WAIT.FAILED)
{
Debug.Fail("Wait failed: " + Marshal.GetLastWin32Error());
}
else if (result == WAIT.TIMEOUT)
{
//just re-loop so that we have the latest list of events to monitor.
}
else
{
Debug.Fail("unexpected WaitForMultipleObjects() return code!: " + result);
}
}
}
}
