GCNotificationStatus Enum
Definition
Important
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Provides information about the current registration for notification of the next full garbage collection.
public enum class GCNotificationStatuspublic enum GCNotificationStatus[System.Serializable]
public enum GCNotificationStatustype GCNotificationStatus = [<System.Serializable>]
type GCNotificationStatus = Public Enum GCNotificationStatus- Inheritance
- Attributes
Fields
| Name | Value | Description |
|---|---|---|
| Succeeded | 0 | The notification was successful and the registration was not canceled. |
| Failed | 1 | The notification failed for any reason. |
| Canceled | 2 | The current registration was canceled by the user. |
| Timeout | 3 | The time specified by the |
| NotApplicable | 4 | This value can result when there's no current registration for a garbage collection notification, or a full GC has happened but was done as a background GC (that is, a GC that runs mostly concurrently with user threads) instead of a full blocking GC. Background GC is enabled by default; disabling it improves the prediction accuracy but incurs larger GC pauses. |
Examples
The following example obtains a GCNotificationStatus enumeration from the WaitForFullGCApproach method. If the enumeration returns Succeeded, it calls the custom method OnFullGCApproachNotify to perform actions in response to the approaching full garbage collection. This code example is part of a larger example provided for Garbage Collection Notifications topic.
public static void WaitForFullGCProc()
{
while (true)
{
// CheckForNotify is set to true and false in Main.
while (checkForNotify)
{
// Check for a notification of an approaching collection.
GCNotificationStatus s = GC.WaitForFullGCApproach();
if (s == GCNotificationStatus.Succeeded)
{
Console.WriteLine("GC Notification raised.");
OnFullGCApproachNotify();
}
else if (s == GCNotificationStatus.Canceled)
{
Console.WriteLine("GC Notification cancelled.");
break;
}
else
{
// This can occur if a timeout period
// is specified for WaitForFullGCApproach(Timeout)
// or WaitForFullGCComplete(Timeout)
// and the time out period has elapsed.
Console.WriteLine("GC Notification not applicable.");
break;
}
// Check for a notification of a completed collection.
GCNotificationStatus status = GC.WaitForFullGCComplete();
if (status == GCNotificationStatus.Succeeded)
{
Console.WriteLine("GC Notification raised.");
OnFullGCCompleteEndNotify();
}
else if (status == GCNotificationStatus.Canceled)
{
Console.WriteLine("GC Notification cancelled.");
break;
}
else
{
// Could be a time out.
Console.WriteLine("GC Notification not applicable.");
break;
}
}
Thread.Sleep(500);
// FinalExit is set to true right before
// the main thread cancelled notification.
if (finalExit)
{
break;
}
}
}
let waitForFullGCProc () =
let mutable broken = false
while not broken do
let mutable broken = false
// CheckForNotify is set to true and false in Main.
while checkForNotify && not broken do
// Check for a notification of an approaching collection.
match GC.WaitForFullGCApproach() with
| GCNotificationStatus.Succeeded ->
printfn "GC Notification raised."
onFullGCApproachNotify ()
// Check for a notification of a completed collection.
match GC.WaitForFullGCComplete() with
| GCNotificationStatus.Succeeded ->
printfn "GC Notification raised."
onFullGCCompleteEndNotify ()
| GCNotificationStatus.Canceled ->
printfn "GC Notification cancelled."
broken <- true
| _ ->
// Could be a time out.
printfn "GC Notification not applicable."
broken <- true
| GCNotificationStatus.Canceled ->
printfn "GC Notification cancelled."
broken <- true
| _ ->
// This can occur if a timeout period
// is specified for WaitForFullGCApproach(Timeout)
// or WaitForFullGCComplete(Timeout)
// and the time out period has elapsed.
printfn "GC Notification not applicable."
broken <- true
Thread.Sleep 500
// FinalExit is set to true right before
// the main thread cancelled notification.
if finalExit then broken <- true
Public Shared Sub WaitForFullGCProc()
While True
' CheckForNotify is set to true and false in Main.
While checkForNotify
' Check for a notification of an approaching collection.
Dim s As GCNotificationStatus = GC.WaitForFullGCApproach
If (s = GCNotificationStatus.Succeeded) Then
Console.WriteLine("GC Notification raised.")
OnFullGCApproachNotify()
ElseIf (s = GCNotificationStatus.Canceled) Then
Console.WriteLine("GC Notification cancelled.")
Exit While
Else
' This can occur if a timeout period
' is specified for WaitForFullGCApproach(Timeout)
' or WaitForFullGCComplete(Timeout)
' and the time out period has elapsed.
Console.WriteLine("GC Notification not applicable.")
Exit While
End If
' Check for a notification of a completed collection.
s = GC.WaitForFullGCComplete
If (s = GCNotificationStatus.Succeeded) Then
Console.WriteLine("GC Notifiction raised.")
OnFullGCCompleteEndNotify()
ElseIf (s = GCNotificationStatus.Canceled) Then
Console.WriteLine("GC Notification cancelled.")
Exit While
Else
' Could be a time out.
Console.WriteLine("GC Notification not applicable.")
Exit While
End If
End While
Thread.Sleep(500)
' FinalExit is set to true right before
' the main thread cancelled notification.
If finalExit Then
Exit While
End If
End While
End Sub
Remarks
Use the RegisterForFullGCNotification method to register for a full garbage collection notification. Then use the WaitForFullGCApproach method or the WaitForFullGCComplete method to return a GCNotificationStatus enumeration that contains the status of the notification.
