ThreadPool.UnsafeQueueUserWorkItem Method
Definition
Important
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Overloads
| UnsafeQueueUserWorkItem(IThreadPoolWorkItem, Boolean) |
Queues the specified work item object to the thread pool. |
| UnsafeQueueUserWorkItem(WaitCallback, Object) |
Queues the specified delegate to the thread pool, but does not propagate the calling stack to the worker thread. |
| UnsafeQueueUserWorkItem<TState>(Action<TState>, TState, Boolean) |
Queues a method specified by an Action<T> delegate for execution, and specifies an object containing data to be used by the method. The method executes when a thread pool thread becomes available. |
UnsafeQueueUserWorkItem(IThreadPoolWorkItem, Boolean)
- Source:
- ThreadPoolWorkQueue.cs
- Source:
- ThreadPoolWorkQueue.cs
- Source:
- ThreadPoolWorkQueue.cs
Queues the specified work item object to the thread pool.
public:
static bool UnsafeQueueUserWorkItem(System::Threading::IThreadPoolWorkItem ^ callBack, bool preferLocal);public static bool UnsafeQueueUserWorkItem (System.Threading.IThreadPoolWorkItem callBack, bool preferLocal);static member UnsafeQueueUserWorkItem : System.Threading.IThreadPoolWorkItem * bool -> boolPublic Shared Function UnsafeQueueUserWorkItem (callBack As IThreadPoolWorkItem, preferLocal As Boolean) As BooleanParameters
- callBack
- IThreadPoolWorkItem
The work item to invoke when a thread in the thread pool picks up the work item.
- preferLocal
- Boolean
true to prefer queueing the work item in a queue close to the current thread; false to prefer queueing the work item to the thread pool's shared queue.
Returns
true if the method succeeds; OutOfMemoryException is thrown if the work item could not be queued.
Exceptions
callback is null.
The work item is a Task.
The work item could not be queued.
Remarks
The thread pool will invoke the work item's Execute() method. It is the responsibility of that work item to propagate ExecutionContext if it's needed; the thread pool will not do so.
Applies to
UnsafeQueueUserWorkItem(WaitCallback, Object)
- Source:
- ThreadPoolWorkQueue.cs
- Source:
- ThreadPoolWorkQueue.cs
- Source:
- ThreadPoolWorkQueue.cs
Queues the specified delegate to the thread pool, but does not propagate the calling stack to the worker thread.
public:
static bool UnsafeQueueUserWorkItem(System::Threading::WaitCallback ^ callBack, System::Object ^ state);public static bool UnsafeQueueUserWorkItem (System.Threading.WaitCallback callBack, object? state);public static bool UnsafeQueueUserWorkItem (System.Threading.WaitCallback callBack, object state);[System.Security.SecurityCritical]
public static bool UnsafeQueueUserWorkItem (System.Threading.WaitCallback callBack, object state);static member UnsafeQueueUserWorkItem : System.Threading.WaitCallback * obj -> bool[<System.Security.SecurityCritical>]
static member UnsafeQueueUserWorkItem : System.Threading.WaitCallback * obj -> boolPublic Shared Function UnsafeQueueUserWorkItem (callBack As WaitCallback, state As Object) As BooleanParameters
- callBack
- WaitCallback
A WaitCallback that represents the delegate to invoke when a thread in the thread pool picks up the work item.
- state
- Object
The object that is passed to the delegate when serviced from the thread pool.
Returns
true if the method succeeds; OutOfMemoryException is thrown if the work item could not be queued.
- Attributes
Exceptions
The caller does not have the required permission.
An out-of-memory condition was encountered.
The work item could not be queued.
callBack is null.
Remarks
Unlike the QueueUserWorkItem method, UnsafeQueueUserWorkItem does not propagate the calling stack to the worker thread. This allows code to lose the calling stack and thereby to elevate its security privileges.
Caution
Using UnsafeQueueUserWorkItem could inadvertently open up a security hole. Code access security bases its permission checks on the permissions of all the callers on the stack. When work is queued on a thread pool thread using UnsafeQueueUserWorkItem, the stack of the thread pool thread will not have the context of the actual callers. Malicious code might be able exploit this to avoid permission checks.
See also
Applies to
UnsafeQueueUserWorkItem<TState>(Action<TState>, TState, Boolean)
- Source:
- ThreadPoolWorkQueue.cs
- Source:
- ThreadPoolWorkQueue.cs
- Source:
- ThreadPoolWorkQueue.cs
Queues a method specified by an Action<T> delegate for execution, and specifies an object containing data to be used by the method. The method executes when a thread pool thread becomes available.
public:
generic <typename TState>
static bool UnsafeQueueUserWorkItem(Action<TState> ^ callBack, TState state, bool preferLocal);public static bool UnsafeQueueUserWorkItem<TState> (Action<TState> callBack, TState state, bool preferLocal);static member UnsafeQueueUserWorkItem : Action<'State> * 'State * bool -> boolPublic Shared Function UnsafeQueueUserWorkItem(Of TState) (callBack As Action(Of TState), state As TState, preferLocal As Boolean) As BooleanType Parameters
- TState
The type of elements of state.
Parameters
- callBack
- Action<TState>
A delegate representing the method to execute.
- state
- TState
An object containing data to be used by the method.
- preferLocal
- Boolean
true to prefer queueing the work item in a queue close to the current thread; false to prefer queueing the work item to the thread pool's shared queue.
Returns
true if the method is successfully queued; NotSupportedException is thrown if the work item could not be queued.
Exceptions
callback is null.
The work item could not be queued.
Applies to
.NET