.NET Framework Class Library |
Parallel..::.For<(Of <(TLocal>)>) Method (Int32, Int32, ParallelOptions, Func<(Of <(TLocal>)>), Func<(Of <(Int32, ParallelLoopState, TLocal, TLocal>)>), Action<(Of <(TLocal>)>)) |
Parallel Class See Also Send Feedback |
Namespace:
System.Threading.Tasks
Assembly:
System.Threading (in System.Threading.dll)
Syntax
Visual Basic (Declaration) |
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Public Shared Function For(Of TLocal) ( _ fromInclusive As Integer, _ toExclusive As Integer, _ parallelOptions As ParallelOptions, _ localInit As Func(Of TLocal), _ body As Func(Of Integer, ParallelLoopState, TLocal, TLocal), _ localFinally As Action(Of TLocal) _ ) As ParallelLoopResult |
C# |
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public static ParallelLoopResult For<TLocal>( int fromInclusive, int toExclusive, ParallelOptions parallelOptions, Func<TLocal> localInit, Func<int, ParallelLoopState, TLocal, TLocal> body, Action<TLocal> localFinally ) |
Parameters
- fromInclusive
- Type: System..::.Int32
The start index, inclusive.
- toExclusive
- Type: System..::.Int32
The end index, exclusive.
- parallelOptions
- Type: System.Threading.Tasks..::.ParallelOptions
A ParallelOptions instance that configures the behavior of this operation.
- localInit
- Type: System..::.Func<(Of <(TLocal>)>)
The function delegate that returns the initial state of the local data for each thread.
- body
- Type: System..::.Func<(Of <(Int32, ParallelLoopState, TLocal, TLocal>)>)
The delegate that is invoked once per iteration.
- localFinally
- Type: System..::.Action<(Of <(TLocal>)>)
The delegate that performs a final action on the local state of each thread.
Type Parameters
- TLocal
- The type of the thread-local data.
Return Value
A ParallelLoopResult structure that contains information on what portion of the loop completed.Remarks
The body delegate is invoked once for each value in the iteration range: [fromInclusive, toExclusive). It is provided with the following parameters: the iteration count (an Int32), a ParallelLoopState instance that may be used to break out of the loop prematurely, and some local state that may be shared amongst iterations that execute on the same thread.
The localInit delegate is invoked once for each thread that participates in the loop's execution and returns the initial local state for each of those threads. These initial states are passed to the first body invocations on each thread. Then, every subsequent body invocation returns a possibly modified state value that is passed to the next body invocation. Finally, the last body invocation on each thread returns a state value that is passed to the localFinally delegate. The localFinally delegate is invoked once per thread to perform a final action on each thread's local state.
Exceptions
Exception | Condition |
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System..::.ArgumentNullException | The exception that is thrown when the body argument is null. |
System..::.ArgumentNullException | The exception that is thrown when the localInit argument is null. |
System..::.ArgumentNullException | The exception that is thrown when the localFinally argument is null. |
System..::.ArgumentNullException | The exception that is thrown when the parallelOptions argument is null. |
System..::.OperationCanceledException | The exception that is thrown when the CancellationToken in the parallelOptions argument is set. |
System..::.AggregateException | The exception that is thrown to contain an exception thrown from one of the specified delegates. |
System..::.ObjectDisposedException | The exception that is thrown when the the CancellationTokenSource associated with the the CancellationToken in the parallelOptions has been disposed. |