StartParallel(Func<IEnumerable<INotifyCompleted>>,Action<CoroutineOperation>) Method

Start parallel exeuction of multiple asynchronous actions.

Syntax

Visual Basic
C#

'Declaration
 
Public Overloads Shared Function StartParallel( _
   ByVal coroutine As Func(Of IEnumerable(Of INotifyCompleted)), _
   Optional ByVal completedHandler As Action(Of CoroutineOperation) _
) As CoroutineOperation

'Usage
 
Dim coroutine As Func(Of IEnumerable(Of INotifyCompleted))
Dim completedHandler As Action(Of CoroutineOperation)
Dim value As CoroutineOperation
 
value = Coroutine.StartParallel(coroutine, completedHandler)

public static CoroutineOperation StartParallel( 
   Func<IEnumerable<INotifyCompleted>> coroutine,
   Action<CoroutineOperation> completedHandler
)

Parameters

coroutine: An iterator block containing asynchronous actions
completedHandler: Optional completion handler

Return Value

A CoroutineOperation representing this operation

Remarks

Used to start parallel execution of the asynchronous actions within the specified iterator block. Each asychronous action is started on its own thread. Once all actions have completed, the completion handler is called. The CoroutineOperation.Notifications can be used to check the results of each action.

See the second example below for how to pass arguments into the iterator.

Example

public void CoroutineSampleParallel() {

   // Start some parallel async operations.
   var op = Coroutine.StartParallel(SampleActions);

   // Listen for completion. 
   op.Completed += (s, e) => {
     MessageBox.Show(e.Notifications.Count.ToString() + " operations completed");
     // You can loop thru notifications for results from each operation.
   };
 }

 // A block of asynchronous actions to be performed in parallel.
 private IEnumerable<INotifyCompleted> SampleActions() {

   // Start a query for all customers in specified country.
   yield return _entityManager.Customers.Where(c => c.Country == "UK").ExecuteAsync();

   // Start another query for all employees.  This will run in parallel.
   yield return _entityManager.Employees.ExecuteAsync();
 }              
   
/***************************************************************************************/
// Sample 2 - passing arguments to an iterator    
   
 public void CoroutineSampleParallel2() {

   // Start some parallel async operations.
   var op = Coroutine.StartParallel(() => SampleActions2("UK"));

   // Listen for completion. 
   op.Completed += (s, e) => {
     MessageBox.Show(e.Notifications.Count.ToString() + " operations completed");
     // You can loop thru notifications for results from each operation.
   };
 }

 // A block of asynchronous actions to be performed in parallel.
 private IEnumerable<INotifyCompleted> SampleActions2(string country) {

   // Start a query for all customers in specified country.
   yield return _em1.Customers.Where(c => c.Country == country).ExecuteAsync();

   // Start another query for all employeesin specified country. This will run in parallel.
   yield return _em1.Employees.Where(e=> e.Country == country).ExecuteAsync();
 }

Requirements

Target Platforms: Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

Reference

Coroutine Class
Coroutine Members
Overload List