Monitor.TryEnter メソッド

[アーティクル]
03/28/2008

指定したオブジェクトの排他ロックの取得を試みます。

オーバーロードの一覧

指定したオブジェクトの排他ロックの取得を試みます。

[Visual Basic] Overloads Public Shared Function TryEnter(Object) As Boolean

[C#] public static bool TryEnter(object);

[C++] public: static bool TryEnter(Object*);

[JScript] public static function TryEnter(Object) : Boolean;

指定したミリ秒間に、指定したオブジェクトの排他ロックの取得を試みます。

[Visual Basic] Overloads Public Shared Function TryEnter(Object, Integer) As Boolean

[C#] public static bool TryEnter(object, int);

[C++] public: static bool TryEnter(Object*, int);

[JScript] public static function TryEnter(Object, int) : Boolean;

指定した時間内に、指定したオブジェクトの排他ロックの取得を試みます。

[Visual Basic] Overloads Public Shared Function TryEnter(Object, TimeSpan) As Boolean

[C#] public static bool TryEnter(object, TimeSpan);

[C++] public: static bool TryEnter(Object*, TimeSpan);

[JScript] public static function TryEnter(Object, TimeSpan) : Boolean;

使用例

[Visual Basic, C#, C++] TryEnter メソッドを使用する方法を次のコード例に示します。

[Visual Basic, C#, C++] メモここでは、TryEnter のオーバーロード形式のうちの 1 つだけについて、使用例を示します。その他の例については、各オーバーロード形式のトピックを参照してください。

 
Imports System
Imports System.Threading
Imports System.Collections


Class MonitorSample
    'Define the queue to safe thread access.
    Private m_inputQueue As Queue

    Public Sub New()
        m_inputQueue = New Queue()
    End Sub

    'Add an element to the queue and obtain the monitor lock for the queue object.
    Public Sub AddElement(ByVal qValue As Object)
        'Lock the queue.
        Monitor.Enter(m_inputQueue)
        'Add an element.
        m_inputQueue.Enqueue(qValue)
        'Unlock the queue.
        Monitor.Exit(m_inputQueue)
    End Sub

    'Try to add an element to the queue.
    'Add the element to the queue only if the queue object is unlocked.
    Public Function AddElementWithoutWait(ByVal qValue As Object) As Boolean
        'Determine whether the queue is locked.
        If Not Monitor.TryEnter(m_inputQueue) Then
            Return False
        Else
            m_inputQueue.Enqueue(qValue)
            Monitor.Exit(m_inputQueue)
            Return True
        End If
    End Function

    'Try to add an element to the queue. 
    'Add the element to the queue only if during the specified time the queue object will be unlocked.
    Public Function WaitToAddElement(ByVal qValue As Object, ByVal waitTime As Integer) As Boolean
        'Wait while the queue is locked.
        If Not Monitor.TryEnter(m_inputQueue, waitTime) Then
            Return False
        Else
            m_inputQueue.Enqueue(qValue)
            Monitor.Exit(m_inputQueue)
            Return True
        End If
    End Function

    'Delete all elements that equal the given object and obtain the monitor lock for the queue object.
    Public Sub DeleteElement(ByVal qValue As Object)
        'Lock the queue.
        Monitor.Enter(m_inputQueue)
        Dim counter As Integer = m_inputQueue.Count
        While (counter > 0)    
            'Check each element.
            Dim elm As Object = m_inputQueue.Dequeue()
            If Not elm.Equals(qValue) Then
                m_inputQueue.Enqueue(elm)
            End If
            counter = counter - 1
        End While
        'Unlock the queue.
        Monitor.Exit(m_inputQueue)
    End Sub

    'Print all queue elements.
    Public Sub PrintAllElements()
        'Lock the queue.
        Monitor.Enter(m_inputQueue)
        Dim elmEnum As IEnumerator = m_inputQueue.GetEnumerator()
        While elmEnum.MoveNext()
            'Print the next element.
            Console.WriteLine(elmEnum.Current.ToString())
        End While
        'Unlock the queue.
        Monitor.Exit(m_inputQueue)
    End Sub

    Public Shared Sub Main()
        Dim sample As MonitorSample = New MonitorSample()
        Dim i As Integer

        For i = 0 To 29
            sample.AddElement(i)
        Next i
        sample.PrintAllElements()
        sample.DeleteElement(0)
        sample.DeleteElement(10)
        sample.DeleteElement(20)
        sample.PrintAllElements()
    End Sub

End Class

[C#] 
using System;
using System.Collections;
using System.Threading;

namespace MonitorCS2
{
    /// <summary>
    /// Summary description for Class1.
    /// </summary>
    class MonitorSample
    {
        //Define the queue to safe thread access.
        private Queue m_inputQueue;

        public MonitorSample()
        {
            m_inputQueue = new Queue(); 
        }

        //Add an element to the queue and obtain the monitor lock for the queue object.
        public void AddElement(object qValue)
        {
            //Lock the queue.
            Monitor.Enter(m_inputQueue);
            //Add element
            m_inputQueue.Enqueue(qValue);
            //Unlock the queue.
            Monitor.Exit(m_inputQueue);
        }

        //Try to add an element to the queue.
        //Add the element to the queue only if the queue object is unlocked.
        public bool AddElementWithoutWait(object qValue)
        {
            //Determine whether the queue is locked 
            if(!Monitor.TryEnter(m_inputQueue))
                return false;
            m_inputQueue.Enqueue(qValue);

            Monitor.Exit(m_inputQueue);
            return true;
        }

        //Try to add an element to the queue. 
        //Add the element to the queue only if during the specified time the queue object will be unlocked.
        public bool WaitToAddElement(object qValue, int waitTime)
        {
            //Wait while the queue is locked.
            if(!Monitor.TryEnter(m_inputQueue,waitTime))
                return false;
            m_inputQueue.Enqueue(qValue);
            Monitor.Exit(m_inputQueue);

            return true;
        }
        
        //Delete all elements that equal the given object and obtain the monitor lock for the queue object.
        public void DeleteElement(object qValue)
        {
            //Lock the queue.
            Monitor.Enter(m_inputQueue);
            int counter = m_inputQueue.Count;
            while(counter > 0)
            {    
                //Check each element.
                object elm = m_inputQueue.Dequeue();
                if(!elm.Equals(qValue))
                {
                    m_inputQueue.Enqueue(elm);
                }
                --counter;
            }
            //Unlock the queue.
            Monitor.Exit(m_inputQueue);
        }
        
        //Print all queue elements.
        public void PrintAllElements()
        {
            //Lock the queue.
            Monitor.Enter(m_inputQueue);            
            IEnumerator elmEnum = m_inputQueue.GetEnumerator();
            while(elmEnum.MoveNext())
            {
                //Print the next element.
                Console.WriteLine(elmEnum.Current.ToString());
            }
            //Unlock the queue.
            Monitor.Exit(m_inputQueue);    
        }

        static void Main(string[] args)
        {
            MonitorSample sample = new MonitorSample();
            
            for(int i = 0; i < 30; i++)
                sample.AddElement(i);
            sample.PrintAllElements();
            sample.DeleteElement(0);
            sample.DeleteElement(10);
            sample.DeleteElement(20);
            sample.PrintAllElements();

        }
    }
}

[C++] 
#using <mscorlib.dll>

using namespace System;
using namespace System::Collections;
using namespace System::Threading;

// Class definition
public __gc class MonitorSample {
public:

    MonitorSample();
    void AddElement(Object* qValue);
    bool AddElementWithoutWait(Object* qValue);
    bool WaitToAddElement(Object* qValue, int waitTime);
    void DeleteElement(Object* qValue);
    void PrintAllElements();

private:

    Queue* m_inputQueue;
};

//Define the queue to safe thread access.
MonitorSample::MonitorSample()
{
    m_inputQueue = new Queue();
}

//Add an element to the queue and obtain the monitor lock for the queue object.
void MonitorSample::AddElement(Object* qValue)
{
    //Lock the queue.
    Monitor::Enter(m_inputQueue);
    //Add element
    m_inputQueue->Enqueue(qValue);
    //Unlock the queue.
    Monitor::Exit(m_inputQueue);
}

//Try to add an element to the queue.
//Add the element to the queue only if the queue object is unlocked.
bool MonitorSample::AddElementWithoutWait(Object* qValue)
{
    //Determine whether the queue is locked 
    if(!Monitor::TryEnter(m_inputQueue))
        return false;
    m_inputQueue->Enqueue(qValue);

    Monitor::Exit(m_inputQueue);
    return true;
}

//Try to add an element to the queue. 
//Add the element to the queue only if during the specified time the queue object will be unlocked.
bool MonitorSample::WaitToAddElement(Object* qValue, int waitTime)
{
    //Wait while the queue is locked.
    if(!Monitor::TryEnter(m_inputQueue,waitTime))
        return false;
    m_inputQueue->Enqueue(qValue);
    Monitor::Exit(m_inputQueue);

    return true;
}

//Delete all elements that equal the given object and obtain the monitor lock for the queue object.
void MonitorSample::DeleteElement(Object* qValue)
{
    //Lock the queue.
    Monitor::Enter(m_inputQueue);
    int counter = m_inputQueue->Count;
    while(counter > 0)
    {   
        //Check each element.
        Object* elm = m_inputQueue->Dequeue();
        if(!elm->Equals(qValue))
        {
            m_inputQueue->Enqueue(elm);
        }
        --counter;
    }
    //Unlock the queue.
    Monitor::Exit(m_inputQueue);
}

//Print all queue elements.
void MonitorSample::PrintAllElements()
{
    //Lock the queue.
    Monitor::Enter(m_inputQueue);         
    IEnumerator* elmEnum = m_inputQueue->GetEnumerator();
    while(elmEnum->MoveNext())
    {
        //Print the next element.
        Console::WriteLine(elmEnum->Current->ToString());
    }
    //Unlock the queue.
    Monitor::Exit(m_inputQueue);   
}

int main() {
    MonitorSample* sample = new MonitorSample();

    for(int i = 0; i < 30; i++)
        sample->AddElement(__box(i));
    sample->PrintAllElements();
    sample->DeleteElement(__box(0));
    sample->DeleteElement(__box(10));
    sample->DeleteElement(__box(20));
    sample->PrintAllElements();
}

[JScript] JScript のサンプルはありません。Visual Basic、C#、および C++ のサンプルを表示するには、このページの左上隅にある言語のフィルタボタンをクリックします。

参照

Monitor クラス | Monitor メンバ | System.Threading 名前空間

次の方法で共有

Monitor.TryEnter メソッド

オーバーロードの一覧

使用例

参照

その他のリソース