blocks|key|269841|text|我认为这是因为Parallel.For()只使用动态分区器，因此传入数组可以动态地进行分区，并且每个分区由一个单独的任务/线程处理：|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|269842|MSDN:如何:实现动态分区
每次分区在枚举数上调用MoveNext时，枚举数都会为分区提供一个列表元素。对于PLINQ和ForEach，分区是一个任务实例。因为请求同时发生在多个线程上，所以对当前索引的访问是同步的。|ordered-list-item|269843|(我相信Parallel.For()也是如此)|269844|MSDN:自定义分配器
PLINQ支持固定数量的分区(尽管数据可以在运行时动态地重新分配到这些分区以实现负载平衡)。For和ForEach只支持动态分区，这意味着分区数在运行时会发生变化。有关更多信息，请参见PLINQ和TPL的自定义分配器。|269845|-+[MSDN:+Introduction+to+PLINQ](http://msdn.microsoft.com/en-us/library/dd997425.aspx)
-+[Does+Parallel.For+use+one+Task+per+iteration?](http://blogs.msdn.com/b/pfxteam/archive/2009/05/26/9641563.aspx)|code-block|syntax|javascript|269846|​|269847|entityMap|0|LINK|mutability|MUTABLE|url|http://msdn.microsoft.com/en-us/library/dd997416.aspx|1|http://msdn.microsoft.com/en-us/library/dd997425.aspx^0|7|E|0|0|E|0|0|4|E|0|0|B|1|0|0|0^^$0|@$1|2|3|4|5|6|7|13|8|@$9|14|A|15|B|C]]|D|@]|E|$]]|$1|F|3|G|5|H|7|16|8|@]|D|@$9|17|A|18|1|19]]|E|$]]|$1|I|3|J|5|6|7|1A|8|@$9|1B|A|1C|B|C]]|D|@]|E|$]]|$1|K|3|L|5|H|7|1D|8|@]|D|@$9|1E|A|1F|1|1G]]|E|$]]|$1|M|3|N|5|O|7|1H|8|@]|D|@]|E|$P|Q]]|$1|R|3|S|5|6|7|1I|8|@]|D|@]|E|$]]|$1|T|3|-4|5|6|7|1J|8|@]|D|@]|E|$]]]|U|$V|$5|W|X|Y|E|$Z|10]]|11|$5|W|X|Y|E|$Z|12]]]]

I believe this is because <code>Parallel.For()</code> uses only dynamic partitioner so passed in array could be partitioned on-the-fly and each partition is processed by a separate Task/Thread:

<ol>
<li><a href="http://msdn.microsoft.com/en-us/library/dd997416.aspx" rel="nofollow">MSDN: How to: Implement Dynamic Partitions</a>

<blockquote>
 Each time a partition calls MoveNext on the enumerator, the enumerator
 provides the partition with one list element. In the case of PLINQ and
 ForEach, the partition is a Task instance. Because requests are
 happening concurrently on multiple threads, access to the current
 index is synchronized.
</blockquote>

(I believe the same is true for <code>Parallel.For()</code>)</li>
<li><a href="http://msdn.microsoft.com/en-us/library/dd997425.aspx" rel="nofollow">MSDN: Custom Partitioners</a>

<blockquote>
 PLINQ supports a fixed number of partitions (although data may be
 dynamically reassigned to those partitions during run time for load
 balancing.). For and ForEach support only dynamic partitioning, which
 means that the number of partitions changes at run time. For more
 information, see Custom Partitioners for PLINQ and TPL.
</blockquote>

<ul>
<li><a href="http://msdn.microsoft.com/en-us/library/dd997425.aspx" rel="nofollow">MSDN: Introduction to PLINQ</a></li>
<li><a href="http://blogs.msdn.com/b/pfxteam/archive/2009/05/26/9641563.aspx" rel="nofollow">Does Parallel.For use one Task per iteration?</a></li>
</ul></li>
</ol>

blocks|key|2093368|text|Parallel.For使用线程池线程。MaxDegreeOfParallelism控制使用的最大并发线程数，而不是5个特定线程--线程池可以自由处理其任何线程上的工作，而Parallel.For确保只有5个线程同时运行。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|2093369|entityMap^0|0|C|K|M|2E|C|0^^$0|@$1|2|3|4|5|6|7|H|8|@$9|I|A|J|B|C]|$9|K|A|L|B|C]|$9|M|A|N|B|C]]|D|@]|E|$]]|$1|F|3|-4|5|6|7|O|8|@]|D|@]|E|$]]]|G|$]]

<code>Parallel.For</code> uses thread pool threads. The <code>MaxDegreeOfParallelism</code> controls the maximum concurrent number of threads being used, not 5 particular threads - the thread pool is at liberty to process work on any of its threads, and <code>Parallel.For</code> makes sure only 5 are running at the same time.

I have developed a .net application using .net framework 4.0 where I have used parallel.for() loop for multi threading. I have used the following configuration:

<ol>
<li>Windows 7</li>
<li>IIS 7.0</li>
<li>Framework v4.0.30319</li>
</ol>

I have used ParallelOptions() class and the "MaxDegreeOfParallelism" property of this class is set to 5. I have logged the "Thread.CurrentThread.ManagedThreadId" in a log file to check whether 5 threads were created at the runtime. I have tested this application in two different environments. When the application is running at the environment where it has been developed it's creating 5 thread IDs. But while it's running at the other environment it's creating 6 or 7 threads IDs. The application is compiled at the 1st environment only. I have used the published version of the application to test at the 2nd environment.
Can anyone help me by informing why this is happening and how to resolve it?

Parallel.for() loop creating wrong thread IDs

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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我使用.net Framework4.0开发了一个.net应用程序，其中我使用parallel.for()循环进行多线程处理。我使用了以下配置：Windows 7IIS 7.0框架v4.0.30319我使用了ParallelOptions()类，这个类的"MaxDegreeOfParallelism“属性设置为5，我在...

问Parallel.for()循环创建错误的线程ID
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