How can I convert this foreach code to Parallel ForEach

Question

I am a bit of confused about Parallel ForEach  What is Parallel ForEach and what does it exactly do  Please don t reference any MSDN link     Here s a simple example     string   lines   File ReadAllLines txtProxyListPath Text   List lt string gt  list lines   new List lt string gt  lines    foreach  string line in list lines          My Stuff     How can I rewrite this example with Parallel ForEach

User · Accepted Answer

string   lines   File ReadAllLines txtProxyListPath Text   List lt string gt  list lines   new List lt string gt  lines   Parallel ForEach list lines  line   gt          Your stuff

User · Answer

These lines Worked for me   string   lines   File ReadAllLines txtProxyListPath Text   var options   new ParallelOptions   MaxDegreeOfParallelism   Environment ProcessorCount   10    Parallel ForEach lines   options   item    gt       My Stuff

User · Answer

Foreach loop         Iterations takes place sequentially  one by one   foreach loop is run from a single Thread    foreach loop is defined in every framework of  NET   Execution of slow processes can be slower  as they re run serially         Process 2 can t start until 1 is done  Process 3 can t start until 2  amp  1 are done         Execution of quick processes can be faster  as there is no threading overhead      Parallel ForEach         Execution takes place in parallel way    Parallel ForEach uses multiple Threads    Parallel ForEach is defined in  Net 4 0 and above frameworks    Execution of slow processes can be faster  as they can be run in parallel         Processes 1  2   amp  3 may run concurrently  see reused threads in example  below       Execution of quick processes can be slower  because of additional threading overhead      The following example clearly demonstrates the difference between traditional foreach loop and   Parallel ForEach   Example     using System  using System Diagnostics  using System Threading  using System Threading Tasks  namespace ParallelForEachExample       class Program               static void Main                         string   colors                                        1  Red                                      2  Green                                      3  Blue                                      4  Yellow                                      5  White                                      6  Black                                      7  Violet                                      8  Brown                                      9  Orange                                      10  Pink                                               Console WriteLine  Traditional foreach loop n                  start the stopwatch for  for  loop             var sw   Stopwatch StartNew                foreach  string color in colors                                Console WriteLine   0   Thread Id   1    color  Thread CurrentThread ManagedThreadId                   Thread Sleep 10                             Console WriteLine  foreach loop execution time    0  seconds n   sw Elapsed TotalSeconds               Console WriteLine  Using Parallel ForEach                  start the stopwatch for  Parallel ForEach               sw   Stopwatch StartNew                Parallel ForEach colors  color   gt                                Console WriteLine   0   Thread Id   1    color  Thread CurrentThread ManagedThreadId                   Thread Sleep 10                                            Console WriteLine  Parallel ForEach   execution time    0  seconds   sw Elapsed TotalSeconds               Console Read                        Output  Traditional foreach loop 1  Red  Thread Id  10 2  Green  Thread Id  10 3  Blue  Thread Id  10 4  Yellow  Thread Id  10 5  White  Thread Id  10 6  Black  Thread Id  10 7  Violet  Thread Id  10 8  Brown  Thread Id  10 9  Orange  Thread Id  10 10  Pink  Thread Id  10 foreach loop execution time   0 1054376 seconds   Using Parallel ForEach example  1  Red  Thread Id  10 3  Blue  Thread Id  11 4  Yellow  Thread Id  11 2  Green  Thread Id  10 5  White  Thread Id  12 7  Violet  Thread Id  14 9  Orange  Thread Id  13 6  Black  Thread Id  11 8  Brown  Thread Id  10 10  Pink  Thread Id  12 Parallel ForEach   execution time   0 055976 seconds

User · Answer

For big file use the following code  you are less memory hungry   Parallel ForEach File ReadLines txtProxyListPath Text   line   gt          Your stuff

User · Answer

string   lines   File ReadAllLines txtProxyListPath Text       No need for the list    List lt string gt  list lines   new List lt string gt  lines     Parallel ForEach lines  line   gt          My Stuff       This will cause the lines to be parsed in parallel  within the loop   If you want a more detailed  less  reference oriented  introduction to the Parallel class  I wrote a series on the TPL which includes a section on Parallel ForEach

[c#] How can I convert this foreach code to Parallel.ForEach?

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