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  37.     <div id="doc" class="markdown-body container-fluid comment-inner comment-enabled" data-hard-breaks="true"><h1 id="Week-2---Concurrency-and-Parallelism" data-id="Week-2---Concurrency-and-Parallelism"><a class="anchor hidden-xs" href="#Week-2---Concurrency-and-Parallelism" title="Week-2---Concurrency-and-Parallelism"><span class="octicon octicon-link"></span></a><span>Week 2 - Concurrency and Parallelism</span></h1><blockquote>

  38. <p><span>Distributed Systems and Network Programming - Spring 2023</span></p>

  39. </blockquote><h2 id="Task" data-id="Task"><a class="anchor hidden-xs" href="#Task" title="Task"><span class="octicon octicon-link"></span></a><span>Task</span></h2><p><span>Your tasks for this lab:</span></p><ul>

  40. <li><span>Write a multi-threaded TCP server that communicates with a given client</span></li>

  41. <li><span>Optimize the runtime of the client using </span><a href="https://docs.python.org/3/library/threading.html" target="_blank" rel="noopener"><span>threading</span></a><span> and </span><a href="https://docs.python.org/3/library/multiprocessing.html" target="_blank" rel="noopener"><span>multiprocessing</span></a></li>

  42. </ul><h2 id="Server-Implementation" data-id="Server-Implementation"><a class="anchor hidden-xs" href="#Server-Implementation" title="Server-Implementation"><span class="octicon octicon-link"></span></a><span>Server Implementation</span></h2><ul>

  43. <li><strong><span>The server should do the following:</span></strong>

  44. <ol>

  45. <li><span>Accept a client connection</span></li>

  46. <li><span>Spawn a new thread to handle the connection</span></li>

  47. <li><span>Generate a random 10x10 image (you can use </span><a href="https://python-pillow.org/" target="_blank" rel="noopener"><span>pillow</span></a><span> module for that)</span></li>

  48. <li><span>Send the image to the connected client, then close that connection</span></li>

  49. </ol>

  50. </li>

  51. <li><strong><span>Additional requirements:</span></strong>

  52. <ul>

  53. <li><span>The server should stay listening all the time and should not terminate unless a </span><code>KeyboardInterrupt</code><span> is received.</span></li>

  54. <li><span>The server should be able to handle multiple connections simultaneously.</span></li>

  55. <li><span>The server socket is marked for address reuse so that the OS would immediately release the bound address after server termination. You can do so by calling the </span><code>setsockopt</code><span> on the server socket before binding the address as follows:</span><pre><code class="python hljs">server_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, <span class="hljs-number">1</span>)

  56. server_socket.bind((SERVER_IP, SERVER_PORT))

  57. </code></pre>

  58. </li>

  59. </ul>

  60. </li>

  61. </ul><h2 id="Client-Implementation" data-id="Client-Implementation"><a class="anchor hidden-xs" href="#Client-Implementation" title="Client-Implementation"><span class="octicon octicon-link"></span></a><span>Client Implementation</span></h2><p><strong><span>The client does the following:</span></strong></p><ol>

  62. <li><span>Connect to the TCP server multiple times to download 5000 images, one by one.</span></li>

  63. <li><span>Download the images to a directory called </span><code>frames</code><span> (creating the directory if it does not exist).</span></li>

  64. <li><span>Create a GIF by combining the downloaded frames.</span></li>

  65. <li><span>Use </span><a href="https://docs.python.org/3/library/time.html" target="_blank" rel="noopener"><span>time</span></a><span> module to calculate the total time taken for frame download and GIF generation.</span></li>

  66. </ol><h2 id="Your-task" data-id="Your-task"><a class="anchor hidden-xs" href="#Your-task" title="Your-task"><span class="octicon octicon-link"></span></a><span>Your task</span></h2><ol>

  67. <li><span>Once you understand how the client code works, start by writing the server.</span></li>

  68. <li><span>Once the server works fine. It’s time to optimize the runtime of the client.</span></li>

  69. <li><span>Use </span><code>threading</code><span> to spawn multiple threads that download the required frames concurrently.</span></li>

  70. <li><span>Use </span><code>multiprocessing</code><span> to spawn multiple processes (not more that your CPU core count) to process the frames in parallel to create the GIF faster. You may use </span><code>multiprocessing.Pool()</code><span> to achieve the task.</span></li>

  71. <li><span>Check the time taken in each stage and verify that the client runtime was improved.</span></li>

  72. </ol><h2 id="Example-run" data-id="Example-run"><a class="anchor hidden-xs" href="#Example-run" title="Example-run"><span class="octicon octicon-link"></span></a><span>Example run</span></h2><pre><code class="bash hljs">$ python3 NameSurname_server.py

  73. Listening on 0.0.0.0:1234

  74. Sent an image to (127.0.0.1, 50125)

  75. Sent an image to (127.0.0.1, 58754)

  76. ...

  77. 

  78. <span class="hljs-comment"># Before optimizing client</span>

  79. $ python3 NameSurname_client.py

  80. Frames download time: 25.516422748565674

  81. GIF creation time: 30.278062343597412

  82. 

  83. <span class="hljs-comment"># After optimizing client</span>

  84. $ python3 NameSurname_client.py

  85. Frames download time: 18.751099348068237

  86. GIF creation time: 9.695139408111572

  87. </code></pre><h2 id="Checklist" data-id="Checklist"><a class="anchor hidden-xs" href="#Checklist" title="Checklist"><span class="octicon octicon-link"></span></a><span>Checklist</span></h2><p><span>Your submitted code should satisfy the following requirements. Failing to satisfy an item will result in partial grade deduction or an assignment failure (depending on the severity).</span></p><ul class="contains-task-list">

  88. <li class="task-list-item enabled"><input class="task-list-item-checkbox" type="checkbox" disabled="disabled"><span> Two submitted files named according to the format </span><code>NameSurname_client.py</code><span> and </span><code>NameSurname_server.py</code></li>

  89. <li class="task-list-item enabled"><input class="task-list-item-checkbox" type="checkbox" disabled="disabled"><span> The source code executes successfully under the </span><a href="https://www.python.org/downloads/" target="_blank" rel="noopener"><span>latest stable Python interpreter</span></a><span>.</span></li>

  90. <li class="task-list-item enabled"><input class="task-list-item-checkbox" type="checkbox" disabled="disabled"><span> The code does not use any external dependencies (apart from </span><a href="https://python-pillow.org/" target="_blank" rel="noopener"><span>pillow</span></a><span>)</span></li>

  91. <li class="task-list-item enabled"><input class="task-list-item-checkbox" type="checkbox" disabled="disabled"><span> The code is readable and nicely formatted (e.g., according to </span><a href="https://peps.python.org/pep-0008/" target="_blank" rel="noopener"><span>PEP8</span></a><span>)</span></li>

  92. <li class="task-list-item enabled"><input class="task-list-item-checkbox" type="checkbox" disabled="disabled"><span> The client runtime is improved after using </span><code>threading</code><span> and </span><code>multiprocessing</code></li>

  93. <li class="task-list-item enabled"><input class="task-list-item-checkbox" type="checkbox" disabled="disabled"><span> The source code is the author’s original work. Both parties will be penalized for detected plagiarism.</span></li>

  94. </ul></div>

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  102. <li class=""><a href="#Week-2---Concurrency-and-Parallelism" title="Week 2 - Concurrency and Parallelism">Week 2 - Concurrency and Parallelism</a><ul class="nav">

  103. <li class=""><a href="#Task" title="Task">Task</a></li>

  104. <li class=""><a href="#Server-Implementation" title="Server Implementation">Server Implementation</a></li>

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  119. <li class=""><a href="#Task" title="Task">Task</a></li>

  120. <li class=""><a href="#Server-Implementation" title="Server Implementation">Server Implementation</a></li>

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