Threads; Computing the value of $\pi$

The following http://siber.cankaya.edu.tr/ParallelComputing/cfiles/code24.c program computes the value of the $\pi$ number by a given number of threads;

• Analyze the code for the possible synchronization issues.
• Compile and execute the code by increasing the number of the threads and number of the intervals.
• Make the following procedures:
  • Draw a figure as Execution Time vs Number of Threads. If you increase the number of threads as the multiple of 2, then take the $ln$. If you increase the number of threads as the multiple of 10, then take the $log$.
  • Label the curve as "local". Make the Speed-Up and Efficiency analysis.