LAB#3 Pre-Work DUE: 2/9/2023 Submit a ZIP file of your work for TA to run you program WARNING: Independent work, NO COPYING ALLOWED !!!! 1. Copy the example program C4.1.c in the book as t.c Modify N to let A be an 8x8 matrix. Compile and run the program. Record the total output value ___________. 2. Define a global int total = 0; Modify the func() code to let each thread add its row sum to total, as in //------------------------------------- int tmp = total; // tmp = current total tmp += sum; // update tmp locally sleep(1); // simulate interrupts, which may switch process/threads total = tmp; // write tmp to total //------------------------------------- Modify main() to join with all threads; then print total value Run the modified program. What's the total output value? _____________ 3. Devise a way to make the modified code work CORRECTLY. HINT: read example program C4.3