OS – hw2solution

Description

Multi-Threading

Programming

Example – Hello Thread!

hello_thread.c

Output

Tools for showing threads

• NCTU Workstation > top

(THR means the num of threads under the process)

Tools for showing threads

• Ubuntu -> sudo apt-get install htop

• • – – press <F2> to enter htop setup menu.

• • – – Choose “Display option” under “Setup” column, and toggle on “Three view” and “Show custom thread names” options.

• • – – Presss <F10> to exit the setup.

Tools for showing threads

• Mac -> Enter the terminal > top

Problem: Sum Checker-input

• Input file: test.txt (it contains a 2D array.) Ex. (-1 means the (x=0 or y=0) of the 2D array. )

Problem: Sum Checker-rules

• Given a 9×9 2D-array and each item of the array must be the digits 1 to 9.

• Sum of each row, column, and each of the nine sub-grids must be the same and every digits only show once.

• Hint:

• 1. A thread to check that each sum of the rows.

• 2. A thread to check that each sum of the cols.

• 3. Nine threads to check each sum of the 3×3 sub-grids.

Example

Row

s

Colum

ns

3×3

subgrids

Problem: Sum

Checker-Output

Code output

Check num of the threads under your process

Problem: Sum Checker- Time

Command: time ./exe

Multi-thread Single thread

Requirements

1. You can write codes in C/C++.

2. You need to hand in one single-thread version and the other multi-thread version. Put all of *.c or *.cpp source files and OS_hw2_report.pdf into same compressed file. The type of compressed file must be

“studentID_hw2.zip” (ex. 010101_hw2.zip)

3. Use NCTU workstation as your environment

Grade

0. • Total score: 100 pts: COPY WILL GET A 0 POINT!

0. Input sample +10 pts

0. Two testing data + 10 pts (5 pts for each)

0. multithreading +40 pts

( report Q3: speed up= Ts/Tm ;

Ts:Time of single thread code ; Tm:Time of multi-thread code)

4. OS report (format OS_report.pdf) + 40 pts

4. Incorrect filename format will get -5 pts

4. • Incorrect output format will get -5 pts

DELAYED SUBMISSION WILL GET 0 POINT!