Producer_Consumer

Visualizing Producer-Consumer problem as a photocopy centre where clients are producers and printers are consumers

About the Files

Here a circular queue is stored inside the shared memory These programs will be working with shared memory

The repo has three main files

• main.c - creates shared memory
• client.c - inserts data into shared memory
• devices.c - views and deletes data from shared memory

and three additional files which provides support to above main files

• circular_queue.c - has functions to work with Circular Queue
• circular_queue.h - has Circular queue's structure
• photocopy.h - has Photocopy's structure

Working

The Circular queue structure has an array of Photocopy structure. Main program creates a queue for a store and the program will run for the time mentioned as a cmd arg. Client program inserts data into queue. Devices program views the queue and does nothing when the queue is empty, else it simulates printing the data for a specified time and deletes data if time elapsed is 0. All programs will terminate if main program for a store terminates. (i.e) Only a store has a queue, if there is no store then there will be no queue for a closed store.

Run the files

Execute in this order To create a queue

./main -t <total_run_time> -n <no_of_printers> -l <length_of_queue>

it will return key for store and queue. use it in next 2 programs.

To view and work with the queue.

./devices -s <store's_key> -q <queue's_key> -b <max_break_time> -w <max_work_time>

To insert data into the queue.

./client -s <store's_key> -q <queue's_key> -n <no_of_copies> -p <no_of_pages> -f <file_name>

Problem in the code

The code has a rare type of bug known as Heisenbug. The program seems to work perfect when debugger is turned on and crashes when it is turned off ( for more details about Heisenbug click here )