The goal of this project was to implement a multi-threaded network application in C that executes and manages jobs submitted remotely over a TCP-based client-server architecture. The system consists of a job execution server that schedules and executes tasks using worker threads and a client application for remote job submission, concurrency control, and job management. The implementation ensures efficiency, correctness, and adaptability under high-load conditions.
jobExecutorServer: A multi-threaded server that manages incoming job requests, schedules execution, and maintains concurrency control.jobCommander: A client application that allows users to submit jobs, adjust concurrency, cancel tasks, and terminate the server.
- Multi-threaded Server: Uses worker threads for parallel job execution, synchronized via POSIX condition variables and mutexes.
- Network Communication: Implements a TCP-based protocol for efficient client-server interaction.
- Dynamic Concurrency Control: Allows real-time adjustment of active worker threads while ensuring correctness.
- Job Queueing & Management: Supports job submission, cancellation, and polling of pending jobs.
- Graceful Shutdown: Ensures safe termination while completing active tasks.
make./bin/jobExecutorServer [portnum] [bufferSize] [threadPoolSize]
Example:
./bin/jobExecutorServer 7856 8 5
This starts the server on port 7856 with a job queue buffer size of 8 and a thread pool of 5 worker threads.
./bin/jobCommander [serverName] [portNum] [command]
Example (issueJob command):
./bin/jobCommander localhost 7856 issueJob ls -l
This connects to a server running on localhost at port 7856 and submits a job to list directory contents.
| Command | Description | Example |
|---|---|---|
issueJob <job> |
Submits a job (a shell command) for execution. | issueJob ls -l |
setConcurrency <N> |
Sets the number of worker threads actively executing jobs. | setConcurrency 4 |
stop <jobID> |
Removes a job from the queue (if not yet running). | stop job_2 |
poll |
Lists all queued jobs waiting for execution. | poll |
exit |
Gracefully shuts down the server after completing running jobs. | exit |
This project was developed as part of the 2nd assignment of the "Systems Programming" (hence the name syspro2) course (6th semester, Spring 2024, Professor Alexandros Ntoulas) at the National and Kapodistrian University of Athens (NKUA). It received a grade of 100/100 along with excellent feedback.