C interview questions

Simple and functional C interview questions. Essential concepts like signal handling, job queue, logging and multi-threading knowledge are required for implementing answers.

Structure

Answers are wrapped between // AX part N and // AX part N end where X is question number. All files are given to a interviewee with stripping answers.

Files:

• main.c
• jobs.c
• jobs.h
• debug.h
• Makefile

Questions

1. Add job_myjob_destroy function to free job context & rand_id in ctx1
2. If rand_is is greater than UINT8 / 2 then replace it with another rand_id and let it run again.
3. Add signal handler: when USR1 receive print all queue'd jobs, when SIGTERM OR SIGINT received free all queue and gradually exit. All unhandled signals should exit immediately.
4. log_helper should print DEBUG_ID, filename and line info to LOG_FILE.
5. Create multiple threads, pull and run jobs from the queue. Properly lock the queue, process jobs concurrently.
6. Create a Makefile which will define a flag for printing logs to stdout instead of a file. Also add debug and release build options.

Build

LOG_STDOUT=y make