C++ System Programming Cookbook

How it works...

The POSIX standard defines the following policies:

• SCHED_OTHER: The normal scheduler policy (that is, not for real-time processes)
• SCHED_FIFO: First-in/first-out
• SCHED_RR: Round-robin

Here, SCHED_OTHER is the default one and SCHED_FIFO and SCHED_RR are the real-time ones. Actually, Linux defines SCHED_NORMAL, SCHED_BATCH, and SCHED_IDLE as other real-time policies. These are defined in the sched.h header file.

Step 1 calls sched_getscheduler() to check the current policy of the process. As expected, the default is SCHED_OTHER. We passed the input to the getpid() function (<unistd.h>), which returns the PID of the current process. sched_getscheduler() also accepts 0, which in this case represents the current process.

Step ...