How can I detect hung processes in Linux using C? [duplicate]

Question

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Linux API to list running processes?

How can I detect hung processes in Linux using C?

Answer 1

Under linux the way to do this is by examining the contents of /proc/[PID]/* a good one-stop location would be /proc/*/status. Its first two lines are:

Name: [program name] State: R (running)

Of course, detecting hung processes is an entirely separate issue.

/proc//stat is a more machine-readable format of the same info as /proc//status, and is, in fact, what the ps(1) command reads to produce its output.

Answer 2

Monitoring and/or killing a process is just a matter of system calls. I'd think the toughest part of your question would really be reliably determining that a process is "hung", rather than meerly very busy (or waiting for a temporary condition).

In the general case, I'd think this would be rather difficult. Even Windows asks for a decision from the user when it thinks a program might be "hung" (on my system it is often wrong about that, too).

However, if you have a specific program that likes to hang in a specific way, I'd think you ought to be able to reliably detect that.