proc_pid_timers - Man Page

/proc/pid/timers (since Linux 3.10)

A list of the POSIX timers for this process. Each timer is listed with a line that starts with the string "ID:". For example:

ID: 1
signal: 60/00007fff86e452a8
notify: signal/pid.2634
ClockID: 0
ID: 0
signal: 60/00007fff86e452a8
notify: signal/pid.2634
ClockID: 1

The lines shown for each timer have the following meanings:

ID

The ID for this timer. This is not the same as the timer ID returned by timer_create(2); rather, it is the same kernel-internal ID that is available via the si_timerid field of the siginfo_t structure (see sigaction(2)).

signal

This is the signal number that this timer uses to deliver notifications followed by a slash, and then the sigev_value value supplied to the signal handler. Valid only for timers that notify via a signal.

notify

The part before the slash specifies the mechanism that this timer uses to deliver notifications, and is one of "thread", "signal", or "none". Immediately following the slash is either the string "tid" for timers with SIGEV_THREAD_ID notification, or "pid" for timers that notify by other mechanisms. Following the "." is the PID of the process (or the kernel thread ID of the thread)  that will be delivered a signal if the timer delivers notifications via a signal.

ClockID

This field identifies the clock that the timer uses for measuring time. For most clocks, this is a number that matches one of the user-space CLOCK_* constants exposed via <time.h>. CLOCK_PROCESS_CPUTIME_ID timers display with a value of -6 in this field. CLOCK_THREAD_CPUTIME_ID timers display with a value of -2 in this field.

This file is available only when the kernel was configured with CONFIG_CHECKPOINT_RESTORE.

proc(5)