pprof/
timer.rs

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1// Copyright 2019 TiKV Project Authors. Licensed under Apache-2.0.
2
3use std::os::raw::c_int;
4use std::ptr::null_mut;
5use std::time::{Duration, Instant, SystemTime};
6
7#[repr(C)]
8#[derive(Clone)]
9struct Timeval {
10    pub tv_sec: i64,
11    pub tv_usec: i64,
12}
13
14#[repr(C)]
15#[derive(Clone)]
16struct Itimerval {
17    pub it_interval: Timeval,
18    pub it_value: Timeval,
19}
20
21extern "C" {
22    fn setitimer(which: c_int, new_value: *mut Itimerval, old_value: *mut Itimerval) -> c_int;
23}
24
25const ITIMER_PROF: c_int = 2;
26
27pub struct Timer {
28    pub frequency: c_int,
29    pub start_time: SystemTime,
30    pub start_instant: Instant,
31}
32
33impl Timer {
34    pub fn new(frequency: c_int) -> Timer {
35        let interval = 1e6 as i64 / i64::from(frequency);
36        let it_interval = Timeval {
37            tv_sec: interval / 1e6 as i64,
38            tv_usec: interval % 1e6 as i64,
39        };
40        let it_value = it_interval.clone();
41
42        unsafe {
43            setitimer(
44                ITIMER_PROF,
45                &mut Itimerval {
46                    it_interval,
47                    it_value,
48                },
49                null_mut(),
50            )
51        };
52
53        Timer {
54            frequency,
55            start_time: SystemTime::now(),
56            start_instant: Instant::now(),
57        }
58    }
59
60    /// Returns a `ReportTiming` struct having this timer's frequency and start
61    /// time; and the time elapsed since its creation as duration.
62    pub fn timing(&self) -> ReportTiming {
63        ReportTiming {
64            frequency: self.frequency,
65            start_time: self.start_time,
66            duration: self.start_instant.elapsed(),
67        }
68    }
69}
70
71impl Drop for Timer {
72    fn drop(&mut self) {
73        let it_interval = Timeval {
74            tv_sec: 0,
75            tv_usec: 0,
76        };
77        let it_value = it_interval.clone();
78        unsafe {
79            setitimer(
80                ITIMER_PROF,
81                &mut Itimerval {
82                    it_interval,
83                    it_value,
84                },
85                null_mut(),
86            )
87        };
88    }
89}
90
91/// Timing metadata for a collected report.
92#[derive(Clone)]
93pub struct ReportTiming {
94    /// Frequency at which samples were collected.
95    pub frequency: i32,
96    /// Collection start time.
97    pub start_time: SystemTime,
98    /// Collection duration.
99    pub duration: Duration,
100}
101
102impl Default for ReportTiming {
103    fn default() -> Self {
104        Self {
105            frequency: 1,
106            start_time: SystemTime::UNIX_EPOCH,
107            duration: Default::default(),
108        }
109    }
110}
pprof/timer.rs

pprof/
timer.rs
