perf_event_data/records/
throttle.rs

1use crate::prelude::*;
2
3/// Record for a throttle or unthrottle events.
4///
5/// These are generated when the sampler generates too many events during a
6/// given timer tick. In that case, the kernel will disable the counter for
7/// the rest of the tick and instead generate a throttle/unthrottle record
8/// pair indicating when throttling started and ended.
9///
10/// This struct is used for both `PERF_RECORD_THROTTLE` and
11/// `PERF_RECORD_UNTHROTTLE`. See the [manpage] for more documentation.
12///
13/// [manpage]: http://man7.org/linux/man-pages/man2/perf_event_open.2.html
14#[derive(Clone, Debug)]
15#[allow(missing_docs)]
16pub struct Throttle {
17    pub time: u64,
18    pub id: u64,
19    pub stream_id: u64,
20}
21
22impl<'p> Parse<'p> for Throttle {
23    fn parse<B, E>(p: &mut Parser<B, E>) -> ParseResult<Self>
24    where
25        E: Endian,
26        B: ParseBuf<'p>,
27    {
28        Ok(Self {
29            time: p.parse()?,
30            id: p.parse()?,
31            stream_id: p.parse()?,
32        })
33    }
34}
35
36#[cfg(test)]
37mod tests {
38    use crate::endian::Little;
39
40    use super::*;
41
42    #[test]
43    #[cfg_attr(not(target_endian = "little"), ignore)]
44    fn test_parse() {
45        #[rustfmt::skip]
46        let bytes: &[u8] = &[
47            0x10, 0x20, 0x30, 0x40, 0x50, 0x60, 0x70, 0x80,
48            0x90, 0xA0, 0xB0, 0xC0, 0xD0, 0xE0, 0xF0, 0x00,
49            0xEF, 0xBE, 0xAD, 0xDE, 0xFE, 0xCA, 0xEF, 0xBE,
50        ];
51
52        let mut parser: Parser<_, Little> = Parser::new(bytes, ParseConfig::default());
53        let throttle: Throttle = parser.parse().unwrap();
54
55        assert_eq!(throttle.time, 0x8070605040302010);
56        assert_eq!(throttle.id, 0x00F0E0D0C0B0A090);
57        assert_eq!(throttle.stream_id, 0xBEEFCAFEDEADBEEF);
58    }
59}
perf_event_data/records/throttle.rs

perf_event_data/records/
throttle.rs
