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// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
use inherent::inherent;
use std::collections::HashMap;
use std::convert::TryInto;
use std::sync::{
atomic::{AtomicUsize, Ordering},
RwLock,
};
use std::time::{Duration, Instant};
use super::{CommonMetricData, MetricId, TimeUnit};
use glean::{DistributionData, ErrorType, TimerId};
use crate::ipc::{need_ipc, with_ipc_payload};
use glean::traits::TimingDistribution;
/// A timing distribution metric.
///
/// Timing distributions are used to accumulate and store time measurements for analyzing distributions of the timing data.
pub enum TimingDistributionMetric {
Parent {
/// The metric's ID.
///
/// No longer test-only, is also used for GIFFT.
id: MetricId,
inner: glean::private::TimingDistributionMetric,
},
Child(TimingDistributionMetricIpc),
}
#[derive(Debug)]
pub struct TimingDistributionMetricIpc {
metric_id: MetricId,
next_timer_id: AtomicUsize,
instants: RwLock<HashMap<u64, Instant>>,
}
impl TimingDistributionMetric {
/// Create a new timing distribution metric.
pub fn new(id: MetricId, meta: CommonMetricData, time_unit: TimeUnit) -> Self {
if need_ipc() {
TimingDistributionMetric::Child(TimingDistributionMetricIpc {
metric_id: id,
next_timer_id: AtomicUsize::new(0),
instants: RwLock::new(HashMap::new()),
})
} else {
let inner = glean::private::TimingDistributionMetric::new(meta, time_unit);
TimingDistributionMetric::Parent { id, inner }
}
}
#[cfg(test)]
pub(crate) fn child_metric(&self) -> Self {
match self {
TimingDistributionMetric::Parent { id, .. } => {
TimingDistributionMetric::Child(TimingDistributionMetricIpc {
metric_id: *id,
next_timer_id: AtomicUsize::new(0),
instants: RwLock::new(HashMap::new()),
})
}
TimingDistributionMetric::Child(_) => {
panic!("Can't get a child metric from a child metric")
}
}
}
/// Accumulates a time duration sample for the provided metric.
///
/// Adds a count to the corresponding bucket in the timing distribution.
/// Saturates at u64::MAX nanoseconds.
///
/// Prefer start() and stop_and_accumulate() where possible.
///
/// Users of this API are responsible for ensuring the timing source used
/// to calculate the duration is monotonic and consistent across platforms.
///
/// # Arguments
///
/// * `duration` - The [`Duration`] of the accumulated sample.
pub fn accumulate_raw_duration(&self, duration: Duration) {
let sample = duration.as_nanos().try_into().unwrap_or_else(|_| {
// TODO: Instrument this error
log::warn!(
"Elapsed nanoseconds larger than fits into 64-bytes. Saturating at u64::MAX."
);
u64::MAX
});
// May be unused in builds without gecko.
let _sample_ms = duration.as_millis().try_into().unwrap_or_else(|_| {
// TODO: Instrument this error
log::warn!(
"Elapsed milliseconds larger than fits into 32-bytes. Saturating at u32::MAX."
);
u32::MAX
});
match self {
TimingDistributionMetric::Parent {
id: _metric_id,
inner,
} => {
#[cfg(feature = "with_gecko")]
{
extern "C" {
fn GIFFT_TimingDistributionAccumulateRawMillis(metric_id: u32, sample: u32);
}
// SAFETY: using only primitives, no return value.
unsafe {
GIFFT_TimingDistributionAccumulateRawMillis(_metric_id.0, _sample_ms);
}
}
inner.accumulate_raw_samples_nanos(vec![sample]);
}
TimingDistributionMetric::Child(c) => {
#[cfg(feature = "with_gecko")]
{
extern "C" {
fn GIFFT_TimingDistributionAccumulateRawMillis(metric_id: u32, sample: u32);
}
// SAFETY: using only primitives, no return value.
unsafe {
GIFFT_TimingDistributionAccumulateRawMillis(c.metric_id.0, _sample_ms);
}
}
with_ipc_payload(move |payload| {
if let Some(v) = payload.timing_samples.get_mut(&c.metric_id) {
v.push(sample);
} else {
payload.timing_samples.insert(c.metric_id, vec![sample]);
}
});
}
}
}
}
#[inherent]
impl TimingDistribution for TimingDistributionMetric {
/// Starts tracking time for the provided metric.
///
/// This records an error if it’s already tracking time (i.e.
/// [`start`](TimingDistribution::start) was already called with no corresponding
/// [`stop_and_accumulate`](TimingDistribution::stop_and_accumulate)): in that case the
/// original start time will be preserved.
///
/// # Returns
///
/// A unique [`TimerId`] for the new timer.
pub fn start(&self) -> TimerId {
match self {
TimingDistributionMetric::Parent { id: _id, inner } => {
let timer_id = inner.start();
#[cfg(feature = "with_gecko")]
{
extern "C" {
fn GIFFT_TimingDistributionStart(metric_id: u32, timer_id: u64);
}
// SAFETY: using only primitives, no return value.
unsafe {
GIFFT_TimingDistributionStart(_id.0, timer_id.id);
}
}
timer_id.into()
}
TimingDistributionMetric::Child(c) => {
// There is no glean-core on this process to give us a TimerId,
// so we'll have to make our own and do our own bookkeeping.
let id = c
.next_timer_id
.fetch_add(1, Ordering::SeqCst)
.try_into()
.unwrap();
let mut map = c
.instants
.write()
.expect("lock of instants map was poisoned");
if let Some(_v) = map.insert(id, Instant::now()) {
// TODO: report an error and find a different TimerId.
}
#[cfg(feature = "with_gecko")]
{
extern "C" {
fn GIFFT_TimingDistributionStart(metric_id: u32, timer_id: u64);
}
// SAFETY: using only primitives, no return value.
unsafe {
GIFFT_TimingDistributionStart(c.metric_id.0, id);
}
}
id.into()
}
}
}
/// Stops tracking time for the provided metric and associated timer id.
///
/// Adds a count to the corresponding bucket in the timing distribution.
/// This will record an error if no [`start`](TimingDistribution::start) was
/// called.
///
/// # Arguments
///
/// * `id` - The [`TimerId`] to associate with this timing. This allows
/// for concurrent timing of events associated with different ids to the
/// same timespan metric.
pub fn stop_and_accumulate(&self, id: TimerId) {
match self {
TimingDistributionMetric::Parent {
id: _metric_id,
inner,
} => {
#[cfg(feature = "with_gecko")]
{
extern "C" {
fn GIFFT_TimingDistributionStopAndAccumulate(metric_id: u32, timer_id: u64);
}
// SAFETY: using only primitives, no return value.
unsafe {
GIFFT_TimingDistributionStopAndAccumulate(_metric_id.0, id.id);
}
}
inner.stop_and_accumulate(id);
}
TimingDistributionMetric::Child(c) => {
#[cfg(feature = "with_gecko")]
{
extern "C" {
fn GIFFT_TimingDistributionStopAndAccumulate(metric_id: u32, timer_id: u64);
}
// SAFETY: using only primitives, no return value.
unsafe {
GIFFT_TimingDistributionStopAndAccumulate(c.metric_id.0, id.id);
}
}
let mut map = c
.instants
.write()
.expect("Write lock must've been poisoned.");
if let Some(start) = map.remove(&id.id) {
let now = Instant::now();
let sample = now
.checked_duration_since(start)
.map(|s| s.as_nanos().try_into());
let sample = match sample {
Some(Ok(sample)) => sample,
Some(Err(_)) => {
log::warn!("Elapsed time larger than fits into 64-bytes. Saturating at u64::MAX.");
u64::MAX
}
None => {
log::warn!("Time went backwards. Not recording.");
// TODO: report an error (timer id for stop was started, but time went backwards).
return;
}
};
with_ipc_payload(move |payload| {
if let Some(v) = payload.timing_samples.get_mut(&c.metric_id) {
v.push(sample);
} else {
payload.timing_samples.insert(c.metric_id, vec![sample]);
}
});
} else {
// TODO: report an error (timer id for stop wasn't started).
}
}
}
}
/// Aborts a previous [`start`](TimingDistribution::start) call. No
/// error is recorded if no [`start`](TimingDistribution::start) was
/// called.
///
/// # Arguments
///
/// * `id` - The [`TimerId`] to associate with this timing. This allows
/// for concurrent timing of events associated with different ids to the
/// same timing distribution metric.
pub fn cancel(&self, id: TimerId) {
match self {
TimingDistributionMetric::Parent {
id: _metric_id,
inner,
} => {
#[cfg(feature = "with_gecko")]
{
extern "C" {
fn GIFFT_TimingDistributionCancel(metric_id: u32, timer_id: u64);
}
// SAFETY: using only primitives, no return value.
unsafe {
GIFFT_TimingDistributionCancel(_metric_id.0, id.id);
}
}
inner.cancel(id);
}
TimingDistributionMetric::Child(c) => {
let mut map = c
.instants
.write()
.expect("Write lock must've been poisoned.");
if map.remove(&id.id).is_none() {
// TODO: report an error (cancelled a non-started id).
}
#[cfg(feature = "with_gecko")]
{
extern "C" {
fn GIFFT_TimingDistributionCancel(metric_id: u32, timer_id: u64);
}
// SAFETY: using only primitives, no return value.
unsafe {
GIFFT_TimingDistributionCancel(c.metric_id.0, id.id);
}
}
}
}
}
/// Accumulates the provided signed samples in the metric.
///
/// This is required so that the platform-specific code can provide us with
/// 64 bit signed integers if no `u64` comparable type is available. This
/// will take care of filtering and reporting errors for any provided negative
/// sample.
///
/// Please note that this assumes that the provided samples are already in
/// the "unit" declared by the instance of the metric type (e.g. if the
/// instance this method was called on is using [`crate::TimeUnit::Second`], then
/// `samples` are assumed to be in that unit).
///
/// # Arguments
///
/// * `samples` - The vector holding the samples to be recorded by the metric.
///
/// ## Notes
///
/// Discards any negative value in `samples` and report an [`ErrorType::InvalidValue`]
/// for each of them. Reports an [`ErrorType::InvalidOverflow`] error for samples that
/// are longer than `MAX_SAMPLE_TIME`.
pub fn accumulate_samples(&self, samples: Vec<i64>) {
match self {
TimingDistributionMetric::Parent { id: _id, inner } => {
inner.accumulate_samples(samples)
}
TimingDistributionMetric::Child(_c) => {
// TODO: Instrument this error
log::error!("Can't record samples for a timing distribution from a child metric");
}
}
}
/// Accumulates the provided samples in the metric.
///
/// # Arguments
///
/// * `samples` - A list of samples recorded by the metric.
/// Samples must be in nanoseconds.
/// ## Notes
///
/// Reports an [`ErrorType::InvalidOverflow`] error for samples that
/// are longer than `MAX_SAMPLE_TIME`.
pub fn accumulate_raw_samples_nanos(&self, samples: Vec<u64>) {
match self {
TimingDistributionMetric::Parent { id: _id, inner } => {
inner.accumulate_raw_samples_nanos(samples)
}
TimingDistributionMetric::Child(_c) => {
// TODO: Instrument this error
log::error!("Can't record samples for a timing distribution from a child metric");
}
}
}
pub fn accumulate_single_sample(&self, sample: i64) {
match self {
TimingDistributionMetric::Parent { id: _id, inner } => {
inner.accumulate_single_sample(sample)
}
TimingDistributionMetric::Child(_c) => {
// TODO: Instrument this error
log::error!("Can't record samples for a timing distribution from a child metric");
}
}
}
/// **Exported for test purposes.**
///
/// Gets the currently stored value of the metric.
///
/// This doesn't clear the stored value.
///
/// # Arguments
///
/// * `ping_name` - represents the optional name of the ping to retrieve the
/// metric for. Defaults to the first value in `send_in_pings`.
pub fn test_get_value<'a, S: Into<Option<&'a str>>>(
&self,
ping_name: S,
) -> Option<DistributionData> {
let ping_name = ping_name.into().map(|s| s.to_string());
match self {
TimingDistributionMetric::Parent { inner, .. } => inner.test_get_value(ping_name),
TimingDistributionMetric::Child(c) => {
panic!("Cannot get test value for {:?} in non-parent process!", c)
}
}
}
/// **Exported for test purposes.**
///
/// Gets the number of recorded errors for the given error type.
///
/// # Arguments
///
/// * `error` - The type of error
/// * `ping_name` - represents the optional name of the ping to retrieve the
/// metric for. Defaults to the first value in `send_in_pings`.
///
/// # Returns
///
/// The number of errors recorded.
pub fn test_get_num_recorded_errors(&self, error: ErrorType) -> i32 {
match self {
TimingDistributionMetric::Parent { inner, .. } => {
inner.test_get_num_recorded_errors(error)
}
TimingDistributionMetric::Child(c) => panic!(
"Cannot get number of recorded errors for {:?} in non-parent process!",
c
),
}
}
}
#[cfg(test)]
mod test {
use crate::{common_test::*, ipc, metrics};
#[test]
fn smoke_test_timing_distribution() {
let _lock = lock_test();
let metric = &metrics::test_only_ipc::a_timing_dist;
let id = metric.start();
// Stopping right away might not give us data, if the underlying clock source is not precise
// enough.
// So let's cancel and make sure nothing blows up.
metric.cancel(id);
// We can't inspect the values yet.
assert!(metric.test_get_value("store1").is_none());
}
#[test]
fn timing_distribution_child() {
let _lock = lock_test();
let parent_metric = &metrics::test_only_ipc::a_timing_dist;
let id = parent_metric.start();
std::thread::sleep(std::time::Duration::from_millis(10));
parent_metric.stop_and_accumulate(id);
{
let child_metric = parent_metric.child_metric();
// scope for need_ipc RAII
let _raii = ipc::test_set_need_ipc(true);
let id = child_metric.start();
let id2 = child_metric.start();
assert_ne!(id, id2);
std::thread::sleep(std::time::Duration::from_millis(10));
child_metric.stop_and_accumulate(id);
child_metric.cancel(id2);
}
let buf = ipc::take_buf().unwrap();
assert!(buf.len() > 0);
assert!(ipc::replay_from_buf(&buf).is_ok());
let data = parent_metric
.test_get_value("store1")
.expect("should have some data");
// No guarantees from timers means no guarantees on buckets.
// But we can guarantee it's only two samples.
assert_eq!(
2,
data.values.values().fold(0, |acc, count| acc + count),
"record 2 values, one parent, one child measurement"
);
assert!(0 < data.sum, "record some time");
}
}