use std::os::raw::c_int;
use backtrace::Frame;
use nix::sys::signal;
use crate::collector::Collector;
use crate::frames::UnresolvedFrames;
use crate::timer::Timer;
use crate::Result;
use crate::{Error, MAX_DEPTH};
use crate::{ReportBuilder, MAX_THREAD_NAME};
lazy_static::lazy_static! {
pub static ref PROFILER: spin::RwLock<Result<Profiler>> = spin::RwLock::new(Profiler::new());
}
pub struct Profiler {
pub data: Collector<UnresolvedFrames>,
sample_counter: i32,
pub running: bool,
}
pub struct ProfilerGuard<'a> {
profiler: &'a spin::RwLock<Result<Profiler>>,
_timer: Timer,
}
impl ProfilerGuard<'_> {
pub fn new(frequency: c_int) -> Result<ProfilerGuard<'static>> {
match PROFILER.write().as_mut() {
Err(err) => {
log::error!("Error in creating profiler: {}", err);
Err(Error::CreatingError)
}
Ok(profiler) => match profiler.start() {
Ok(()) => Ok(ProfilerGuard::<'static> {
profiler: &PROFILER,
_timer: Timer::new(frequency),
}),
Err(err) => Err(err),
},
}
}
pub fn report(&self) -> ReportBuilder {
ReportBuilder::new(&self.profiler)
}
}
impl<'a> Drop for ProfilerGuard<'a> {
fn drop(&mut self) {
match self.profiler.write().as_mut() {
Err(_) => {}
Ok(profiler) => match profiler.stop() {
Ok(()) => {}
Err(err) => log::error!("error while stopping profiler {}", err),
},
}
}
}
extern "C" fn perf_signal_handler(_signal: c_int) {
let mut bt: [Frame; MAX_DEPTH] = unsafe { std::mem::MaybeUninit::uninit().assume_init() };
let mut index = 0;
backtrace::trace(|frame| {
if index < MAX_DEPTH {
bt[index] = frame.clone();
index += 1;
true
} else {
false
}
});
if let Some(mut guard) = PROFILER.try_write() {
if let Ok(profiler) = guard.as_mut() {
let current_thread = unsafe { libc::pthread_self() };
let mut name: [libc::c_char; MAX_THREAD_NAME] =
unsafe { std::mem::MaybeUninit::uninit().assume_init() };
let name_ptr = &mut name as *mut [libc::c_char] as *mut libc::c_char;
let ret =
unsafe { libc::pthread_getname_np(current_thread, name_ptr, MAX_THREAD_NAME) };
if ret == 0 {
let name = unsafe { std::ffi::CStr::from_ptr(name_ptr) };
profiler.sample(&bt[0..index], name.to_bytes(), current_thread as u64);
}
}
}
}
impl Profiler {
fn new() -> Result<Self> {
Ok(Profiler {
data: Collector::new()?,
sample_counter: 0,
running: false,
})
}
}
impl Profiler {
pub fn start(&mut self) -> Result<()> {
log::info!("starting cpu profiler");
if self.running {
Err(Error::Running)
} else {
self.register_signal_handler()?;
self.running = true;
Ok(())
}
}
fn init(&mut self) -> Result<()> {
self.sample_counter = 0;
self.data = Collector::new()?;
self.running = false;
Ok(())
}
pub fn stop(&mut self) -> Result<()> {
log::info!("stopping cpu profiler");
if self.running {
self.unregister_signal_handler()?;
self.init()?;
Ok(())
} else {
Err(Error::NotRunning)
}
}
pub fn register_signal_handler(&self) -> Result<()> {
let handler = signal::SigHandler::Handler(perf_signal_handler);
unsafe { signal::signal(signal::SIGPROF, handler) }?;
Ok(())
}
pub fn ignore_signal_handler(&self) -> Result<()> {
let handler = signal::SigHandler::SigIgn;
unsafe { signal::signal(signal::SIGPROF, handler) }?;
Ok(())
}
fn unregister_signal_handler(&self) -> Result<()> {
let handler = signal::SigHandler::SigDfl;
unsafe { signal::signal(signal::SIGPROF, handler) }?;
Ok(())
}
pub fn sample(&mut self, backtrace: &[Frame], thread_name: &[u8], thread_id: u64) {
let frames = UnresolvedFrames::new(backtrace, thread_name, thread_id);
self.sample_counter += 1;
if let Ok(()) = self.data.add(frames) {}
}
}