Adds timing info to each sample

CHANGELOG.md

@@ -9,6 +9,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Changed
 - Remove `backtrace-rs` feature, as the default choice when not specified (#130)
 
+### Added
+- Add `sample_timestamp` to Frames and UnresolvedFrames in order to have more fine-grained info on when the samples are collected (#133)
+
 ## [0.9.1] - 2022-05-19
 
 ### Fixed

src/frames.rs

@@ -5,6 +5,7 @@ use std::fmt::{self, Debug, Display, Formatter};
 use std::hash::{Hash, Hasher};
 use std::os::raw::c_void;
 use std::path::PathBuf;
+use std::time::SystemTime;
 
 use smallvec::SmallVec;
 use symbolic_demangle::demangle;
@@ -18,6 +19,7 @@ pub struct UnresolvedFrames {
     pub thread_name: [u8; MAX_THREAD_NAME],
     pub thread_name_length: usize,
     pub thread_id: u64,
+    pub sample_timestamp: SystemTime,
 }
 
 impl Default for UnresolvedFrames {
@@ -28,6 +30,7 @@ impl Default for UnresolvedFrames {
             thread_name: [0; MAX_THREAD_NAME],
             thread_name_length: 0,
             thread_id: 0,
+            sample_timestamp: SystemTime::now(),
         }
     }
 }
@@ -43,6 +46,7 @@ impl UnresolvedFrames {
         frames: SmallVec<[<TraceImpl as Trace>::Frame; MAX_DEPTH]>,
         tn: &[u8],
         thread_id: u64,
+        sample_timestamp: SystemTime,
     ) -> Self {
         let thread_name_length = tn.len();
         let mut thread_name = [0; MAX_THREAD_NAME];
@@ -53,6 +57,7 @@ impl UnresolvedFrames {
             thread_name,
             thread_name_length,
             thread_id,
+            sample_timestamp,
         }
     }
 }
@@ -164,6 +169,7 @@ pub struct Frames {
     pub frames: Vec<Vec<Symbol>>,
     pub thread_name: String,
     pub thread_id: u64,
+    pub sample_timestamp: SystemTime,
 }
 
 impl Frames {
@@ -210,6 +216,7 @@ impl From<UnresolvedFrames> for Frames {
             thread_name: String::from_utf8_lossy(&frames.thread_name[0..frames.thread_name_length])
                 .into_owned(),
             thread_id: frames.thread_id,
+            sample_timestamp: frames.sample_timestamp,
         }
     }
 }

src/profiler.rs

@@ -2,6 +2,7 @@
 
 use std::convert::TryInto;
 use std::os::raw::c_int;
+use std::time::SystemTime;
 
 use nix::sys::signal;
 use once_cell::sync::Lazy;
@@ -284,6 +285,8 @@ extern "C" fn perf_signal_handler(
             let mut bt: SmallVec<[<TraceImpl as Trace>::Frame; MAX_DEPTH]> =
                 SmallVec::with_capacity(MAX_DEPTH);
             let mut index = 0;
+
+            let sample_timestamp: SystemTime = SystemTime::now();
             TraceImpl::trace(ucontext, |frame| {
                 let ip = Frame::ip(frame);
                 if profiler.is_blocklisted(ip) {
@@ -306,7 +309,7 @@ extern "C" fn perf_signal_handler(
             write_thread_name(current_thread, &mut name);
 
             let name = unsafe { std::ffi::CStr::from_ptr(name_ptr) };
-            profiler.sample(bt, name.to_bytes(), current_thread as u64);
+            profiler.sample(bt, name.to_bytes(), current_thread as u64, sample_timestamp);
         }
     }
 }
@@ -392,8 +395,9 @@ impl Profiler {
         backtrace: SmallVec<[<TraceImpl as Trace>::Frame; MAX_DEPTH]>,
         thread_name: &[u8],
         thread_id: u64,
+        sample_timestamp: SystemTime,
     ) {
-        let frames = UnresolvedFrames::new(backtrace, thread_name, thread_id);
+        let frames = UnresolvedFrames::new(backtrace, thread_name, thread_id, sample_timestamp);
         self.sample_counter += 1;
 
         if let Ok(()) = self.data.add(frames, 1) {}