Merge pull request OptimatistOpenSource#19 from Thaumy/add-reset

Introduce `reset` fn for sampling mode and tracing mode

src/perf_event/sampling/group/fixed.rs

@@ -30,6 +30,10 @@ impl FixedSamplerGroup {
         self.inner().disable()
     }
 
+    pub fn reset(&self) -> io::Result<()> {
+        self.inner().reset()
+    }
+
     pub fn next_record(&mut self, guard: &SamplerGuard) -> Option<Record> {
         self.inner_mut().next_record(guard.event_id())
     }

src/perf_event/sampling/group/inner.rs

@@ -101,6 +101,19 @@ impl Inner {
         )
     }
 
+    pub fn reset(&self) -> io::Result<()> {
+        self.leader().map_or_else(
+            || Err(io::Error::new(ErrorKind::Other, "Group has no members")),
+            |leader| {
+                ioctl_wrapped(
+                    &leader.file,
+                    PERF_EVENT_IOCTL_RESET,
+                    Some(PERF_IOC_FLAG_GROUP),
+                )
+            },
+        )
+    }
+
     pub fn next_record(&mut self, event_id: u64) -> Option<Record> {
         self.members
             .get_mut(&event_id)

src/perf_event/sampling/single/mod.rs

@@ -95,6 +95,10 @@ impl Sampler {
         ioctl_wrapped::<()>(&self.file, PERF_EVENT_IOCTL_DISABLE, None)
     }
 
+    pub fn reset(&self) -> io::Result<()> {
+        ioctl_wrapped::<()>(&self.file, PERF_EVENT_IOCTL_RESET, None)
+    }
+
     #[cfg(feature = "linux-4.7")]
     pub fn pause(&self) -> io::Result<()> {
         ioctl_wrapped(&self.file, PERF_EVENT_IOCTL_PAUSE_OUTPUT, Some(1i32))

src/perf_event/tracing/tracer/mod.rs

@@ -78,6 +78,10 @@ impl Tracer {
         self.sampler.disable()
     }
 
+    pub fn reset(&self) -> io::Result<()> {
+        self.sampler.reset()
+    }
+
     #[cfg(feature = "linux-4.7")]
     pub fn pause(&self) -> io::Result<()> {
         self.sampler.pause()