Add perfmon initialization

Cargo.toml

@@ -33,6 +33,8 @@ atomic-traits = "0.2.0"
 atomic = "0.4.6"
 spin = "0.5.2"
 env_logger = "0.8.2"
+[target.'cfg(target_os = "linux")'.dependencies]
+pfm-sys = "0.0.4"
 
 [dev-dependencies]
 crossbeam = "0.7.3"

src/util/statistics/mod.rs

@@ -3,3 +3,5 @@ pub use self::counter::Timer;
 
 pub mod counter;
 pub mod stats;
+#[cfg(target_os = "linux")]
+pub mod perf;

src/util/statistics/perf.rs

@@ -0,0 +1,26 @@
+use pfm_sys::{pfm_initialize, pfm_strerror, PFM_SUCCESS};
+use std::ffi::CStr;
+
+struct Perf {
+    initialized: bool,
+}
+
+impl Default for Perf {
+    fn default() -> Perf {
+        Perf { initialized: false }
+    }
+}
+
+impl Perf {
+    fn initialize(&mut self) -> Result<(), String> {
+        let result = unsafe { pfm_initialize() };
+        if result == PFM_SUCCESS {
+            self.initialized = true;
+            Ok(())
+        } else {
+            let err_c_char = unsafe { pfm_strerror(result) };
+            let cstr = unsafe { CStr::from_ptr(err_c_char) };
+            Err(String::from(cstr.to_str().unwrap()))
+        }
+    }
+}