unix support for life demo cpu timing

Author: mdonoughe

rayon-demo/Cargo.toml

@@ -11,6 +11,7 @@ docopt = "1"
 fixedbitset = "0.1.5"
 glium = "0.21"
 lazy_static = "1"
+libc = "0.2"
 odds = "0.3"
 rand = "0.5"
 regex = "1"

rayon-demo/src/life/cpu_time/mod.rs

@@ -5,7 +5,12 @@ mod win;
 #[cfg(windows)]
 pub use self::win::get_cpu_time;
 
-#[cfg(not(windows))]
+#[cfg(unix)]
+mod unix;
+#[cfg(unix)]
+pub use self::unix::get_cpu_time;
+
+#[cfg(not(any(unix, windows)))]
 pub fn get_cpu_time() -> Option<u64> {
     None
 }

rayon-demo/src/life/cpu_time/unix.rs

@@ -0,0 +1,14 @@
+use libc::{getrusage, rusage, RUSAGE_SELF};
+use std::mem;
+
+pub fn get_cpu_time() -> Option<u64> {
+    unsafe {
+        let mut usage: rusage = mem::uninitialized();
+        getrusage(RUSAGE_SELF, &mut usage);
+        let user = 1_000_000_000 * (usage.ru_utime.tv_sec as u64)
+            + 1_000 * (usage.ru_utime.tv_usec as u64);
+        let system = 1_000_000_000 * (usage.ru_stime.tv_sec as u64)
+            + 1_000 * (usage.ru_stime.tv_usec as u64);
+        Some(user + system)
+    }
+}

rayon-demo/src/main.rs

@@ -33,6 +33,7 @@ extern crate serde; // all
 extern crate cgmath; // nbody
 #[macro_use]
 extern crate glium; // nbody
+extern crate libc; // life
 extern crate rand; // nbody
 extern crate time; // nbody, sieve
 extern crate odds; // sieve