Implement sched::sched_getaffinity()

sched_getaffinity(2) get a process's CPU affinity mask

src/sched.rs

@@ -96,6 +96,22 @@ mod sched_linux_like {
         Errno::result(res).map(drop)
     }
 
+    pub fn sched_getaffinity(pid: Pid) -> Result<CpuSet> {
+        let mut cpuset = CpuSet::new();
+        let res = unsafe {
+            libc::sched_getaffinity(
+                pid.into(),
+                mem::size_of::<CpuSet>() as libc::size_t,
+                & mut cpuset.cpu_set,
+            )
+        };
+
+        match res {
+            0 => Ok(cpuset),
+            _ => Err(Error::from_errno(Errno::from_i32(res))),
+        }
+    }
+
     pub fn clone(
         mut cb: CloneCb,
         stack: &mut [u8],