Add os.sched_yield, os.sched_get_priority_min, os.sched_get_priority_max

zetwhite · zetwhite · commit c90cd0f41efb · 2021-09-01T20:22:44.000+09:00
diff --git a/vm/src/stdlib/os.rs b/vm/src/stdlib/os.rs
@@ -2086,6 +2086,8 @@ mod posix {
     const EX_NOPERM: i8 = exitcode::NOPERM as i8;
     #[pyattr]
     const EX_CONFIG: i8 = exitcode::CONFIG as i8;
+    #[pyattr]
+    use libc::{SCHED_BATCH, SCHED_FIFO, SCHED_IDLE, SCHED_OTHER, SCHED_RR};
 
     #[cfg(any(target_os = "linux", target_os = "freebsd", target_os = "macos"))]
     #[pyattr]
@@ -2369,6 +2371,38 @@ mod posix {
         }
     }
 
+    #[cfg(target_os = "linux")]
+    #[pyfunction]
+    fn sched_get_priority_max(policy: i32, vm: &VirtualMachine) -> PyResult<i32> {
+        let max = unsafe { libc::sched_get_priority_max(policy) };
+        if max == -1 {
+            Err(errno_err(vm))
+        } else {
+            Ok(max)
+        }
+    }
+
+    #[cfg(target_os = "linux")]
+    #[pyfunction]
+    fn sched_get_priority_min(policy: i32, vm: &VirtualMachine) -> PyResult<i32> {
+        let min = unsafe { libc::sched_get_priority_min(policy) };
+        if min == -1 {
+            Err(errno_err(vm))
+        } else {
+            Ok(min)
+        }
+    }
+
+    #[cfg(target_os = "linux")]
+    #[pyfunction]
+    fn sched_yield(vm: &VirtualMachine) -> PyResult<()> {
+        let res = nix::sched::sched_yield();
+        match res {
+            Ok(_) => Ok(()),
+            Err(err) => Err(err.into_pyexception(vm)),
+        }
+    }
+
     #[pyfunction]
     fn get_inheritable(fd: RawFd, vm: &VirtualMachine) -> PyResult<bool> {
         use nix::fcntl::fcntl;
