From 2e9697353cf479ea08ebf10778b1e2481d964588 Mon Sep 17 00:00:00 2001
From: Jeremy Soller <jackpot51@gmail.com>
Date: Thu, 22 Sep 2016 10:10:27 -0600
Subject: [PATCH] Add wnohang, make PS/2 driver write input to display scheme,
 which then passes it to the shell

---
 syscall/process.rs | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/syscall/process.rs b/syscall/process.rs
index 34d5751..b38aee6 100644
--- a/syscall/process.rs
+++ b/syscall/process.rs
@@ -18,7 +18,7 @@ use elf::{self, program_header};
 use scheme;
 use syscall;
 use syscall::error::*;
-use syscall::flag::{CLONE_VM, CLONE_FS, CLONE_FILES, MAP_WRITE, MAP_WRITE_COMBINE};
+use syscall::flag::{CLONE_VM, CLONE_FS, CLONE_FILES, MAP_WRITE, MAP_WRITE_COMBINE, WNOHANG};
 use syscall::validate::{validate_slice, validate_slice_mut};
 
 pub fn brk(address: usize) -> Result<usize> {
@@ -594,7 +594,7 @@ pub fn sched_yield() -> Result<usize> {
     Ok(0)
 }
 
-pub fn waitpid(pid: usize, status_ptr: usize, _options: usize) -> Result<usize> {
+pub fn waitpid(pid: usize, status_ptr: usize, flags: usize) -> Result<usize> {
     //TODO: Implement status_ptr and options
     loop {
         {
@@ -616,6 +616,8 @@ pub fn waitpid(pid: usize, status_ptr: usize, _options: usize) -> Result<usize>
             if exited {
                 let mut contexts = context::contexts_mut();
                 return contexts.remove(pid).ok_or(Error::new(ESRCH)).and(Ok(pid));
+            } else if flags & WNOHANG == WNOHANG {
+                return Ok(0);
             }
         }