From c31f5334d7d1b3b8625ab3c789b68630c80c258c Mon Sep 17 00:00:00 2001
From: "Tate, Hongliang Tian" <tatetian@gmail.com>
Date: Fri, 4 Jan 2019 21:50:28 +0800
Subject: [PATCH] Small fix to Waiter and WaitQueue

---
 src/libos/src/process/exit.rs |  3 +--
 src/libos/src/process/wait.rs | 14 +++++++-------
 2 files changed, 8 insertions(+), 9 deletions(-)

diff --git a/src/libos/src/process/exit.rs b/src/libos/src/process/exit.rs
index 356475fa..21ec212e 100644
--- a/src/libos/src/process/exit.rs
+++ b/src/libos/src/process/exit.rs
@@ -15,7 +15,6 @@ unsafe impl Send for ChildProcessFilter {}
 pub fn do_exit(exit_status: i32) {
     let current_ref = get_current();
     let mut current = current_ref.lock().unwrap();
-
     // Update current
     current.exit_status = exit_status;
     current.status = Status::ZOMBIE;
@@ -98,7 +97,7 @@ pub fn do_wait4(child_filter: &ChildProcessFilter, exit_status: &mut i32)
         waiter
     };
 
-    let child_pid = waiter.wait_on();
+    let child_pid = Waiter::sleep_until_woken_with_result(waiter);
     if child_pid == 0 { panic!("THIS SHOULD NEVER HAPPEN!"); }
 
     {
diff --git a/src/libos/src/process/wait.rs b/src/libos/src/process/wait.rs
index 7cf4d37f..aabb9ddf 100644
--- a/src/libos/src/process/wait.rs
+++ b/src/libos/src/process/wait.rs
@@ -14,7 +14,7 @@ unsafe impl<D, R> Send for Waiter<D, R> where D: Sized + Copy, R: Sized + Copy {
 struct WaiterInner<D, R>
     where D: Sized + Copy, R: Sized + Copy
 {
-    has_waken: bool,
+    is_woken: bool,
     data: D,
     result: Option<R>,
 }
@@ -26,7 +26,7 @@ impl<D, R> Waiter<D, R>
         Waiter {
             thread: unsafe { sgx_thread_get_self() },
             inner: Arc::new(SgxMutex::new(WaiterInner {
-                has_waken: false,
+                is_woken: false,
                 data: *data,
                 result: None,
             })),
@@ -37,14 +37,14 @@ impl<D, R> Waiter<D, R>
         self.inner.lock().unwrap().data
     }
 
-    pub fn wait_on(&self) -> R {
-        if !self.inner.lock().unwrap().has_waken {
+    pub fn sleep_until_woken_with_result(waiter: Waiter<D, R>) -> R {
+        while !waiter.inner.lock().unwrap().is_woken {
             unsafe {
-                wait_event(self.thread);
+                wait_event(waiter.thread);
             }
         }
 
-        self.inner.lock().unwrap().result.unwrap()
+        waiter.inner.lock().unwrap().result.unwrap()
     }
 }
 
@@ -81,7 +81,7 @@ impl<D, R> WaitQueue<D, R>
             let waiter_i = waiters.iter().position(|waiter| {
                 let mut waiter_inner = waiter.inner.lock().unwrap();
                 if let Some(waiter_result) = cond(&waiter_inner.data) {
-                    waiter_inner.has_waken = true;
+                    waiter_inner.is_woken = true;
                     waiter_inner.result = Some(waiter_result);
                     true
                 }