SGX target: convert a bunch of panics to aborts

[rust.git] / src / libstd / sys / sgx / waitqueue.rs

diff --git a/src/libstd/sys/sgx/waitqueue.rs b/src/libstd/sys/sgx/waitqueue.rs
index f4adb7d1e16067e2f8028ce52b48e25735ad61dc..d542f9b41012793bc4b90d62e827c901dde9515a 100644 (file)
--- a/src/libstd/sys/sgx/waitqueue.rs
+++ b/src/libstd/sys/sgx/waitqueue.rs
@@ -121,7 +121,7 @@ fn drop(&mut self) {
             NotifiedTcs::Single(tcs) => Some(tcs),
             NotifiedTcs::All { .. } => None
         };
-        usercalls::send(EV_UNPARK, target_tcs).unwrap();
+        rtunwrap!(Ok, usercalls::send(EV_UNPARK, target_tcs));
     }
 }
 
@@ -141,6 +141,7 @@ pub fn is_empty(&self) -> bool {
     ///
     /// This function does not return until this thread has been awoken.
     pub fn wait<T>(mut guard: SpinMutexGuard<'_, WaitVariable<T>>) {
+        // very unsafe: check requirements of UnsafeList::push
         unsafe {
             let mut entry = UnsafeListEntry::new(SpinMutex::new(WaitEntry {
                 tcs: thread::current(),
@@ -149,10 +150,9 @@ pub fn wait<T>(mut guard: SpinMutexGuard<'_, WaitVariable<T>>) {
             let entry = guard.queue.inner.push(&mut entry);
             drop(guard);
             while !entry.lock().wake {
-                assert_eq!(
-                    usercalls::wait(EV_UNPARK, WAIT_INDEFINITE).unwrap() & EV_UNPARK,
-                    EV_UNPARK
-                );
+                // don't panic, this would invalidate `entry` during unwinding
+                let eventset = rtunwrap!(Ok, usercalls::wait(EV_UNPARK, WAIT_INDEFINITE));
+                rtassert!(eventset & EV_UNPARK == EV_UNPARK);
             }
         }
     }
@@ -269,7 +269,7 @@ pub fn is_empty(&self) -> bool {
                         // ,-------> /---------\ next ---,
                         // |         |head_tail|         |
                         // `--- prev \---------/ <-------`
-                        assert_eq!(self.head_tail.as_ref().prev, first);
+                        rtassert!(self.head_tail.as_ref().prev == first);
                         true
                     } else {
                         false
@@ -285,7 +285,9 @@ pub fn is_empty(&self) -> bool {
         /// # Safety
         ///
         /// The entry must remain allocated until the entry is removed from the
-        /// list AND the caller who popped is done using the entry.
+        /// list AND the caller who popped is done using the entry. Special
+        /// care must be taken in the caller of `push` to ensure unwinding does
+        /// not destroy the stack frame containing the entry.
         pub unsafe fn push<'a>(&mut self, entry: &'a mut UnsafeListEntry<T>) -> &'a T {
             self.init();
 
@@ -303,6 +305,7 @@ pub unsafe fn push<'a>(&mut self, entry: &'a mut UnsafeListEntry<T>) -> &'a T {
             entry.as_mut().prev = prev_tail;
             entry.as_mut().next = self.head_tail;
             prev_tail.as_mut().next = entry;
+            // unwrap ok: always `Some` on non-dummy entries
             (*entry.as_ptr()).value.as_ref().unwrap()
         }
 
@@ -333,6 +336,7 @@ pub unsafe fn pop<'a>(&mut self) -> Option<&'a T> {
                 second.as_mut().prev = self.head_tail;
                 first.as_mut().next = NonNull::dangling();
                 first.as_mut().prev = NonNull::dangling();
+                // unwrap ok: always `Some` on non-dummy entries
                 Some((*first.as_ptr()).value.as_ref().unwrap())
             }
         }