openssl async job: clear the wait ctx when dropped

lib/g3-openssl/src/async_job/task.rs

@@ -72,6 +72,26 @@ pub struct OpensslAsyncTask<T: AsyncOperation> {
     action: Box<UnsafeCell<Action<T>>>,
 }
 
+impl<T: AsyncOperation> Drop for OpensslAsyncTask<T> {
+    fn drop(&mut self) {
+        if !self.job.is_null() {
+            let mut ret: c_int = 0;
+
+            // reset ctx in job to be null before we drop it
+            unsafe {
+                ffi::ASYNC_start_job(
+                    &mut self.job,
+                    ptr::null_mut(),
+                    &mut ret,
+                    None,            // ignored
+                    ptr::null_mut(), // ignored
+                    0,               // ignored
+                )
+            };
+        }
+    }
+}
+
 /// NOTE: OpensslAsyncTask in fact is not Send,
 /// make sure you call it in a single threaded async runtime
 unsafe impl<T: AsyncOperation + Send> Send for OpensslAsyncTask<T> {}
@@ -241,6 +261,8 @@ where
     type Output = Result<T::Output, OpensslAsyncTaskError>;
 
     fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
-        self.get_mut().poll_run(cx)
+        let r = ready!(self.get_mut().poll_run(cx));
+        self.job = ptr::null_mut(); // reset
+        Poll::Ready(r)
     }
 }