From 9b97dc73dcdbabe554cddea5e9292f149cfbe5e6 Mon Sep 17 00:00:00 2001
From: Gabriel Ebner <gebner@gebner.org>
Date: Thu, 1 Dec 2016 09:07:15 -0500
Subject: [PATCH] fix(library/task_queue): do not keep references to cancelled
 task_results in the exception

We store this exception in the task_result itself, which creates a
reference cycle.
---
 src/library/task_queue.cpp | 3 +--
 src/library/task_queue.h   | 3 ---
 2 files changed, 1 insertion(+), 5 deletions(-)

diff --git a/src/library/task_queue.cpp b/src/library/task_queue.cpp
index de77722e54..202835ad06 100644
--- a/src/library/task_queue.cpp
+++ b/src/library/task_queue.cpp
@@ -72,8 +72,7 @@ task_queue & get_global_task_queue() {
     return *g_tq;
 }
 
-task_cancellation_exception::task_cancellation_exception(generic_task_result const & cancelled_task) :
-        m_cancelled_task(cancelled_task) {
+task_cancellation_exception::task_cancellation_exception(generic_task_result const & cancelled_task) {
     std::ostringstream out;
     if (cancelled_task) {
         out << "task cancelled: " << cancelled_task.description();
diff --git a/src/library/task_queue.h b/src/library/task_queue.h
index 21b80ed2ff..849521bb93 100644
--- a/src/library/task_queue.h
+++ b/src/library/task_queue.h
@@ -212,14 +212,11 @@ task_result<T> mk_pure_task_result(T const & t, std::string const & desc) {
 }
 
 class task_cancellation_exception : public std::exception {
-    generic_task_result m_cancelled_task;
     std::string m_msg;
 public:
     task_cancellation_exception() : task_cancellation_exception(generic_task_result()) {}
     task_cancellation_exception(generic_task_result const & cancelled_task);
     char const * what() const noexcept override;
-
-    generic_task_result get_cancelled_task() const { return m_cancelled_task; }
 };
 
 class task_queue {