Join worker tasks before destroying TileData

Fixes #1309

1 files changed, 10 insertions, 4 deletions

diff --git a/src/mbgl/util/worker.cpp b/src/mbgl/util/worker.cpp
index 9792f1a099..7f5620e1fa 100644
--- a/src/mbgl/util/worker.cpp
+++ b/src/mbgl/util/worker.cpp
@@ -2,6 +2,7 @@
 #include <mbgl/platform/platform.hpp>
 
 #include <cassert>
+#include <future>
 
 namespace mbgl {
 
@@ -9,8 +10,8 @@ class Worker::Impl {
 public:
     Impl(uv_loop_t*) {}
 
-    void doWork(Fn work) {
-        work();
+    void doWork(std::packaged_task<void ()>& task) {
+        task();
     }
 };
 
@@ -22,9 +23,14 @@ Worker::Worker(std::size_t count) {
 
 Worker::~Worker() = default;
 
-void Worker::send(Fn&& work, Fn&& after) {
-    threads[current]->invokeWithResult(&Worker::Impl::doWork, std::move(after), std::move(work));
+WorkRequest Worker::send(Fn work, Fn after) {
+    std::packaged_task<void ()> task(work);
+    std::future<void> future = task.get_future();
+
+    threads[current]->invokeWithResult(&Worker::Impl::doWork, std::move(after), task);
+
     current = (current + 1) % threads.size();
+    return WorkRequest(std::move(future));
 }
 
 }