[android] Fix possibly race on undefined behaviorupstream/tmpsantos-android_race

`runnable->iter = runnables.end()` assumes that `::end()` is a
`static` or `constxpr` and thread-safe. This is likely to be true
for most of the implementations. That said we cannot rely on
undefined behavior and we should assume the worse case scenario.

1 files changed, 1 insertions, 0 deletions

diff --git a/platform/android/src/run_loop.cpp b/platform/android/src/run_loop.cpp
index f655f13ea8..b55f2be190 100644
--- a/platform/android/src/run_loop.cpp
+++ b/platform/android/src/run_loop.cpp
@@ -167,6 +167,7 @@ void RunLoop::Impl::removeRunnable(Runnable* runnable) {
 }
 
 void RunLoop::Impl::initRunnable(Runnable* runnable) {
+    std::lock_guard<std::recursive_mutex> lock(mtx);
     runnable->iter = runnables.end();
 }