1 files changed, 11 insertions, 0 deletions
diff --git a/works/life/computer-network-experiment/Output.cpp b/works/life/computer-network-experiment/Output.cpp
index 2989c98..db97e5e 100644
--- a/works/life/computer-network-experiment/Output.cpp
+++ b/works/life/computer-network-experiment/Output.cpp
@@ -2,9 +2,12 @@
 
 #include <folly/CancellationToken.h>
 
+#include <mutex>
 #include <ostream>
 #include <type_traits>
 
+std::mutex m;
+
 folly::MPMCQueue<Output> output_queue(100);
 
 folly::CancellationSource cancellation_source;
@@ -44,6 +47,8 @@ void PrintOutput(const Output &output) {
 
 void OutputThread() {
   while (true) {
+    m.lock();
+
     if (cancellation_source.getToken().isCancellationRequested()) {
       while (true) {
         Output output;
@@ -58,6 +63,8 @@ void OutputThread() {
     Output output;
     if (output_queue.readIfNotEmpty(output))
       PrintOutput(output);
+
+    m.unlock();
   }
 }
 
@@ -65,3 +72,7 @@ void SignalAndWaitForOutputThreadStop() {
   cancellation_source.requestCancellation();
   output_thread.join();
 }
+
+std::lock_guard<std::mutex> BlockOutputThread() {
+  return std::lock_guard<std::mutex>(m);
+}