Merge pull request #8617 from apple/jdevlieghere/cherrypick-2f343fc1574f36b3b5ff1acf63407c53dcdac331

[lldb] Print a message when background tasks take a while to complete…

Author: JDevlieghere

lldb/tools/driver/Driver.cpp

@@ -32,6 +32,7 @@
 #include <bitset>
 #include <clocale>
 #include <csignal>
+#include <future>
 #include <string>
 #include <thread>
 #include <utility>
@@ -821,6 +822,18 @@ int main(int argc, char const *argv[]) {
     }
   }
 
-  SBDebugger::Terminate();
+  // When terminating the debugger we have to wait on all the background tasks
+  // to complete, which can take a while. Print a message when this takes longer
+  // than 1 second.
+  {
+    std::future<void> future =
+        std::async(std::launch::async, []() { SBDebugger::Terminate(); });
+
+    if (future.wait_for(std::chrono::seconds(1)) == std::future_status::timeout)
+      fprintf(stderr, "Waiting for background tasks to complete...\n");
+
+    future.wait();
+  }
+
   return exit_code;
 }