threadloop: fix race condition in get_id access

threadloop::get_id() can be called with a non-initialized thread_ variable.
If this call is done under the loop thread, right after its creation,
and if InterruptedThreadLoop::wait_for is call, an non catched exception
is thrown and std::terminate stops all the application.
This patch proposes to fix this race condition and fix the non-catched
exception to let the application in a safe state.

Issue: #81210
Change-Id: I3d8409ac505be181d1a54c5bdd0e679fdb81bf88

src/threadloop.cpp

@@ -24,10 +24,12 @@
 namespace ring {
 
 void
-ThreadLoop::mainloop(const std::function<bool()> setup,
+ThreadLoop::mainloop(std::thread::id& tid,
+                     const std::function<bool()> setup,
                      const std::function<void()> process,
                      const std::function<void()> cleanup)
 {
+    tid = std::this_thread::get_id();
     try {
         if (setup()) {
             while (state_ == RUNNING)
@@ -37,7 +39,9 @@ ThreadLoop::mainloop(const std::function<bool()> setup,
             RING_ERR("setup failed");
         }
     } catch (const ThreadLoopException& e) {
-        RING_ERR("%s", e.what());
+        RING_ERR("[threadloop:%p] ThreadLoopException: %s", this, e.what());
+    } catch (const std::exception& e) {
+        RING_ERR("[threadloop:%p] Unwaited exception: %s", this, e.what());
     }
 }
 
@@ -85,7 +89,8 @@ ThreadLoop::start()
     }
 
     state_ = RUNNING;
-    thread_ = std::thread(&ThreadLoop::mainloop, this, setup_, process_, cleanup_);
+    thread_ = std::thread(&ThreadLoop::mainloop, this, std::ref(threadId_), setup_, process_, cleanup_);
+    threadId_ = thread_.get_id();
 }
 
 void
@@ -124,7 +129,7 @@ ThreadLoop::isStopping() const noexcept
 std::thread::id
 ThreadLoop::get_id() const noexcept
 {
-    return thread_.get_id();
+    return threadId_;
 }
 
 void

src/threadloop.h

@@ -66,11 +66,13 @@ private:
     std::function<void()> process_;
     std::function<void()> cleanup_;
 
-    void mainloop(const std::function<bool()> setup,
+    void mainloop(std::thread::id& tid,
+                  const std::function<bool()> setup,
                   const std::function<void()> process,
                   const std::function<void()> cleanup);
 
     std::atomic<ThreadState> state_ {READY};
+    std::thread::id threadId_;
     std::thread thread_;
 };