Merge pull request #21605 from vespa-engine/havardpe/remove-tsan-warnings-from-fastos

make some variables atomic to make tsan happy

3 files changed, 13 insertions, 7 deletions

diff --git a/fastos/src/tests/job.h b/fastos/src/tests/job.h
index 15356270972..4546cfe1daa 100644
--- a/fastos/src/tests/job.h
+++ b/fastos/src/tests/job.h
@@ -28,7 +28,7 @@ public:
    std::mutex *mutex;
    std::condition_variable *condition;
    FastOS_ThreadInterface *otherThread, *ownThread;
-   int result;
+   std::atomic<int> result;
    FastOS_ThreadId _threadId;
 
    Job()
diff --git a/fastos/src/tests/thread_test_base.hpp b/fastos/src/tests/thread_test_base.hpp
index 49d37209b6a..eb994537f6e 100644
--- a/fastos/src/tests/thread_test_base.hpp
+++ b/fastos/src/tests/thread_test_base.hpp
@@ -5,7 +5,7 @@
 #include <chrono>
 #include <thread>
 
-static volatile int64_t number;
+static std::atomic<int64_t> number;
 #define INCREASE_NUMBER_AMOUNT 10000
 
 using namespace std::chrono_literals;
@@ -97,11 +97,11 @@ void ThreadTestBase::Run (FastOS_ThreadInterface *thread, void *arg)
              guard = std::unique_lock<std::mutex>(*job->mutex);
          }
 
-         result = static_cast<int>(number);
+         result = static_cast<int>(number.load(std::memory_order_relaxed));
 
          int sleepOn = (INCREASE_NUMBER_AMOUNT/2) * 321/10000;
          for (int i=0; i<(INCREASE_NUMBER_AMOUNT/2); i++) {
-            number = number + 2;
+            number.fetch_add(2, std::memory_order_relaxed);
 
             if (i == sleepOn)
                 std::this_thread::sleep_for(1ms);
diff --git a/fastos/src/vespa/fastos/thread.h b/fastos/src/vespa/fastos/thread.h
index 0f4cc4c09f7..f881095c29a 100644
--- a/fastos/src/vespa/fastos/thread.h
+++ b/fastos/src/vespa/fastos/thread.h
@@ -50,7 +50,7 @@ private:
     bool _closeCalledFlag;
 
     // Always lock in this order
-    std::mutex _freeMutex;
+    mutable std::mutex _freeMutex;
     std::mutex _liveMutex;
     std::condition_variable _liveCond;
     /**
@@ -191,7 +191,10 @@ public:
      * @ref GetNumActiveThreads() and @ref GetNumInactiveThreads().
      * @return   Number of currently active threads
      */
-    int GetNumActiveThreads () const { return _numActive; }
+    int GetNumActiveThreads () const {
+        std::lock_guard<std::mutex> guard(_freeMutex);
+        return _numActive;
+    }
 
     /**
      * Get the number of currently inactive threads.
@@ -199,7 +202,10 @@ public:
      * @ref GetNumActiveThreads() and @ref GetNumInactiveThreads().
      * @return   Number of currently inactive threads
      */
-    int GetNumInactiveThreads () const { return _numFree; }
+    int GetNumInactiveThreads () const {
+        std::lock_guard<std::mutex> guard(_freeMutex);
+        return _numFree;
+    }
 
     /**
      * Get the number of started threads since instantiation of the thread pool.