Make logger stop flag atomic

src/Logger.cpp

@@ -122,7 +122,7 @@ void Logger::start()
 
 void Logger::stop()
 {
-    mStop = true;
+    mStop.store(true);
     std::unique_lock<std::mutex> lck(mMtx);
     mCond.notify_one();
 }
@@ -131,11 +131,11 @@ void Logger::run()
 {
     std::vector<LogUnit*> logs(mFree.capacity());
     logs.resize(0);
-    while (!mStop) {
+    while (!mStop.load()) {
         long missLogs = 0;
         do {
             std::unique_lock<std::mutex> lck(mMtx);
-            while (mLogs.empty() && !mStop) {
+            while (mLogs.empty() && !mStop.load()) {
                 mCond.wait(lck);
             }
             logs.swap(mLogs);
@@ -211,7 +211,7 @@ LogUnit* Logger::getLogUnit()
             ++mLogUnitCnt;
             log = new LogUnit();
         } else {
-            while (mFree.empty() && !mStop) {
+            while (mFree.empty() && !mStop.load()) {
                 mCond.wait(lck);
             }
             if (!mFree.empty()) {

src/Logger.h

@@ -101,7 +101,7 @@ private:
     LogUnit* getLogUnit();
     void run();
 private:
-    bool mStop;
+    Atomic<bool> mStop;
     bool mAllowMissLog;
     AtomicLong mMissLogs;
     int mLogSample[LogLevel::Sentinel];

test/logger_stop_atomic.cpp

@@ -0,0 +1,17 @@
+/*
+ * Compile-only test to ensure Logger::mStop is atomic.
+ */
+
+#define private public
+#include "../src/Logger.h"
+#undef private
+
+#include <type_traits>
+#include <utility>
+
+int main() {
+    using StopType = decltype(std::declval<Logger>().mStop);
+    static_assert(std::is_same<StopType, Atomic<bool>>::value,
+                  "Logger::mStop should be atomic");
+    return 0;
+}

test/logger_stop_atomic.py

@@ -0,0 +1,44 @@
+#!/usr/bin/env python3
+#
+# Build and run the Logger::mStop atomic type check.
+#
+
+import os
+import subprocess
+import tempfile
+from test_util import parse_args, exit_with_result
+
+
+def run_test(project_root):
+    src = os.path.join(project_root, "test", "logger_stop_atomic.cpp")
+    if not os.path.exists(src):
+        print("FAIL: logger_stop_atomic.cpp not found")
+        return False
+
+    with tempfile.TemporaryDirectory() as tmp:
+        exe = os.path.join(tmp, "logger_stop_atomic")
+        cmd = [
+            "g++",
+            "-std=c++11",
+            src,
+            "-o",
+            exe,
+        ]
+        try:
+            subprocess.check_call(cmd, stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)
+        except Exception as exc:
+            print("FAIL: compile logger_stop_atomic:", exc)
+            return False
+        try:
+            subprocess.check_call([exe], stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)
+        except subprocess.CalledProcessError as exc:
+            print("FAIL: logger_stop_atomic returned", exc.returncode)
+            return False
+    return True
+
+
+if __name__ == "__main__":
+    _ = parse_args("Logger stop atomic test")
+    root = os.path.abspath(os.path.join(os.path.dirname(__file__), ".."))
+    success = run_test(root)
+    exit_with_result(success, "logger stop atomic", "logger stop atomic")

test/run.sh

@@ -151,6 +151,7 @@ TESTS=(
     "test/logger_unbounded_logunit.py"
     "test/string_to_int.py"
     "test/handler_stop_atomic.py"
+    "test/logger_stop_atomic.py"
     "test/pubsub_long_name.py"
     "test/pubsub_large_message.py"
     "test/transaction_forbid.py"