SERVER-46008 Fix so logging works during global shutdown

4 files changed, 60 insertions, 16 deletions

diff --git a/src/mongo/logv2/log_domain_global.cpp b/src/mongo/logv2/log_domain_global.cpp
index 7b8e117fa02..000ed72ffe3 100644
--- a/src/mongo/logv2/log_domain_global.cpp
+++ b/src/mongo/logv2/log_domain_global.cpp
@@ -68,6 +68,8 @@ struct LogDomainGlobal::Impl {
 
     const ConfigurationOptions& config() const;
 
+    LogSource& source();
+
     LogDomainGlobal& _parent;
     LogComponentSettings _settings;
     ConfigurationOptions _config;
@@ -76,6 +78,9 @@ struct LogDomainGlobal::Impl {
 #ifndef _WIN32
     boost::shared_ptr<boost::log::sinks::unlocked_sink<SyslogBackend>> _syslogSink;
 #endif
+    AtomicWord<int32_t> activeSourceThreadLocals{0};
+    LogSource shutdownLogSource{&_parent, true};
+    bool isInShutdown{false};
 };
 
 LogDomainGlobal::Impl::Impl(LogDomainGlobal& parent) : _parent(parent) {
@@ -96,6 +101,10 @@ LogDomainGlobal::Impl::Impl(LogDomainGlobal& parent) : _parent(parent) {
 
     // Set default configuration
     invariant(configure({}).isOK());
+
+    // Make a call to source() to make sure the internal thread_local is created as early as
+    // possible and thus destroyed as late as possible.
+    source();
 }
 
 Status LogDomainGlobal::Impl::configure(LogDomainGlobal::ConfigurationOptions const& options) {
@@ -214,6 +223,36 @@ Status LogDomainGlobal::Impl::rotate(bool rename, StringData renameSuffix) {
     return Status::OK();
 }
 
+LogSource& LogDomainGlobal::Impl::source() {
+    // Use a thread_local logger so we don't need to have locking. thread_locals are destroyed
+    // before statics so keep track of number of thread_locals we have active and if this code
+    // is hit when it is zero then we are in shutdown and can use a global LogSource that does
+    // not provide synchronization instead.
+    class SourceCache {
+    public:
+        SourceCache(Impl* domain) : _domain(domain), _source(&domain->_parent) {
+            _domain->activeSourceThreadLocals.addAndFetch(1);
+        }
+        ~SourceCache() {
+            if (_domain->activeSourceThreadLocals.subtractAndFetch(1) == 0) {
+                _domain->isInShutdown = true;
+            }
+        }
+
+        LogSource& source() {
+            return _source;
+        }
+
+    private:
+        Impl* _domain;
+        LogSource _source;
+    };
+    thread_local SourceCache cache(this);
+    if (isInShutdown)
+        return shutdownLogSource;
+    return cache.source();
+}
+
 LogDomainGlobal::LogDomainGlobal() {
     _impl = std::make_unique<Impl>(*this);
 }
@@ -221,9 +260,7 @@ LogDomainGlobal::LogDomainGlobal() {
 LogDomainGlobal::~LogDomainGlobal() {}
 
 LogSource& LogDomainGlobal::source() {
-    // Use a thread_local logger so we don't need to have locking
-    thread_local LogSource lg(this);
-    return lg;
+    return _impl->source();
 }
 
 
diff --git a/src/mongo/logv2/log_manager.cpp b/src/mongo/logv2/log_manager.cpp
index c532989b5d7..8f8453417e2 100644
--- a/src/mongo/logv2/log_manager.cpp
+++ b/src/mongo/logv2/log_manager.cpp
@@ -51,8 +51,8 @@ LogManager::LogManager() {
 LogManager::~LogManager() {}
 
 LogManager& LogManager::global() {
-    static LogManager globalLogManager;
-    return globalLogManager;
+    static LogManager* globalLogManager = new LogManager();
+    return *globalLogManager;
 }
 
 LogDomain& LogManager::getGlobalDomain() {
diff --git a/src/mongo/logv2/log_source.h b/src/mongo/logv2/log_source.h
index 25eea5c36b4..99269bcdba2 100644
--- a/src/mongo/logv2/log_source.h
+++ b/src/mongo/logv2/log_source.h
@@ -57,7 +57,7 @@ private:
         basic_logger<char, LogSource, boost::log::sources::single_thread_model>;
 
 public:
-    LogSource(const LogDomain::Internal* domain)
+    explicit LogSource(const LogDomain::Internal* domain, bool isShutdown)
         : _domain(domain),
           _severity(LogSeverity::Log()),
           _component(LogComponent::kDefault),
@@ -73,11 +73,14 @@ public:
         add_attribute_unlocked(attributes::timeStamp(), boost::log::attributes::make_function([]() {
                                    return Date_t::now();
                                }));
-        add_attribute_unlocked(
-            attributes::threadName(),
-            boost::log::attributes::make_function([]() { return getThreadName(); }));
+        add_attribute_unlocked(attributes::threadName(),
+                               boost::log::attributes::make_function([isShutdown]() {
+                                   return isShutdown ? "shutdown"_sd : getThreadName();
+                               }));
     }
 
+    explicit LogSource(const LogDomain::Internal* domain) : LogSource(domain, false) {}
+
     boost::log::record open_record(int32_t id,
                                    LogSeverity severity,
                                    LogComponent component,
diff --git a/src/mongo/logv2/log_test_v2.cpp b/src/mongo/logv2/log_test_v2.cpp
index 0da56af42ea..12a592975d9 100644
--- a/src/mongo/logv2/log_test_v2.cpp
+++ b/src/mongo/logv2/log_test_v2.cpp
@@ -163,10 +163,10 @@ BSONObj toBSON(const TypeWithNonMemberFormatting&) {
     return builder.obj();
 }
 
-class LogDuringInitTester {
+class LogDuringInitShutdownTester {
 public:
-    LogDuringInitTester() {
-        std::vector<std::string> lines;
+    LogDuringInitShutdownTester() {
+
         auto sink = LogCaptureBackend::create(lines);
         sink->set_filter(ComponentSettingsFilter(LogManager::global().getGlobalDomain(),
                                                  LogManager::global().getGlobalSettings()));
@@ -174,13 +174,17 @@ public:
         boost::log::core::get()->add_sink(sink);
 
         LOGV2(20001, "log during init");
-        ASSERT(lines.back() == "log during init");
-
-        boost::log::core::get()->remove_sink(sink);
+        ASSERT_EQUALS(lines.back(), "log during init");
     }
+    ~LogDuringInitShutdownTester() {
+        LOGV2(4600800, "log during shutdown");
+        ASSERT_EQUALS(lines.back(), "log during shutdown");
+    }
+
+    std::vector<std::string> lines;
 };
 
-LogDuringInitTester logDuringInit;
+LogDuringInitShutdownTester logDuringInitAndShutdown;
 
 TEST_F(LogTestV2, Basic) {
     std::vector<std::string> lines;