Fixed issue #396 and added some tests to catch it

include/spdlog/async_logger.h

@@ -63,6 +63,11 @@ public:
     //Wait for the queue to be empty, and flush synchronously
     //Warning: this can potentialy last forever as we wait it to complete
     void flush() override;
+
+	// Error handler
+	virtual void set_error_handler(log_err_handler) override;
+	virtual log_err_handler error_handler() override;
+
 protected:
     void _sink_it(details::log_msg& msg) override;
     void _set_formatter(spdlog::formatter_ptr msg_formatter) override;

include/spdlog/details/async_log_helper.h

@@ -135,6 +135,7 @@ public:
 
 			void flush(bool wait_for_q);
 
+			void set_error_handler(spdlog::log_err_handler err_handler);
 
 		private:
 			formatter_ptr _formatter;
@@ -215,13 +216,13 @@ inline spdlog::details::async_log_helper::async_log_helper(
 // and wait for it to finish gracefully
 inline spdlog::details::async_log_helper::~async_log_helper()
 {
-    try
+	try {
-    {
 		push_msg(async_msg(async_msg_type::terminate));
 		_worker_thread.join();
 	}
 	catch (...) // don't crash in destructor
-    {}
+	{
+	}
 }
 
 
@@ -233,16 +234,13 @@ inline void spdlog::details::async_log_helper::log(const details::log_msg& msg)
 
 inline void spdlog::details::async_log_helper::push_msg(details::async_log_helper::async_msg&& new_msg)
 {
-    if (!_q.enqueue(std::move(new_msg)) && _overflow_policy != async_overflow_policy::discard_log_msg)
+	if (!_q.enqueue(std::move(new_msg)) && _overflow_policy != async_overflow_policy::discard_log_msg) {
-    {
 		auto last_op_time = details::os::now();
 		auto now = last_op_time;
-        do
+		do {
-        {
 			now = details::os::now();
 			sleep_or_yield(now, last_op_time);
-        }
+		} while (!_q.enqueue(std::move(new_msg)));
-        while (!_q.enqueue(std::move(new_msg)));
 	}
 }
 
@@ -255,24 +253,26 @@ inline void spdlog::details::async_log_helper::flush(bool wait_for_q)
 }
 
 inline void spdlog::details::async_log_helper::worker_loop()
-{
-    try
 {
 	if (_worker_warmup_cb) _worker_warmup_cb();
 	auto last_pop = details::os::now();
 	auto last_flush = last_pop;
-        while(process_next_msg(last_pop, last_flush));
+	auto active = true;
-        if (_worker_teardown_cb) _worker_teardown_cb();
+	while (active) {
+		try {
+			active = process_next_msg(last_pop, last_flush);
 		}
-    catch (const std::exception &ex)
+		catch (const std::exception &ex) {
-    {
 			_err_handler(ex.what());
 		}
-    catch (...)
+		catch (...) {
-    {
 			_err_handler("Unknown exception");
 		}
 	}
+	if (_worker_teardown_cb) _worker_teardown_cb();
+
+
+}
 
 // process next message in the queue
 // return true if this thread should still be active (while no terminate msg was received)
@@ -280,11 +280,9 @@ inline bool spdlog::details::async_log_helper::process_next_msg(log_clock::time_
 {
 	async_msg incoming_async_msg;
 
-    if (_q.dequeue(incoming_async_msg))
+	if (_q.dequeue(incoming_async_msg)) {
-    {
 		last_pop = details::os::now();
-        switch (incoming_async_msg.msg_type)
+		switch (incoming_async_msg.msg_type) {
-        {
 		case async_msg_type::flush:
 			_flush_requested = true;
 			break;
@@ -298,10 +296,8 @@ inline bool spdlog::details::async_log_helper::process_next_msg(log_clock::time_
 			log_msg incoming_log_msg;
 			incoming_async_msg.fill_log_msg(incoming_log_msg);
 			_formatter->format(incoming_log_msg);
-            for (auto &s : _sinks)
+			for (auto &s : _sinks) {
-            {
+				if (s->should_log(incoming_log_msg.level)) {
-                if(s->should_log( incoming_log_msg.level))
-                {
 					s->log(incoming_log_msg);
 				}
 			}
@@ -311,8 +307,7 @@ inline bool spdlog::details::async_log_helper::process_next_msg(log_clock::time_
 
 	// Handle empty queue..
 	// This is the only place where the queue can terminate or flush to avoid losing messages already in the queue
-    else
+	else {
-    {
 		auto now = details::os::now();
 		handle_flush_interval(now, last_flush);
 		sleep_or_yield(now, last_pop);
@@ -324,8 +319,7 @@ inline bool spdlog::details::async_log_helper::process_next_msg(log_clock::time_
 inline void spdlog::details::async_log_helper::handle_flush_interval(log_clock::time_point& now, log_clock::time_point& last_flush)
 {
 	auto should_flush = _flush_requested || (_flush_interval_ms != std::chrono::milliseconds::zero() && now - last_flush >= _flush_interval_ms);
-    if (should_flush)
+	if (should_flush) {
-    {
 		for (auto &s : _sinks)
 			s->flush();
 		now = last_flush = details::os::now();
@@ -368,11 +362,15 @@ inline void spdlog::details::async_log_helper::sleep_or_yield(const spdlog::log_
 inline void spdlog::details::async_log_helper::wait_empty_q()
 {
 	auto last_op = details::os::now();
-    while (_q.approx_size() > 0)
+	while (_q.approx_size() > 0) {
-    {
 		sleep_or_yield(details::os::now(), last_op);
 	}
 }
 
+inline void spdlog::details::async_log_helper::set_error_handler(spdlog::log_err_handler err_handler)
+{
+	_err_handler = err_handler;
+}
+
 
 

include/spdlog/details/async_logger_impl.h

@@ -57,6 +57,19 @@ inline void spdlog::async_logger::flush()
     _async_log_helper->flush(true);
 }
 
+// Error handler
+inline void spdlog::async_logger::set_error_handler(spdlog::log_err_handler err_handler)
+{
+	_err_handler = err_handler;
+	_async_log_helper->set_error_handler(err_handler);
+	
+}
+inline spdlog::log_err_handler spdlog::async_logger::error_handler()
+{
+	return _err_handler;
+}
+
+
 inline void spdlog::async_logger::_set_formatter(spdlog::formatter_ptr msg_formatter)
 {
     _formatter = msg_formatter;

include/spdlog/logger.h

@@ -59,10 +59,6 @@ public:
     void set_pattern(const std::string&);
     void set_formatter(formatter_ptr);
    
-    // error handler
-    void set_error_handler(log_err_handler);
-    log_err_handler error_handler();
-
     // automatically call flush() if message level >= log_level
     void flush_on(level::level_enum log_level);
 
@@ -70,6 +66,10 @@ public:
 
     const std::vector<sink_ptr>& sinks() const;
 
+	// error handler
+	virtual void set_error_handler(log_err_handler);
+	virtual log_err_handler error_handler();
+
 protected:
     virtual void _sink_it(details::log_msg&);
     virtual void _set_pattern(const std::string&);

tests/errors.cpp

@@ -6,6 +6,19 @@
 #include<iostream>
 
 
+
+
+class failing_sink: public spdlog::sinks::sink
+{
+	void log(const spdlog::details::log_msg& msg) override
+	{
+		throw std::runtime_error("some error happened during log");
+	}
+
+	void flush()
+	{}
+};
+
 TEST_CASE("default_error_handler", "[errors]]")
 {
 	prepare_logdir();
@@ -22,15 +35,17 @@ TEST_CASE("default_error_handler", "[errors]]")
 }
 
 
-struct custom_ex {};
+
+
+struct custom_ex
+{};
 TEST_CASE("custom_error_handler", "[errors]]")
 {
 	prepare_logdir();
 	std::string filename = "logs/simple_log.txt";
 	auto logger = spdlog::create<spdlog::sinks::simple_file_sink_mt>("logger", filename, true);
 	logger->flush_on(spdlog::level::info);
-    logger->set_error_handler([=](const std::string& msg)
+	logger->set_error_handler([=](const std::string& msg) {
-    {
 		throw custom_ex();
 	});
 	logger->info("Good message #1");
@@ -39,6 +54,16 @@ TEST_CASE("custom_error_handler", "[errors]]")
 	REQUIRE(count_lines(filename) == 2);
 }
 
+TEST_CASE("default_error_handler2", "[errors]]")
+{
+
+	auto logger = spdlog::create<failing_sink>("failed_logger");
+	logger->set_error_handler([=](const std::string& msg) {
+		throw custom_ex();
+	});
+	REQUIRE_THROWS_AS(logger->info("Some message"), custom_ex);
+}
+
 TEST_CASE("async_error_handler", "[errors]]")
 {
 	prepare_logdir();
@@ -47,8 +72,7 @@ TEST_CASE("async_error_handler", "[errors]]")
 	std::string filename = "logs/simple_async_log.txt";
 	{
 		auto logger = spdlog::create<spdlog::sinks::simple_file_sink_mt>("logger", filename, true);
-        logger->set_error_handler([=](const std::string& msg)
+		logger->set_error_handler([=](const std::string& msg) {
-        {
 			std::ofstream ofs("logs/custom_err.txt");
 			if (!ofs) throw std::runtime_error("Failed open logs/custom_err.txt");
 			ofs << err_msg;
@@ -62,3 +86,24 @@ TEST_CASE("async_error_handler", "[errors]]")
 	REQUIRE(count_lines(filename) == 2);
 	REQUIRE(file_contents("logs/custom_err.txt") == err_msg);
 }
+
+// Make sure async error handler is executed
+TEST_CASE("async_error_handler2", "[errors]]")
+{
+	prepare_logdir();
+	std::string err_msg("This is async handler error message");
+	spdlog::set_async_mode(128);
+	{
+		auto logger = spdlog::create<failing_sink>("failed_logger");
+		logger->set_error_handler([=](const std::string& msg) {
+			std::ofstream ofs("logs/custom_err2.txt");
+			if (!ofs) throw std::runtime_error("Failed open logs/custom_err2.txt");
+			ofs << err_msg;
+		});
+		logger->info("Hello failure");
+		spdlog::drop("failed_logger"); //force logger to drain the queue and shutdown
+		spdlog::set_sync_mode();
+	}
+
+	REQUIRE(file_contents("logs/custom_err2.txt") == err_msg);
+}

tests/utils.cpp

@@ -4,11 +4,12 @@ void prepare_logdir()
 {
     spdlog::drop_all();
 #ifdef _WIN32
-    auto rv = system("del /F /Q logs\\*");
+	system("if not exist logs mkdir logs");
+    system("del /F /Q logs\\*");
 #else
-    auto rv = system("rm -f logs/*");
+	system("mkdir -p logs");
+    system("rm -f logs/*");
 #endif    
-    (void)rv;
 }