Replaced backtace implementation

9 files changed, 103 insertions, 368 deletions

diff --git a/example/example.cpp b/example/example.cpp
index c84caef3..1d01b0ae 100644
--- a/example/example.cpp
+++ b/example/example.cpp
@@ -23,217 +23,12 @@ void clone_example();
 
 int main(int, char *[])
 {
-    spdlog::info("Welcome to spdlog version {}.{}.{}  !", SPDLOG_VER_MAJOR, SPDLOG_VER_MINOR, SPDLOG_VER_PATCH);
-    spdlog::warn("Easy padding in numbers like {:08d}", 12);
-    spdlog::critical("Support for int: {0:d};  hex: {0:x};  oct: {0:o}; bin: {0:b}", 42);
-    spdlog::info("Support for floats {:03.2f}", 1.23456);
-    spdlog::info("Positional args are {1} {0}..", "too", "supported");
-    spdlog::info("{:>8} aligned, {:<8} aligned", "right", "left");
-
-    // Runtime log levels
-    spdlog::set_level(spdlog::level::info); // Set global log level to info
-    spdlog::debug("This message should not be displayed!");
-    spdlog::set_level(spdlog::level::trace); // Set specific logger's log level
-    spdlog::debug("This message should be displayed..");
-    spdlog::set_level(spdlog::level::info); // Set specific logger's log level
-
-    // Customize msg format for all loggers
-    spdlog::set_pattern("[%H:%M:%S %z] [%^%L%$] [thread %t] %v");
-    spdlog::info("This an info message with custom format");
-    spdlog::set_pattern("%+"); // back to default format
 
     // Backtrace support of latest debug/trace messages
     spdlog::enable_backtrace(16);
+
     spdlog::trace("Backtrace message 1");
     spdlog::debug("Backtrace message 2");
+    spdlog::info("Hello");
     spdlog::dump_backtrace();
-    
-    try
-    {
-        stdout_logger_example();
-        basic_example();
-        rotating_example();
-        daily_example();
-        clone_example();
-        async_example();
-        binary_example();
-        multi_sink_example();
-        user_defined_example();
-        err_handler_example();
-        trace_example();
-
-        // Flush all *registered* loggers using a worker thread every 3 seconds.
-        // note: registered loggers *must* be thread safe for this to work correctly!
-        spdlog::flush_every(std::chrono::seconds(3));
-
-        // Apply some function on all registered loggers
-        spdlog::apply_all([&](std::shared_ptr<spdlog::logger> l) { l->info("End of example."); });
-
-        // Release all spdlog resources, and drop all loggers in the registry.
-        // This is optional (only mandatory if using windows + async log).
-        spdlog::shutdown();
-    }
-
-    // Exceptions will only be thrown upon failed logger or sink construction (not during logging).
-    catch (const spdlog::spdlog_ex &ex)
-    {
-        std::printf("Log initialization failed: %s\n", ex.what());
-        return 1;
-    }
-}
-
-#include "spdlog/sinks/stdout_color_sinks.h"
-// or #include "spdlog/sinks/stdout_sinks.h" if no colors needed.
-void stdout_logger_example()
-{
-    // Create color multi threaded logger.
-    auto console = spdlog::stdout_color_mt("console");
-    // or for stderr:
-    // auto console = spdlog::stderr_color_mt("error-logger");
-}
-
-#include "spdlog/sinks/basic_file_sink.h"
-void basic_example()
-{
-    // Create basic file logger (not rotated).
-    auto my_logger = spdlog::basic_logger_mt("file_logger", "logs/basic-log.txt");
-}
-
-#include "spdlog/sinks/rotating_file_sink.h"
-void rotating_example()
-{
-    // Create a file rotating logger with 5mb size max and 3 rotated files.
-    auto rotating_logger = spdlog::rotating_logger_mt("some_logger_name", "logs/rotating.txt", 1048576 * 5, 3);
-}
-
-#include "spdlog/sinks/daily_file_sink.h"
-void daily_example()
-{
-    // Create a daily logger - a new file is created every day on 2:30am.
-    auto daily_logger = spdlog::daily_logger_mt("daily_logger", "logs/daily.txt", 2, 30);
-}
-
-// Clone a logger and give it new name.
-// Useful for creating component/subsystem loggers from some "root" logger.
-void clone_example()
-{
-    auto network_logger = spdlog::default_logger()->clone("network");
-    network_logger->info("Logging network stuff..");
-}
-
-#include "spdlog/async.h"
-void async_example()
-{
-    // Default thread pool settings can be modified *before* creating the async logger:
-    // spdlog::init_thread_pool(32768, 1); // queue with max 32k items 1 backing thread.
-    auto async_file = spdlog::basic_logger_mt<spdlog::async_factory>("async_file_logger", "logs/async_log.txt");
-    // alternatively:
-    // auto async_file = spdlog::create_async<spdlog::sinks::basic_file_sink_mt>("async_file_logger", "logs/async_log.txt");
-
-    for (int i = 1; i < 101; ++i)
-    {
-        async_file->info("Async message #{}", i);
-    }
-}
-
-// Log binary data as hex.
-// Many types of std::container<char> types can be used.
-// Iterator ranges are supported too.
-// Format flags:
-// {:X} - print in uppercase.
-// {:s} - don't separate each byte with space.
-// {:p} - don't print the position on each line start.
-// {:n} - don't split the output to lines.
-
-#include "spdlog/fmt/bin_to_hex.h"
-void binary_example()
-{
-    std::vector<char> buf;
-    for (int i = 0; i < 80; i++)
-    {
-        buf.push_back(static_cast<char>(i & 0xff));
-    }
-    spdlog::info("Binary example: {}", spdlog::to_hex(buf));
-    spdlog::info("Another binary example:{:n}", spdlog::to_hex(std::begin(buf), std::begin(buf) + 10));
-    // more examples:
-    // logger->info("uppercase: {:X}", spdlog::to_hex(buf));
-    // logger->info("uppercase, no delimiters: {:Xs}", spdlog::to_hex(buf));
-    // logger->info("uppercase, no delimiters, no position info: {:Xsp}", spdlog::to_hex(buf));
-}
-
-// Compile time log levels.
-// define SPDLOG_ACTIVE_LEVEL to required level (e.g. SPDLOG_LEVEL_TRACE)
-void trace_example()
-{
-    // trace from default logger
-    SPDLOG_TRACE("Some trace message.. {} ,{}", 1, 3.23);
-    // debug from default logger
-    SPDLOG_DEBUG("Some debug message.. {} ,{}", 1, 3.23);
-
-    // trace from logger object
-    auto logger = spdlog::get("file_logger");
-    SPDLOG_LOGGER_TRACE(logger, "another trace message");
-}
-
-// A logger with multiple sinks (stdout and file) - each with a different format and log level.
-void multi_sink_example()
-{
-    auto console_sink = std::make_shared<spdlog::sinks::stdout_color_sink_mt>();
-    console_sink->set_level(spdlog::level::warn);
-    console_sink->set_pattern("[multi_sink_example] [%^%l%$] %v");
-
-    auto file_sink = std::make_shared<spdlog::sinks::basic_file_sink_mt>("logs/multisink.txt", true);
-    file_sink->set_level(spdlog::level::trace);
-
-    spdlog::logger logger("multi_sink", {console_sink, file_sink});
-    logger.set_level(spdlog::level::debug);
-    logger.warn("this should appear in both console and file");
-    logger.info("this message should not appear in the console, only in the file");
-}
-
-// User defined types logging by implementing operator<<
-#include "spdlog/fmt/ostr.h" // must be included
-struct my_type
-{
-    int i;
-    template<typename OStream>
-    friend OStream &operator<<(OStream &os, const my_type &c)
-    {
-        return os << "[my_type i=" << c.i << "]";
-    }
-};
-
-void user_defined_example()
-{
-    spdlog::info("user defined type: {}", my_type{14});
-}
-
-// Custom error handler. Will be triggered on log failure.
-void err_handler_example()
-{
-    // can be set globally or per logger(logger->set_error_handler(..))
-    spdlog::set_error_handler([](const std::string &msg) { printf("*** Custom log error handler: %s ***\n", msg.c_str()); });
-}
-
-// syslog example (linux/osx/freebsd)
-#ifndef _WIN32
-#include "spdlog/sinks/syslog_sink.h"
-void syslog_example()
-{
-    std::string ident = "spdlog-example";
-    auto syslog_logger = spdlog::syslog_logger_mt("syslog", ident, LOG_PID);
-    syslog_logger->warn("This is warning that will end up in syslog.");
-}
-#endif
-
-// Android example.
-#if defined(__ANDROID__)
-#include "spdlog/sinks/android_sink.h"
-void android_example()
-{
-    std::string tag = "spdlog-android";
-    auto android_logger = spdlog::android_logger_mt("android", tag);
-    android_logger->critical("Use \"adb shell logcat\" to view this message.");
-}
-
-#endif
+}
\ No newline at end of file
diff --git a/include/spdlog/async_logger-inl.h b/include/spdlog/async_logger-inl.h
index b0a6fc54..96137921 100644
--- a/include/spdlog/async_logger-inl.h
+++ b/include/spdlog/async_logger-inl.h
@@ -50,18 +50,6 @@ SPDLOG_INLINE void spdlog::async_logger::flush_()
     }
 }
 
-SPDLOG_INLINE void spdlog::async_logger::dump_backtrace_()
-{
-    if (auto pool_ptr = thread_pool_.lock())
-    {
-        pool_ptr->post_dump_backtrace(shared_from_this(), overflow_policy_);
-    }
-    else
-    {
-        SPDLOG_THROW(spdlog_ex("async dump_backtrace: thread pool doesn't exist anymore"));
-    }
-}
-
 //
 // backend functions - called from the thread pool to do the actual job
 //
@@ -90,11 +78,6 @@ SPDLOG_INLINE void spdlog::async_logger::backend_flush_()
     spdlog::logger::flush_();
 }
 
-SPDLOG_INLINE void spdlog::async_logger::backend_dump_backtrace_()
-{
-    spdlog::logger::dump_backtrace_();
-}
-
 SPDLOG_INLINE std::shared_ptr<spdlog::logger> spdlog::async_logger::clone(std::string new_name)
 {
     auto cloned = std::make_shared<spdlog::async_logger>(*this);
diff --git a/include/spdlog/async_logger.h b/include/spdlog/async_logger.h
index 497c9522..0a685186 100644
--- a/include/spdlog/async_logger.h
+++ b/include/spdlog/async_logger.h
@@ -54,10 +54,8 @@ public:
 protected:
     void sink_it_(const details::log_msg &msg) override;
     void flush_() override;
-    void dump_backtrace_() override;
     void backend_sink_it_(const details::log_msg &incoming_log_msg);
     void backend_flush_();
-    void backend_dump_backtrace_();
 
 private:
     std::weak_ptr<details::thread_pool> thread_pool_;
diff --git a/include/spdlog/details/backtracer.h b/include/spdlog/details/backtracer.h
new file mode 100644
index 00000000..bdd151ae
--- /dev/null
+++ b/include/spdlog/details/backtracer.h
@@ -0,0 +1,45 @@
+// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+
+#pragma once
+
+#include "spdlog/common.h"
+#include "spdlog/details/log_msg_buffer.h"
+#include "spdlog/details/circular_q.h"
+#include "spdlog/sinks/sink.h"
+#include <mutex>
+
+// Store log messages in circular buffer.
+// Useful for storing debug data in case of error/warning happens.
+
+namespace spdlog {
+namespace details {
+class backtracer
+{
+    std::mutex mutex_;
+    circular_q<log_msg_buffer> messages_;
+
+public:
+    explicit backtracer(size_t n_message)
+        : messages_{n_message}
+    {}
+
+    void add_msg(const log_msg &msg)
+    {
+        std::lock_guard<std::mutex> lock{mutex_};
+        messages_.push_back(log_msg_buffer{msg});
+    }
+
+    // pop all items in the q and apply the give fun on each of them.
+    void foreach_pop(std::function<void(const details::log_msg)> fun)
+    {
+        while (!messages_.empty())
+        {
+            log_msg_buffer popped;
+            messages_.pop_front(popped);
+            fun(popped);
+        }
+    }
+};
+} // namespace details
+} // namespace spdlog
\ No newline at end of file
diff --git a/include/spdlog/details/thread_pool-inl.h b/include/spdlog/details/thread_pool-inl.h
index c9b4852c..77d0b1fb 100644
--- a/include/spdlog/details/thread_pool-inl.h
+++ b/include/spdlog/details/thread_pool-inl.h
@@ -62,11 +62,6 @@ void SPDLOG_INLINE thread_pool::post_flush(async_logger_ptr &&worker_ptr, async_
     post_async_msg_(async_msg(std::move(worker_ptr), async_msg_type::flush), overflow_policy);
 }
 
-void SPDLOG_INLINE thread_pool::post_dump_backtrace(async_logger_ptr &&worker_ptr, async_overflow_policy overflow_policy)
-{
-    post_async_msg_(async_msg(std::move(worker_ptr), async_msg_type::dump_backtrace), overflow_policy);
-}
-
 size_t SPDLOG_INLINE thread_pool::overrun_counter()
 {
     return q_.overrun_counter();
@@ -114,18 +109,17 @@ bool SPDLOG_INLINE thread_pool::process_next_msg_()
         return true;
     }
 
-    case async_msg_type ::dump_backtrace:
+    case async_msg_type::terminate:
     {
-        incoming_async_msg.worker_ptr->backend_dump_backtrace_();
-        return true;
+        return false;
     }
 
-    case async_msg_type::terminate:
+    default:
     {
-        return false;
+        assert(false && "Unexpected async_msg_type");
     }
     }
-    assert(false && "Unexpected async_msg_type");
+
     return true;
 }
 
diff --git a/include/spdlog/details/thread_pool.h b/include/spdlog/details/thread_pool.h
index 577e1243..81bd12de 100644
--- a/include/spdlog/details/thread_pool.h
+++ b/include/spdlog/details/thread_pool.h
@@ -24,8 +24,7 @@ enum class async_msg_type
 {
     log,
     flush,
-    terminate,
-    dump_backtrace
+    terminate
 };
 
 #include "spdlog/details/log_msg_buffer.h"
@@ -97,7 +96,6 @@ public:
 
     void post_log(async_logger_ptr &&worker_ptr, const details::log_msg &msg, async_overflow_policy overflow_policy);
     void post_flush(async_logger_ptr &&worker_ptr, async_overflow_policy overflow_policy);
-    void post_dump_backtrace(async_logger_ptr &&worker_ptr, async_overflow_policy overflow_policy);
     size_t overrun_counter();
 
 private:
diff --git a/include/spdlog/logger-inl.h b/include/spdlog/logger-inl.h
index ba0e54ce..a482d17e 100644
--- a/include/spdlog/logger-inl.h
+++ b/include/spdlog/logger-inl.h
@@ -8,7 +8,7 @@
 #endif
 
 #include "spdlog/sinks/sink.h"
-#include "spdlog/sinks/backtrace_sink.h"
+#include "spdlog/details/backtracer.h"
 #include "spdlog/details/pattern_formatter.h"
 
 #include <cstdio>
@@ -22,7 +22,7 @@ SPDLOG_INLINE logger::logger(const logger &other)
     , level_(other.level_.load(std::memory_order_relaxed))
     , flush_level_(other.flush_level_.load(std::memory_order_relaxed))
     , custom_err_handler_(other.custom_err_handler_)
-    , backtrace_sink_(other.backtrace_sink_)
+    , tracer_(other.tracer_)
 {}
 
 SPDLOG_INLINE logger::logger(logger &&other) SPDLOG_NOEXCEPT : name_(std::move(other.name_)),
@@ -30,7 +30,7 @@ SPDLOG_INLINE logger::logger(logger &&other) SPDLOG_NOEXCEPT : name_(std::move(o
                                                                level_(other.level_.load(std::memory_order_relaxed)),
                                                                flush_level_(other.flush_level_.load(std::memory_order_relaxed)),
                                                                custom_err_handler_(std::move(other.custom_err_handler_)),
-                                                               backtrace_sink_(std::move(other.backtrace_sink_))
+                                                               tracer_(std::move(other.tracer_))
 
 {}
 
@@ -56,7 +56,7 @@ SPDLOG_INLINE void logger::swap(spdlog::logger &other) SPDLOG_NOEXCEPT
     other.flush_level_.store(tmp);
 
     custom_err_handler_.swap(other.custom_err_handler_);
-    backtrace_sink_.swap(other.backtrace_sink_);
+    tracer_.swap(other.tracer_);
 }
 
 SPDLOG_INLINE void swap(logger &a, logger &b)
@@ -66,6 +66,11 @@ SPDLOG_INLINE void swap(logger &a, logger &b)
 
 SPDLOG_INLINE void logger::log(source_loc loc, level::level_enum lvl, string_view_t msg)
 {
+    if (tracer_)
+    {
+        save_backtrace_(details::log_msg(loc, string_view_t(name_), lvl, msg));
+    }
+
     if (!should_log(lvl))
     {
         return;
@@ -87,16 +92,7 @@ SPDLOG_INLINE bool logger::should_log(level::level_enum msg_level) const
 
 SPDLOG_INLINE void logger::set_level(level::level_enum log_level)
 {
-    if (backtrace_sink_)
-    {
-        auto tracer = static_cast<sinks::backtrace_sink_mt *>(backtrace_sink_.get());
-        tracer->set_filter_level(log_level);
-        level_.store(level::trace);
-    }
-    else
-    {
-        level_.store(log_level);
-    }
+    level_.store(log_level);
 }
 
 SPDLOG_INLINE level::level_enum logger::level() const
@@ -136,24 +132,13 @@ SPDLOG_INLINE void logger::set_pattern(std::string pattern, pattern_time_type ti
 // create new backtrace sink and move to it all our child sinks
 SPDLOG_INLINE void logger::enable_backtrace(size_t n_messages)
 {
-    if (!backtrace_sink_)
-    {
-        backtrace_sink_ = std::make_shared<sinks::backtrace_sink_mt>(std::move(sinks_), level(), n_messages);
-        sinks().push_back(backtrace_sink_);
-        level_.store(level::trace); // pass all messages to the backtrace sink.
-    }
+    tracer_ = std::make_shared<details::backtracer>(n_messages);
 }
 
 // restore orig sinks and level and delete the backtrace sink
 SPDLOG_INLINE void logger::disable_backtrace()
 {
-    if (backtrace_sink_)
-    {
-        auto tracer = static_cast<sinks::backtrace_sink_mt *>(backtrace_sink_.get());
-        sinks_ = std::move(tracer->sinks());
-        level_.store(tracer->get_filter_level());
-        backtrace_sink_.reset();
-    }
+    tracer_.reset();
 }
 
 SPDLOG_INLINE void logger::dump_backtrace()
@@ -235,16 +220,19 @@ SPDLOG_INLINE void logger::flush_()
     }
 }
 
+SPDLOG_INLINE void logger::save_backtrace_(const details::log_msg &msg)
+{
+    tracer_->add_msg(msg);
+}
+
 SPDLOG_INLINE void logger::dump_backtrace_()
 {
-    if (backtrace_sink_)
+    using details::log_msg;
+    if (tracer_)
     {
-        auto tracer = static_cast<sinks::backtrace_sink_mt *>(backtrace_sink_.get());
-        SPDLOG_TRY
-        {
-            tracer->dump_backtrace(name());
-        }
-        SPDLOG_LOGGER_CATCH()
+        sink_it_(log_msg{name(), level::info, "****************** Backtrace Start ******************"});
+        tracer_->foreach_pop([this](const details::log_msg &msg) { this->sink_it_(msg); });
+        sink_it_(log_msg{name(), level::info, "****************** Backtrace End ********************"});
     }
 }
 
diff --git a/include/spdlog/logger.h b/include/spdlog/logger.h
index 3fea1965..4c686ba8 100644
--- a/include/spdlog/logger.h
+++ b/include/spdlog/logger.h
@@ -38,6 +38,11 @@
 #endif
 
 namespace spdlog {
+
+namespace details {
+class backtracer;
+}
+
 class logger
 {
 public:
@@ -81,6 +86,10 @@ public:
             fmt::format_to(buf, fmt, args...);
             details::log_msg log_msg(loc, name_, lvl, string_view_t(buf.data(), buf.size()));
             sink_it_(log_msg);
+            if (tracer_)
+            {
+                save_backtrace_(log_msg);
+            }
         }
         SPDLOG_LOGGER_CATCH()
     }
@@ -149,6 +158,10 @@ public:
     template<class T, typename std::enable_if<std::is_convertible<const T &, spdlog::string_view_t>::value, T>::type * = nullptr>
     void log(source_loc loc, level::level_enum lvl, const T &msg)
     {
+        if (tracer_)
+        {
+            save_backtrace_(details::log_msg(loc, name_, lvl, msg));
+        }
         if (!should_log(lvl))
         {
             return;
@@ -164,6 +177,13 @@ public:
                           T>::type * = nullptr>
     void log(source_loc loc, level::level_enum lvl, const T &msg)
     {
+        if (tracer_)
+        {
+            fmt::memory_buffer buf;
+            fmt::format_to(buf, "{}", msg);
+            save_backtrace_(details::log_msg(loc, name_, lvl, string_view_t(buf.data(), buf.size())));
+        }
+
         if (!should_log(lvl))
         {
             return;
@@ -323,7 +343,9 @@ public:
 
     void set_pattern(std::string pattern, pattern_time_type time_type = pattern_time_type::local);
 
-    void enable_backtrace(size_t n_messages = 16);
+    // backtrace support.
+    // efficiently store all debug/trace messages in a circular buffer until needed for debugging.
+    void enable_backtrace(size_t n_messages);
     void disable_backtrace();
     void dump_backtrace();
 
@@ -349,12 +371,13 @@ protected:
     spdlog::level_t level_{level::info};
     spdlog::level_t flush_level_{level::off};
     err_handler custom_err_handler_{nullptr};
-    sink_ptr backtrace_sink_;
-    // bool backtrace_enabled_{false};
+    std::shared_ptr<details::backtracer> tracer_;
 
     virtual void sink_it_(const details::log_msg &msg);
     virtual void flush_();
-    virtual void dump_backtrace_();
+
+    void save_backtrace_(const details::log_msg &msg);
+    void dump_backtrace_();
     bool should_flush_(const details::log_msg &msg);
 
     // handle errors during logging.
diff --git a/include/spdlog/sinks/backtrace_sink.h b/include/spdlog/sinks/backtrace_sink.h
deleted file mode 100644
index fe265ac5..00000000
--- a/include/spdlog/sinks/backtrace_sink.h
+++ /dev/null
@@ -1,89 +0,0 @@
-// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
-// Distributed under the MIT License (http://opensource.org/licenses/MIT)
-
-#pragma once
-
-#include "dist_sink.h"
-#include "spdlog/common.h"
-#include "spdlog/details/log_msg_buffer.h"
-#include "spdlog/details/circular_q.h"
-
-#include <mutex>
-#include <string>
-#include <chrono>
-
-// Store log messages in circular buffer.
-// If it encounters a message with high enough level, it will send all previous message to it child sinks.
-// Useful for storing debug data in case of error/warning happens.
-
-namespace spdlog {
-namespace sinks {
-template<typename Mutex>
-class backtrace_sink : public dist_sink<Mutex>
-{
-public:
-    backtrace_sink(std::vector<std::shared_ptr<sink>> &&child_sinks, spdlog::level::level_enum filter_level, size_t n_messages)
-        : filter_level_{filter_level}
-        , traceback_msgs_{n_messages}
-    {
-        dist_sink<Mutex>::set_sinks(std::move(child_sinks));
-    }
-
-    void set_filter_level(spdlog::level::level_enum filter_level)
-    {
-        std::lock_guard<Mutex> lock(base_sink<Mutex>::mutex_);
-        filter_level_ = filter_level;
-    }
-
-    spdlog::level::level_enum get_filter_level()
-    {
-        std::lock_guard<Mutex> lock(base_sink<Mutex>::mutex_);
-        return filter_level_;
-    }
-
-    void dump_backtrace(string_view_t logger_name)
-    {
-        std::lock_guard<Mutex> lock(base_sink<Mutex>::mutex_);
-        dump_backtrace_(logger_name);
-    }
-
-protected:
-    spdlog::level::level_enum filter_level_;
-    details::circular_q<details::log_msg_buffer> traceback_msgs_;
-
-    // save the messages in a circular queue
-    void sink_it_(const details::log_msg &msg) override
-    {
-        traceback_msgs_.push_back(details::log_msg_buffer(msg));
-
-        if (msg.level >= filter_level_)
-        {
-            dist_sink<Mutex>::sink_it_(msg);
-        }
-    }
-
-    void dump_backtrace_(string_view_t logger_name)
-    {
-        if (traceback_msgs_.empty())
-        {
-            return;
-        }
-        dist_sink<Mutex>::sink_it_(
-            details::log_msg{logger_name, level::info, "********************* Backtrace Start *********************"});
-
-        do
-        {
-            details::log_msg_buffer popped;
-            traceback_msgs_.pop_front(popped);
-            dist_sink<Mutex>::sink_it_(popped);
-        } while (!traceback_msgs_.empty());
-
-        dist_sink<Mutex>::sink_it_(
-            details::log_msg{logger_name, level::info, "********************* Backtrace End ***********************"});
-    }
-};
-
-using backtrace_sink_mt = backtrace_sink<std::mutex>;
-
-} // namespace sinks
-} // namespace spdlog