support using a priority inheritance protocol

Provides initial support for utilizing a priority inheritance protocol
for mutexes if supported by the threading library. Developers can opt to
build with `SPDLOG_PRIORITY_INHERITANCE` enabled to help avoid
priority inversion scenarios.

Signed-off-by: James Knight <git@jdknight.me>

CMakeLists.txt

@@ -91,6 +91,7 @@ option(SPDLOG_USE_STD_FORMAT "Use std::format instead of fmt library." OFF)
 option(SPDLOG_FMT_EXTERNAL "Use external fmt library instead of bundled" OFF)
 option(SPDLOG_FMT_EXTERNAL_HO "Use external fmt header-only library instead of bundled" OFF)
 option(SPDLOG_NO_EXCEPTIONS "Compile with -fno-exceptions. Call abort() on any spdlog exceptions" OFF)
+option(SPDLOG_PRIORITY_INHERITANCE "Compile with priority inheritance protocols" OFF)
 
 if (SPDLOG_FMT_EXTERNAL AND SPDLOG_FMT_EXTERNAL_HO)
     message(FATAL_ERROR "SPDLOG_FMT_EXTERNAL and SPDLOG_FMT_EXTERNAL_HO are mutually exclusive")
@@ -280,6 +281,7 @@ foreach (
         SPDLOG_NO_TLS
         SPDLOG_NO_ATOMIC_LEVELS
         SPDLOG_DISABLE_DEFAULT_LOGGER
+        SPDLOG_PRIORITY_INHERITANCE
         SPDLOG_USE_STD_FORMAT)
     if (${SPDLOG_OPTION})
         target_compile_definitions(spdlog PUBLIC ${SPDLOG_OPTION})

include/spdlog/details/backtracer-inl.h

@@ -9,50 +9,50 @@
 namespace spdlog {
 namespace details {
 SPDLOG_INLINE backtracer::backtracer(const backtracer &other) {
-    std::lock_guard<std::mutex> lock(other.mutex_);
+    std::lock_guard<spdlog_mutex> lock(other.mutex_);
     enabled_ = other.enabled();
     messages_ = other.messages_;
 }
 
 SPDLOG_INLINE backtracer::backtracer(backtracer &&other) SPDLOG_NOEXCEPT {
-    std::lock_guard<std::mutex> lock(other.mutex_);
+    std::lock_guard<spdlog_mutex> lock(other.mutex_);
     enabled_ = other.enabled();
     messages_ = std::move(other.messages_);
 }
 
 SPDLOG_INLINE backtracer &backtracer::operator=(backtracer other) {
-    std::lock_guard<std::mutex> lock(mutex_);
+    std::lock_guard<spdlog_mutex> lock(mutex_);
     enabled_ = other.enabled();
     messages_ = std::move(other.messages_);
     return *this;
 }
 
 SPDLOG_INLINE void backtracer::enable(size_t size) {
-    std::lock_guard<std::mutex> lock{mutex_};
+    std::lock_guard<spdlog_mutex> lock{mutex_};
     enabled_.store(true, std::memory_order_relaxed);
     messages_ = circular_q<log_msg_buffer>{size};
 }
 
 SPDLOG_INLINE void backtracer::disable() {
-    std::lock_guard<std::mutex> lock{mutex_};
+    std::lock_guard<spdlog_mutex> lock{mutex_};
     enabled_.store(false, std::memory_order_relaxed);
 }
 
 SPDLOG_INLINE bool backtracer::enabled() const { return enabled_.load(std::memory_order_relaxed); }
 
 SPDLOG_INLINE void backtracer::push_back(const log_msg &msg) {
-    std::lock_guard<std::mutex> lock{mutex_};
+    std::lock_guard<spdlog_mutex> lock{mutex_};
     messages_.push_back(log_msg_buffer{msg});
 }
 
 SPDLOG_INLINE bool backtracer::empty() const {
-    std::lock_guard<std::mutex> lock{mutex_};
+    std::lock_guard<spdlog_mutex> lock{mutex_};
     return messages_.empty();
 }
 
 // pop all items in the q and apply the given fun on each of them.
 SPDLOG_INLINE void backtracer::foreach_pop(std::function<void(const details::log_msg &)> fun) {
-    std::lock_guard<std::mutex> lock{mutex_};
+    std::lock_guard<spdlog_mutex> lock{mutex_};
     while (!messages_.empty()) {
         auto &front_msg = messages_.front();
         fun(front_msg);

include/spdlog/details/backtracer.h

@@ -5,6 +5,7 @@
 
 #include <spdlog/details/circular_q.h>
 #include <spdlog/details/log_msg_buffer.h>
+#include <spdlog/details/mutex.h>
 
 #include <atomic>
 #include <functional>
@@ -16,7 +17,7 @@
 namespace spdlog {
 namespace details {
 class SPDLOG_API backtracer {
-    mutable std::mutex mutex_;
+    mutable spdlog_mutex mutex_;
     std::atomic<bool> enabled_{false};
     circular_q<log_msg_buffer> messages_;
 

include/spdlog/details/console_globals.h

@@ -4,6 +4,7 @@
 #pragma once
 
 #include <mutex>
+#include <spdlog/details/mutex.h>
 #include <spdlog/details/null_mutex.h>
 
 namespace spdlog {
@@ -12,8 +13,8 @@ namespace details {
 struct console_mutex {
     using mutex_t = std::mutex;
     static mutex_t &mutex() {
-        static mutex_t s_mutex;
-        return s_mutex;
+        static spdlog_mutex s_mutex;
+        return s_mutex.mtx();
     }
 };
 

include/spdlog/details/mpmc_blocking_q.h

@@ -11,6 +11,7 @@
 // passed.
 
 #include <spdlog/details/circular_q.h>
+#include <spdlog/details/mutex.h>
 
 #include <atomic>
 #include <condition_variable>
@@ -30,7 +31,7 @@ public:
     // try to enqueue and block if no room left
     void enqueue(T &&item) {
         {
-            std::unique_lock<std::mutex> lock(queue_mutex_);
+            std::unique_lock<std::mutex> lock(queue_mutex_.mtx());
             pop_cv_.wait(lock, [this] { return !this->q_.full(); });
             q_.push_back(std::move(item));
         }
@@ -40,7 +41,7 @@ public:
     // enqueue immediately. overrun oldest message in the queue if no room left.
     void enqueue_nowait(T &&item) {
         {
-            std::unique_lock<std::mutex> lock(queue_mutex_);
+            std::unique_lock<std::mutex> lock(queue_mutex_.mtx());
             q_.push_back(std::move(item));
         }
         push_cv_.notify_one();
@@ -49,7 +50,7 @@ public:
     void enqueue_if_have_room(T &&item) {
         bool pushed = false;
         {
-            std::unique_lock<std::mutex> lock(queue_mutex_);
+            std::unique_lock<std::mutex> lock(queue_mutex_.mtx());
             if (!q_.full()) {
                 q_.push_back(std::move(item));
                 pushed = true;
@@ -67,7 +68,7 @@ public:
     // Return true, if succeeded dequeue item, false otherwise
     bool dequeue_for(T &popped_item, std::chrono::milliseconds wait_duration) {
         {
-            std::unique_lock<std::mutex> lock(queue_mutex_);
+            std::unique_lock<std::mutex> lock(queue_mutex_.mtx());
             if (!push_cv_.wait_for(lock, wait_duration, [this] { return !this->q_.empty(); })) {
                 return false;
             }
@@ -81,7 +82,7 @@ public:
     // blocking dequeue without a timeout.
     void dequeue(T &popped_item) {
         {
-            std::unique_lock<std::mutex> lock(queue_mutex_);
+            std::unique_lock<std::mutex> lock(queue_mutex_.mtx());
             push_cv_.wait(lock, [this] { return !this->q_.empty(); });
             popped_item = std::move(q_.front());
             q_.pop_front();
@@ -95,7 +96,7 @@ public:
 
     // try to enqueue and block if no room left
     void enqueue(T &&item) {
-        std::unique_lock<std::mutex> lock(queue_mutex_);
+        std::unique_lock<std::mutex> lock(queue_mutex_.mtx());
         pop_cv_.wait(lock, [this] { return !this->q_.full(); });
         q_.push_back(std::move(item));
         push_cv_.notify_one();
@@ -103,14 +104,14 @@ public:
 
     // enqueue immediately. overrun oldest message in the queue if no room left.
     void enqueue_nowait(T &&item) {
-        std::unique_lock<std::mutex> lock(queue_mutex_);
+        std::unique_lock<std::mutex> lock(queue_mutex_.mtx());
         q_.push_back(std::move(item));
         push_cv_.notify_one();
     }
 
     void enqueue_if_have_room(T &&item) {
         bool pushed = false;
-        std::unique_lock<std::mutex> lock(queue_mutex_);
+        std::unique_lock<std::mutex> lock(queue_mutex_.mtx());
         if (!q_.full()) {
             q_.push_back(std::move(item));
             pushed = true;
@@ -126,7 +127,7 @@ public:
     // dequeue with a timeout.
     // Return true, if succeeded dequeue item, false otherwise
     bool dequeue_for(T &popped_item, std::chrono::milliseconds wait_duration) {
-        std::unique_lock<std::mutex> lock(queue_mutex_);
+        std::unique_lock<std::mutex> lock(queue_mutex_.mtx());
         if (!push_cv_.wait_for(lock, wait_duration, [this] { return !this->q_.empty(); })) {
             return false;
         }
@@ -138,7 +139,7 @@ public:
 
     // blocking dequeue without a timeout.
     void dequeue(T &popped_item) {
-        std::unique_lock<std::mutex> lock(queue_mutex_);
+        std::unique_lock<std::mutex> lock(queue_mutex_.mtx());
         push_cv_.wait(lock, [this] { return !this->q_.empty(); });
         popped_item = std::move(q_.front());
         q_.pop_front();
@@ -148,26 +149,26 @@ public:
 #endif
 
     size_t overrun_counter() {
-        std::lock_guard<std::mutex> lock(queue_mutex_);
+        std::lock_guard<std::mutex> lock(queue_mutex_.mtx());
         return q_.overrun_counter();
     }
 
     size_t discard_counter() { return discard_counter_.load(std::memory_order_relaxed); }
 
     size_t size() {
-        std::lock_guard<std::mutex> lock(queue_mutex_);
+        std::lock_guard<std::mutex> lock(queue_mutex_.mtx());
         return q_.size();
     }
 
     void reset_overrun_counter() {
-        std::lock_guard<std::mutex> lock(queue_mutex_);
+        std::lock_guard<std::mutex> lock(queue_mutex_.mtx());
         q_.reset_overrun_counter();
     }
 
     void reset_discard_counter() { discard_counter_.store(0, std::memory_order_relaxed); }
 
 private:
-    std::mutex queue_mutex_;
+    spdlog_mutex queue_mutex_;
     std::condition_variable push_cv_;
     std::condition_variable pop_cv_;
     spdlog::details::circular_q<T> q_;

include/spdlog/details/mutex.h

@@ -0,0 +1,144 @@
+// SPDX-License-Identifier: MIT
+// Copyright(c) spdlog contributors
+
+// Mutexes used to help support priority inheritance support
+//
+// Standard library implementations will typically create mutexes that do
+// not take into consideration the priority and scheduling of the thread
+// they claim ownership on. In (near) real-time implementations, this is
+// not ideal since this may lead to priority inversion scenarios.
+//
+// The following provides mutex implementations that can help avoid priority
+// inversion scenarios by ensuring the underlying mutexes used take advantage
+// of priority inheritance protocols. spdlog uses `std::mutex` and
+// `std::recursive_mutex`, which are typically not priority inversion "safe".
+// Therefore, we introduces custom mutexes for them below. Calls such as
+// `std::condition_variable` are fine if the managed mutex used by the
+// `std::unique_lock` are safe. However, the use of
+// `std::condition_variable_any` is not due their implementations relying on
+// both a provided mutex and an internal `std::mutex`. This is why the
+// implementation opts for using `std::condition_variable` with the help of
+// `mtx()` methods over using `std::condition_variable_any`.
+
+#pragma once
+
+#include <mutex>
+#include <spdlog/common.h>
+
+namespace spdlog {
+namespace details {
+
+
+class spdlog_mutex {
+public:
+    spdlog_mutex() {
+#ifdef SPDLOG_PRIORITY_INHERITANCE
+#if defined(_GLIBCXX_HAS_GTHREADS) || defined(_LIBCPP_HAS_THREAD_API_PTHREAD)
+        pthread_mutexattr_t attr;
+        int ret = pthread_mutexattr_init(&attr);
+        if (ret != 0) {
+            return;
+        }
+   
+        ret = pthread_mutexattr_setprotocol(&attr, PTHREAD_PRIO_INHERIT);
+        if (ret != 0) {
+            return;
+        }
+
+        auto handle = mtx_.native_handle();
+        ret = pthread_mutex_destroy(handle);
+        if (ret < 0) {
+            throw_spdlog_ex("failed to tear down mutex", ret);
+        }
+
+        ret = pthread_mutex_init(handle, &attr);
+        if (ret < 0) {
+            throw_spdlog_ex("failed to build mutex", ret);
+        }
+#else
+    #error Priority inheritance is not supported.
+#endif
+#endif
+    }
+
+    void lock() {
+        mtx_.lock();
+    }
+
+    bool try_lock() {
+        return mtx_.try_lock();
+    }
+
+    void unlock() {
+        mtx_.unlock();
+    }
+
+    std::mutex& mtx() {
+        return mtx_;
+    }
+
+private:
+    std::mutex mtx_;
+};
+
+
+class spdlog_recursive_mutex {
+public:
+    spdlog_recursive_mutex() {
+#ifdef SPDLOG_PRIORITY_INHERITANCE
+#if defined(_GLIBCXX_HAS_GTHREADS) || defined(_LIBCPP_HAS_THREAD_API_PTHREAD)
+        pthread_mutexattr_t attr;
+        int ret = pthread_mutexattr_init(&attr);
+        if (ret != 0) {
+            return;
+        }
+
+        ret = pthread_mutexattr_setprotocol(&attr, PTHREAD_PRIO_INHERIT);
+        if (ret != 0) {
+            return;
+        }
+
+        ret = pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE);
+        if (ret != 0) {
+            return;
+        }
+
+        auto handle = mtx_.native_handle();
+        ret = pthread_mutex_destroy(handle);
+        if (ret < 0) {
+            throw_spdlog_ex("failed to tear down mutex", ret);
+        }
+
+        ret = pthread_mutex_init(handle, &attr);
+        if (ret < 0) {
+            throw_spdlog_ex("failed to build mutex", ret);
+        }
+#else
+    #error Priority inheritance is not supported.
+#endif
+#endif
+    }
+
+    void lock() {
+        mtx_.lock();
+    }
+
+    bool try_lock() {
+        return mtx_.try_lock();
+    }
+
+    void unlock() {
+        mtx_.unlock();
+    }
+
+    std::recursive_mutex& mtx() {
+        return mtx_;
+    }
+
+private:
+    std::recursive_mutex mtx_;
+};
+
+
+}  // namespace details
+}  // namespace spdlog

include/spdlog/details/periodic_worker-inl.h

@@ -14,7 +14,7 @@ namespace details {
 SPDLOG_INLINE periodic_worker::~periodic_worker() {
     if (worker_thread_.joinable()) {
         {
-            std::lock_guard<std::mutex> lock(mutex_);
+            std::lock_guard<spdlog_mutex> lock(mutex_);
             active_ = false;
         }
         cv_.notify_one();

include/spdlog/details/periodic_worker.h

@@ -10,6 +10,8 @@
 //    stops and joins the thread on destruction (if the thread is executing a callback, wait for it
 //    to finish first).
 
+#include <spdlog/details/mutex.h>
+
 #include <chrono>
 #include <condition_variable>
 #include <functional>
@@ -30,7 +32,7 @@ public:
 
         worker_thread_ = std::thread([this, callback_fun, interval]() {
             for (;;) {
-                std::unique_lock<std::mutex> lock(this->mutex_);
+                std::unique_lock<std::mutex> lock(this->mutex_.mtx());
                 if (this->cv_.wait_for(lock, interval, [this] { return !this->active_; })) {
                     return;  // active_ == false, so exit this thread
                 }
@@ -47,7 +49,7 @@ public:
 private:
     bool active_;
     std::thread worker_thread_;
-    std::mutex mutex_;
+    spdlog_mutex mutex_;
     std::condition_variable cv_;
 };
 }  // namespace details

include/spdlog/details/registry-inl.h

@@ -50,12 +50,12 @@ SPDLOG_INLINE registry::registry()
 SPDLOG_INLINE registry::~registry() = default;
 
 SPDLOG_INLINE void registry::register_logger(std::shared_ptr<logger> new_logger) {
-    std::lock_guard<std::mutex> lock(logger_map_mutex_);
+    std::lock_guard<spdlog_mutex> lock(logger_map_mutex_);
     register_logger_(std::move(new_logger));
 }
 
 SPDLOG_INLINE void registry::initialize_logger(std::shared_ptr<logger> new_logger) {
-    std::lock_guard<std::mutex> lock(logger_map_mutex_);
+    std::lock_guard<spdlog_mutex> lock(logger_map_mutex_);
     new_logger->set_formatter(formatter_->clone());
 
     if (err_handler_) {
@@ -79,13 +79,13 @@ SPDLOG_INLINE void registry::initialize_logger(std::shared_ptr<logger> new_logge
 }
 
 SPDLOG_INLINE std::shared_ptr<logger> registry::get(const std::string &logger_name) {
-    std::lock_guard<std::mutex> lock(logger_map_mutex_);
+    std::lock_guard<spdlog_mutex> lock(logger_map_mutex_);
     auto found = loggers_.find(logger_name);
     return found == loggers_.end() ? nullptr : found->second;
 }
 
 SPDLOG_INLINE std::shared_ptr<logger> registry::default_logger() {
-    std::lock_guard<std::mutex> lock(logger_map_mutex_);
+    std::lock_guard<spdlog_mutex> lock(logger_map_mutex_);
     return default_logger_;
 }
 
@@ -98,7 +98,7 @@ SPDLOG_INLINE logger *registry::get_default_raw() { return default_logger_.get()
 // set default logger.
 // default logger is stored in default_logger_ (for faster retrieval) and in the loggers_ map.
 SPDLOG_INLINE void registry::set_default_logger(std::shared_ptr<logger> new_default_logger) {
-    std::lock_guard<std::mutex> lock(logger_map_mutex_);
+    std::lock_guard<spdlog_mutex> lock(logger_map_mutex_);
     if (new_default_logger != nullptr) {
         loggers_[new_default_logger->name()] = new_default_logger;
     }
@@ -106,18 +106,18 @@ SPDLOG_INLINE void registry::set_default_logger(std::shared_ptr<logger> new_defa
 }
 
 SPDLOG_INLINE void registry::set_tp(std::shared_ptr<thread_pool> tp) {
-    std::lock_guard<std::recursive_mutex> lock(tp_mutex_);
+    std::lock_guard<spdlog_recursive_mutex> lock(tp_mutex_);
     tp_ = std::move(tp);
 }
 
 SPDLOG_INLINE std::shared_ptr<thread_pool> registry::get_tp() {
-    std::lock_guard<std::recursive_mutex> lock(tp_mutex_);
+    std::lock_guard<spdlog_recursive_mutex> lock(tp_mutex_);
     return tp_;
 }
 
 // Set global formatter. Each sink in each logger will get a clone of this object
 SPDLOG_INLINE void registry::set_formatter(std::unique_ptr<formatter> formatter) {
-    std::lock_guard<std::mutex> lock(logger_map_mutex_);
+    std::lock_guard<spdlog_mutex> lock(logger_map_mutex_);
     formatter_ = std::move(formatter);
     for (auto &l : loggers_) {
         l.second->set_formatter(formatter_->clone());
@@ -125,7 +125,7 @@ SPDLOG_INLINE void registry::set_formatter(std::unique_ptr<formatter> formatter)
 }
 
 SPDLOG_INLINE void registry::enable_backtrace(size_t n_messages) {
-    std::lock_guard<std::mutex> lock(logger_map_mutex_);
+    std::lock_guard<spdlog_mutex> lock(logger_map_mutex_);
     backtrace_n_messages_ = n_messages;
 
     for (auto &l : loggers_) {
@@ -134,7 +134,7 @@ SPDLOG_INLINE void registry::enable_backtrace(size_t n_messages) {
 }
 
 SPDLOG_INLINE void registry::disable_backtrace() {
-    std::lock_guard<std::mutex> lock(logger_map_mutex_);
+    std::lock_guard<spdlog_mutex> lock(logger_map_mutex_);
     backtrace_n_messages_ = 0;
     for (auto &l : loggers_) {
         l.second->disable_backtrace();
@@ -142,7 +142,7 @@ SPDLOG_INLINE void registry::disable_backtrace() {
 }
 
 SPDLOG_INLINE void registry::set_level(level::level_enum log_level) {
-    std::lock_guard<std::mutex> lock(logger_map_mutex_);
+    std::lock_guard<spdlog_mutex> lock(logger_map_mutex_);
     for (auto &l : loggers_) {
         l.second->set_level(log_level);
     }
@@ -150,7 +150,7 @@ SPDLOG_INLINE void registry::set_level(level::level_enum log_level) {
 }
 
 SPDLOG_INLINE void registry::flush_on(level::level_enum log_level) {
-    std::lock_guard<std::mutex> lock(logger_map_mutex_);
+    std::lock_guard<spdlog_mutex> lock(logger_map_mutex_);
     for (auto &l : loggers_) {
         l.second->flush_on(log_level);
     }
@@ -158,7 +158,7 @@ SPDLOG_INLINE void registry::flush_on(level::level_enum log_level) {
 }
 
 SPDLOG_INLINE void registry::set_error_handler(err_handler handler) {
-    std::lock_guard<std::mutex> lock(logger_map_mutex_);
+    std::lock_guard<spdlog_mutex> lock(logger_map_mutex_);
     for (auto &l : loggers_) {
         l.second->set_error_handler(handler);
     }
@@ -167,21 +167,21 @@ SPDLOG_INLINE void registry::set_error_handler(err_handler handler) {
 
 SPDLOG_INLINE void registry::apply_all(
     const std::function<void(const std::shared_ptr<logger>)> &fun) {
-    std::lock_guard<std::mutex> lock(logger_map_mutex_);
+    std::lock_guard<spdlog_mutex> lock(logger_map_mutex_);
     for (auto &l : loggers_) {
         fun(l.second);
     }
 }
 
 SPDLOG_INLINE void registry::flush_all() {
-    std::lock_guard<std::mutex> lock(logger_map_mutex_);
+    std::lock_guard<spdlog_mutex> lock(logger_map_mutex_);
     for (auto &l : loggers_) {
         l.second->flush();
     }
 }
 
 SPDLOG_INLINE void registry::drop(const std::string &logger_name) {
-    std::lock_guard<std::mutex> lock(logger_map_mutex_);
+    std::lock_guard<spdlog_mutex> lock(logger_map_mutex_);
     auto is_default_logger = default_logger_ && default_logger_->name() == logger_name;
     loggers_.erase(logger_name);
     if (is_default_logger) {
@@ -190,7 +190,7 @@ SPDLOG_INLINE void registry::drop(const std::string &logger_name) {
 }
 
 SPDLOG_INLINE void registry::drop_all() {
-    std::lock_guard<std::mutex> lock(logger_map_mutex_);
+    std::lock_guard<spdlog_mutex> lock(logger_map_mutex_);
     loggers_.clear();
     default_logger_.reset();
 }
@@ -198,27 +198,27 @@ SPDLOG_INLINE void registry::drop_all() {
 // clean all resources and threads started by the registry
 SPDLOG_INLINE void registry::shutdown() {
     {
-        std::lock_guard<std::mutex> lock(flusher_mutex_);
+        std::lock_guard<spdlog_mutex> lock(flusher_mutex_);
         periodic_flusher_.reset();
     }
 
     drop_all();
 
     {
-        std::lock_guard<std::recursive_mutex> lock(tp_mutex_);
+        std::lock_guard<spdlog_recursive_mutex> lock(tp_mutex_);
         tp_.reset();
     }
 }
 
-SPDLOG_INLINE std::recursive_mutex &registry::tp_mutex() { return tp_mutex_; }
+SPDLOG_INLINE std::recursive_mutex &registry::tp_mutex() { return tp_mutex_.mtx(); }
 
 SPDLOG_INLINE void registry::set_automatic_registration(bool automatic_registration) {
-    std::lock_guard<std::mutex> lock(logger_map_mutex_);
+    std::lock_guard<spdlog_mutex> lock(logger_map_mutex_);
     automatic_registration_ = automatic_registration;
 }
 
 SPDLOG_INLINE void registry::set_levels(log_levels levels, level::level_enum *global_level) {
-    std::lock_guard<std::mutex> lock(logger_map_mutex_);
+    std::lock_guard<spdlog_mutex> lock(logger_map_mutex_);
     log_levels_ = std::move(levels);
     auto global_level_requested = global_level != nullptr;
     global_log_level_ = global_level_requested ? *global_level : global_log_level_;
@@ -239,7 +239,7 @@ SPDLOG_INLINE registry &registry::instance() {
 }
 
 SPDLOG_INLINE void registry::apply_logger_env_levels(std::shared_ptr<logger> new_logger) {
-    std::lock_guard<std::mutex> lock(logger_map_mutex_);
+    std::lock_guard<spdlog_mutex> lock(logger_map_mutex_);
     auto it = log_levels_.find(new_logger->name());
     auto new_level = it != log_levels_.end() ? it->second : global_log_level_;
     new_logger->set_level(new_level);

include/spdlog/details/registry.h

@@ -10,6 +10,7 @@
 
 #include <spdlog/common.h>
 #include <spdlog/details/periodic_worker.h>
+#include <spdlog/details/mutex.h>
 
 #include <chrono>
 #include <functional>
@@ -65,13 +66,13 @@ public:
 
     template <typename Rep, typename Period>
     void flush_every(std::chrono::duration<Rep, Period> interval) {
-        std::lock_guard<std::mutex> lock(flusher_mutex_);
+        std::lock_guard<spdlog_mutex> lock(flusher_mutex_);
         auto clbk = [this]() { this->flush_all(); };
         periodic_flusher_ = details::make_unique<periodic_worker>(clbk, interval);
     }
 
     std::unique_ptr<periodic_worker> &get_flusher() {
-        std::lock_guard<std::mutex> lock(flusher_mutex_);
+        std::lock_guard<spdlog_mutex> lock(flusher_mutex_);
         return periodic_flusher_;
     }
 
@@ -106,8 +107,8 @@ private:
     void throw_if_exists_(const std::string &logger_name);
     void register_logger_(std::shared_ptr<logger> new_logger);
     bool set_level_from_cfg_(logger *logger);
-    std::mutex logger_map_mutex_, flusher_mutex_;
-    std::recursive_mutex tp_mutex_;
+    spdlog_mutex logger_map_mutex_, flusher_mutex_;
+    spdlog_recursive_mutex tp_mutex_;
     std::unordered_map<std::string, std::shared_ptr<logger>> loggers_;
     log_levels log_levels_;
     std::unique_ptr<formatter> formatter_;