Add support for FreeRTOS

include/plog/Util.h

@@ -81,6 +81,12 @@
 #   endif
 #endif
 
+#ifdef __FREERTOS__ // There is no standard way to know if the code is compiled for FreeRTOS. We expect __FREERTOS__ macro to be defined in such case.
+#   include <FreeRTOS.h>
+#   include <semphr.h>
+#   include <task.h>
+#endif
+
 #if PLOG_CHAR_IS_UTF8
 #   define PLOG_NSTR(x)    x
 #else
@@ -170,7 +176,9 @@ namespace plog
 
         inline unsigned int gettid()
         {
-#ifdef _WIN32
+#if defined(__FREERTOS__) && defined(INCLUDE_xTaskGetCurrentTaskHandle)
+            return static_cast<unsigned int>(reinterpret_cast<uintptr_t>(xTaskGetCurrentTaskHandle()));
+#elif defined(_WIN32)
             return GetCurrentThreadId();
 #elif defined(__linux__)
             return static_cast<unsigned int>(::syscall(__NR_gettid));
@@ -501,7 +509,10 @@ namespace plog
         public:
             Mutex()
             {
-#ifdef _WIN32
+#ifdef __FREERTOS__
+                m_sync = xSemaphoreCreateBinary();
+                xSemaphoreGive(m_sync);
+#elif defined(_WIN32)
                 InitializeCriticalSection(&m_sync);
 #elif defined(__rtems__)
                 rtems_semaphore_create(0, 1,
@@ -515,7 +526,9 @@ namespace plog
 
             ~Mutex()
             {
-#ifdef _WIN32
+#ifdef __FREERTOS__
+                vSemaphoreDelete(m_sync);
+#elif defined(_WIN32)
                 DeleteCriticalSection(&m_sync);
 #elif defined(__rtems__)
                 rtems_semaphore_delete(m_sync);
@@ -529,7 +542,9 @@ namespace plog
         private:
             void lock()
             {
-#ifdef _WIN32
+#ifdef __FREERTOS__
+                xSemaphoreTake(m_sync, portMAX_DELAY);
+#elif defined(_WIN32)
                 EnterCriticalSection(&m_sync);
 #elif defined(__rtems__)
                 rtems_semaphore_obtain(m_sync, RTEMS_WAIT, RTEMS_NO_TIMEOUT);
@@ -540,7 +555,9 @@ namespace plog
 
             void unlock()
             {
-#ifdef _WIN32
+#ifdef __FREERTOS__
+                xSemaphoreGive(m_sync);
+#elif defined(_WIN32)
                 LeaveCriticalSection(&m_sync);
 #elif defined(__rtems__)
                 rtems_semaphore_release(m_sync);
@@ -550,7 +567,9 @@ namespace plog
             }
 
         private:
-#ifdef _WIN32
+#ifdef __FREERTOS__
+            SemaphoreHandle_t m_sync;
+#elif defined(_WIN32)
             CRITICAL_SECTION m_sync;
 #elif defined(__rtems__)
             rtems_id m_sync;

samples/CMakeLists.txt

@@ -67,6 +67,7 @@ add_subdirectory(DisableLogging)
 add_subdirectory(DynamicAppender)
 add_subdirectory(EventLog)
 add_subdirectory(Facilities)
+add_subdirectory(FreeRTOS)
 add_subdirectory(Hello)
 add_subdirectory(HexDump)
 add_subdirectory(Library)

samples/FreeRTOS/CMakeLists.txt

@@ -0,0 +1,29 @@
+if(CMAKE_SYSTEM_NAME STREQUAL "Linux")
+    include(FetchContent)
+
+    # Select FreeRTOS port
+    set(FREERTOS_PORT "GCC_POSIX")
+
+    # Select FreeRTOS heap
+    set(FREERTOS_HEAP "4")
+
+    # Add the freertos_config for FreeRTOS-Kernel
+    add_subdirectory(freertos_config)
+
+    # Download FreeRTOS-Kernel sources
+    FetchContent_Declare(
+        freertos_kernel
+        URL                        https://github.com/FreeRTOS/FreeRTOS-Kernel/archive/refs/tags/V11.1.0.tar.gz
+        URL_HASH                   SHA256=0e21928b3bcc4f9bcaf7333fb1c8c0299d97e2ec9e13e3faa2c5a7ac8a3bc573
+        DOWNLOAD_EXTRACT_TIMESTAMP TRUE
+    )
+
+    FetchContent_MakeAvailable(freertos_kernel)
+
+    # Describe our executable
+    add_executable(FreeRTOS main.cpp)
+    target_link_libraries(FreeRTOS freertos_kernel freertos_config plog::plog)
+
+    # Important!!! There is no standard way to know if the code is compiled for FreeRTOS. So we define __FREERTOS__ macro.
+    target_compile_definitions(FreeRTOS PUBLIC __FREERTOS__)
+endif()

samples/FreeRTOS/freertos_config/CMakeLists.txt

@@ -0,0 +1,2 @@
+add_library(freertos_config INTERFACE)
+target_include_directories(freertos_config INTERFACE .)