mutex_freertos.h

/******************************************************************************
The MIT License(MIT)
 
Embedded Template Library.
https://github.com/ETLCPP/etl
https://www.etlcpp.com
 
Copyright(c) 2020 Phil Wise phil@phil-wise.com
 
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#ifndef ETL_MUTEX_FREERTOS_INCLUDED
#define ETL_MUTEX_FREERTOS_INCLUDED
 
#include "../platform.h"
 
#include "FreeRTOS.h"
#include <semphr.h>
 
namespace etl
{
  //***************************************************************************
  //***************************************************************************
  class mutex
  {
  public:
 
    mutex()
    {
      access = xSemaphoreCreateMutexStatic(&mutex_allocation);
    }
 
    void lock()
    {
      xSemaphoreTake(access, portMAX_DELAY); // portMAX_DELAY=block forever
    }
 
    bool try_lock()
    {
      return xSemaphoreTake(access, 0) == pdTRUE;
    }
 
    void unlock()
    {
      xSemaphoreGive(access);
    }
 
   private:
    // Non-copyable
    mutex(const mutex&) ETL_DELETE;
    mutex& operator=(const mutex&) ETL_DELETE;
 
    // Memory to hold the mutex
    StaticSemaphore_t mutex_allocation;
  
    // The mutex handle itself
    SemaphoreHandle_t access;
  };
}
 
#endif