请教关于RTOS优先级0 到 configMAX_PRIORITIES – 1的问题。

2360985396

教程中说到：
FreeRTOS 中任务的最高优先级是通过 FreeRTOSConfig.h 文件中的 configMAX_PRIORITIES 进行配置的，用户实际可以使用的优先级范围是 0 到 configMAX_PRIORITIES – 1。比如我们配置此宏定义为 5，那么用户可以使用的优先级号是 0,1,2,3,4，不包含 5，对于这一点，初学者要特别的注意。


但是在STM32 Cube MX生成的源码中的优先级枚举是这样的

// ==== Enumeration, structures, defines ====

/// Priority used for thread control.
/// \note MUST REMAIN UNCHANGED: \b osPriority shall be consistent in every CMSIS-RTOS.
typedef enum  {
  osPriorityIdle          = -3,          ///< priority: idle (lowest)
  osPriorityLow           = -2,          ///< priority: low
  osPriorityBelowNormal   = -1,          ///< priority: below normal
  osPriorityNormal        =  0,          ///< priority: normal (default)
  osPriorityAboveNormal   = +1,          ///< priority: above normal
  osPriorityHigh          = +2,          ///< priority: high
  osPriorityRealtime      = +3,          ///< priority: realtime (highest)
  osPriorityError         =  0x84        ///< system cannot determine priority or thread has illegal priority
} osPriority;


1.这个枚举是负数
2.这个优先级是如何 和教程中的 0 到 configMAX_PRIORITIES – 1 对应的？

eric2013

CMSIS-RTOS V1别研究它了，已经被ARM淘汰了，直接看CMSIS-RTOS V2

将其直接配置到最大
#define configMAX_PRIORITIES                    56

[C] 纯文本查看 复制代码

/// Priority values.
typedef enum {
  osPriorityNone          =  0,         ///< No priority (not initialized).
  osPriorityIdle          =  1,         ///< Reserved for Idle thread.
  osPriorityLow           =  8,         ///< Priority: low
  osPriorityLow1          =  8+1,       ///< Priority: low + 1
  osPriorityLow2          =  8+2,       ///< Priority: low + 2
  osPriorityLow3          =  8+3,       ///< Priority: low + 3
  osPriorityLow4          =  8+4,       ///< Priority: low + 4
  osPriorityLow5          =  8+5,       ///< Priority: low + 5
  osPriorityLow6          =  8+6,       ///< Priority: low + 6
  osPriorityLow7          =  8+7,       ///< Priority: low + 7
  osPriorityBelowNormal   = 16,         ///< Priority: below normal
  osPriorityBelowNormal1  = 16+1,       ///< Priority: below normal + 1
  osPriorityBelowNormal2  = 16+2,       ///< Priority: below normal + 2
  osPriorityBelowNormal3  = 16+3,       ///< Priority: below normal + 3
  osPriorityBelowNormal4  = 16+4,       ///< Priority: below normal + 4
  osPriorityBelowNormal5  = 16+5,       ///< Priority: below normal + 5
  osPriorityBelowNormal6  = 16+6,       ///< Priority: below normal + 6
  osPriorityBelowNormal7  = 16+7,       ///< Priority: below normal + 7
  osPriorityNormal        = 24,         ///< Priority: normal
  osPriorityNormal1       = 24+1,       ///< Priority: normal + 1
  osPriorityNormal2       = 24+2,       ///< Priority: normal + 2
  osPriorityNormal3       = 24+3,       ///< Priority: normal + 3
  osPriorityNormal4       = 24+4,       ///< Priority: normal + 4
  osPriorityNormal5       = 24+5,       ///< Priority: normal + 5
  osPriorityNormal6       = 24+6,       ///< Priority: normal + 6
  osPriorityNormal7       = 24+7,       ///< Priority: normal + 7
  osPriorityAboveNormal   = 32,         ///< Priority: above normal
  osPriorityAboveNormal1  = 32+1,       ///< Priority: above normal + 1
  osPriorityAboveNormal2  = 32+2,       ///< Priority: above normal + 2
  osPriorityAboveNormal3  = 32+3,       ///< Priority: above normal + 3
  osPriorityAboveNormal4  = 32+4,       ///< Priority: above normal + 4
  osPriorityAboveNormal5  = 32+5,       ///< Priority: above normal + 5
  osPriorityAboveNormal6  = 32+6,       ///< Priority: above normal + 6
  osPriorityAboveNormal7  = 32+7,       ///< Priority: above normal + 7
  osPriorityHigh          = 40,         ///< Priority: high
  osPriorityHigh1         = 40+1,       ///< Priority: high + 1
  osPriorityHigh2         = 40+2,       ///< Priority: high + 2
  osPriorityHigh3         = 40+3,       ///< Priority: high + 3
  osPriorityHigh4         = 40+4,       ///< Priority: high + 4
  osPriorityHigh5         = 40+5,       ///< Priority: high + 5
  osPriorityHigh6         = 40+6,       ///< Priority: high + 6
  osPriorityHigh7         = 40+7,       ///< Priority: high + 7
  osPriorityRealtime      = 48,         ///< Priority: realtime
  osPriorityRealtime1     = 48+1,       ///< Priority: realtime + 1
  osPriorityRealtime2     = 48+2,       ///< Priority: realtime + 2
  osPriorityRealtime3     = 48+3,       ///< Priority: realtime + 3
  osPriorityRealtime4     = 48+4,       ///< Priority: realtime + 4
  osPriorityRealtime5     = 48+5,       ///< Priority: realtime + 5
  osPriorityRealtime6     = 48+6,       ///< Priority: realtime + 6
  osPriorityRealtime7     = 48+7,       ///< Priority: realtime + 7
  osPriorityISR           = 56,         ///< Reserved for ISR deferred thread.
  osPriorityError         = -1,         ///< System cannot determine priority or illegal priority.
  osPriorityReserved      = 0x7FFFFFFF  ///< Prevents enum down-size compiler optimization.
} osPriority_t;