diff options
Diffstat (limited to 'cpukit/score/include/rtems/score/priority.h')
| -rw-r--r-- | cpukit/score/include/rtems/score/priority.h | 81 |
1 files changed, 53 insertions, 28 deletions
diff --git a/cpukit/score/include/rtems/score/priority.h b/cpukit/score/include/rtems/score/priority.h index 58b70add1b..bfe43e282d 100644 --- a/cpukit/score/include/rtems/score/priority.h +++ b/cpukit/score/include/rtems/score/priority.h @@ -7,7 +7,7 @@ */ /* - * COPYRIGHT (c) 1989-2004. + * COPYRIGHT (c) 1989-2006. * On-Line Applications Research Corporation (OAR). * * The license and distribution terms for this file may be @@ -23,7 +23,16 @@ /** * @defgroup ScorePriority Priority Handler * - * This group contains functionality which XXX + * This handler encapsulates functionality which is used to manage + * thread priorities. At the SuperCore level 256 priority levels + * are supported with lower numbers representing logically more important + * threads. The priority level 0 is reserved for internal RTEMS use. + * Typically it is assigned to threads which defer internal RTEMS + * actions from an interrupt to thread level to improve interrupt response. + * Priority level 255 is assigned to the IDLE thread and really should not + * be used by application threads. The default IDLE thread implementation + * is an infinite "branch to self" loop which never yields to other threads + * at the same priority. */ /**@{*/ @@ -31,43 +40,48 @@ extern "C" { #endif -/* +/** * The following type defines the control block used to manage * thread priorities. * * @note Priority 0 is reserved for internal threads only. */ - typedef uint32_t Priority_Control; -#define PRIORITY_MINIMUM 0 /* highest thread priority */ -#define PRIORITY_MAXIMUM 255 /* lowest thread priority */ +/** This defines the highest (most important) thread priority. */ +#define PRIORITY_MINIMUM 0 +/** This defines the lowest (least important) thread priority. */ +#define PRIORITY_MAXIMUM 255 -/* +/** * The following record defines the information associated with * each thread to manage its interaction with the priority bit maps. */ - typedef struct { - Priority_Bit_map_control *minor; /* addr of minor bit map slot */ - Priority_Bit_map_control ready_major; /* priority bit map ready mask */ - Priority_Bit_map_control ready_minor; /* priority bit map ready mask */ - Priority_Bit_map_control block_major; /* priority bit map block mask */ - Priority_Bit_map_control block_minor; /* priority bit map block mask */ + /** This is the address of minor bit map slot. */ + Priority_Bit_map_control *minor; + /** This is the priority bit map ready mask. */ + Priority_Bit_map_control ready_major; + /** This is the priority bit map ready mask. */ + Priority_Bit_map_control ready_minor; + /** This is the priority bit map block mask. */ + Priority_Bit_map_control block_major; + /** This is the priority bit map block mask. */ + Priority_Bit_map_control block_minor; } Priority_Information; -/* - * The following data items are the priority bit map. - * Each of the sixteen bits used in the _Priority_Major_bit_map is - * associated with one of the sixteen entries in the _Priority_Bit_map. - * Each bit in the _Priority_Bit_map indicates whether or not there are +/** + * Each sixteen bit entry in this array is associated with one of + * the sixteen entries in the Priority Bit map. + */ +SCORE_EXTERN volatile Priority_Bit_map_control _Priority_Major_bit_map; + +/** Each bit in the Priority Bitmap indicates whether or not there are * threads ready at a particular priority. The mapping of * individual priority levels to particular bits is processor * dependent as is the value of each bit used to indicate that * threads are ready at that priority. */ - -SCORE_EXTERN volatile Priority_Bit_map_control _Priority_Major_bit_map; SCORE_EXTERN Priority_Bit_map_control _Priority_Bit_map[16] CPU_STRUCTURE_ALIGNMENT; @@ -76,22 +90,33 @@ SCORE_EXTERN Priority_Bit_map_control * */ -/* - * Priority Bitfield Manipulation Routines +#if ( CPU_USE_GENERIC_BITFIELD_CODE == FALSE ) +/** + * This method returns the priority bit mask for the specified major + * or minor bit number. * - * @note + * @param[in] _bit_number is the bit number for which we need a mask * - * These may simply be pass throughs to CPU dependent routines. + * @return the priority bit mask + * + * @note This may simply be a pass through to a CPU dependent implementation. */ - -#if ( CPU_USE_GENERIC_BITFIELD_CODE == FALSE ) - #define _Priority_Mask( _bit_number ) \ _CPU_Priority_Mask( _bit_number ) +#endif +#if ( CPU_USE_GENERIC_BITFIELD_CODE == FALSE ) +/** + * This method returns the bit index position for the specified priority. + * + * @param[in] _priority is the priority for which we need the index. + * + * @return This method returns the array index into the priority bit map. + * + * @note This may simply be a pass through to a CPU dependent implementation. + */ #define _Priority_Bits_index( _priority ) \ _CPU_Priority_bits_index( _priority ) - #endif #ifndef __RTEMS_APPLICATION__ |