LXR 6.1/​cpukit/​include/​rtems/​score/​smplockstats.h	Source navigation Diff markup Identifier search General search
	Version: 6.1 Revert   Change

File indexing completed on 2025-05-11 08:24:13

 /* SPDX-License-Identifier: BSD-2-Clause */
 
 /**
  * @file
  *
  * @ingroup RTEMSScoreSMPLock
  *
  * @brief This header file provides the interfaces of the
  *   @ref RTEMSScoreSMPLock related to lock statistics.
  */
 
 /*
  * Copyright (C) 2013, 2018 embedded brains GmbH & Co. KG
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  * POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef _RTEMS_SCORE_SMPLOCKSTATS_H
 #define _RTEMS_SCORE_SMPLOCKSTATS_H
 
 #include <rtems/score/cpu.h>
 
 #if defined(RTEMS_SMP)
 
 #include <rtems/score/chain.h>
 
 #ifdef __cplusplus
 extern "C" {
 #endif /* __cplusplus */
 
 /**
  * @addtogroup RTEMSScoreSMPLock
  *
  * @{
  */
 
 #if defined(RTEMS_PROFILING)
 
 /**
  * @brief Count of lock contention counters for lock statistics.
  */
 #define SMP_LOCK_STATS_CONTENTION_COUNTS 4
 
 /**
  * @brief SMP lock statistics.
  *
  * The lock acquire attempt instant is the point in time right after the
  * interrupt disable action in the lock acquire sequence.
  *
  * The lock acquire instant is the point in time right after the lock
  * acquisition.  This is the begin of the critical section code execution.
  *
  * The lock release instant is the point in time right before the interrupt
  * enable action in the lock release sequence.
  *
  * The lock section time is the time elapsed between the lock acquire instant
  * and the lock release instant.
  *
  * The lock acquire time is the time elapsed between the lock acquire attempt
  * instant and the lock acquire instant.
  */
 typedef struct {
   /**
    * @brief Node for SMP lock statistics chain.
    */
   Chain_Node Node;
 
   /**
    * @brief The maximum lock acquire time in CPU counter ticks.
    */
   CPU_Counter_ticks max_acquire_time;
 
   /**
    * @brief The maximum lock section time in CPU counter ticks.
    */
   CPU_Counter_ticks max_section_time;
 
   /**
    * @brief The count of lock uses.
    *
    * This value may overflow.
    */
   uint64_t usage_count;
 
   /**
    * @brief Total lock acquire time in nanoseconds.
    *
    * The average lock acquire time is the total acquire time divided by the
    * lock usage count.  The ration of the total section and total acquire times
    * gives a measure for the lock contention.
    *
    * This value may overflow.
    */
   uint64_t total_acquire_time;
 
   /**
    * @brief The counts of lock acquire operations by contention.
    *
    * The contention count for index N corresponds to a lock acquire attempt
    * with an initial queue length of N.  The last index corresponds to all
    * lock acquire attempts with an initial queue length greater than or equal
    * to SMP_LOCK_STATS_CONTENTION_COUNTS minus one.
    *
    * The values may overflow.
    */
   uint64_t contention_counts[SMP_LOCK_STATS_CONTENTION_COUNTS];
 
   /**
    * @brief Total lock section time in CPU counter ticks.
    *
    * The average lock section time is the total section time divided by the
    * lock usage count.
    *
    * This value may overflow.
    */
   uint64_t total_section_time;
 
   /**
    * @brief The lock name.
    */
   const char *name;
 } SMP_lock_Stats;
 
 /**
  * @brief Local context for SMP lock statistics.
  */
 typedef struct {
   /**
    * @brief The last lock acquire instant in CPU counter ticks.
    *
    * This value is used to measure the lock section time.
    */
   CPU_Counter_ticks acquire_instant;
 
   /**
    * @brief The lock stats used for the last lock acquire.
    */
   SMP_lock_Stats *stats;
 } SMP_lock_Stats_context;
 
 /**
  * @brief SMP lock statistics initializer for static initialization.
  */
 #define SMP_LOCK_STATS_INITIALIZER( name ) \
   { { NULL, NULL }, 0, 0, 0, 0, { 0, 0, 0, 0 }, 0, name }
 
 /**
  * @brief Initializes an SMP lock statistics block.
  *
  * @param[in, out] stats The SMP lock statistics block.
  * @param name The name for the SMP lock statistics.  This name must be
  * persistent throughout the life time of this statistics block.
  */
 static inline void _SMP_lock_Stats_initialize(
   SMP_lock_Stats *stats,
   const char *name
 )
 {
   SMP_lock_Stats init = SMP_LOCK_STATS_INITIALIZER( name );
 
   *stats = init;
 }
 
 /**
  * @brief Destroys an SMP lock statistics block.
  *
  * @param[out] stats The SMP lock statistics block.
  */
 void _SMP_lock_Stats_destroy( SMP_lock_Stats *stats );
 
 /**
  * @brief Sets the max section time of the SMP lock statistics block and
  *      registers it.
  *
  * @param[in, out] stats The SMP lock statistics block.
  * @param max_section_time The max section time for @a stats.
  */
 void _SMP_lock_Stats_register_or_max_section_time(
   SMP_lock_Stats    *stats,
   CPU_Counter_ticks  max_section_time
 );
 
 typedef struct {
   CPU_Counter_ticks first;
 } SMP_lock_Stats_acquire_context;
 
 /**
  * @brief Starts the lock stats for acquire.
  *
  * @param[in, out] acquire_context The acquire context.
  */
 static inline void _SMP_lock_Stats_acquire_begin(
   SMP_lock_Stats_acquire_context *acquire_context
 )
 {
   acquire_context->first = _CPU_Counter_read();
 }
 
 /**
  * @brief Ends the lock stats for acquire.
  *
  * @param acquire_context The acquire context for the operation.
  * @param[in, out] stats The stats to modify.
  * @param[out] stats_context The context for the stats.
  * @param queue_length The queue length for the stats contention counts.
  */
 static inline void _SMP_lock_Stats_acquire_end(
   const SMP_lock_Stats_acquire_context *acquire_context,
   SMP_lock_Stats                       *stats,
   SMP_lock_Stats_context               *stats_context,
   unsigned int                          queue_length
 )
 {
   CPU_Counter_ticks second;
   CPU_Counter_ticks delta;
 
   second = _CPU_Counter_read();
   stats_context->acquire_instant = second;
   delta = second - acquire_context->first;
 
   ++stats->usage_count;
 
   stats->total_acquire_time += delta;
 
   if ( stats->max_acquire_time < delta ) {
     stats->max_acquire_time = delta;
   }
 
   if ( queue_length >= SMP_LOCK_STATS_CONTENTION_COUNTS ) {
     queue_length = SMP_LOCK_STATS_CONTENTION_COUNTS - 1;
   }
   ++stats->contention_counts[ queue_length ];
 
   stats_context->stats = stats;
 }
 
 /**
  * @brief Updates an SMP lock statistics block during a lock release.
  *
  * @param[in, out] stats_context The SMP lock statistics context.
  */
 static inline void _SMP_lock_Stats_release_update(
   const SMP_lock_Stats_context *stats_context
 )
 {
   SMP_lock_Stats    *stats;
   CPU_Counter_ticks  first;
   CPU_Counter_ticks  second;
   CPU_Counter_ticks  delta;
 
   stats = stats_context->stats;
   first = stats_context->acquire_instant;
   second = _CPU_Counter_read();
   delta = second - first;
 
   stats->total_section_time += delta;
 
   if ( stats->max_section_time < delta ) {
     _SMP_lock_Stats_register_or_max_section_time( stats, delta );
   }
 }
 
 typedef struct {
   Chain_Node Node;
   SMP_lock_Stats *current;
 } SMP_lock_Stats_iteration_context;
 
 /**
  * @brief Adds a newly initialized node to the iteration context.
  *
  * @param[in, out] iteration_context The iteration context for the operation.
  */
 void _SMP_lock_Stats_iteration_start(
   SMP_lock_Stats_iteration_context *iteration_context
 );
 
 /**
  * @brief Gets the next statistics node, if it is valid.
  *
  * @param[in, out] iteration_context The iteration context.
  * @param[out] snapshot Contains the next node of the stats chain.
  * @param[in, out] name The name for @a snapshot.
  * @param name_size The size of @a name.
  *
  * @retval true The node is valid.
  * @retval false The node is not valid.
  */
 bool _SMP_lock_Stats_iteration_next(
   SMP_lock_Stats_iteration_context *iteration_context,
   SMP_lock_Stats                   *snapshot,
   char                             *name,
   size_t                            name_size
 );
 
 /**
  * @brief Removes a node from the iteration context.
  *
  * @param[in, out] iteration_context The iteration context for the operation.
  */
 void _SMP_lock_Stats_iteration_stop(
   SMP_lock_Stats_iteration_context *iteration_context
 );
 
 #else /* RTEMS_PROFILING */
 
 #define _SMP_lock_Stats_initialize( stats, name ) do { } while ( 0 )
 
 #define _SMP_lock_Stats_destroy( stats ) do { } while ( 0 )
 
 #endif /* !RTEMS_PROFILING */
 
 /** @} */
 
 #ifdef __cplusplus
 }
 #endif /* __cplusplus */
 
 #endif /* RTEMS_SMP */
 
 #endif /* _RTEMS_SCORE_SMPLOCKSTATS_H */

This page was automatically generated by the 2.3.7 LXR engine. The LXR team