smplockstats.h

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/* SPDX-License-Identifier: BSD-2-Clause */
 
/*
 * 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 */
 
#if defined(RTEMS_PROFILING)
 
#define SMP_LOCK_STATS_CONTENTION_COUNTS 4
 
typedef struct {
  Chain_Node Node;
 
  CPU_Counter_ticks max_acquire_time;
 
  CPU_Counter_ticks max_section_time;
 
  uint64_t usage_count;
 
  uint64_t total_acquire_time;
 
  uint64_t contention_counts[SMP_LOCK_STATS_CONTENTION_COUNTS];
 
  uint64_t total_section_time;
 
  const char *name;
} SMP_lock_Stats;
 
typedef struct {
  CPU_Counter_ticks acquire_instant;
 
  SMP_lock_Stats *stats;
} SMP_lock_Stats_context;
 
#define SMP_LOCK_STATS_INITIALIZER( name ) \
  { { NULL, NULL }, 0, 0, 0, 0, { 0, 0, 0, 0 }, 0, name }
 
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;
}
 
void _SMP_lock_Stats_destroy( SMP_lock_Stats *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;
 
static inline void _SMP_lock_Stats_acquire_begin(
  SMP_lock_Stats_acquire_context *acquire_context
)
{
  acquire_context->first = _CPU_Counter_read();
}
 
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;
}
 
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;
 
void _SMP_lock_Stats_iteration_start(
  SMP_lock_Stats_iteration_context *iteration_context
);
 
bool _SMP_lock_Stats_iteration_next(
  SMP_lock_Stats_iteration_context *iteration_context,
  SMP_lock_Stats                   *snapshot,
  char                             *name,
  size_t                            name_size
);
 
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 */