nuttx/sched/sched/sched_cpuload_oneshot.c
Gregory Nutt 153eee6de2 Make more OS internal names consistent
1. Internal scheduler functions should begin with nxsched_, not sched_
2. Follow the consistent naming patter of https://cwiki.apache.org/confluence/display/NUTTX/Naming+of+OS+Internal+Functions

    # clock_systimer -> clock_systime_tick
    # clock_systimespec -> clock_systime_timespec
    sched_oneshot_extclk -> nxsched_oneshot_extclk
    sched_period_extclk -> nxsched_period_extclk
    # nxsem_setprotocol -> nxsem_set_protocol
    # nxsem_getprotocol -> nxsem_get_protocol
    # nxsem_getvalue -> nxsem_get_value
    nxsem_initholders -> nxsem_initialize_holders
    nxsem_addholder -> nxsem_add_holder
    nxsem_addholder_tcb -> nxsem_add_holder_tcb
    nxsem_boostpriority -> nxsem_boost_priority
    nxsem_releaseholder -> nxsem_release_holder
    nxsem_restorebaseprio -> nxsem_restore_baseprio

Some planned name changed were skipped for now because they effect too many files (and would require many hours of coding style fixups).
2020-05-10 22:47:07 +08:00

290 lines
8.4 KiB
C

/****************************************************************************
* sched/sched/sched_cpuload_oneshot.c
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <time.h>
#include <assert.h>
#include <debug.h>
#include <nuttx/arch.h>
#include <nuttx/clock.h>
#include <nuttx/lib/xorshift128.h>
#include <nuttx/timers/oneshot.h>
#include "clock/clock.h"
#ifdef CONFIG_CPULOAD_ONESHOT
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Configuration ************************************************************/
#if !defined(CONFIG_SCHED_CPULOAD) || !defined(CONFIG_SCHED_CPULOAD_EXTCLK)
# error CONFIG_SCHED_CPULOAD and CONFIG_SCHED_CPULOAD_EXTCLK must be defined
#endif
/* CONFIG_SCHED_CPULOAD_TICKSPERSEC is the frequency of the external clock
* source.
*/
#ifndef CONFIG_SCHED_CPULOAD_TICKSPERSEC
# error CONFIG_SCHED_CPULOAD_TICKSPERSEC not defined
#endif
/* CONFIG_CPULOAD_ENTROPY determines that amount of random "jitter"
* that will be added to the nominal sample interval. Specified as a number
* bits.
*/
#ifndef CONFIG_CPULOAD_ENTROPY
# warning CONFIG_CPULOAD_ENTROPY not defined
# define CONFIG_CPULOAD_ENTROPY 0
#endif
/* Calculate the nominal sample interval in microseconds:
*
* nominal = (1,000,000 usec/sec) / Frequency cycles/sec) = Period usec/cycle
*/
#define CPULOAD_ONESHOT_NOMINAL (1000000 / CONFIG_SCHED_CPULOAD_TICKSPERSEC)
#if CPULOAD_ONESHOT_NOMINAL < 1 || CPULOAD_ONESHOT_NOMINAL > 0x7fffffff
# error CPULOAD_ONESHOT_NOMINAL is out of range
#endif
/* Convert the entropy from number of bits to a numeric value */
#define CPULOAD_ONESHOT_ENTROPY (1 << CONFIG_CPULOAD_ENTROPY)
#if CPULOAD_ONESHOT_NOMINAL < CPULOAD_ONESHOT_ENTROPY
# error CPULOAD_ONESHOT_NOMINAL too small for CONFIG_CPULOAD_ENTROPY
#endif
#define CPULOAD_ONESHOT_ENTROPY_MASK (CPULOAD_ONESHOT_ENTROPY - 1)
/****************************************************************************
* Private Types
****************************************************************************/
struct sched_oneshot_s
{
FAR struct oneshot_lowerhalf_s *oneshot;
#if CONFIG_CPULOAD_ENTROPY > 0
struct xorshift128_state_s prng;
int32_t maxdelay;
int32_t error;
#endif
};
/****************************************************************************
* Private Function Prototypes
****************************************************************************/
static void nxsched_oneshot_start(void);
static void nxsched_oneshot_callback(FAR struct oneshot_lowerhalf_s *lower,
FAR void *arg);
/****************************************************************************
* Private Data
****************************************************************************/
static struct sched_oneshot_s g_sched_oneshot;
/****************************************************************************
* Private Functions
****************************************************************************/
/****************************************************************************
* Name: nxsched_oneshot_start
*
* Description:
* [Re-]start the oneshot timer, applying entropy as configured
*
* Input Parameters:
* None
* lower - An instance of the lower half driver
* arg - The opaque argument provided when the interrupt was registered
*
* Returned Value:
* None
*
****************************************************************************/
static void nxsched_oneshot_start(void)
{
struct timespec ts;
#if CONFIG_CPULOAD_ENTROPY > 0
uint32_t entropy;
#endif
int32_t secs;
int32_t usecs;
/* Get the next delay */
#if CONFIG_CPULOAD_ENTROPY > 0
/* The one shot will be set to this interval:
*
* CPULOAD_ONESHOT_NOMINAL - (CPULOAD_ONESHOT_ENTROPY / 2) + error
* + nrand(CPULOAD_ONESHOT_ENTROPY)
*/
usecs = (CPULOAD_ONESHOT_NOMINAL - CPULOAD_ONESHOT_ENTROPY / 2) +
g_sched_oneshot.error;
/* Add the random value in the range 0..(CPULOAD_ONESHOT_ENTRY - 1) */
entropy = xorshift128(&g_sched_oneshot.prng);
usecs += (int32_t)(entropy & CPULOAD_ONESHOT_ENTROPY_MASK);
DEBUGASSERT(usecs > 0); /* Check for overflow to negative or zero */
/* Make sure that the accumulated value does not exceed the maximum delay */
if (usecs > g_sched_oneshot.maxdelay)
{
tmrwarn("WARNING: Truncating\n");
usecs = g_sched_oneshot.maxdelay;
}
/* Save the new error value */
g_sched_oneshot.error = CPULOAD_ONESHOT_NOMINAL +
g_sched_oneshot.error - usecs;
#else
/* No entropy */
usecs = CPULOAD_ONESHOT_NOMINAL;
#endif
/* Then re-start the oneshot timer */
secs = usecs / 1000000;
usecs -= 100000 * secs;
ts.tv_sec = secs;
ts.tv_nsec = 1000 * usecs;
DEBUGVERIFY(ONESHOT_START(g_sched_oneshot.oneshot,
nxsched_oneshot_callback, NULL, &ts));
}
/****************************************************************************
* Name: nxsched_oneshot_callback
*
* Description:
* This is the callback function that will be invoked when the oneshot
* timer expires.
*
* Input Parameters:
* lower - An instance of the lower half driver
* arg - The opaque argument provided when the interrupt was registered
*
* Returned Value:
* None
*
****************************************************************************/
static void nxsched_oneshot_callback(FAR struct oneshot_lowerhalf_s *lower,
FAR void *arg)
{
/* Perform CPU load measurements */
#ifdef CONFIG_HAVE_WEAKFUNCTIONS
if (nxsched_process_cpuload != NULL)
#endif
{
nxsched_process_cpuload();
}
/* Then restart the oneshot */
nxsched_oneshot_start();
}
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: nxsched_oneshot_extclk
*
* Description:
* Configure to use a oneshot timer as described in
* include/nuttx/timers/oneshot.h to provide external clocking to assess
* the CPU load.
*
* Input Parameters:
* lower - An instance of the oneshot timer interface as defined in
* include/nuttx/timers/oneshot.h
*
* Returned Value:
* None
*
****************************************************************************/
void nxsched_oneshot_extclk(FAR struct oneshot_lowerhalf_s *lower)
{
#if CONFIG_CPULOAD_ENTROPY > 0
struct timespec ts;
#endif
DEBUGASSERT(lower != NULL && lower->ops != NULL);
DEBUGASSERT(lower->ops->start != NULL);
#if CONFIG_CPULOAD_ENTROPY > 0
DEBUGASSERT(lower->ops->max_delay != NULL);
/* Get the maximum delay */
DEBUGVERIFY(ONESHOT_MAX_DELAY(lower, &ts));
if (ts.tv_sec >= 0)
{
g_sched_oneshot.maxdelay = INT32_MAX;
}
else
{
g_sched_oneshot.maxdelay = ts.tv_nsec / 1000;
}
tmrinfo("madelay = %ld usec\n", (long)g_sched_oneshot.maxdelay);
DEBUGASSERT(CPULOAD_ONESHOT_NOMINAL < g_sched_oneshot.maxdelay);
/* Seed the PRNG */
g_sched_oneshot.prng.w = 97;
g_sched_oneshot.prng.x = 101;
g_sched_oneshot.prng.y = g_sched_oneshot.prng.w << 17;
g_sched_oneshot.prng.z = g_sched_oneshot.prng.x << 25;
#endif
/* Then start the oneshot */
g_sched_oneshot.oneshot = lower;
nxsched_oneshot_start();
}
#endif