Files
nuttx/sched/clock/clock.h
chao an d8b4d53444 sched/tickless: Fix CLOCK_MONOTONIC always 0 by updating sched ticks
Fix the issue where clock_gettime(CLOCK_MONOTONIC) always returns 0 in
tickless mode, caused by the scheduler tick counter (g_system_ticks) not
being updated with the actual timer ticks.

1. Add clock_update_sched_ticks() function to sched/clock/clock_sched_ticks.c:
  a. This function directly sets the system tick counter to a specific value
     (vs incrementing in clock_increase_sched_ticks), with full documentation
     matching the existing code style.
  b. Uses seqlock to ensure thread-safe access to g_system_ticks.

2. Call clock_update_sched_ticks() in nxsched_process_timer() (sched_processtickless.c):

  a. Syncs the scheduler tick counter with the actual timer ticks retrieved via up_timer_gettick().

With this fix, g_system_ticks is properly updated in tickless mode,
and clock_gettime(CLOCK_MONOTONIC) returns the correct non-zero monotonic time.

Signed-off-by: chao an <anchao.archer@bytedance.com>
2026-03-03 11:01:02 -05:00

159 lines
5.1 KiB
C

/****************************************************************************
* sched/clock/clock.h
*
* SPDX-License-Identifier: Apache-2.0
*
* 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.
*
****************************************************************************/
#ifndef __SCHED_CLOCK_CLOCK_H
#define __SCHED_CLOCK_CLOCK_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <stdint.h>
#include <nuttx/clock.h>
#include <nuttx/compiler.h>
#include <nuttx/spinlock_type.h>
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* 32-bit mask for 64-bit timer values */
#define TIMER_MASK32 0x00000000ffffffff
/* Configuration ************************************************************/
/* If CONFIG_SYSTEM_TIME64 is selected and the CPU supports long long types,
* then a 64-bit system time will be used.
*/
#ifndef CONFIG_HAVE_LONG_LONG
# undef CONFIG_SYSTEM_TIME64
#endif
/****************************************************************************
* Public Type Definitions
****************************************************************************/
/****************************************************************************
* Public Data
****************************************************************************/
#ifndef CONFIG_CLOCK_TIMEKEEPING
extern struct timespec g_basetime;
extern spinlock_t g_basetime_lock;
#endif
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
/****************************************************************************
* Name: clock_basetime
*
* Description:
* Get the initial time value from the best source available.
*
****************************************************************************/
int clock_basetime(FAR struct timespec *tp);
/****************************************************************************
* Name: clock_initialize
*
* Description:
* Perform one-time initialization of the timing facilities.
*
****************************************************************************/
void clock_initialize(void);
/****************************************************************************
* Name: clock_update_sched_ticks
*
* Description:
* Update the scheduler tick counter to a specific value. This function
* directly sets the system tick counter to the given value (rather than
* incrementing it), typically used for synchronizing or resetting the
* scheduler tick count to a known state.
*
* Input Parameters:
* ticks - The new value to set for the scheduler tick counter
*
* Returned Value:
* None
*
****************************************************************************/
void clock_update_sched_ticks(clock_t ticks);
/****************************************************************************
* Name: clock_increase_sched_ticks
*
* Description:
* Increment the scheduler tick counter. This function should be called
* each time the real-time clock interrupt occurs, indicating the passage
* of one or more scheduling ticks.
*
* Input Parameters:
* ticks - The number of ticks to increment (typically 1)
*
* Returned Value:
* None
*
****************************************************************************/
void clock_increase_sched_ticks(clock_t ticks);
/****************************************************************************
* Name: clock_get_sched_ticks
*
* Description:
* Return the current value of the scheduler tick counter. This counter
* only increases while the scheduler is running, and is independent of
* the real-time clock.
*
* Returned Value:
* The current number of scheduler ticks.
*
****************************************************************************/
clock_t clock_get_sched_ticks(void);
#ifdef CONFIG_SCHED_CPULOAD_SYSCLK
/****************************************************************************
* Name: cpuload_init
*
* Description:
* Initialize the CPU load measurement logic.
*
****************************************************************************/
void cpuload_init(void);
#endif
#endif /* __SCHED_CLOCK_CLOCK_H */