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- /****************************************************************************
- * sched/clock/clock_gettime.c
- *
- * Copyright (C) 2007, 2009, 2011, 2014, 2016 Gregory Nutt. All rights reserved.
- * Author: Gregory Nutt <gnutt@nuttx.org>
- *
- * 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.
- * 3. Neither the name NuttX nor the names of its contributors may be
- * used to endorse or promote products derived from this software
- * without specific prior written permission.
- *
- * 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.
- *
- ****************************************************************************/
- /****************************************************************************
- * Included Files
- ****************************************************************************/
- #include <nuttx/config.h>
- #include <stdint.h>
- #include <time.h>
- #include <assert.h>
- #include <errno.h>
- #include <debug.h>
- #include <arch/irq.h>
- #include <nuttx/arch.h>
- #include "clock/clock.h"
- #ifdef CONFIG_CLOCK_TIMEKEEPING
- # include "clock/clock_timekeeping.h"
- #endif
- /****************************************************************************
- * Public Functions
- ****************************************************************************/
- /****************************************************************************
- * Name: clock_gettime
- *
- * Description:
- * Clock Functions based on POSIX APIs
- *
- ****************************************************************************/
- int clock_gettime(clockid_t clock_id, struct timespec *tp)
- {
- struct timespec ts;
- uint32_t carry;
- int ret = OK;
- sinfo("clock_id=%d\n", clock_id);
- DEBUGASSERT(tp != NULL);
- #ifdef CONFIG_CLOCK_MONOTONIC
- /* CLOCK_MONOTONIC is an optional under POSIX: "If the Monotonic Clock
- * option is supported, all implementations shall support a clock_id
- * of CLOCK_MONOTONIC defined in <time.h>. This clock represents the
- * monotonic clock for the system. For this clock, the value returned
- * by clock_gettime() represents the amount of time (in seconds and
- * nanoseconds) since an unspecified point in the past (for example,
- * system start-up time, or the Epoch). This point does not change
- * after system start-up time. The value of the CLOCK_MONOTONIC clock
- * cannot be set via clock_settime(). This function shall fail if it
- * is invoked with a clock_id argument of CLOCK_MONOTONIC."
- */
- if (clock_id == CLOCK_MONOTONIC)
- {
- /* The the time elapsed since the timer was initialized at power on
- * reset.
- */
- ret = clock_systimespec(tp);
- }
- else
- #endif
- /* CLOCK_REALTIME - POSIX demands this to be present. CLOCK_REALTIME
- * represents the machine's best-guess as to the current wall-clock,
- * time-of-day time. This means that CLOCK_REALTIME can jump forward and
- * backward as the system time-of-day clock is changed.
- */
- if (clock_id == CLOCK_REALTIME)
- {
- /* Get the elapsed time since the time-of-day was last set.
- * clock_systimespec() provides the time since power was applied;
- * the bias value corresponds to the time when the time-of-day was
- * last set.
- */
- #if defined(CONFIG_CLOCK_TIMEKEEPING)
- ret = clock_timekeeping_get_wall_time(tp);
- #else
- ret = clock_systimespec(&ts);
- if (ret == OK)
- {
- irqstate_t flags;
- /* Add the base time to this. The base time is the time-of-day
- * setting. When added to the elapsed time since the time-of-day
- * was last set, this gives us the current time.
- */
- flags = spin_lock_irqsave();
- ts.tv_sec += (uint32_t)g_basetime.tv_sec;
- ts.tv_nsec += (uint32_t)g_basetime.tv_nsec;
- spin_unlock_irqrestore(flags);
- /* Handle carry to seconds. */
- if (ts.tv_nsec >= NSEC_PER_SEC)
- {
- carry = ts.tv_nsec / NSEC_PER_SEC;
- ts.tv_sec += carry;
- ts.tv_nsec -= (carry * NSEC_PER_SEC);
- }
- /* And return the result to the caller. */
- tp->tv_sec = ts.tv_sec;
- tp->tv_nsec = ts.tv_nsec;
- }
- #endif /* CONFIG_CLOCK_TIMEKEEPING */
- }
- else
- {
- ret = -EINVAL;
- }
- /* Check for errors and set the errno value if necessary */
- if (ret < 0)
- {
- serr("Returning ERROR\n");
- set_errno(-ret);
- ret = ERROR;
- }
- else
- {
- sinfo("Returning tp=(%d,%d)\n", (int)tp->tv_sec, (int)tp->tv_nsec);
- }
- return ret;
- }
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