diff options
Diffstat (limited to 'nuttx/sched/clock_gettime.c')
-rw-r--r-- | nuttx/sched/clock_gettime.c | 148 |
1 files changed, 148 insertions, 0 deletions
diff --git a/nuttx/sched/clock_gettime.c b/nuttx/sched/clock_gettime.c new file mode 100644 index 0000000000..ac9270975c --- /dev/null +++ b/nuttx/sched/clock_gettime.c @@ -0,0 +1,148 @@ +/************************************************************ + * clock_gettime.c + * + * Copyright (C) 2007 Gregory Nutt. All rights reserved. + * Author: Gregory Nutt <spudmonkey@racsa.co.cr> + * + * 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 Gregory Nutt 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 <sys/types.h> +#include <time.h> +#include <errno.h> +#include <debug.h> +#include "clock_internal.h" + +/************************************************************ + * Definitions + ************************************************************/ + +/************************************************************ + * Private Type Declarations + ************************************************************/ + +/************************************************************ + * Private Function Prototypes + ************************************************************/ + +/********************************************************** + * Public Constant Data + **********************************************************/ + +/************************************************************ + * Public Variables + ************************************************************/ + +/********************************************************** + * Private Variables + **********************************************************/ + +/************************************************************ + * Private Functions + ************************************************************/ + +/************************************************************ + * Public Functions + ************************************************************/ + +/************************************************************ + * Function: clock_gettime + * + * Description: + * Clock Functions based on POSIX APIs + * + ************************************************************/ + +int clock_gettime(clockid_t clock_id, struct timespec *tp) +{ + uint32 msecs; + uint32 secs; + uint32 nsecs; + int ret = OK; + + dbg("%s: clock_id=%d\n", __FUNCTION__, clock_id); + + /* Only CLOCK_REALTIME is supported */ + + if (clock_id != CLOCK_REALTIME) + { + dbg("%s: Returning ERROR\n", __FUNCTION__); + + *get_errno_ptr() = EINVAL; + ret = ERROR; + } + else + { + /* Get the elapsed time since power up (in milliseconds) biased + * as appropriate. + */ + + msecs = MSEC_PER_TICK * (g_system_timer - g_tickbias); + + dbg("%s: msecs = %d g_tickbias=%d\n", __FUNCTION__, + (int)msecs, (int)g_tickbias); + + /* Get the elapsed time in seconds and nanoseconds. */ + + secs = msecs / MSEC_PER_SEC; + nsecs = (msecs - (secs * MSEC_PER_SEC)) * NSEC_PER_MSEC; + + dbg("%s: secs = %d + %d nsecs = %d + %d\n", __FUNCTION__, + (int)msecs, (int)g_basetime.tv_sec, + (int)nsecs, (int)g_basetime.tv_nsec); + + /* Add the base time to this. */ + + secs += (uint32)g_basetime.tv_sec; + nsecs += (uint32)g_basetime.tv_nsec; + + /* Handle carry to seconds. */ + + if (nsecs > NSEC_PER_SEC) + { + uint32 dwCarrySecs = nsecs / NSEC_PER_SEC; + secs += dwCarrySecs; + nsecs -= (dwCarrySecs * NSEC_PER_SEC); + } + + /* And return the result to the caller. */ + + tp->tv_sec = (time_t)secs; + tp->tv_nsec = (long)nsecs; + + dbg("%s: Returning tp=(%d,%d)\n", __FUNCTION__, + (int)tp->tv_sec, (int)tp->tv_nsec); + } + + return ret; +} |