freebsd-dev/sys/compat/cloudabi/cloudabi_clock.c
Ed Schouten 072cb63ddc Make clock_gettime() and clock_getres() work for CloudABI programs.
Though the standard C library uses a 'struct timespec' using a 64-bit
'time_t', there is no need to use such a type at the system call level.
CloudABI uses a simple 64-bit unsigned timestamp in nanoseconds. This is
sufficient to express any time value from 1970 to 2554.

The CloudABI low-level interface also supports fetching timestamp values
with a lower precision. Instead of overloading the clock ID argument for
this purpose, the system call provides a precision argument that may be
used to specify the maximum slack. The current system call
implementation does not use this information, but it's good to already
have this available.

Expose cloudabi_convert_timespec(), as we're going to need this for
fstat() as well.

Obtained from:	https://github.com/NuxiNL/freebsd
2015-07-21 15:08:13 +00:00

126 lines
3.6 KiB
C

/*-
* Copyright (c) 2015 Nuxi, https://nuxi.nl/
*
* 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 AUTHOR 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 AUTHOR 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/proc.h>
#include <sys/stdint.h>
#include <sys/syscallsubr.h>
#include <compat/cloudabi/cloudabi_proto.h>
#include <compat/cloudabi/cloudabi_syscalldefs.h>
#include <compat/cloudabi/cloudabi_util.h>
/* Converts a CloudABI clock ID to a FreeBSD clock ID. */
static int
cloudabi_convert_clockid(cloudabi_clockid_t in, clockid_t *out)
{
switch (in) {
case CLOUDABI_CLOCK_MONOTONIC:
*out = CLOCK_MONOTONIC;
return (0);
case CLOUDABI_CLOCK_PROCESS_CPUTIME_ID:
*out = CLOCK_PROCESS_CPUTIME_ID;
return (0);
case CLOUDABI_CLOCK_REALTIME:
*out = CLOCK_REALTIME;
return (0);
case CLOUDABI_CLOCK_THREAD_CPUTIME_ID:
*out = CLOCK_THREAD_CPUTIME_ID;
return (0);
default:
return (EINVAL);
}
}
/* Converts a struct timespec to a CloudABI timestamp. */
int
cloudabi_convert_timespec(const struct timespec *in, cloudabi_timestamp_t *out)
{
cloudabi_timestamp_t s, ns;
if (in->tv_sec < 0) {
/* Timestamps from before the Epoch cannot be expressed. */
*out = 0;
return (EOVERFLOW);
}
s = in->tv_sec;
ns = in->tv_nsec;
if (s > UINT64_MAX / 1000000000 ||
(s == UINT64_MAX / 1000000000 && ns > UINT64_MAX % 1000000000)) {
/* Addition of seconds and nanoseconds would overflow. */
*out = UINT64_MAX;
return (EOVERFLOW);
}
*out = s * 1000000000 + ns;
return (0);
}
int
cloudabi_sys_clock_res_get(struct thread *td,
struct cloudabi_sys_clock_res_get_args *uap)
{
struct timespec ts;
cloudabi_timestamp_t cts;
int error;
clockid_t clockid;
error = cloudabi_convert_clockid(uap->clock_id, &clockid);
if (error != 0)
return (error);
error = kern_clock_getres(td, clockid, &ts);
if (error != 0)
return (error);
error = cloudabi_convert_timespec(&ts, &cts);
if (error != 0)
return (error);
td->td_retval[0] = cts;
return (0);
}
int
cloudabi_sys_clock_time_get(struct thread *td,
struct cloudabi_sys_clock_time_get_args *uap)
{
struct timespec ts;
cloudabi_timestamp_t cts;
int error;
clockid_t clockid;
error = cloudabi_convert_clockid(uap->clock_id, &clockid);
if (error != 0)
return (error);
error = kern_clock_gettime(td, clockid, &ts);
if (error != 0)
return (error);
error = cloudabi_convert_timespec(&ts, &cts);
if (error != 0)
return (error);
td->td_retval[0] = cts;
return (0);
}