glibc/sysdeps/mach/clock_nanosleep.c
2020-02-10 01:03:53 +00:00

117 lines
3.3 KiB
C

/* clock_nanosleep - high-resolution sleep with specifiable clock.
Copyright (C) 2002-2020 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include <errno.h>
#include <mach.h>
#include <time.h>
#include <unistd.h>
#include <posix-timer.h>
#include <shlib-compat.h>
#include <sysdep-cancel.h>
static int
nanosleep_call (const struct timespec *req, struct timespec *rem)
{
mach_port_t recv;
struct timespec before;
error_t err;
const mach_msg_timeout_t ms
= req->tv_sec * 1000
+ (req->tv_nsec + 999999) / 1000000;
recv = __mach_reply_port ();
if (rem != NULL)
__clock_gettime (CLOCK_REALTIME, &before);
int cancel_oldtype = LIBC_CANCEL_ASYNC();
err = __mach_msg (NULL, MACH_RCV_MSG|MACH_RCV_TIMEOUT|MACH_RCV_INTERRUPT,
0, 0, recv, ms, MACH_PORT_NULL);
LIBC_CANCEL_RESET (cancel_oldtype);
__mach_port_destroy (mach_task_self (), recv);
if (err == EMACH_RCV_INTERRUPTED)
{
if (rem != NULL)
{
struct timespec after, elapsed;
__clock_gettime (CLOCK_REALTIME, &after);
timespec_sub (&elapsed, &after, &before);
timespec_sub (rem, req, &elapsed);
}
return EINTR;
}
return 0;
}
int
__clock_nanosleep (clockid_t clock_id, int flags, const struct timespec *req,
struct timespec *rem)
{
if (clock_id != CLOCK_REALTIME
|| !valid_nanoseconds (req->tv_nsec)
|| (flags != 0 && flags != TIMER_ABSTIME))
return EINVAL;
struct timespec now;
/* If we got an absolute time, remap it. */
if (flags == TIMER_ABSTIME)
{
long int nsec;
long int sec;
/* Make sure we use safe data types. */
assert (sizeof (sec) >= sizeof (now.tv_sec));
/* Get the current time for this clock. */
if (__clock_gettime (clock_id, &now) != 0)
return errno;
/* Compute the difference. */
nsec = req->tv_nsec - now.tv_nsec;
sec = req->tv_sec - now.tv_sec - (nsec < 0);
if (sec < 0)
/* The time has already elapsed. */
return 0;
now.tv_sec = sec;
now.tv_nsec = nsec + (nsec < 0 ? 1000000000 : 0);
/* From now on this is our time. */
req = &now;
/* Make sure we are not modifying the struct pointed to by REM. */
rem = NULL;
}
return nanosleep_call (req, rem);
}
libc_hidden_def (__clock_nanosleep)
versioned_symbol (libc, __clock_nanosleep, clock_nanosleep, GLIBC_2_17);
/* clock_nanosleep moved to libc in version 2.17;
old binaries may expect the symbol version it had in librt. */
#if SHLIB_COMPAT (libc, GLIBC_2_2, GLIBC_2_17)
strong_alias (__clock_nanosleep, __clock_nanosleep_2);
compat_symbol (libc, __clock_nanosleep_2, clock_nanosleep, GLIBC_2_2);
#endif