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/*
* Copyright © 2015 Intel
* Copyright © 2022 Yonggang Luo
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice (including the next
* paragraph) shall be included in all copies or substantial portions of the
* Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*/
#include "util/futex.h"
#if UTIL_FUTEX_SUPPORTED
#if defined(HAVE_LINUX_FUTEX_H)
#include <limits.h>
#include <stdint.h>
#include <unistd.h>
#include <linux/futex.h>
#include <sys/syscall.h>
#ifndef SYS_futex
#define SYS_futex SYS_futex_time64
#endif
static inline long sys_futex(void *addr1, int op, int val1, const struct timespec *timeout, void *addr2, int val3)
{
return syscall(SYS_futex, addr1, op, val1, timeout, addr2, val3);
}
int futex_wake(uint32_t *addr, int count)
{
return sys_futex(addr, FUTEX_WAKE, count, NULL, NULL, 0);
}
int futex_wait(uint32_t *addr, int32_t value, const struct timespec *timeout)
{
/* FUTEX_WAIT_BITSET with FUTEX_BITSET_MATCH_ANY is equivalent to
* FUTEX_WAIT, except that it treats the timeout as absolute. */
return sys_futex(addr, FUTEX_WAIT_BITSET, value, timeout, NULL,
FUTEX_BITSET_MATCH_ANY);
}
#elif defined(__FreeBSD__)
#include <assert.h>
#include <errno.h>
#include <fcntl.h>
#include <sys/types.h>
#include <sys/umtx.h>
int futex_wake(uint32_t *addr, int count)
{
assert(count == (int)(uint32_t)count); /* Check that bits weren't discarded */
return _umtx_op(addr, UMTX_OP_WAKE, (uint32_t)count, NULL, NULL) == -1 ? errno : 0;
}
int futex_wait(uint32_t *addr, int32_t value, const struct timespec *timeout)
{
void *uaddr = NULL, *uaddr2 = NULL;
struct _umtx_time tmo = {
._flags = UMTX_ABSTIME,
._clockid = CLOCK_MONOTONIC
};
assert(value == (int)(uint32_t)value); /* Check that bits weren't discarded */
if (timeout != NULL) {
tmo._timeout = *timeout;
uaddr = (void *)(uintptr_t)sizeof(tmo);
uaddr2 = (void *)&tmo;
}
return _umtx_op(addr, UMTX_OP_WAIT_UINT, (uint32_t)value, uaddr, uaddr2) == -1 ? errno : 0;
}
#elif defined(__OpenBSD__)
#include <sys/futex.h>
#include <sys/time.h>
int futex_wake(uint32_t *addr, int count)
{
return futex(addr, FUTEX_WAKE, count, NULL, NULL);
}
int futex_wait(uint32_t *addr, int32_t value, const struct timespec *timeout)
{
struct timespec tsnow, tsrel;
if (timeout == NULL)
return futex(addr, FUTEX_WAIT, value, NULL, NULL);
clock_gettime(CLOCK_MONOTONIC, &tsnow);
if (timespeccmp(&tsnow, timeout, <))
timespecsub(timeout, &tsnow, &tsrel);
else
timespecclear(&tsrel);
return futex(addr, FUTEX_WAIT, value, &tsrel, NULL);
}
#elif defined(_WIN32) && !defined(WINDOWS_NO_FUTEX)
#include <windows.h>
#include <stdint.h>
#include <limits.h>
#include <assert.h>
#include <errno.h>
int futex_wake(uint32_t *addr, int count)
{
/* All current callers fall into one of these buckets, and we'll get the semantics
* wrong if someone tries to be more clever.
*/
assert(count == 1 || count == INT32_MAX);
if (count == 1)
WakeByAddressSingle(addr);
else
WakeByAddressAll(addr);
return count;
}
int futex_wait(uint32_t *addr, int32_t value, const struct timespec *timeout)
{
DWORD timeout_ms = INFINITE;
if (timeout != NULL) {
struct timespec tsnow;
timespec_get(&tsnow, TIME_UTC);
timeout_ms = (timeout->tv_sec - tsnow.tv_nsec) * 1000 +
(timeout->tv_nsec - tsnow.tv_nsec) / 1000000;
}
if (WaitOnAddress(addr, &value, sizeof(value), timeout_ms))
return 0;
return GetLastError() == ERROR_TIMEOUT ? ETIMEDOUT : -1;
}
#else
#error UTIL_FUTEX_SUPPORTED is not implemented but the header told it is supported on this platform
#endif
#endif /* UTIL_FUTEX_SUPPORTED */
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