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weston/libweston/linux-sync-file.c

82 lines
2.4 KiB

/*
* Copyright © 2018 Collabora, Ltd
*
* 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 "config.h"
#include <assert.h>
#include <errno.h>
#include <poll.h>
#include <stddef.h>
#include <sys/ioctl.h>
#ifdef HAVE_LINUX_SYNC_FILE_H
#include <linux/sync_file.h>
#else
#include "linux-sync-file-uapi.h"
#endif
#include "linux-sync-file.h"
#include "shared/timespec-util.h"
/* Check that a file descriptor represents a valid sync file
*
* \param fd[in] a file descriptor
* \return true if fd is a valid sync file, false otherwise
*/
bool
linux_sync_file_is_valid(int fd)
{
struct sync_file_info file_info = { { 0 } };
if (ioctl(fd, SYNC_IOC_FILE_INFO, &file_info) < 0)
return false;
return file_info.num_fences > 0;
}
/* Read the timestamp stored in a sync file
*
* \param fd[in] fd a file descriptor for a sync file
* \param ts[out] the timespec struct to fill with the timestamp
* \return 0 if a timestamp was read, -1 on error
*/
int
linux_sync_file_read_timestamp(int fd, struct timespec *ts)
{
struct sync_file_info file_info = { { 0 } };
struct sync_fence_info fence_info = { { 0 } };
assert(ts != NULL);
file_info.sync_fence_info = (uint64_t)(uintptr_t)&fence_info;
file_info.num_fences = 1;
if (ioctl(fd, SYNC_IOC_FILE_INFO, &file_info) < 0)
return -1;
timespec_from_nsec(ts, fence_info.timestamp_ns);
return 0;
}