mirror of
https://github.com/jart/cosmopolitan.git
synced 2025-01-31 19:43:32 +00:00
4f98ad1054
- Improve i/o perf on New Technology - Code cleanup on read() for New Technology - Fix bad bug with dup() of socket on New Technology - Clean up some more strace errors on New Technology
43 lines
2.6 KiB
C
43 lines
2.6 KiB
C
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
|
||
│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
|
||
╞══════════════════════════════════════════════════════════════════════════════╡
|
||
│ Copyright 2020 Justine Alexandra Roberts Tunney │
|
||
│ │
|
||
│ Permission to use, copy, modify, and/or distribute this software for │
|
||
│ any purpose with or without fee is hereby granted, provided that the │
|
||
│ above copyright notice and this permission notice appear in all copies. │
|
||
│ │
|
||
│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
|
||
│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
|
||
│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
|
||
│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
|
||
│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
|
||
│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
|
||
│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
|
||
│ PERFORMANCE OF THIS SOFTWARE. │
|
||
╚─────────────────────────────────────────────────────────────────────────────*/
|
||
#include "libc/calls/calls.h"
|
||
#include "libc/calls/internal.h"
|
||
#include "libc/calls/strace.internal.h"
|
||
#include "libc/dce.h"
|
||
|
||
/**
|
||
* Drops hints to O/S about intended I/O behavior.
|
||
*
|
||
* It makes a huge difference. For example, when copying a large file,
|
||
* it can stop the system from persisting GBs of useless memory content.
|
||
*
|
||
* @param len 0 means ‘til end of file
|
||
* @param advice can be MADV_SEQUENTIAL, MADV_RANDOM, etc.
|
||
* @return -1 on error
|
||
*/
|
||
int fadvise(int fd, uint64_t offset, uint64_t len, int advice) {
|
||
int rc;
|
||
if (!IsWindows()) {
|
||
rc = sys_fadvise(fd, offset, len, advice); /* linux & freebsd */
|
||
} else {
|
||
rc = sys_fadvise_nt(fd, offset, len, advice);
|
||
}
|
||
STRACE("fadvise(%d, %'lu, %'lu, %d) → %d% m", fd, offset, len, advice, rc);
|
||
return rc;
|
||
}
|