cosmopolitan/libc/calls/posix_fadvise.c
Justine Tunney ebf784d4f5
Make improvements
- Introduce ualarm() function
- Make rename() report EISEMPTY on Windows
- Always raise EINVAL upon open(O_RDONLY|O_TRUNC)
- Add macro so ./configure will detect SOCK_CLOEXEC
- Fix O_TRUNC without O_CREAT not working on Windows
- Let fcntl(F_SETFL) change O_APPEND status on Windows
- Make sure pwrite() / pread() report ESPIPE on sockets
- Raise ESPIPE on Windows when pwrite() is used on pipe
- Properly compute O_APPEND CreateFile() flags on Windows
- Don't require O_DIRECTORY to open directories on Windows
- Fix more instances of Windows reporting EISDIR and ENOTDIR
- Normalize EFTYPE and EMLINK to ELOOP on NetBSD and FreeBSD
- Make unlink() / rmdir() work on read-only files on Windows
- Validate UTF-8 on Windows paths to fix bug with overlong NUL
- Always print signal name to stderr when crashing due to SIG_DFL
- Fix Windows bug where denormalized paths >260 chars didn't work
- Block signals on BSDs when thread exits before trashing its own stack
2023-08-21 02:34:17 -07:00

75 lines
3.6 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/assert.h"
#include "libc/calls/calls.h"
#include "libc/calls/internal.h"
#include "libc/calls/struct/fd.internal.h"
#include "libc/calls/syscall-nt.internal.h"
#include "libc/calls/syscall-sysv.internal.h"
#include "libc/dce.h"
#include "libc/errno.h"
#include "libc/fmt/magnumstrs.internal.h"
#include "libc/intrin/strace.internal.h"
#include "libc/str/str.h"
#include "libc/sysv/errfuns.h"
int sys_fadvise_netbsd(int, int, int64_t, int64_t, int) asm("sys_fadvise");
/**
* 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 until end of file
* @param advice can be POSIX_FADV_SEQUENTIAL, POSIX_FADV_RANDOM, etc.
* @return 0 on success, or errno on error
* @raise EBADF if `fd` isn't a valid file descriptor
* @raise EINVAL if `advice` is invalid or `len` is huge
* @raise ESPIPE if `fd` refers to a pipe
* @raise ENOTSUP if `fd` is a /zip file
* @raise ENOSYS on XNU and OpenBSD
* @returnserrno
* @threadsafe
*/
errno_t posix_fadvise(int fd, int64_t offset, int64_t len, int advice) {
int rc, e = errno;
if (fd < g_fds.n && g_fds.p[fd].kind == kFdZip) {
rc = enotsup();
} else if (IsLinux()) {
rc = sys_fadvise(fd, offset, len, advice);
} else if (IsFreebsd()) {
rc = sys_fadvise(fd, offset, len, advice);
unassert(rc >= 0);
} else if (IsNetbsd()) {
rc = sys_fadvise_netbsd(fd, offset, offset, len, advice);
unassert(rc >= 0);
} else if (IsWindows()) {
rc = sys_fadvise_nt(fd, offset, len, advice);
} else {
rc = enosys();
}
if (rc == -1) {
rc = errno;
errno = e;
}
STRACE("posix_fadvise(%d, %'lu, %'lu, %d) → %s", fd, offset, len, advice,
!rc ? "0" : _strerrno(rc));
return rc;
}