mirror of
https://github.com/jart/cosmopolitan.git
synced 2024-05-17 02:52:40 +00:00
2ab9e9f7fd
- Introduce portable sched_getcpu() api - Support GCC's __target_clones__ feature - Make fma() go faster on x86 in default mode - Remove some asan checks from core libraries - WinMain() now ensures $HOME and $USER are defined
110 lines
4.3 KiB
C
110 lines
4.3 KiB
C
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
|
|
│ vi: set et 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/state.internal.h"
|
|
#include "libc/calls/struct/fd.internal.h"
|
|
#include "libc/calls/struct/sigset.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/intrin/kprintf.h"
|
|
#include "libc/intrin/strace.internal.h"
|
|
#include "libc/intrin/weaken.h"
|
|
#include "libc/runtime/zipos.internal.h"
|
|
#include "libc/sock/syscall_fd.internal.h"
|
|
#include "libc/sysv/errfuns.h"
|
|
|
|
// for performance reasons we want to avoid holding __fds_lock()
|
|
// while sys_close() is happening. this leaves the kernel / libc
|
|
// having a temporarily inconsistent state. routines that obtain
|
|
// file descriptors the way __zipos_open() does need to retry if
|
|
// there's indication this race condition happened.
|
|
|
|
static int close_impl(int fd) {
|
|
|
|
if (fd < 0) {
|
|
return ebadf();
|
|
}
|
|
|
|
// give kprintf() the opportunity to dup() stderr
|
|
if (fd == 2 && _weaken(kloghandle)) {
|
|
_weaken(kloghandle)();
|
|
}
|
|
|
|
if (__isfdkind(fd, kFdZip)) {
|
|
unassert(_weaken(__zipos_close));
|
|
return _weaken(__zipos_close)(fd);
|
|
}
|
|
|
|
if (!IsWindows() && !IsMetal()) {
|
|
return sys_close(fd);
|
|
}
|
|
|
|
if (IsWindows()) {
|
|
return sys_close_nt(fd, fd);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
/**
|
|
* Closes file descriptor.
|
|
*
|
|
* This function releases resources returned by functions such as:
|
|
*
|
|
* - openat()
|
|
* - socket()
|
|
* - accept()
|
|
* - epoll_create()
|
|
* - landlock_create_ruleset()
|
|
*
|
|
* This function should never be reattempted if an error is returned;
|
|
* however, that doesn't mean the error should be ignored. This goes
|
|
* against the conventional wisdom of looping on `EINTR`.
|
|
*
|
|
* @return 0 on success, or -1 w/ errno
|
|
* @raise EINTR if signal was delivered; do *not* retry
|
|
* @raise EBADF if `fd` is negative or not open; however, an exception
|
|
* is made by Cosmopolitan Libc for `close(-1)` which returns zero
|
|
* and does nothing, in order to assist with code that may wish to
|
|
* close the same resource multiple times without dirtying `errno`
|
|
* @raise EIO if a low-level i/o error occurred
|
|
* @asyncsignalsafe
|
|
* @vforksafe
|
|
*/
|
|
int close(int fd) {
|
|
int rc;
|
|
if (__isfdkind(fd, kFdZip)) { // XXX IsWindows()?
|
|
BLOCK_SIGNALS;
|
|
__fds_lock();
|
|
rc = close_impl(fd);
|
|
if (!__vforked) __releasefd(fd);
|
|
__fds_unlock();
|
|
ALLOW_SIGNALS;
|
|
} else {
|
|
rc = close_impl(fd);
|
|
if (!__vforked) __releasefd(fd);
|
|
}
|
|
STRACE("close(%d) → %d% m", fd, rc);
|
|
return rc;
|
|
}
|