mirror of
https://github.com/jart/cosmopolitan.git
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3f0bcdc3ef
- Exhaustively document cancellation points - Rename SIGCANCEL to SIGTHR just like BSDs - Further improve POSIX thread cancellations - Ensure asynchronous cancellations work correctly - Elevate the quality of getrandom() and getentropy() - Make futexes cancel correctly on OpenBSD 6.x and 7.x - Add reboot.com and shutdown.com to examples directory - Remove underscore prefix from awesome timespec_*() APIs - Create assertions that help verify our cancellation points - Remove bad timespec APIs (cmp generalizes eq/ne/gt/gte/lt/lte)
95 lines
4.8 KiB
C
95 lines
4.8 KiB
C
/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│
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│vi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi│
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╞══════════════════════════════════════════════════════════════════════════════╡
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│ Copyright 2020 Justine Alexandra Roberts Tunney │
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│ │
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│ Permission to use, copy, modify, and/or distribute this software for │
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│ any purpose with or without fee is hereby granted, provided that the │
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│ above copyright notice and this permission notice appear in all copies. │
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│ │
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│ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │
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│ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │
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│ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │
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│ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │
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│ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │
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│ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │
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│ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │
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│ PERFORMANCE OF THIS SOFTWARE. │
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╚─────────────────────────────────────────────────────────────────────────────*/
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#include "libc/calls/cp.internal.h"
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#include "libc/calls/internal.h"
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#include "libc/calls/struct/iovec.h"
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#include "libc/calls/struct/iovec.internal.h"
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#include "libc/calls/syscall-sysv.internal.h"
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#include "libc/dce.h"
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#include "libc/intrin/asan.internal.h"
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#include "libc/intrin/strace.internal.h"
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#include "libc/intrin/weaken.h"
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#include "libc/sock/sock.h"
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#include "libc/sysv/errfuns.h"
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#include "libc/zipos/zipos.internal.h"
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/**
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* Writes data to file descriptor.
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*
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* This function changes the current file position. For documentation
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* on file position behaviors and gotchas, see the lseek() function.
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* This function may be used on socket file descriptors, including on
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* Windows.
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*
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* @param fd is open file descriptor
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* @param buf is copied from, cf. copy_file_range(), sendfile(), etc.
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* @return [1..size] bytes on success, or -1 w/ errno; noting zero is
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* impossible unless size was passed as zero to do an error check
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* @raise EBADF if `fd` is negative or not an open file descriptor
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* @raise EBADF if `fd` wasn't opened with `O_WRONLY` or `O_RDWR`
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* @raise EPIPE if `fd` is a pipe whose other reader end was closed,
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* after the `SIGPIPE` signal was delivered, blocked, or ignored
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* @raise EFBIG if `RLIMIT_FSIZE` soft limit was exceeded, after the
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* `SIGXFSZ` signal was either delivered, blocked, or ignored
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* @raise EFAULT if `size` is nonzero and `buf` points to bad memory
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* @raise EPERM if pledge() is in play without the stdio promise
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* @raise ENOSPC if device containing `fd` is full
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* @raise EIO if low-level i/o error happened
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* @raise EINTR if signal was delivered instead
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* @raise ECANCELED if thread was cancelled in masked mode
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* @raise EAGAIN if `O_NONBLOCK` is in play and write needs to block
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* @raise ENOBUFS if kernel lacked internal resources; which FreeBSD
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* and XNU say could happen with sockets, and OpenBSD documents it
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* as a general possibility; whereas other system don't specify it
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* @raise ENXIO is specified only by POSIX and XNU when a request is
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* made of a nonexistent device or outside device capabilities
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* @cancellationpoint
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* @asyncsignalsafe
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* @restartable
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* @vforksafe
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*/
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ssize_t write(int fd, const void *buf, size_t size) {
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ssize_t rc;
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BEGIN_CANCELLATION_POINT;
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if (fd >= 0) {
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if ((!buf && size) || (IsAsan() && !__asan_is_valid(buf, size))) {
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rc = efault();
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} else if (fd < g_fds.n && g_fds.p[fd].kind == kFdZip) {
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rc = _weaken(__zipos_write)(
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(struct ZiposHandle *)(intptr_t)g_fds.p[fd].handle,
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&(struct iovec){buf, size}, 1, -1);
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} else if (!IsWindows() && !IsMetal()) {
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rc = sys_write(fd, buf, size);
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} else if (fd >= g_fds.n) {
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rc = ebadf();
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} else if (IsMetal()) {
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rc = sys_writev_metal(g_fds.p + fd, &(struct iovec){buf, size}, 1);
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} else {
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rc = sys_writev_nt(fd, &(struct iovec){buf, size}, 1);
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}
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} else {
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rc = ebadf();
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}
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END_CANCELLATION_POINT;
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DATATRACE("write(%d, %#.*hhs%s, %'zu) → %'zd% m", fd, MAX(0, MIN(40, rc)),
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buf, rc > 40 ? "..." : "", size, rc);
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return rc;
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}
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