cosmopolitan/libc/calls/read-nt.c
Justine Tunney 933411ba99 Improve synchronization
- Fix bugs in kDos2Errno definition
- malloc() should now be thread safe
- Fix bug in rollup.com header generator
- Fix open(O_APPEND) on the New Technology
- Fix select() on the New Technology and test it
- Work towards refactoring i/o for thread safety
- Socket reads and writes on NT now poll for signals
- Work towards i/o completion ports on the New Technology
- Make read() and write() intermittently check for signals
- Blinkenlights keyboard i/o so much better on NT w/ poll()
- You can now poll() files and sockets at the same time on NT
- Fix bug in appendr() that manifests with dlmalloc footers off
2022-04-15 15:31:55 -07:00

87 lines
4 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/bits/bits.h"
#include "libc/bits/weaken.h"
#include "libc/calls/internal.h"
#include "libc/calls/sig.internal.h"
#include "libc/calls/strace.internal.h"
#include "libc/calls/struct/iovec.h"
#include "libc/errno.h"
#include "libc/intrin/kprintf.h"
#include "libc/limits.h"
#include "libc/nt/enum/wait.h"
#include "libc/nt/errors.h"
#include "libc/nt/files.h"
#include "libc/nt/ipc.h"
#include "libc/nt/runtime.h"
#include "libc/nt/struct/overlapped.h"
#include "libc/nt/synchronization.h"
#include "libc/sock/internal.h"
#include "libc/sysv/errfuns.h"
static textwindows ssize_t sys_read_nt_impl(struct Fd *fd, void *data,
size_t size, ssize_t offset) {
uint32_t err, got, avail;
struct NtOverlapped overlap;
if (fd->worker) {
for (;;) {
if (!PeekNamedPipe(fd->handle, 0, 0, 0, &avail, 0)) break;
if (avail) break;
if (SleepEx(__SIG_POLLING_INTERVAL_MS, true) == kNtWaitIoCompletion ||
_check_interrupts(true, g_fds.p)) {
return eintr();
}
}
}
if (ReadFile(fd->handle, data, _clampio(size), &got,
_offset2overlap(fd->handle, offset, &overlap))) {
return got;
}
err = GetLastError();
// make sure read() returns 0 on broken pipe
if (err == kNtErrorBrokenPipe) return 0;
// make sure read() returns 0 on closing named pipe
if (err == kNtErrorNoData) return 0;
// make sure pread() returns 0 if we start reading after EOF
if (err == kNtErrorHandleEof) return 0;
return __winerr();
}
textwindows ssize_t sys_read_nt(struct Fd *fd, const struct iovec *iov,
size_t iovlen, ssize_t opt_offset) {
ssize_t rc;
uint32_t size;
size_t i, total;
if (_check_interrupts(true, fd)) return eintr();
while (iovlen && !iov[0].iov_len) iov++, iovlen--;
if (iovlen) {
for (total = i = 0; i < iovlen; ++i) {
if (!iov[i].iov_len) continue;
rc = sys_read_nt_impl(fd, iov[i].iov_base, iov[i].iov_len, opt_offset);
if (rc == -1) return -1;
total += rc;
if (opt_offset != -1) opt_offset += rc;
if (rc < iov[i].iov_len) break;
}
return total;
} else {
return sys_read_nt_impl(fd, NULL, 0, opt_offset);
}
}