mirror of
https://github.com/jart/cosmopolitan.git
synced 2024-05-17 02:52:40 +00:00
2046c0d2ae
- Expand redbean UNIX module - Expand redbean documentation - Ensure Lua copyright is embedded in binary - Increase the PATH_MAX limit especially on NT - Use column major sorting for linenoise completions - Fix some suboptimalities in redbean's new UNIX API - Figured out right flags for Multics newline in raw mode
106 lines
5.1 KiB
C
106 lines
5.1 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"
|
||
#include "libc/errno.h"
|
||
#include "libc/intrin/asan.internal.h"
|
||
#include "libc/intrin/describeflags.internal.h"
|
||
#include "libc/intrin/kprintf.h"
|
||
#include "libc/macros.internal.h"
|
||
#include "libc/sock/internal.h"
|
||
#include "libc/sock/sock.h"
|
||
#include "libc/sysv/errfuns.h"
|
||
|
||
/**
|
||
* Waits for something to happen on multiple file descriptors at once.
|
||
*
|
||
* Warning: XNU has an inconsistency with other platforms. If you have
|
||
* pollfds with fd≥0 and none of the meaningful events flags are added
|
||
* e.g. POLLIN then XNU won't check for POLLNVAL. This matters because
|
||
* one of the use-cases for poll() is quickly checking for open files.
|
||
*
|
||
* Note: Polling works best on Windows for sockets. We're able to poll
|
||
* input on named pipes. But for anything that isn't a socket, or pipe
|
||
* with POLLIN, (e.g. regular file) then POLLIN/POLLOUT are always set
|
||
* into revents if they're requested, provided they were opened with a
|
||
* mode that permits reading and/or writing.
|
||
*
|
||
* Note: Windows has a limit of 64 file descriptors and ENOMEM with -1
|
||
* is returned if that limit is exceeded. In practice the limit is not
|
||
* this low. For example, pollfds with fd<0 don't count. So the caller
|
||
* could flip the sign bit with a short timeout, to poll a larger set.
|
||
*
|
||
* @param fds[𝑖].fd should be a socket, input pipe, or conosle input
|
||
* and if it's a negative number then the entry is ignored
|
||
* @param fds[𝑖].events flags can have POLLIN, POLLOUT, POLLPRI,
|
||
* POLLRDNORM, POLLWRNORM, POLLRDBAND, POLLWRBAND as well as
|
||
* POLLERR, POLLHUP, and POLLNVAL although the latter are
|
||
* always implied (assuming fd≥0) so they're ignored here
|
||
* @param timeout_ms if 0 means don't wait and -1 means wait forever
|
||
* @return number of items fds whose revents field has been set to
|
||
* nonzero to describe its events, or 0 if the timeout elapsed,
|
||
* or -1 w/ errno
|
||
* @return fds[𝑖].revents is always zero initializaed and then will
|
||
* be populated with POLL{IN,OUT,PRI,HUP,ERR,NVAL} if something
|
||
* was determined about the file descriptor
|
||
* @asyncsignalsafe
|
||
* @threadsafe
|
||
* @norestart
|
||
*/
|
||
int poll(struct pollfd *fds, size_t nfds, int timeout_ms) {
|
||
int i, rc;
|
||
uint64_t millis;
|
||
|
||
if (IsAsan() && !__asan_is_valid(fds, nfds * sizeof(struct pollfd))) {
|
||
rc = efault();
|
||
} else if (!IsWindows()) {
|
||
if (!IsMetal()) {
|
||
rc = sys_poll(fds, nfds, timeout_ms);
|
||
} else {
|
||
rc = sys_poll_metal(fds, nfds, timeout_ms);
|
||
}
|
||
} else {
|
||
millis = timeout_ms;
|
||
rc = sys_poll_nt(fds, nfds, &millis);
|
||
}
|
||
|
||
#if defined(SYSDEBUG) && _POLLTRACE
|
||
if (__strace > 0) {
|
||
if (rc == -1 && errno == EFAULT) {
|
||
STRACE("poll(%p, %'lu, %'d) → %d% lm", fds, nfds, timeout_ms, rc);
|
||
} else {
|
||
char flagbuf[2][64];
|
||
kprintf(STRACE_PROLOGUE "poll({");
|
||
for (i = 0; i < MIN(5, nfds); ++i) {
|
||
kprintf(
|
||
"%s{%d, %s, %s}", i ? ", " : "", fds[i].fd,
|
||
DescribePollFlags(flagbuf[0], sizeof(flagbuf[0]), fds[i].events),
|
||
DescribePollFlags(flagbuf[1], sizeof(flagbuf[1]), fds[i].revents));
|
||
}
|
||
kprintf("%s}, %'zu, %'d) → %d% lm\n", i == 5 ? "..." : "", nfds,
|
||
timeout_ms, rc);
|
||
}
|
||
}
|
||
#endif
|
||
|
||
return rc;
|
||
}
|