/*-*- 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/sig.internal.h" #include "libc/calls/state.internal.h" #include "libc/calls/struct/sigaction.h" #include "libc/calls/struct/timespec.h" #include "libc/dce.h" #include "libc/errno.h" #include "libc/intrin/atomic.h" #include "libc/intrin/bits.h" #include "libc/intrin/strace.internal.h" #include "libc/macros.internal.h" #include "libc/mem/mem.h" #include "libc/nt/console.h" #include "libc/nt/enum/filetype.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/pollfd.h" #include "libc/nt/synchronization.h" #include "libc/nt/thread.h" #include "libc/nt/thunk/msabi.h" #include "libc/nt/winsock.h" #include "libc/sock/internal.h" #include "libc/sock/struct/pollfd.h" #include "libc/sock/struct/pollfd.internal.h" #include "libc/sysv/consts/o.h" #include "libc/sysv/consts/poll.h" #include "libc/sysv/consts/sig.h" #include "libc/sysv/errfuns.h" #include "libc/thread/posixthread.internal.h" #include "libc/thread/tls.h" #ifdef __x86_64__ // Polls on the New Technology. // // This function is used to implement poll() and select(). You may poll // on both sockets and files at the same time. We also poll for signals // while poll is polling. textwindows int sys_poll_nt(struct pollfd *fds, uint64_t nfds, uint32_t *ms, const sigset_t *sigmask) { bool ok; uint64_t m; bool interrupted; sigset_t oldmask; uint32_t cm, avail, waitfor; struct sys_pollfd_nt pipefds[8]; struct sys_pollfd_nt sockfds[64]; int pipeindices[ARRAYLEN(pipefds)]; int sockindices[ARRAYLEN(sockfds)]; int i, rc, sn, pn, gotinvals, gotpipes, gotsocks; #if IsModeDbg() struct timespec noearlier = timespec_add(timespec_real(), timespec_frommillis(ms ? *ms : -1u)); #endif // do the planning // we need to read static variables // we might need to spawn threads and open pipes m = atomic_exchange(&__get_tls()->tib_sigmask, -1); __fds_lock(); for (gotinvals = rc = sn = pn = i = 0; i < nfds; ++i) { if (fds[i].fd < 0) continue; if (__isfdopen(fds[i].fd)) { if (__isfdkind(fds[i].fd, kFdSocket)) { if (sn < ARRAYLEN(sockfds)) { // the magnums for POLLIN/OUT/PRI on NT include the other ones too // we need to clear ones like POLLNVAL or else WSAPoll shall whine sockindices[sn] = i; sockfds[sn].handle = g_fds.p[fds[i].fd].handle; sockfds[sn].events = fds[i].events & (POLLPRI | POLLIN | POLLOUT); sockfds[sn].revents = 0; ++sn; } else { // too many socket fds rc = enomem(); break; } } else if (pn < ARRAYLEN(pipefds)) { pipeindices[pn] = i; pipefds[pn].handle = g_fds.p[fds[i].fd].handle; pipefds[pn].events = 0; pipefds[pn].revents = 0; switch (g_fds.p[fds[i].fd].flags & O_ACCMODE) { case O_RDONLY: pipefds[pn].events = fds[i].events & POLLIN; break; case O_WRONLY: pipefds[pn].events = fds[i].events & POLLOUT; break; case O_RDWR: pipefds[pn].events = fds[i].events & (POLLIN | POLLOUT); break; default: __builtin_unreachable(); } ++pn; } else { // too many non-socket fds rc = enomem(); break; } } else { ++gotinvals; } } __fds_unlock(); atomic_store_explicit(&__get_tls()->tib_sigmask, m, memory_order_release); if (rc) { // failed to create a polling solution goto Finished; } // perform the i/o and sleeping and looping for (;;) { // see if input is available on non-sockets for (gotpipes = i = 0; i < pn; ++i) { if (pipefds[i].events & POLLOUT) { // we have no way of polling if a non-socket is writeable yet // therefore we assume that if it can happen, it shall happen pipefds[i].revents |= POLLOUT; } if (pipefds[i].events & POLLIN) { if (GetFileType(pipefds[i].handle) == kNtFileTypePipe) { ok = PeekNamedPipe(pipefds[i].handle, 0, 0, 0, &avail, 0); POLLTRACE("PeekNamedPipe(%ld, 0, 0, 0, [%'u], 0) → %hhhd% m", pipefds[i].handle, avail, ok); if (ok) { if (avail) { pipefds[i].revents |= POLLIN; } } else { pipefds[i].revents |= POLLERR; } } else if (GetConsoleMode(pipefds[i].handle, &cm)) { if (CountConsoleInputBytes(g_fds.p + fds[pipeindices[i]].fd)) { pipefds[i].revents |= POLLIN; } } else { // we have no way of polling if a non-socket is readable yet // therefore we assume that if it can happen it shall happen pipefds[i].revents |= POLLIN; } } if (pipefds[i].revents) { ++gotpipes; } } // if we haven't found any good results yet then here we // compute a small time slice we don't mind sleeping for if (sn) { if ((gotsocks = WSAPoll(sockfds, sn, 0)) == -1) { return __winsockerr(); } } else { gotsocks = 0; } waitfor = MIN(__SIG_POLL_INTERVAL_MS, *ms); if (!gotinvals && !gotsocks && !gotpipes && waitfor) { POLLTRACE("poll() sleeping for %'d out of %'u ms", waitfor, *ms); struct PosixThread *pt = _pthread_self(); pt->abort_errno = 0; if (sigmask) __sig_mask(SIG_SETMASK, sigmask, &oldmask); interrupted = _check_interrupts(0) || __pause_thread(waitfor); if (sigmask) __sig_mask(SIG_SETMASK, &oldmask, 0); if (interrupted) return -1; if (*ms != -1u) { if (waitfor < *ms) { *ms -= waitfor; } else { *ms = 0; } } } // we gave all the sockets and all the named pipes a shot // if we found anything at all then it's time to end work if (gotinvals || gotpipes || gotsocks || !*ms) { break; } } // the system call is going to succeed // it's now ok to start setting the output memory for (i = 0; i < nfds; ++i) { if (fds[i].fd < 0 || __isfdopen(fds[i].fd)) { fds[i].revents = 0; } else { fds[i].revents = POLLNVAL; } } for (i = 0; i < pn; ++i) { fds[pipeindices[i]].revents = pipefds[i].revents; } for (i = 0; i < sn; ++i) { fds[sockindices[i]].revents = sockfds[i].revents; } // and finally return rc = gotinvals + gotpipes + gotsocks; Finished: #if IsModeDbg() struct timespec ended = timespec_real(); if (!rc && timespec_cmp(ended, noearlier) < 0) { STRACE("poll() ended %'ld ns too soon!", timespec_tonanos(timespec_sub(noearlier, ended))); } #endif return rc; } #endif /* __x86_64__ */