/*-*- 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/sigset.internal.h" #include "libc/calls/struct/timespec.h" #include "libc/dce.h" #include "libc/errno.h" #include "libc/intrin/atomic.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/runtime/runtime.h" #include "libc/sock/internal.h" #include "libc/sock/struct/pollfd.h" #include "libc/sock/struct/pollfd.internal.h" #include "libc/stdio/sysparam.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__ #define POLL_INTERVAL_MS 10 // Polls on the New Technology. // // This function is used to implement poll() and select(). You may poll // on sockets, files and the console at the same time. We also poll for // both signals and posix thread cancelation, while the poll is polling static textwindows int sys_poll_nt_impl(struct pollfd *fds, uint64_t nfds, uint32_t *ms, sigset_t sigmask) { bool ok; uint64_t millis; 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)]; struct timespec started, deadline, remain, now; int i, rc, sn, pn, gotinvals, gotpipes, gotsocks; started = timespec_real(); deadline = timespec_add(started, timespec_frommillis(ms ? *ms : -1u)); // do the planning // we need to read static variables // we might need to spawn threads and open pipes __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: break; } ++pn; } else { // too many non-socket fds rc = enomem(); break; } } else { ++gotinvals; } } __fds_unlock(); if (rc) { // failed to create a polling solution return rc; } // 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()) { pipefds[i].revents |= POLLIN; // both >0 and -1 (eof) are 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; } // add some artificial delay, which we use as an opportunity to also // check for pending signals, thread cancelation, etc. waitfor = 0; if (!gotinvals && !gotsocks && !gotpipes) { now = timespec_real(); if (timespec_cmp(now, deadline) < 0) { remain = timespec_sub(deadline, now); millis = timespec_tomillis(remain); waitfor = MIN(millis, 0xffffffffu); waitfor = MIN(waitfor, POLL_INTERVAL_MS); if (waitfor) { POLLTRACE("poll() sleeping for %'d out of %'lu ms", waitfor, timespec_tomillis(remain)); if ((rc = _park_norestart(waitfor, sigmask)) == -1) { return -1; // eintr, ecanceled, etc. } } } } // 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 || !waitfor) { 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 return gotinvals + gotpipes + gotsocks; } textwindows int sys_poll_nt(struct pollfd *fds, uint64_t nfds, uint32_t *ms, const sigset_t *sigmask) { int rc; BLOCK_SIGNALS; rc = sys_poll_nt_impl(fds, nfds, ms, sigmask ? *sigmask : 0); ALLOW_SIGNALS; return rc; } #endif /* __x86_64__ */