diff options
Diffstat (limited to 'winsup/cygwin/poll.cc')
| -rw-r--r-- | winsup/cygwin/poll.cc | 146 |
1 files changed, 146 insertions, 0 deletions
diff --git a/winsup/cygwin/poll.cc b/winsup/cygwin/poll.cc new file mode 100644 index 00000000000..3ce46fab616 --- /dev/null +++ b/winsup/cygwin/poll.cc @@ -0,0 +1,146 @@ +/* poll.cc. Implements poll(2) via usage of select(2) call. + + Copyright 2000, 2001, 2002, 2003, 2004, 2005 Red Hat, Inc. + + This file is part of Cygwin. + + This software is a copyrighted work licensed under the terms of the + Cygwin license. Please consult the file "CYGWIN_LICENSE" for + details. */ + +#define __INSIDE_CYGWIN_NET__ + +#define FD_SETSIZE 16384 // lots of fds +#include "winsup.h" +#include <sys/time.h> +#include <sys/poll.h> +#include <sys/socket.h> +#include <stdlib.h> +#define USE_SYS_TYPES_FD_SET +#include <winsock2.h> +#include "cygerrno.h" +#include "security.h" +#include "path.h" +#include "fhandler.h" +#include "dtable.h" +#include "cygheap.h" +#include "sigproc.h" + +extern "C" int +poll (struct pollfd *fds, unsigned int nfds, int timeout) +{ + int max_fd = 0; + fd_set *read_fds, *write_fds, *except_fds; + struct timeval tv = { timeout / 1000, (timeout % 1000) * 1000 }; + + for (unsigned int i = 0; i < nfds; ++i) + if (fds[i].fd > max_fd) + max_fd = fds[i].fd; + + size_t fds_size = howmany (max_fd + 1, NFDBITS) * sizeof (fd_mask); + + read_fds = (fd_set *) alloca (fds_size); + write_fds = (fd_set *) alloca (fds_size); + except_fds = (fd_set *) alloca (fds_size); + + if (!read_fds || !write_fds || !except_fds) + { + set_errno (EINVAL); /* According to SUSv3. */ + return -1; + } + + memset (read_fds, 0, fds_size); + memset (write_fds, 0, fds_size); + memset (except_fds, 0, fds_size); + + int invalid_fds = 0; + for (unsigned int i = 0; i < nfds; ++i) + { + fds[i].revents = 0; + if (!cygheap->fdtab.not_open (fds[i].fd)) + { + if (fds[i].events & POLLIN) + FD_SET(fds[i].fd, read_fds); + if (fds[i].events & POLLOUT) + FD_SET(fds[i].fd, write_fds); + /* On sockets, except_fds is needed to catch failed connects. */ + if ((fds[i].events & POLLPRI) + || cygheap->fdtab[fds[i].fd]->is_socket ()) + FD_SET(fds[i].fd, except_fds); + } + else if (fds[i].fd >= 0) + { + ++invalid_fds; + fds[i].revents = POLLNVAL; + } + } + + if (invalid_fds) + return invalid_fds; + + int ret = cygwin_select (max_fd + 1, read_fds, write_fds, except_fds, timeout < 0 ? NULL : &tv); + + if (ret > 0) + for (unsigned int i = 0; i < nfds; ++i) + { + if (fds[i].fd >= 0) + { + if (cygheap->fdtab.not_open (fds[i].fd)) + fds[i].revents = POLLHUP; + else + { + fhandler_socket *sock; + + if (FD_ISSET(fds[i].fd, read_fds)) + { + char peek[1]; + sock = cygheap->fdtab[fds[i].fd]->is_socket (); + if (!sock) + fds[i].revents |= POLLIN; + else if (sock->listener ()) + { + fds[i].revents |= POLLIN; + } + else + { + /* The following action can change errno. We have to + reset it to it's old value. */ + int old_errno = get_errno (); + switch (sock->recvfrom (peek, sizeof (peek), MSG_PEEK, + NULL, NULL)) + { + case -1: + fds[i].revents |= POLLERR; + break; + case 0: /* Closed on the read side... */ + /* ...or shutdown(SHUT_WR) on the write side. + We set revents to POLLHUP until 1.5.18, but + this is semantically borderline. */ + fds[i].revents |= POLLIN; + break; + default: + fds[i].revents |= POLLIN; + break; + } + set_errno (old_errno); + } + } + /* Handle failed connect. */ + if (FD_ISSET(fds[i].fd, write_fds) + && FD_ISSET(fds[i].fd, except_fds) + && (sock = cygheap->fdtab[fds[i].fd]->is_socket ()) + && sock->connect_state () == connect_failed) + fds[i].revents |= (POLLIN | POLLERR); + else + { + if (FD_ISSET(fds[i].fd, write_fds)) + fds[i].revents |= POLLOUT; + if (FD_ISSET(fds[i].fd, except_fds)) + fds[i].revents |= POLLPRI; + } + } + } + } + + return ret; +} |