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Diffstat (limited to '')
-rw-r--r-- | openbsd-compat/bsd-poll.c | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/openbsd-compat/bsd-poll.c b/openbsd-compat/bsd-poll.c new file mode 100644 index 0000000..c8e6222 --- /dev/null +++ b/openbsd-compat/bsd-poll.c @@ -0,0 +1,117 @@ +/* + * Copyright (c) 2004, 2005, 2007 Darren Tucker (dtucker at zip com au). + * + * Permission to use, copy, modify, and 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 "includes.h" +#if !defined(HAVE_POLL) + +#include <sys/types.h> +#include <sys/time.h> +#ifdef HAVE_SYS_SELECT_H +# include <sys/select.h> +#endif + +#include <errno.h> +#include <stdlib.h> +#include <unistd.h> +#include "bsd-poll.h" + +/* + * A minimal implementation of poll(2), built on top of select(2). + * + * Only supports POLLIN and POLLOUT flags in pfd.events, and POLLIN, POLLOUT + * and POLLERR flags in revents. + * + * Supports pfd.fd = -1 meaning "unused" although it's not standard. + */ + +int +poll(struct pollfd *fds, nfds_t nfds, int timeout) +{ + nfds_t i; + int saved_errno, ret, fd, maxfd = 0; + fd_set *readfds = NULL, *writefds = NULL, *exceptfds = NULL; + size_t nmemb; + struct timeval tv, *tvp = NULL; + + for (i = 0; i < nfds; i++) { + fd = fds[i].fd; + if (fd >= FD_SETSIZE) { + errno = EINVAL; + return -1; + } + maxfd = MAX(maxfd, fd); + } + + nmemb = howmany(maxfd + 1 , NFDBITS); + if ((readfds = calloc(nmemb, sizeof(fd_mask))) == NULL || + (writefds = calloc(nmemb, sizeof(fd_mask))) == NULL || + (exceptfds = calloc(nmemb, sizeof(fd_mask))) == NULL) { + saved_errno = ENOMEM; + ret = -1; + goto out; + } + + /* populate event bit vectors for the events we're interested in */ + for (i = 0; i < nfds; i++) { + fd = fds[i].fd; + if (fd == -1) + continue; + if (fds[i].events & POLLIN) { + FD_SET(fd, readfds); + FD_SET(fd, exceptfds); + } + if (fds[i].events & POLLOUT) { + FD_SET(fd, writefds); + FD_SET(fd, exceptfds); + } + } + + /* poll timeout is msec, select is timeval (sec + usec) */ + if (timeout >= 0) { + tv.tv_sec = timeout / 1000; + tv.tv_usec = (timeout % 1000) * 1000; + tvp = &tv; + } + + ret = select(maxfd + 1, readfds, writefds, exceptfds, tvp); + saved_errno = errno; + + /* scan through select results and set poll() flags */ + for (i = 0; i < nfds; i++) { + fd = fds[i].fd; + fds[i].revents = 0; + if (fd == -1) + continue; + if (FD_ISSET(fd, readfds)) { + fds[i].revents |= POLLIN; + } + if (FD_ISSET(fd, writefds)) { + fds[i].revents |= POLLOUT; + } + if (FD_ISSET(fd, exceptfds)) { + fds[i].revents |= POLLERR; + } + } + +out: + free(readfds); + free(writefds); + free(exceptfds); + if (ret == -1) + errno = saved_errno; + return ret; +} +#endif |