aboutsummaryrefslogtreecommitdiff
path: root/lib/select.c
diff options
context:
space:
mode:
authorDaniel Stenberg <daniel@haxx.se>2004-11-19 08:52:33 +0000
committerDaniel Stenberg <daniel@haxx.se>2004-11-19 08:52:33 +0000
commit1a05a90f1ce86394d7966aaaa9539adaa228c6bf (patch)
tree2b9cafe58b4fa7bf01d1b58a23bc5e66157d3279 /lib/select.c
parentdcea109bb5ce1c8afeb0510945eb15e86cfcf1dc (diff)
David Phillips' FD_SETSIZE fix
Diffstat (limited to 'lib/select.c')
-rw-r--r--lib/select.c231
1 files changed, 231 insertions, 0 deletions
diff --git a/lib/select.c b/lib/select.c
new file mode 100644
index 000000000..fb337d421
--- /dev/null
+++ b/lib/select.c
@@ -0,0 +1,231 @@
+/***************************************************************************
+ * _ _ ____ _
+ * Project ___| | | | _ \| |
+ * / __| | | | |_) | |
+ * | (__| |_| | _ <| |___
+ * \___|\___/|_| \_\_____|
+ *
+ * Copyright (C) 1998 - 2004, Daniel Stenberg, <daniel@haxx.se>, et al.
+ *
+ * This software is licensed as described in the file COPYING, which
+ * you should have received as part of this distribution. The terms
+ * are also available at http://curl.haxx.se/docs/copyright.html.
+ *
+ * You may opt to use, copy, modify, merge, publish, distribute and/or sell
+ * copies of the Software, and permit persons to whom the Software is
+ * furnished to do so, under the terms of the COPYING file.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ * $Id$
+ ***************************************************************************/
+
+#include "setup.h"
+
+#ifdef HAVE_SYS_SELECT_H
+#include <sys/select.h>
+#endif
+
+#ifndef HAVE_SELECT
+#error "We can't compile without select() support!"
+#endif
+
+#include "select.h"
+
+/*
+ * This is an internal function used for waiting for read or write
+ * events on single file descriptors. It attempts to replace select()
+ * in order to avoid limits with FD_SETSIZE.
+ *
+ * Return values:
+ * -1 = system call error
+ * 0 = timeout
+ * CSELECT_IN | CSELECT_OUT | CSELECT_ERR
+ */
+int Curl_select(int readfd, int writefd, int timeout_ms)
+{
+#ifdef HAVE_POLL_FINE
+ struct pollfd pfd[2];
+ int num;
+ int r;
+ int ret;
+
+ num = 0;
+ if (readfd != CURL_SOCKET_BAD) {
+ pfd[num].fd = readfd;
+ pfd[num].events = POLLIN;
+ num++;
+ }
+ if (writefd != CURL_SOCKET_BAD) {
+ pfd[num].fd = writefd;
+ pfd[num].events = POLLOUT;
+ num++;
+ }
+
+ r = poll(pfd, num, timeout_ms);
+
+ if (r < 0)
+ return -1;
+ if (r == 0)
+ return 0;
+
+ ret = 0;
+ num = 0;
+ if (readfd != CURL_SOCKET_BAD) {
+ if (pfd[num].revents & POLLIN)
+ ret |= CSELECT_IN;
+ if (pfd[num].revents & POLLERR)
+ ret |= CSELECT_ERR;
+ num++;
+ }
+ if (writefd != CURL_SOCKET_BAD) {
+ if (pfd[num].revents & POLLOUT)
+ ret |= CSELECT_OUT;
+ if (pfd[num].revents & POLLERR)
+ ret |= CSELECT_ERR;
+ }
+
+ return ret;
+#else
+ struct timeval timeout;
+ fd_set fds_read;
+ fd_set fds_write;
+ fd_set fds_err;
+ int maxfd;
+ int r;
+ int ret;
+
+ timeout.tv_sec = timeout_ms / 1000;
+ timeout.tv_usec = (timeout_ms % 1000) * 1000;
+
+ FD_ZERO(&fds_err);
+ maxfd = -1;
+
+ FD_ZERO(&fds_read);
+ if (readfd != CURL_SOCKET_BAD) {
+ if ((readfd < 0) || (readfd >= FD_SETSIZE)) {
+ errno = EINVAL;
+ return -1;
+ }
+ FD_SET(readfd, &fds_read);
+ FD_SET(readfd, &fds_err);
+ maxfd = readfd;
+ }
+
+ FD_ZERO(&fds_write);
+ if (writefd != CURL_SOCKET_BAD) {
+ if ((writefd < 0) || (writefd >= FD_SETSIZE)) {
+ errno = EINVAL;
+ return -1;
+ }
+ FD_SET(writefd, &fds_write);
+ FD_SET(writefd, &fds_err);
+ if (writefd > maxfd)
+ maxfd = writefd;
+ }
+
+ r = select(maxfd + 1, &fds_read, &fds_write, &fds_err, &timeout);
+
+ if (r < 0)
+ return -1;
+ if (r == 0)
+ return 0;
+
+ ret = 0;
+ if (readfd != CURL_SOCKET_BAD) {
+ if (FD_ISSET(readfd, &fds_read))
+ ret |= CSELECT_IN;
+ if (FD_ISSET(readfd, &fds_err))
+ ret |= CSELECT_ERR;
+ }
+ if (writefd != CURL_SOCKET_BAD) {
+ if (FD_ISSET(writefd, &fds_write))
+ ret |= CSELECT_OUT;
+ if (FD_ISSET(writefd, &fds_err))
+ ret |= CSELECT_ERR;
+ }
+
+ return ret;
+#endif
+}
+
+/*
+ * This is a wrapper around poll(). If poll() does not exist, then
+ * select() is used instead. An error is returned if select() is
+ * being used and a file descriptor too large for FD_SETSIZE.
+ *
+ * Return values:
+ * -1 = system call error or fd >= FD_SETSIZE
+ * 0 = timeout
+ * 1 = number of structures with non zero revent fields
+ */
+int Curl_poll(struct pollfd ufds[], unsigned int nfds, int timeout_ms)
+{
+#ifdef HAVE_POLL_FINE
+ return poll(ufds, nfds, timeout_ms);
+#else
+ struct timeval timeout;
+ struct timeval *ptimeout;
+ fd_set fds_read;
+ fd_set fds_write;
+ fd_set fds_err;
+ int maxfd;
+ int r;
+ unsigned int i;
+
+ FD_ZERO(&fds_read);
+ FD_ZERO(&fds_write);
+ FD_ZERO(&fds_err);
+ maxfd = -1;
+
+ for (i = 0; i < nfds; i++) {
+ if (ufds[i].fd < 0)
+ continue;
+ if (ufds[i].fd >= FD_SETSIZE) {
+ errno = EINVAL;
+ return -1;
+ }
+ if (ufds[i].fd > maxfd)
+ maxfd = ufds[i].fd;
+ if (ufds[i].events & POLLIN)
+ FD_SET(ufds[i].fd, &fds_read);
+ if (ufds[i].events & POLLOUT)
+ FD_SET(ufds[i].fd, &fds_write);
+ if (ufds[i].events & POLLERR)
+ FD_SET(ufds[i].fd, &fds_err);
+ }
+
+ if (timeout_ms < 0) {
+ ptimeout = NULL; /* wait forever */
+ } else {
+ timeout.tv_sec = timeout_ms / 1000;
+ timeout.tv_usec = (timeout_ms % 1000) * 1000;
+ ptimeout = &timeout;
+ }
+
+ r = select(maxfd + 1, &fds_read, &fds_write, &fds_err, ptimeout);
+
+ if (r < 0)
+ return -1;
+ if (r == 0)
+ return 0;
+
+ r = 0;
+ for (i = 0; i < nfds; i++) {
+ ufds[i].revents = 0;
+ if (ufds[i].fd < 0)
+ continue;
+ if (FD_ISSET(ufds[i].fd, &fds_read))
+ ufds[i].revents |= POLLIN;
+ if (FD_ISSET(ufds[i].fd, &fds_write))
+ ufds[i].revents |= POLLOUT;
+ if (FD_ISSET(ufds[i].fd, &fds_err))
+ ufds[i].revents |= POLLERR;
+ if (ufds[i].revents != 0)
+ r++;
+ }
+
+ return r;
+#endif
+}