6a39e4f5f5
Renamed directory "dev" to "dev_tools". Replaced the ecasound-2.7.2 with a new download of ecasound. The reason is that the previous ecasound directory had all the Makefiles checked in with hardcoded paths from Naomi's computer. This prevented anyone else from being able to build. I copied over the modified version of ecacontrol.py.
125 lines
3.3 KiB
C++
125 lines
3.3 KiB
C++
// ------------------------------------------------------------------------
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// kvu_fd_io.cpp: Helper functions for reading from, writing to and
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// waiting on UNIX file descriptors.
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//
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// Copyright (C) 2002 Kai Vehmanen
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//
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// This program is free software; you can redistribute it and/or modify
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// it under the terms of the GNU General Public License as published by
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// the Free Software Foundation; either version 2 of the License, or
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// (at your option) any later version.
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//
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// This program is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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//
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// You should have received a copy of the GNU General Public License
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// along with this program; if not, write to the Free Software
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// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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// ------------------------------------------------------------------------
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#include <unistd.h> /* POSIX: read()/write() */
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#include <sys/poll.h> /* XPG4-UNIX: poll() */
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#include "kvu_fd_io.h"
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/**
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* Attempts to read up to 'count' bytes from file descriptor 'fd'
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* into the buffer starting at 'buf'. If no data is available
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* for reading, up to 'timeout' milliseconds will be waited.
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* A negative value means infinite timeout.
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*/
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ssize_t kvu_fd_read(int fd, void *buf, size_t count, int timeout)
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{
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int nfds = 1;
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struct pollfd ufds;
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ssize_t rescount = 0;
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ufds.fd = fd;
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ufds.events = POLLIN | POLLPRI;
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ufds.revents = 0;
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int ret = poll(&ufds, nfds, timeout);
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if (ret > 0) {
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if (ufds.revents & POLLIN ||
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ufds.revents & POLLPRI) {
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rescount = ::read(fd, buf, count);
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}
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}
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else if (ret == 0) {
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/* timeout */
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rescount = -1;
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}
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return(rescount);
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}
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/**
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* Attempts to write up to 'count' bytes to file descriptor 'fd'
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* from the buffer starting at 'buf'. If no space is available
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* for writing, up to 'timeout' milliseconds will be waited.
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* A negative value means infinite timeout.
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*/
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ssize_t kvu_fd_write(int fd, const void *buf, size_t count, int timeout)
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{
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int nfds = 1;
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struct pollfd ufds;
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ssize_t rescount = 0;
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ufds.fd = fd;
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ufds.events = POLLOUT;
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ufds.revents = 0;
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int ret = poll(&ufds, nfds, timeout);
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if (ret > 0) {
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if (ufds.revents & POLLOUT) {
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rescount = ::write(fd, buf, count);
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}
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}
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else if (ret == 0) {
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/* timeout */
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rescount = -1;
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}
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return(rescount);
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}
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/**
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* Blocks until state of file descriptor 'fd'
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* changes. State changes include 'fd' becoming
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* readable, writing or an error condition.
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* A maximum of 'timeout' milliseconds will be
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* waited. A negative value means infinite timeout.
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*
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* @return returns 1 for success, 0 for timeout
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* and -1 on error
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*/
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int kvu_fd_wait(int fd, int timeout)
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{
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int nfds = 1;
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struct pollfd ufds;
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ufds.fd = fd;
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ufds.events = POLLIN | POLLPRI | POLLOUT;
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ufds.revents = 0;
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int ret = poll(&ufds, nfds, timeout);
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if (ret > 0) {
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if (ufds.revents & POLLERR ||
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ufds.revents & POLLHUP ||
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ufds.revents & POLLNVAL) {
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/* error */
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return(-1);
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}
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else {
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/* success */
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return(1);
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}
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}
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else if (ret == 0) {
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/* timeout */
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return(0);
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}
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/* error */
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return(-1);
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}
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