Return from poll_for_request() when CrossThreadChannel is
closed/destroyed. -- see also f4166fb61d
This also cleans up poll API usage, and check for nonnegative
return value is added.
139 lines
3.0 KiB
C++
139 lines
3.0 KiB
C++
/*
|
|
* Copyright (C) 2014-2016 Paul Davis <paul@linuxaudiosystems.com>
|
|
* Copyright (C) 2015-2022 Robin Gareus <robin@gareus.org>
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License along
|
|
* with this program; if not, write to the Free Software Foundation, Inc.,
|
|
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
|
|
*/
|
|
|
|
#include <poll.h>
|
|
|
|
CrossThreadChannel::CrossThreadChannel (bool non_blocking)
|
|
: receive_channel (0)
|
|
, receive_source (0)
|
|
{
|
|
fds[0] = -1;
|
|
fds[1] = -1;
|
|
|
|
if (pipe (fds)) {
|
|
error << "cannot create x-thread pipe for read (%2)" << ::strerror (errno) << endmsg;
|
|
return;
|
|
}
|
|
|
|
if (non_blocking) {
|
|
if (fcntl (fds[0], F_SETFL, O_NONBLOCK)) {
|
|
error << "cannot set non-blocking mode for x-thread pipe (read) (" << ::strerror (errno) << ')' << endmsg;
|
|
return;
|
|
}
|
|
|
|
if (fcntl (fds[1], F_SETFL, O_NONBLOCK)) {
|
|
error << "cannot set non-blocking mode for x-thread pipe (write) (%2)" << ::strerror (errno) << ')' << endmsg;
|
|
return;
|
|
}
|
|
}
|
|
|
|
receive_channel = g_io_channel_unix_new (fds[0]);
|
|
}
|
|
|
|
CrossThreadChannel::~CrossThreadChannel ()
|
|
{
|
|
if (receive_source) {
|
|
/* this disconnects it from any main context it was attached in
|
|
in ::attach(), this prevent its callback from being invoked
|
|
after the destructor has finished.
|
|
*/
|
|
g_source_destroy (receive_source);
|
|
}
|
|
|
|
if (receive_channel) {
|
|
g_io_channel_unref (receive_channel);
|
|
receive_channel = 0;
|
|
}
|
|
|
|
if (fds[0] >= 0) {
|
|
close (fds[0]);
|
|
fds[0] = -1;
|
|
}
|
|
|
|
if (fds[1] >= 0) {
|
|
close (fds[1]);
|
|
fds[1] = -1;
|
|
}
|
|
}
|
|
|
|
void
|
|
CrossThreadChannel::wakeup ()
|
|
{
|
|
char c = 0;
|
|
(void) ::write (fds[1], &c, 1);
|
|
}
|
|
|
|
void
|
|
CrossThreadChannel::drain ()
|
|
{
|
|
char buf[64];
|
|
while (::read (fds[0], buf, sizeof (buf)) > 0) {};
|
|
}
|
|
|
|
int
|
|
CrossThreadChannel::deliver (char msg)
|
|
{
|
|
return ::write (fds[1], &msg, 1);
|
|
}
|
|
|
|
bool
|
|
CrossThreadChannel::poll_for_request()
|
|
{
|
|
struct pollfd pfd;
|
|
pfd.fd = fds[0];
|
|
pfd.events = POLLIN|POLLERR|POLLHUP|POLLNVAL;
|
|
while(true) {
|
|
#ifdef __APPLE__
|
|
/* on macOS poll() will not return when the pipe
|
|
* is closed in an EOF state. ork around with a timeout.
|
|
*/
|
|
int rv = poll (&pfd, 1, 1000);
|
|
#else
|
|
int rv = poll (&pfd, 1, -1);
|
|
#endif
|
|
if (rv == -1) {
|
|
/* error */
|
|
if (errno == EINTR) {
|
|
continue;
|
|
}
|
|
break;
|
|
}
|
|
|
|
if (pfd.revents & ~POLLIN) {
|
|
break;
|
|
}
|
|
|
|
if (rv > 0 && pfd.revents & POLLIN) {
|
|
return true;
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
int
|
|
CrossThreadChannel::receive (char& msg, bool wait)
|
|
{
|
|
if (wait) {
|
|
if (!poll_for_request ()) {
|
|
return -1;
|
|
}
|
|
}
|
|
return ::read (fds[0], &msg, 1);
|
|
}
|