13
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livetrax/libs/pbd/crossthread.cc

123 lines
2.5 KiB
C++

/*
Copyright (C) 2009 Paul Davis
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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <cstdlib>
#include <cerrno>
#include <cstring>
#include <fcntl.h>
#include <unistd.h>
#include "pbd/error.h"
#include "pbd/crossthread.h"
using namespace std;
using namespace PBD;
using namespace Glib;
CrossThreadChannel::CrossThreadChannel (bool non_blocking)
{
_ios = 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;
}
}
fcntl(fds[0], F_SETFD, fcntl(fds[0], F_GETFD) | FD_CLOEXEC);
fcntl(fds[1], F_SETFD, fcntl(fds[1], F_GETFD) | FD_CLOEXEC);
}
CrossThreadChannel::~CrossThreadChannel ()
{
/* glibmm hack */
drop_ios ();
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);
}
RefPtr<IOSource>
CrossThreadChannel::ios ()
{
if (!_ios) {
_ios = new RefPtr<IOSource> (IOSource::create (fds[0], IOCondition(IO_IN|IO_PRI|IO_ERR|IO_HUP|IO_NVAL)));
}
return *_ios;
}
void
CrossThreadChannel::drop_ios ()
{
delete _ios;
_ios = 0;
}
void
CrossThreadChannel::drain ()
{
drain (fds[0]);
}
void
CrossThreadChannel::drain (int fd)
{
/* drain selectable fd */
char buf[64];
while (::read (fd, buf, sizeof (buf)) > 0) {};
}
int
CrossThreadChannel::deliver (char msg)
{
return ::write (fds[1], &msg, 1);
}
int
CrossThreadChannel::receive (char& msg)
{
return ::read (fds[0], &msg, 1);
}