69 lines
1.4 KiB
C++
69 lines
1.4 KiB
C++
|
/*
|
||
|
|
Copyright (C) 2010 Tim Mayberry
|
||
|
|
|
||
|
|
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 "pbd/glib_semaphore.h"
|
||
|
|
|
||
|
|
namespace PBD {
|
||
|
|
|
||
|
|
GlibSemaphore::GlibSemaphore (gint initial_val)
|
||
|
|
:
|
||
|
|
m_counter(initial_val)
|
||
|
|
{ }
|
||
|
|
|
||
|
|
void
|
||
|
|
GlibSemaphore::wait ()
|
||
|
|
{
|
||
|
|
Glib::Threads::Mutex::Lock guard (m_mutex);
|
||
|
|
|
||
|
|
while (m_counter.get() < 1) {
|
||
|
|
m_cond.wait(m_mutex);
|
||
|
|
}
|
||
|
|
|
||
|
|
// this shouldn't need to be inside the lock
|
||
|
|
--m_counter;
|
||
|
|
}
|
||
|
|
|
||
|
|
bool
|
||
|
|
GlibSemaphore::try_wait ()
|
||
|
|
{
|
||
|
|
if (!m_mutex.trylock())
|
||
|
|
{
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
// lock successful
|
||
|
|
while (m_counter.get() < 1) {
|
||
|
|
m_cond.wait(m_mutex);
|
||
|
|
}
|
||
|
|
|
||
|
|
// the order of these should not matter
|
||
|
|
--m_counter;
|
||
|
|
m_mutex.unlock();
|
||
|
|
return true;
|
||
|
|
}
|
||
|
|
|
||
|
|
void
|
||
|
|
GlibSemaphore::post ()
|
||
|
|
{
|
||
|
|
// atomic, no locking required
|
||
|
|
++m_counter;
|
||
|
|
m_cond.signal();
|
||
|
|
}
|
||
|
|
|
||
|
|
} // namespace PBD
|