Files
UltraGrid/src/utils/message_queue.cpp
2013-08-22 18:19:33 +02:00

95 lines
3.0 KiB
C++

/**
* @file utils/message_queue.cpp
* @author Martin Pulec <pulec@cesnet.cz>
*/
/*
* Copyright (c) 2013 CESNET z.s.p.o.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, is permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* 3. Neither the name of CESNET nor the names of its contributors may be
* used to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING,
* BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
* AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
* EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
* EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#include "config_unix.h"
#include "config_win32.h"
#include "utils/lock_guard.h"
#include "utils/message_queue.h"
message_queue::message_queue(int max_len) :
m_max_len(max_len)
{
pthread_mutex_init(&m_lock, NULL);
pthread_cond_init(&m_queue_incremented, NULL);
pthread_cond_init(&m_queue_decremented, NULL);
}
message_queue::~message_queue()
{
pthread_mutex_destroy(&m_lock);
pthread_cond_destroy(&m_queue_incremented);
pthread_cond_destroy(&m_queue_decremented);
}
int message_queue::size()
{
lock_guard guard(m_lock);
return m_queue.size();
}
void message_queue::push(msg *message)
{
lock_guard guard(m_lock);
if (m_max_len != -1) {
while (m_queue.size() >= (unsigned int) m_max_len) {
pthread_cond_wait(&m_queue_decremented, &m_lock);
}
}
m_queue.push(message);
pthread_cond_signal(&m_queue_incremented);
}
msg *message_queue::pop(bool nonblocking)
{
lock_guard guard(m_lock);
if (m_queue.size() == 0 && nonblocking) {
return NULL;
}
while (m_queue.size() == 0) {
pthread_cond_wait(&m_queue_incremented, &m_lock);
}
msg *ret = m_queue.front();
m_queue.pop();
pthread_cond_signal(&m_queue_decremented);
return ret;
}