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/********************************************************************************
* *
* S e m a p h o r e Q u e u e *
* *
*********************************************************************************
* Copyright (C) 2006,2022 by Jeroen van der Zijp. All Rights Reserved. *
*********************************************************************************
* This library is free software; you can redistribute it and/or modify *
* it under the terms of the GNU Lesser General Public License as published by *
* the Free Software Foundation; either version 3 of the License, or *
* (at your option) any later version. *
* *
* This library 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 Lesser General Public License for more details. *
* *
* You should have received a copy of the GNU Lesser General Public License *
* along with this program. If not, see <http://www.gnu.org/licenses/> *
********************************************************************************/
#include "xincs.h"
#include "fxdefs.h"
#include "FXSemaphore.h"
#include "FXElement.h"
#include "FXPtrList.h"
#include "FXPtrQueue.h"
#include "FXSemaQueue.h"
/*
Notes:
- Fixed sized, circular buffer protected by semaphores.
- The semaphores synchronize producer and consumer; if multiple
consumers or multiple producers are present then these must be
deconflicted with some other mechanism (e.g. mutex around the
push() or pop() commands).
*/
using namespace FX;
/*******************************************************************************/
namespace FX {
// Create a queue and set its size to sz
FXSemaQueue::FXSemaQueue(FXival sz):queue(sz),free(sz),used(0){
}
// Push object into queue
FXbool FXSemaQueue::push(FXptr obj){
free.wait();
queue.push(obj);
used.post();
return true;
}
// Try push object into queue
FXbool FXSemaQueue::trypush(FXptr obj){
if(free.trywait()){
queue.push(obj);
used.post();
return true;
}
return false;
}
// Try push object into queue, waiting up
// to nsec for space to become available.
FXbool FXSemaQueue::trypush(FXptr obj,FXTime nsec){
if(free.wait(nsec)){
queue.push(obj);
used.post();
return true;
}
return false;
}
// Pop onject from queue
FXbool FXSemaQueue::pop(FXptr& obj){
used.wait();
queue.pop(obj);
free.post();
return true;
}
// Try pop object from queue
FXbool FXSemaQueue::trypop(FXptr& obj){
if(used.trywait()){
queue.pop(obj);
free.post();
return true;
}
return false;
}
// Try pop object from queue, waiting up
// to nsec for object to become available.
FXbool FXSemaQueue::trypop(FXptr& obj,FXTime nsec){
if(used.wait(nsec)){
queue.pop(obj);
free.post();
return true;
}
return false;
}
// Pop onject from queue
FXbool FXSemaQueue::pop(){
used.wait();
queue.pop();
free.post();
return true;
}
// Delete queue
FXSemaQueue::~FXSemaQueue(){
}
}
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