boinc/vda/des.h

90 lines
2.3 KiB
C++

// This file is part of BOINC.
// http://boinc.berkeley.edu
// Copyright (C) 2011 University of California
//
// BOINC 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.
//
// BOINC 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 BOINC. If not, see <http://www.gnu.org/licenses/>.
// The world's smallest discrete event simulator.
// Uses the STL "heap" data structure for efficient event storage.
#ifndef _DES_
#define _DES_
#include <vector>
#include <algorithm>
using std::vector;
// base class for events.
// t is the time when the event occurs.
// handle() is the function to call then.
//
struct EVENT {
double t;
virtual void handle(){}
};
inline bool compare(EVENT* e1, EVENT* e2) {
return (e1->t > e2->t);
}
struct SIMULATOR {
vector<EVENT*> events;
double now;
bool done;
// add an event
//
void insert(EVENT* e) {
//printf("adding %x\n", e);
events.push_back(e);
push_heap(events.begin(), events.end(), compare);
}
// remove an event
//
void remove(EVENT* e) {
vector<EVENT*>::iterator i;
//printf("removing %x\n", e);
for (i=events.begin(); i!=events.end(); i++) {
if (*i == e) {
events.erase(i);
make_heap(events.begin(), events.end(), compare);
//printf("removed %x\n", e);
return;
}
}
//printf("%x not found\n", e);
}
// run the simulator for the given time period
//
void simulate(double dur) {
done = false;
while (events.size()) {
EVENT* e = events.front();
pop_heap(events.begin(), events.end(), compare);
events.pop_back();
now = e->t;
if (now > dur) break;
e->handle();
if (done) break;
}
}
};
extern SIMULATOR sim;
#endif