simulate.cc revision 4385:5beaa4f8f821 
1/*
2 * Copyright (c) 2006 The Regents of The University of Michigan
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are
7 * met: redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer;
9 * redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution;
12 * neither the name of the copyright holders nor the names of its
13 * contributors may be used to endorse or promote products derived from
14 * this software without specific prior written permission.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
17 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
20 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 *
28 * Authors: Nathan Binkert
29 *          Steve Reinhardt
30 */
31
32#include "base/misc.hh"
33#include "base/pollevent.hh"
34#include "sim/stat_control.hh"
35#include "sim/async.hh"
36#include "sim/eventq.hh"
37#include "sim/host.hh"
38#include "sim/sim_events.hh"
39#include "sim/sim_exit.hh"
40#include "sim/simulate.hh"
41
42/** Simulate for num_cycles additional cycles.  If num_cycles is -1
43 * (the default), do not limit simulation; some other event must
44 * terminate the loop.  Exported to Python via SWIG.
45 * @return The SimLoopExitEvent that caused the loop to exit.
46 */
47SimLoopExitEvent *
48simulate(Tick num_cycles)
49{
50    warn("Entering event queue @ %d.  Starting simulation...\n", curTick);
51
52    if (num_cycles < 0)
53        fatal("simulate: num_cycles must be >= 0 (was %d)\n", num_cycles);
54    else if (curTick + num_cycles < 0)  //Overflow
55        num_cycles = MaxTick;
56    else
57        num_cycles = curTick + num_cycles;
58
59    Event *limit_event;
60    limit_event = schedExitSimLoop("simulate() limit reached", num_cycles);
61
62    while (1) {
63        // there should always be at least one event (the SimLoopExitEvent
64        // we just scheduled) in the queue
65        assert(!mainEventQueue.empty());
66        assert(curTick <= mainEventQueue.nextTick() &&
67               "event scheduled in the past");
68
69        // forward current cycle to the time of the first event on the
70        // queue
71        curTick = mainEventQueue.nextTick();
72        Event *exit_event = mainEventQueue.serviceOne();
73        if (exit_event != NULL) {
74            // hit some kind of exit event; return to Python
75            // event must be subclass of SimLoopExitEvent...
76            SimLoopExitEvent *se_event;
77            se_event = dynamic_cast<SimLoopExitEvent *>(exit_event);
78
79            if (se_event == NULL)
80                panic("Bogus exit event class!");
81
82            // if we didn't hit limit_event, delete it
83            if (se_event != limit_event) {
84                assert(limit_event->scheduled());
85                limit_event->deschedule();
86                delete limit_event;
87            }
88
89            return se_event;
90        }
91
92        if (async_event) {
93            async_event = false;
94            if (async_statdump || async_statreset) {
95                Stats::StatEvent(async_statdump, async_statreset);
96                async_statdump = false;
97                async_statreset = false;
98            }
99
100            if (async_exit) {
101                async_exit = false;
102                exitSimLoop("user interrupt received");
103            }
104
105            if (async_io || async_alarm) {
106                async_io = false;
107                async_alarm = false;
108                pollQueue.service();
109            }
110
111            if (async_exception) {
112                async_exception = false;
113                return NULL;
114            }
115        }
116    }
117
118    // not reached... only exit is return on SimLoopExitEvent
119}
120
121