gem5/util/systemc/main.cc
Andrew Bardsley e5e5b80690 config: Fix to SystemC example's event handling
This patch fixes checkpoint restore in the SystemC hosting example by handling
early PollEvent events correctly before any EventQueue events are posted.

The SystemC event queue handler (SCEventQueue) reports an error if the event
loop is entered with no Events posted.  It is possible for this to happen
after instantiate due to PollEvent events.  This patch separates out
`external' events into a different handler in sc_module.cc to prevent the
error from occurring.

This fix also improves the event handling of asynchronous events by:

    1) Making asynchronous events 'catch up' gem5 time to SystemC
        time to avoid the appearance that events have been lost
        while servicing an asynchronous event that schedules an
        event loop exit event

    2) Add an in_simulate data member to Module to allow the event
        loop to check whether events should be processed or deferred
        until the next time Module::simulate is entered

    3) Cancel pending events around the entry/exit of the event loop
        in Module::simulate

    4) Moving the state initialisation of the example entirely into
        run to correct a problem with early events in checkpoint
        restore.

It is still possible to schedule asynchronous events (and talk PollQueue
actions) while simulate is not running.  This behaviour may stil cause
some problems.
2014-12-02 06:08:09 -05:00

382 lines
12 KiB
C++

/*
* Copyright (c) 2014 ARM Limited
* All rights reserved
*
* The license below extends only to copyright in the software and shall
* not be construed as granting a license to any other intellectual
* property including but not limited to intellectual property relating
* to a hardware implementation of the functionality of the software
* licensed hereunder. You may use the software subject to the license
* terms below provided that you ensure that this notice is replicated
* unmodified and in its entirety in all distributions of the software,
* modified or unmodified, in source code or in binary form.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met: redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer;
* 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;
* neither the name of the copyright holders 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 COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS 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 COPYRIGHT
* OWNER 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.
*
* Authors: Andrew Bardsley
*/
/**
* @file
*
* Example top level file for SystemC integration with C++-only
* instantiation.
*
* Build with something like:
*
* scons --without-python build/ARM/libgem5_opt.so
*
* g++ -std=c++0x -Ibuild/ARM -Isrc -DTRACING_ON \
* -o gem5cxx.opt -Lbuild/ARM -lgem5_opt \
* src/sim/sc_main_cxx.cc src/sim/cxx_stats.cc \
* src/sim/sc_module.cc src/sim/sc_logger.cc
*/
#include <cstdlib>
#include <iostream>
#include <sstream>
#include <systemc>
#include "base/statistics.hh"
#include "base/str.hh"
#include "base/trace.hh"
#include "cpu/base.hh"
#include "sim/cxx_config_ini.hh"
#include "sim/cxx_manager.hh"
#include "sim/init_signals.hh"
#include "sim/serialize.hh"
#include "sim/simulate.hh"
#include "sim/stat_control.hh"
#include "sim/system.hh"
#include "sc_logger.hh"
#include "sc_module.hh"
#include "stats.hh"
void
usage(const std::string &prog_name)
{
std::cerr << "Usage: " << prog_name << (
" <config_file.ini> [ <option> ]\n\n"
"OPTIONS:\n"
" -p <object> <param> <value> -- set a parameter\n"
" -v <object> <param> <values> -- set a vector parameter from"
" a comma\n"
" separated values string\n"
" -d <flag> -- set a debug flag (-<flag>\n"
" clear a flag)\n"
" -s <dir> <ticks> -- save checkpoint to dir after"
" the given\n"
" number of ticks\n"
" -r <dir> -- restore checkpoint to dir\n"
" -c <from> <to> <ticks> -- switch from cpu 'from' to cpu"
" 'to' after\n"
" the given number of ticks\n"
"\n"
);
std::exit(EXIT_FAILURE);
}
class SimControl : public Gem5SystemC::Module
{
protected:
int argc;
char **argv;
CxxConfigManager *config_manager;
Gem5SystemC::Logger logger;
bool checkpoint_restore;
bool checkpoint_save;
bool switch_cpus;
std::string checkpoint_dir;
std::string from_cpu;
std::string to_cpu;
Tick pre_run_time;
Tick pre_switch_time;
public:
SC_HAS_PROCESS(SimControl);
SimControl(sc_core::sc_module_name name, int argc_, char **argv_);
void run();
};
SimControl::SimControl(sc_core::sc_module_name name,
int argc_, char **argv_) :
Gem5SystemC::Module(name),
argc(argc_),
argv(argv_)
{
SC_THREAD(run);
std::string prog_name(argv[0]);
unsigned int arg_ptr = 1;
if (argc == 1)
usage(prog_name);
cxxConfigInit();
/* Pass DPRINTF messages to SystemC */
Trace::setDebugLogger(&logger);
/* @todo need this as an option */
Gem5SystemC::setTickFrequency();
/* Make a SystemC-synchronising event queue and install it as the
* sole top level gem5 EventQueue */
Gem5SystemC::Module::setupEventQueues(*this);
if (sc_core::sc_get_time_resolution() !=
sc_core::sc_time(1, sc_core::SC_PS))
{
fatal("Time resolution must be set to 1 ps for gem5 to work");
}
/* Enable keyboard interrupt, async I/O etc. */
initSignals();
/* Enable stats */
Stats::initSimStats();
Stats::registerHandlers(CxxConfig::statsReset, CxxConfig::statsDump);
Trace::enabled = true;
setDebugFlag("Terminal");
checkpoint_restore = false;
checkpoint_save = false;
switch_cpus = false;
checkpoint_dir = "";
from_cpu = "";
to_cpu = "";
pre_run_time = 1000000;
pre_switch_time = 1000000;
const std::string config_file(argv[arg_ptr]);
CxxConfigFileBase *conf = new CxxIniFile();
if (!conf->load(config_file.c_str()))
fatal("Can't open config file: %s", config_file);
arg_ptr++;
config_manager = new CxxConfigManager(*conf);
try {
while (arg_ptr < argc) {
std::string option(argv[arg_ptr]);
arg_ptr++;
unsigned num_args = argc - arg_ptr;
if (option == "-p") {
if (num_args < 3)
usage(prog_name);
config_manager->setParam(argv[arg_ptr], argv[arg_ptr + 1],
argv[arg_ptr + 2]);
arg_ptr += 3;
} else if (option == "-v") {
std::vector<std::string> values;
if (num_args < 3)
usage(prog_name);
tokenize(values, argv[2], ',');
config_manager->setParamVector(argv[arg_ptr],
argv[arg_ptr], values);
arg_ptr += 3;
} else if (option == "-d") {
if (num_args < 1)
usage(prog_name);
if (argv[arg_ptr][0] == '-')
clearDebugFlag(argv[arg_ptr] + 1);
else
setDebugFlag(argv[arg_ptr]);
arg_ptr++;
} else if (option == "-r") {
if (num_args < 1)
usage(prog_name);
checkpoint_dir = argv[arg_ptr];
checkpoint_restore = true;
arg_ptr++;
} else if (option == "-s") {
if (num_args < 2)
usage(prog_name);
checkpoint_dir = argv[arg_ptr];
std::istringstream(argv[arg_ptr + 1]) >> pre_run_time;
checkpoint_save = true;
arg_ptr += 2;
} else if (option == "-c") {
if (num_args < 3)
usage(prog_name);
switch_cpus = true;
from_cpu = argv[arg_ptr];
to_cpu = argv[arg_ptr + 1];
std::istringstream(argv[arg_ptr + 2]) >> pre_switch_time;
arg_ptr += 3;
} else {
usage(prog_name);
}
}
} catch (CxxConfigManager::Exception &e) {
fatal("Config problem in sim object %s: %s", e.name, e.message);
}
CxxConfig::statsEnable();
getEventQueue(0)->dump();
try {
config_manager->instantiate();
} catch (CxxConfigManager::Exception &e) {
fatal("Config problem in sim object %s: %s", e.name, e.message);
}
}
void SimControl::run()
{
EventQueue *eventq = getEventQueue(0);
GlobalSimLoopExitEvent *exit_event = NULL;
/* There *must* be no scheduled events yet */
fatal_if(!eventq->empty(), "There must be no posted events"
" before SimControl::run");
try {
if (checkpoint_restore) {
std::cerr << "Restoring checkpoint\n";
Checkpoint *checkpoint = new Checkpoint(checkpoint_dir,
config_manager->getSimObjectResolver());
/* Catch SystemC up with gem5 after checkpoint restore.
* Note that gem5 leading SystemC is always a violation of the
* required relationship between the two, hence this careful
* catchup */
Tick systemc_time = sc_core::sc_time_stamp().value();
if (curTick() > systemc_time) {
Tick wait_period = curTick() - systemc_time;
std::cerr << "Waiting for " << wait_period << "ps for"
" SystemC to catch up to gem5\n";
wait(sc_core::sc_time(wait_period, sc_core::SC_PS));
}
config_manager->loadState(checkpoint);
config_manager->startup();
config_manager->drainResume();
} else {
config_manager->initState();
config_manager->startup();
}
} catch (CxxConfigManager::Exception &e) {
fatal("Config problem in sim object %s: %s", e.name, e.message);
}
fatal_if(eventq->empty(), "No events to process after system startup");
if (checkpoint_save) {
exit_event = simulate(pre_run_time);
DrainManager drain_manager;
unsigned int drain_count = 1;
do {
drain_count = config_manager->drain(&drain_manager);
std::cerr << "Draining " << drain_count << '\n';
if (drain_count > 0) {
drain_manager.setCount(drain_count);
exit_event = simulate();
}
} while (drain_count > 0);
std::cerr << "Simulation stop at tick " << curTick()
<< ", cause: " << exit_event->getCause() << '\n';
std::cerr << "Checkpointing\n";
/* FIXME, this should really be serialising just for
* config_manager rather than using serializeAll's ugly
* SimObject static object list */
Serializable::serializeAll(checkpoint_dir);
std::cerr << "Completed checkpoint\n";
config_manager->drainResume();
}
if (switch_cpus) {
exit_event = simulate(pre_switch_time);
std::cerr << "Switching CPU\n";
/* Assume the system is called system */
System &system = config_manager->getObject<System>("system");
BaseCPU &old_cpu = config_manager->getObject<BaseCPU>(from_cpu);
BaseCPU &new_cpu = config_manager->getObject<BaseCPU>(to_cpu);
DrainManager drain_manager;
unsigned int drain_count = 1;
do {
drain_count = config_manager->drain(&drain_manager);
std::cerr << "Draining " << drain_count << '\n';
if (drain_count > 0) {
drain_manager.setCount(drain_count);
exit_event = simulate();
}
} while (drain_count > 0);
old_cpu.switchOut();
system.setMemoryMode(Enums::timing);
new_cpu.takeOverFrom(&old_cpu);
config_manager->drainResume();
std::cerr << "Switched CPU\n";
}
exit_event = simulate();
std::cerr << "Exit at tick " << curTick()
<< ", cause: " << exit_event->getCause() << '\n';
getEventQueue(0)->dump();
#if TRY_CLEAN_DELETE
config_manager->deleteObjects();
#endif
}
int
sc_main(int argc, char **argv)
{
SimControl sim_control("gem5", argc, argv);
sc_core::sc_start();
return EXIT_SUCCESS;
}