# -*- coding: utf-8 -*-
# Copyright (c) 2019 The Regents of the University of California.
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# Authors: Jason Lowe-Power, Ayaz Akram

""" Script to run NAS parallel benchmarks with gem5.
    The script expects kernel, diskimage, mem_sys,
    cpu (kvm, atomic, or timing), benchmark to run
    and number of cpus as arguments.

    If your application has ROI annotations, this script will count the total
    number of instructions executed in the ROI. It also tracks how much
    wallclock and simulated time.
"""
import argparse
import errno
import os
import sys
import time
import m5
import m5.ticks
from m5.objects import *

from system import *

def writeBenchScript(dir, bench):
    """
    This method creates a script in dir which will be eventually
    passed to the simulated system (to run a specific benchmark
    at bootup).
    """
    file_name = '{}/run_{}'.format(dir, bench)
    bench_file = open(file_name,"w+")
    bench_file.write('/home/gem5/NPB3.3-OMP/bin/{} \n'.format(bench))

    # sleeping for sometime (5 seconds here) makes sure
    # that the benchmark's output has been
    # printed to the console
    bench_file.write('sleep 5 \n')
    bench_file.write('m5 exit \n')
    bench_file.close()
    return file_name

supported_protocols = ["classic", "MI_example", "MESI_Two_Level",
                        "MOESI_CMP_directory"]
supported_cpu_types = ['kvm', 'atomic', 'timing']
benchmark_choices = ['bt.A.x', 'cg.A.x', 'ep.A.x', 'ft.A.x',
                     'is.A.x', 'lu.A.x', 'mg.A.x', 'sp.A.x',
                     'bt.B.x', 'cg.B.x', 'ep.B.x', 'ft.B.x',
                     'is.B.x', 'lu.B.x', 'mg.B.x', 'sp.B.x',
                     'bt.C.x', 'cg.C.x', 'ep.C.x', 'ft.C.x',
                     'is.C.x', 'lu.C.x', 'mg.C.x', 'sp.C.x',
                     'bt.D.x', 'cg.D.x', 'ep.D.x', 'ft.D.x',
                     'is.D.x', 'lu.D.x', 'mg.D.x', 'sp.D.x',
                     'bt.F.x', 'cg.F.x', 'ep.F.x', 'ft.F.x',
                     'is.F.x', 'lu.F.x', 'mg.F.x', 'sp.F.x']

def parse_options():

    parser = argparse.ArgumentParser(description='For use with gem5. This '
                'runs a NAS Parallel Benchmark application. This only works '
                'with x86 ISA.')

    # The manditry position arguments.
    parser.add_argument("kernel", type=str,
                        help="Path to the kernel binary to boot")
    parser.add_argument("disk", type=str,
                        help="Path to the disk image to boot")
    parser.add_argument("cpu", type=str, choices=supported_cpu_types,
                        help="The type of CPU to use in the system")
    parser.add_argument("mem_sys", type=str, choices=supported_protocols,
                        help="Type of memory system or coherence protocol")
    parser.add_argument("benchmark", type=str, choices=benchmark_choices,
                        help="The NPB application to run")
    parser.add_argument("num_cpus", type=int, help="Number of CPU cores")

    # The optional arguments.
    parser.add_argument("--no_host_parallel", action="store_true",
                        help="Do NOT run gem5 on multiple host threads "
                              "(kvm only)")
    parser.add_argument("--second_disk", type=str,
                        help="The second disk image to mount (/dev/hdb)")
    parser.add_argument("--no_prefetchers", action="store_true",
                        help="Enable prefectchers on the caches")
    parser.add_argument("--l1i_size", type=str, default='32kB',
                        help="L1 instruction cache size. Default: 32kB")
    parser.add_argument("--l1d_size", type=str, default='32kB',
                        help="L1 data cache size. Default: 32kB")
    parser.add_argument("--l2_size", type=str, default = "256kB",
                        help="L2 cache size. Default: 256kB")
    parser.add_argument("--l3_size", type=str, default = "4MB",
                        help="L2 cache size. Default: 4MB")

    return parser.parse_args()

if __name__ == "__m5_main__":
    args = parse_options()


    # create the system we are going to simulate
    system = MySystem(args.kernel, args.disk, args.num_cpus, args,
                      no_kvm=False)


    if args.mem_sys == "classic":
        system = MySystem(args.kernel, args.disk, args.num_cpus, args,
                          no_kvm=False)
    else:
        system = MyRubySystem(args.kernel, args.disk, args.mem_sys,
                              args.num_cpus, args)

    # Exit from guest on workbegin/workend
    system.exit_on_work_items = True

    # Create and pass a script to the simulated system to run the reuired
    # benchmark
    system.readfile = writeBenchScript(m5.options.outdir, args.benchmark)

    # set up the root SimObject and start the simulation
    root = Root(full_system = True, system = system)

    if system.getHostParallel():
        # Required for running kvm on multiple host cores.
        # Uses gem5's parallel event queue feature
        # Note: The simulator is quite picky about this number!
        root.sim_quantum = int(1e9) # 1 ms

    #needed for long running jobs
    m5.disableAllListeners()

    # instantiate all of the objects we've created above
    m5.instantiate()

    globalStart = time.time()

    print("Running the simulation")
    print("Using cpu: {}".format(args.cpu))
    exit_event = m5.simulate()

    if exit_event.getCause() == "workbegin":
        print("Done booting Linux")
        # Reached the start of ROI
        # start of ROI is marked by an
        # m5_work_begin() call
        print("Resetting stats at the start of ROI!")
        m5.stats.reset()
        start_tick = m5.curTick()
        start_insts = system.totalInsts()
        # switching cpu if argument cpu == atomic or timing
        if args.cpu == 'atomic':
            system.switchCpus(system.cpu, system.atomicCpu)
        if args.cpu == 'timing':
            system.switchCpus(system.cpu, system.timingCpu)
    else:
        print("Unexpected termination of simulation !")
        exit()

    # Simulate the ROI
    exit_event = m5.simulate()

    # Reached the end of ROI
    # Finish executing the benchmark

    print("Dump stats at the end of the ROI!")
    m5.stats.dump()
    end_tick = m5.curTick()
    end_insts = system.totalInsts()
    m5.stats.reset()

    # Switching back to KVM does not work
    # with Ruby mem protocols, so not
    # switching back to simulate the remaining
    # part

    if args.mem_sys == 'classic':
        # switch cpu back to kvm if atomic/timing was used for ROI
        if args.cpu == 'atomic':
            system.switchCpus(system.atomicCpu, system.cpu)
        if args.cpu == 'timing':
            system.switchCpus(system.timingCpu, system.cpu)

        # Simulate the remaning part of the benchmark
        exit_event = m5.simulate()
    else:
        print("Ruby Mem: Not Switching back to KVM!")

    print("Done with the simulation")
    print()
    print("Performance statistics:")

    print("Simulated time in ROI: %.2fs" % ((end_tick-start_tick)/1e12))
    print("Instructions executed in ROI: %d" % ((end_insts-start_insts)))
    print("Ran a total of", m5.curTick()/1e12, "simulated seconds")
    print("Total wallclock time: %.2fs, %.2f min" % \
                (time.time()-globalStart, (time.time()-globalStart)/60))