gem5/src/dev/multi_packet.hh
Gabor Dozsa fc5bf6713f dev: add support for multi gem5 runs
Multi gem5 is an extension to gem5 to enable parallel simulation of a
distributed system (e.g. simulation of a pool of machines
connected by Ethernet links). A multi gem5 run consists of seperate gem5
processes running in parallel (potentially on different hosts/slots on
a cluster). Each gem5 process executes the simulation of a component of the
simulated distributed system (e.g. a multi-core board with an Ethernet NIC).

The patch implements the "distributed" Ethernet link device
(dev/src/multi_etherlink.[hh.cc]). This device will send/receive
(simulated) Ethernet packets to/from peer gem5 processes. The interface
to talk to the peer gem5 processes is defined in dev/src/multi_iface.hh and
in tcp_iface.hh.

There is also a central message server process (util/multi/tcp_server.[hh,cc])
which acts like an Ethernet switch and transfers messages among the gem5 peers.

A multi gem5 simulations can be kicked off by the util/multi/gem5-multi.sh
wrapper script.

Checkpoints are supported by multi-gem5. The checkpoint must be
initiated by a single gem5 process. E.g., the gem5 process with rank 0
can take a checkpoint from the bootscript just before it invokes
'mpirun' to launch an MPI test. The message server process will notify
all the other peer gem5 processes and make them take a checkpoint, too
(after completing a global synchronisation to ensure that there are no
inflight messages among gem5).
2015-07-15 19:53:50 -05:00

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/*
* Copyright (c) 2015 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: Gabor Dozsa
*/
/* @file
* Header packet class for multi gem5 runs.
*
* For a high level description about multi gem5 see comments in
* header file multi_iface.hh.
*
* The MultiHeaderPkt class defines the format of message headers
* sent among gem5 processes during a multi gem5 simulation. A header packet
* can either carry the description of data packet (i.e. a simulated Ethernet
* packet) or a synchronisation related control command. In case of
* data packet description, the corresponding data packet always follows
* the header packet back-to-back.
*/
#ifndef __DEV_MULTI_PACKET_HH__
#define __DEV_MULTI_PACKET_HH__
#include <cstring>
#include "base/types.hh"
class MultiHeaderPkt
{
private:
MultiHeaderPkt() {}
~MultiHeaderPkt() {}
public:
/**
* Simply type to help with calculating space requirements for
* the corresponding header field.
*/
typedef uint8_t AddressType[6];
/**
* The msg type defines what informarion a multi header packet carries.
*/
enum class MsgType
{
dataDescriptor,
cmdPeriodicSyncReq,
cmdPeriodicSyncAck,
cmdCkptSyncReq,
cmdCkptSyncAck,
cmdAtomicSyncReq,
cmdAtomicSyncAck,
unknown
};
struct Header
{
/**
* The msg type field is valid for all header packets. In case of
* a synchronisation control command this is the only valid field.
*/
MsgType msgType;
Tick sendTick;
Tick sendDelay;
/**
* Actual length of the simulated Ethernet packet.
*/
unsigned dataPacketLength;
/**
* Source MAC address.
*/
AddressType srcAddress;
/**
* Destination MAC address.
*/
AddressType dstAddress;
};
static unsigned maxAddressLength();
/**
* Static functions for manipulating and comparing MAC addresses.
*/
static void clearAddress(AddressType &addr);
static bool isAddressEqual(const AddressType &addr1,
const AddressType &addr2);
static bool isAddressLess(const AddressType &addr1,
const AddressType &addr2);
static void copyAddress(AddressType &dest,
const AddressType &src);
static bool isUnicastAddress(const AddressType &addr);
static bool isMulticastAddress(const AddressType &addr);
static bool isBroadcastAddress(const AddressType &addr);
};
#endif