src/sim/sim_object.hh

   1 /*
   2  * Copyright (c) 2015 ARM Limited
   3  * All rights reserved
   4  *
   5  * The license below extends only to copyright in the software and shall
   6  * not be construed as granting a license to any other intellectual
   7  * property including but not limited to intellectual property relating
   8  * to a hardware implementation of the functionality of the software
   9  * licensed hereunder.  You may use the software subject to the license
  10  * terms below provided that you ensure that this notice is replicated
  11  * unmodified and in its entirety in all distributions of the software,
  12  * modified or unmodified, in source code or in binary form.
  13  *
  14  * Copyright (c) 2001-2005 The Regents of The University of Michigan
  15  * Copyright (c) 2010 Advanced Micro Devices, Inc.
  16  * All rights reserved.
  17  *
  18  * Redistribution and use in source and binary forms, with or without
  19  * modification, are permitted provided that the following conditions are
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  22  * redistributions in binary form must reproduce the above copyright
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  25  * neither the name of the copyright holders nor the names of its
  26  * contributors may be used to endorse or promote products derived from
  27  * this software without specific prior written permission.
  28  *
  29  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
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  31  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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  39  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  40  */
  41
  42 /* @file
  43  * User Console Definitions
  44  */
  45
  46 #ifndef __SIM_OBJECT_HH__
  47 #define __SIM_OBJECT_HH__
  48
  49 #include <string>
  50 #include <vector>
  51
  52 #include "base/stats/group.hh"
  53 #include "params/SimObject.hh"
  54 #include "sim/drain.hh"
  55 #include "sim/eventq.hh"
  56 #include "sim/eventq_impl.hh"
  57 #include "sim/port.hh"
  58 #include "sim/serialize.hh"
  59
  60 class EventManager;
  61 class ProbeManager;
  62
  63 /**
  64  * Abstract superclass for simulation objects.  Represents things that
  65  * correspond to physical components and can be specified via the
  66  * config file (CPUs, caches, etc.).
  67  *
  68  * SimObject initialization is controlled by the instantiate method in
  69  * src/python/m5/simulate.py. There are slightly different
  70  * initialization paths when starting the simulation afresh and when
  71  * loading from a checkpoint.  After instantiation and connecting
  72  * ports, simulate.py initializes the object using the following call
  73  * sequence:
  74  *
  75  * <ol>
  76  * <li>SimObject::init()
  77  * <li>SimObject::regStats()
  78  * <li><ul>
  79  *     <li>SimObject::initState() if starting afresh.
  80  *     <li>SimObject::loadState() if restoring from a checkpoint.
  81  *     </ul>
  82  * <li>SimObject::resetStats()
  83  * <li>SimObject::startup()
  84  * <li>Drainable::drainResume() if resuming from a checkpoint.
  85  * </ol>
  86  *
  87  * @note Whenever a method is called on all objects in the simulator's
  88  * object tree (e.g., init(), startup(), or loadState()), a pre-order
  89  * depth-first traversal is performed (see descendants() in
  90  * SimObject.py). This has the effect of calling the method on the
  91  * parent node <i>before</i> its children.
  92  */
  93 class SimObject : public EventManager, public Serializable, public Drainable,
  94                   public Stats::Group
  95 {
  96   private:
  97     typedef std::vector<SimObject *> SimObjectList;
  98
  99     /** List of all instantiated simulation objects. */
 100     static SimObjectList simObjectList;
 101
 102     /** Manager coordinates hooking up probe points with listeners. */
 103     ProbeManager *probeManager;
 104
 105   protected:
 106     /** Cached copy of the object parameters. */
 107     const SimObjectParams *_params;
 108
 109   public:
 110     typedef SimObjectParams Params;
 111     const Params *params() const { return _params; }
 112     SimObject(const Params *_params);
 113     virtual ~SimObject();
 114
 115   public:
 116
 117     virtual const std::string name() const { return params()->name; }
 118
 119     /**
 120      * init() is called after all C++ SimObjects have been created and
 121      * all ports are connected.  Initializations that are independent
 122      * of unserialization but rely on a fully instantiated and
 123      * connected SimObject graph should be done here.
 124      */
 125     virtual void init();
 126
 127     /**
 128      * loadState() is called on each SimObject when restoring from a
 129      * checkpoint.  The default implementation simply calls
 130      * unserialize() if there is a corresponding section in the
 131      * checkpoint.  However, objects can override loadState() to get
 132      * other behaviors, e.g., doing other programmed initializations
 133      * after unserialize(), or complaining if no checkpoint section is
 134      * found.
 135      *
 136      * @param cp Checkpoint to restore the state from.
 137      */
 138     virtual void loadState(CheckpointIn &cp);
 139
 140     /**
 141      * initState() is called on each SimObject when *not* restoring
 142      * from a checkpoint.  This provides a hook for state
 143      * initializations that are only required for a "cold start".
 144      */
 145     virtual void initState();
 146
 147     /**
 148      * Register probe points for this object.
 149      */
 150     virtual void regProbePoints();
 151
 152     /**
 153      * Register probe listeners for this object.
 154      */
 155     virtual void regProbeListeners();
 156
 157     /**
 158      * Get the probe manager for this object.
 159      */
 160     ProbeManager *getProbeManager();
 161
 162     /**
 163      * Get a port with a given name and index. This is used at binding time
 164      * and returns a reference to a protocol-agnostic port.
 165      *
 166      * @param if_name Port name
 167      * @param idx Index in the case of a VectorPort
 168      *
 169      * @return A reference to the given port
 170      */
 171     virtual Port &getPort(const std::string &if_name,
 172                           PortID idx=InvalidPortID);
 173
 174     /**
 175      * startup() is the final initialization call before simulation.
 176      * All state is initialized (including unserialized state, if any,
 177      * such as the curTick() value), so this is the appropriate place to
 178      * schedule initial event(s) for objects that need them.
 179      */
 180     virtual void startup();
 181
 182     /**
 183      * Provide a default implementation of the drain interface for
 184      * objects that don't need draining.
 185      */
 186     DrainState drain() override { return DrainState::Drained; }
 187
 188     /**
 189      * Write back dirty buffers to memory using functional writes.
 190      *
 191      * After returning, an object implementing this method should have
 192      * written all its dirty data back to memory. This method is
 193      * typically used to prepare a system with caches for
 194      * checkpointing.
 195      */
 196     virtual void memWriteback() {};
 197
 198     /**
 199      * Invalidate the contents of memory buffers.
 200      *
 201      * When the switching to hardware virtualized CPU models, we need
 202      * to make sure that we don't have any cached state in the system
 203      * that might become stale when we return. This method is used to
 204      * flush all such state back to main memory.
 205      *
 206      * @warn This does <i>not</i> cause any dirty state to be written
 207      * back to memory.
 208      */
 209     virtual void memInvalidate() {};
 210
 211     void serialize(CheckpointOut &cp) const override {};
 212     void unserialize(CheckpointIn &cp) override {};
 213
 214     /**
 215      * Serialize all SimObjects in the system.
 216      */
 217     static void serializeAll(CheckpointOut &cp);
 218
 219 #ifdef DEBUG
 220   public:
 221     bool doDebugBreak;
 222     static void debugObjectBreak(const std::string &objs);
 223 #endif
 224
 225     /**
 226      * Find the SimObject with the given name and return a pointer to
 227      * it.  Primarily used for interactive debugging.  Argument is
 228      * char* rather than std::string to make it callable from gdb.
 229      */
 230     static SimObject *find(const char *name);
 231 };
 232
 233 /**
 234  * Base class to wrap object resolving functionality.
 235  *
 236  * This can be provided to the serialization framework to allow it to
 237  * map object names onto C++ objects.
 238  */
 239 class SimObjectResolver
 240 {
 241   public:
 242     virtual ~SimObjectResolver() { }
 243
 244     // Find a SimObject given a full path name
 245     virtual SimObject *resolveSimObject(const std::string &name) = 0;
 246 };
 247
 248 #ifdef DEBUG
 249 void debugObjectBreak(const char *objs);
 250 #endif
 251
 252 #endif // __SIM_OBJECT_HH__