Commit graph

442 commits

Author SHA1 Message Date
Andreas Sandberg 2974dc7a37 python: Move native wrappers to the _m5 namespace
Swig wrappers for native objects currently share the _m5.internal name
space with Python code. This is undesirable if we ever want to switch
from Swig to some other framework for native binding (e.g., PyBind11
or Boost::Python). This changeset moves all of such wrappers to the
_m5 namespace, which is now reserved for native code.

Change-Id: I2d2bc12dbc05b57b7c5a75f072e08124413d77f3
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Curtis Dunham <curtis.dunham@arm.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
2017-01-27 12:40:01 +00:00
Andreas Sandberg c8b1e8f1cf python: Don't use Swig to cast stats
Call the stat visitor from the stat itself rather than casting stats
in Python. This reduces the number of ways visitors are called.

Change-Id: Ic4d0b7b32e3ab9897b9a34cd22d353f4da62d738
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Sascha Bischoff <sascha.bischoff@arm.com>
Reviewed-by: Curtis Dunham <curtis.dunham@arm.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Joe Gross <joseph.gross@amd.com>
2017-01-03 12:03:45 +00:00
Andreas Sandberg abe7ef95cb sim: Remove redundant export_method_cxx_predecls
The headers declared in export_method_cxx_predecls are redundant since a
SimObject's main header is automatically included.

Change-Id: Ied9e84630b36960e54efe91d16f8c66fba7e0da0
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Curtis Dunham <curtis.dunham@arm.com>
Reviewed-by: Joe Gross <joseph.gross@amd.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
2017-01-03 12:03:06 +00:00
Andreas Sandberg 8702208f3f python: Export periodicStatDump
Some configuration scripts need periodic stat dumps. One of the ways
this can be achieved is by using the pariodicStatDump helper
function. This function was previously only exported in the internal
name space. Export it as a normal function in m5.stat instead.

Change-Id: Ic88bf1fd33042a62ab436d5944d8ed778264ac98
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Sascha Bischoff <sascha.bischoff@arm.com>
2016-12-19 16:25:39 +00:00
Curtis Dunham 18461d1522 base: eliminate ipython warning
Change-Id: I3e282baeb969b6bb9534813a2f433d68246c0669
Reviewed-by: Andreas Sandberg <andreas.sandberg@arm.com>
2016-09-15 18:21:38 +01:00
Matt Poremba 4c903d0412 base: Output all AddrRange parameters to config.ini
Currently only 'start' and 'end' of AddrRange are printed in config.ini.
This causes address ranges to be overlapping when loading a c++-only
config with interleaved addresses using CxxConfigManger. This patch adds
prints for the interleave and XOR bits to config.ini such that address
ranges are properly setup with cxx config.
2016-09-13 23:06:18 -04:00
Akash Bagdia 07452aebf5 power: Allow voltage to be configured via cmd line
---
 src/python/m5/params.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
2016-05-27 16:54:59 +01:00
Sascha Bischoff 1097aa1638 misc: Bail out of DVFS dot if we cannot resolve the domains
This changeset updates the dot output to bail out if it is unable to
resolve the voltage or clock domains (which will cause it to raise an
AttributeError). Additionally, the DVFS dot output is disabled by
default for speed purposes.

Minor fixup for 0aeca8f.
2016-04-06 17:55:17 +01:00
Sascha Bischoff 774350b750 misc: Add secondary dot output for DVFS domains
This patch adds a secondary dot output file which shows the DVFS domains. This
has been done separately for now to avoid cluttering the already existing
diagram. Due to the way that the clock domains are assigned to components in
gem5, this output must be generated after the C++ objects have been
instantiated. This further motivates the need to generate this file separately
to the current dot output, and not to replace it entirely.
2015-12-15 09:40:56 +00:00
Andreas Sandberg 2580fcd9d7 style: Refactor the style checker as a Python package
Refactor the style checker into a Python module that can be reused by
command line tools that integrate with git. In particular:

  * Create a style package in util
  * Move style validators from style.py to the style/validators.py.
  * Move style verifiers from style.py to the style/verifiers.py.
  * Move utility functions (sort_includes, region handling,
    file_types) into the style package
  * Move generic code from style.py to style/style.py.

Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Curtis Dunham <curtis.dunham@arm.com>
Reviewed-by: Steve Reinhardt <steve.reinhardt@amd.com>

--HG--
rename : util/style.py => util/hgstyle.py
rename : util/sort_includes.py => util/style/sort_includes.py
extra : rebase_source : ad6cf9b9a18c48350dfc7b7c77bea6c5344fb53c
2016-03-30 15:30:32 +01:00
Andreas Sandberg a91c1e69a8 sim: Add support for forking
This changeset adds forking capabilities to the gem5 python scripts. A fork
method is added to simulate.py. This method is responsible for forking the
simulator itself, and will direct all output files to a new output directory
based on the fork sequence number. The default name of the output directory is
the same as the parent with the suffix ".fN" added where N is the fork sequence
number. The fork method provides the option to specify if the system should be
drained prior to forking, or not. By default the system is drained to ensure
that there are no in-flight transactions.

When forking the simulator, the fork method returns the PID of the child
process, or returns 0 if running in the child. This is in line with the standard
Python forking interface.

Signed-off-by: Andreas Sandberg <andreas@sandberg.pp.se>
[sascha.bischoff@arm.com: Rebased patches onto a newer gem5 version]
Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
[andreas.sandberg@arm.com: Updated to comply with modern draining semantics ]
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
2015-11-26 10:11:57 +00:00
Andreas Sandberg 738d71f6a9 sim: Add support for notifying Drainable objects of a fork
When forking a gem5 process, some objects need to clean up resources
(mainly file descriptions) shared between the child and the parent of
the fork. This changeset adds the notifyFork() method to Drainable,
which is called in the child process.

Signed-off-by: Andreas Sandberg <andreas@sandberg.pp.se>
[sascha.bischoff@arm.com: Rebased patches onto a newer gem5 version]
Signed-off-by: Sascha Bischoff <sascha.bischoff@arm.com>
Signed-off-by: Andreas Sandberg <andreas.sandberg@arm.com>
2015-11-26 10:03:43 +00:00
Michael LeBeane 2ae4cce393 configs: add command-line option to stop debug output
This patch adds a --debug-end flag to main.py so that debug output can be
stoped at a specified tick, while allowing the simulation to continue. It is
useful in situations where you would like to produce a trace for a region of
interest while still collecting stats for the entire run. This is in contrast
to the currently existing --debug-break flag, which terminates the simulation
at the tick.
2016-02-13 12:36:43 -05:00
Steve Reinhardt dc8018a5c3 style: remove trailing whitespace
Result of running 'hg m5style --skip-all --fix-white -a'.
2016-02-06 17:21:18 -08:00
Steve Reinhardt b7ea2bc705 sim: fix redundant --debug-start help string
Just changes the metavar for --debug-start from TIME
to TICK in cset 72046b9b3323 and didn't notice that the
comment "must be in ticks" is now redundant.
2016-01-17 19:18:49 -08:00
Steve Reinhardt 28a0e5a165 sim: don't ignore SIG_TRAP
By ignoring SIG_TRAP, using --debug-break <N> when not connected to
a debugger becomes a no-op.  Apparently this was intended to be a
feature, though the rationale is not clear.

If we don't ignore SIG_TRAP, then using --debug-break <N> when not
connected to a debugger causes the simulation process to terminate
at tick N.  This is occasionally useful, e.g., if you just want to
collect a trace for a specific window of execution then you can combine
this with --debug-start to do exactly that.

In addition to not ignoring the signal, this patch also updates
the --debug-break help message and deletes a handful of unprotected
calls to Debug::breakpoint() that relied on the prior behavior.
2016-01-17 18:27:46 -08:00
Andreas Sandberg c84745e2cb config: Fix broken SimObject listing
The gem5 option '--list-sim-objects' is supposed to list all available
SimObjects and their parameters. It currently chokes on SimObjects
with parameters that have an object instance as their default
value. This is caused by __str__ in SimObject trying to resolve its
complete path. When the path resolution method reaches the parent
object (a MetaSimObject since it hasn't been instantiated), it dies
with a Python exception.

This changeset adds a guard to stop path resolution if the parent
object is a MetaSimObject.
2015-12-01 13:01:05 +00:00
Andrew Bardsley 4375678a0d config: Added missing types to JSON/INI Python reader
Added the missing types EthernetAddr and Current to the JSON/INI file
reader example configs/example/read_config.py.

Also added __str__ to EthernetAddr to make values appear in the same form
in JSON an INI files.
2015-11-22 05:10:21 -05:00
Steve Reinhardt 4b7c1fe610 sim: print pid in output header
This information is useful if you have a bunch of simulations running
and want to know which one to kill, but you've neglected to take
advantage of the previous patch and embed the pid in your output path.
2015-10-06 17:26:50 -07:00
Curtis Dunham 02881a7bf3 base: remove Trace::enabled flag
The DTRACE() macro tests both Trace::enabled and the specific flag. This
change uses the same administrative interface for enabling/disabling
tracing, but masks the SimpleFlags settings directly. This eliminates a
load for every DTRACE() test, e.g. DPRINTF.
2015-09-30 15:21:55 -05:00
Andreas Sandberg f16c0a4a90 sim: Decouple draining from the SimObject hierarchy
Draining is currently done by traversing the SimObject graph and
calling drain()/drainResume() on the SimObjects. This is not ideal
when non-SimObjects (e.g., ports) need draining since this means that
SimObjects owning those objects need to be aware of this.

This changeset moves the responsibility for finding objects that need
draining from SimObjects and the Python-side of the simulator to the
DrainManager. The DrainManager now maintains a set of all objects that
need draining. To reduce the overhead in classes owning non-SimObjects
that need draining, objects inheriting from Drainable now
automatically register with the DrainManager. If such an object is
destroyed, it is automatically unregistered. This means that drain()
and drainResume() should never be called directly on a Drainable
object.

While implementing the new functionality, the DrainManager has now
been made thread safe. In practice, this means that it takes a lock
whenever it manipulates the set of Drainable objects since SimObjects
in different threads may create Drainable objects
dynamically. Similarly, the drain counter is now an atomic_uint, which
ensures that it is manipulated correctly when objects signal that they
are done draining.

A nice side effect of these changes is that it makes the drain state
changes stricter, which the simulation scripts can exploit to avoid
redundant drains.
2015-07-07 09:51:05 +01:00
Andreas Sandberg d5f5fbb855 sim: Move mem(Writeback|Invalidate) to SimObject
The memWriteback() and memInvalidate() calls used to live in the
Serializable interface. In this series of patches, the Serializable
interface will be redesigned to make serialization independent of the
object graph and always work on the entire simulator. This means that
the Serialization interface won't be useful to perform maintenance of
the caches in a sub-graph of the entire SimObject graph. This
changeset moves these memory maintenance methods to the SimObject
interface instead.
2015-07-07 09:51:04 +01:00
Andreas Sandberg 1dc5e63b88 python: Remove redundant drain when changing memory modes
When the Python helper code switches CPU models, it sometimes also
needs to change the memory mode of the simulator. When this happens,
it accidentally tried to drain the simulator despite having done so
already. This changeset removes the redundant drain.
2015-07-07 09:51:04 +01:00
Andreas Sandberg 76cd4393c0 sim: Refactor the serialization base class
Objects that are can be serialized are supposed to inherit from the
Serializable class. This class is meant to provide a unified API for
such objects. However, so far it has mainly been used by SimObjects
due to some fundamental design limitations. This changeset redesigns
to the serialization interface to make it more generic and hide the
underlying checkpoint storage. Specifically:

  * Add a set of APIs to serialize into a subsection of the current
    object. Previously, objects that needed this functionality would
    use ad-hoc solutions using nameOut() and section name
    generation. In the new world, an object that implements the
    interface has the methods serializeSection() and
    unserializeSection() that serialize into a named /subsection/ of
    the current object. Calling serialize() serializes an object into
    the current section.

  * Move the name() method from Serializable to SimObject as it is no
    longer needed for serialization. The fully qualified section name
    is generated by the main serialization code on the fly as objects
    serialize sub-objects.

  * Add a scoped ScopedCheckpointSection helper class. Some objects
    need to serialize data structures, that are not deriving from
    Serializable, into subsections. Previously, this was done using
    nameOut() and manual section name generation. To simplify this,
    this changeset introduces a ScopedCheckpointSection() helper
    class. When this class is instantiated, it adds a new /subsection/
    and subsequent serialization calls during the lifetime of this
    helper class happen inside this section (or a subsection in case
    of nested sections).

  * The serialize() call is now const which prevents accidental state
    manipulation during serialization. Objects that rely on modifying
    state can use the serializeOld() call instead. The default
    implementation simply calls serialize(). Note: The old-style calls
    need to be explicitly called using the
    serializeOld()/serializeSectionOld() style APIs. These are used by
    default when serializing SimObjects.

  * Both the input and output checkpoints now use their own named
    types. This hides underlying checkpoint implementation from
    objects that need checkpointing and makes it easier to change the
    underlying checkpoint storage code.
2015-07-07 09:51:03 +01:00
Steve Reinhardt 5302305255 misc: quote args in echoed command line
Currently if there are shell special characters in a
command-line argument, you can't copy and paste the
echoed command line onto a shell prompt because the
characters aren't quoted properly.  This patch fixes
that problem.
2015-03-23 16:14:18 -07:00
Andreas Hansson ccb512ecc1 base: Add XOR-based hashed address interleaving
This patch extends the current address interleaving with basic hashing
support. Instead of directly comparing a number of address bits with a
matching value, it is now possible to use two independent set of
address bits XOR'ed together. This avoids issues where strided address
patterns are heavily biased to a subset of the interleaved ranges.
2015-02-03 14:25:54 -05:00
Geoffrey Blake 3e33786db8 config: Fix typo in Float param
The Float param was not settable on the command line
due to a typo in the class definition in
python/m5/params.py.  This corrects the typo and allows
floats to be set on the command line as intended.
2015-02-03 14:25:07 -05:00
Andreas Hansson 966c3f4bc5 scons: Ensure dictionary iteration is sorted by key
This patch adds sorting based on the SimObject name or parameter name
for all situations where we iterate over dictionaries. This should
ensure a deterministic and consistent order across the host systems
and hopefully avoid regression results differing across python
versions.
2014-12-02 06:08:22 -05:00
Andreas Hansson 7d05895120 sim: Sort SimObject descendants and ports
This patch fixes a number of occurences where the sorting order of the
objects was implementation defined.
2014-11-12 09:05:21 -05:00
Andreas Hansson 66df7b7fd4 config: Add the ability to read a config file using C++ and Python
This patch adds the ability to load in config.ini files generated from
gem5 into another instance of gem5 built without Python configuration
support. The intended use case is for configuring gem5 when it is a
library embedded in another simulation system.

A parallel config file reader is also provided purely in Python to
demonstrate the approach taken and to provided similar functionality
for as-yet-unknown use models. The Python configuration file reader
can read both .ini and .json files.

C++ configuration file reading:

A command line option has been added for scons to enable C++ configuration
file reading: --with-cxx-config

There is an example in util/cxx_config that shows C++ configuration in action.
util/cxx_config/README explains how to build the example.

Configuration is achieved by the object CxxConfigManager. It handles
reading object descriptions from a CxxConfigFileBase object which
wraps a config file reader. The wrapper class CxxIniFile is provided
which wraps an IniFile for reading .ini files. Reading .json files
from C++ would be possible with a similar wrapper and a JSON parser.

After reading object descriptions, CxxConfigManager creates
SimObjectParam-derived objects from the classes in the (generated with this
patch) directory build/ARCH/cxx_config

CxxConfigManager can then build SimObjects from those SimObjectParams (in an
order dictated by the SimObject-value parameters on other objects) and bind
ports of the produced SimObjects.

A minimal set of instantiate-replacing member functions are provided by
CxxConfigManager and few of the member functions of SimObject (such as drain)
are extended onto CxxConfigManager.

Python configuration file reading (configs/example/read_config.py):

A Python version of the reader is also supplied with a similar interface to
CxxConfigFileBase (In Python: ConfigFile) to config file readers.

The Python config file reading will handle both .ini and .json files.

The object construction strategy is slightly different in Python from the C++
reader as you need to avoid objects prematurely becoming the children of other
objects when setting parameters.

Port binding also needs to be strictly in the same port-index order as the
original instantiation.
2014-10-16 05:49:37 -04:00
Andrew Bardsley d8502ee46d config: Add a --without-python option to build process
Add the ability to build libgem5 without embedded Python or the
ability to configure with Python.

This is a prelude to a patch to allow config.ini files to be loaded
into libgem5 using only C++ which would make embedding gem5 within
other simulation systems easier.

This adds a few registration interfaces to things which cross
between Python and C++.  Namely: stats dumping and SimObject resolving
2014-10-16 05:49:32 -04:00
Andrew Lukefahr f94fd44991 sim: draining bug for fast-forwaring multiple cores
fix draining bug where multiple cores hit max_insts_any_thread simultaneously

Committed by: Nilay Vaish <nilay@cs.wisc.edu>
2014-10-11 15:02:22 -05:00
Andreas Hansson c81517c293 config: Add Current as a parameter type
This patch adds the Python parameter type Current, which is used for
the DRAM power modelling (to start with). With this addition we avoid
implicit unit assumptions.
2014-10-09 17:52:00 -04:00
Andreas Hansson 1f6d5f8f84 mem: Rename Bus to XBar to better reflect its behaviour
This patch changes the name of the Bus classes to XBar to better
reflect the actual timing behaviour. The actual instances in the
config scripts are not renamed, and remain as e.g. iobus or membus.

As part of this renaming, the code has also been clean up slightly,
making use of range-based for loops and tidying up some comments. The
only changes outside the bus/crossbar code is due to the delay
variables in the packet.

--HG--
rename : src/mem/Bus.py => src/mem/XBar.py
rename : src/mem/coherent_bus.cc => src/mem/coherent_xbar.cc
rename : src/mem/coherent_bus.hh => src/mem/coherent_xbar.hh
rename : src/mem/noncoherent_bus.cc => src/mem/noncoherent_xbar.cc
rename : src/mem/noncoherent_bus.hh => src/mem/noncoherent_xbar.hh
rename : src/mem/bus.cc => src/mem/xbar.cc
rename : src/mem/bus.hh => src/mem/xbar.hh
2014-09-20 17:18:32 -04:00
Andrew Bardsley 7329c0e20b config: Cleanup .json config file generation
This patch 'completes' .json config files generation by adding in the
SimObject references and String-valued parameters not currently
printed.

TickParamValues are also changed to print in the same tick-value
format as in .ini files.

This allows .json files to describe a system as fully as the .ini files
currently do.

This patch adds a new function config_value (which mirrors ini_str) to
each ParamValue and to SimObject.  This function can then be explicitly
changed to give different .json and .ini printing behaviour rather than
being written in terms of ini_str.
2014-09-20 17:17:42 -04:00
Geoffrey Blake b0e4de667a config: Fix vectorparam command line parsing
Parsing vectorparams from the command was slightly broken
in that it wouldn't accept the input that the help message
provided to the user and it didn't do the conversion
on the second code path used to convert the string input
to the actual internal representation.  This patch fixes these bugs.
2014-09-09 04:36:34 -04:00
Geoffrey Blake 31e4e475d9 config: Add port splicing capability to PortRef class
The new configuration scripts need the ability to splice
a simobject between a pair of ports that are already connected.
The primary use case is when a CommMonitor needs to be
created after the system is configured and then spliced between
the pair of ports it will monitor.
2014-09-03 07:43:03 -04:00
Mitch Hayenga 23c8540756 config: Change parsing of Addr so hex values work from scripts
When passed from a configuration script with a hexadecimal value (like
"0x80000000"), gem5 would error out. This is because it would call
"toMemorySize" which requires the argument to end with a size specifier (like
1MB, etc).

This modification makes it so raw hex values can be passed through Addr
parameters from the configuration scripts.
2014-09-03 07:42:20 -04:00
Geoffrey Blake 09b5003815 config: Add hooks to enable new config sys
This patch adds helper functions to SimObject.py, params.py and
simulate.py to enable the new configuration system.  Functions like
enumerateParams() in SimObject lets the config system auto-generate
command line options for simobjects to be modified on the command
line.

Params in params.py have __call__() added
to their definition to allow the argparse module to use them
as a type to check command input is in the proper format.
2014-08-10 05:39:13 -04:00
Andrew Bardsley bf78299f04 cpu: Add flag name printing to StaticInst
This patch adds a the member function StaticInst::printFlags to allow all
of an instruction's flags to be printed without using the individual
is... member functions or resorting to exposing the 'flags' vector

It also replaces the enum definition StaticInst::Flags with a
Python-generated enumeration and adds to the enum generation mechanism
in src/python/m5/params.py to allow Enums to be placed in namespaces
other than Enums or, alternatively, in wrapper structs allowing them to
be inherited by other classes (so populating that class's name-space
with the enumeration element names).
2014-05-09 18:58:47 -04:00
Geoffrey Blake 0c1913336a config: Avoid generating a reference to myself for Parent.any
The unproxy code for Parent.any can generate a circular reference
in certain situations with classes hierarchies like those in ClockDomain.py.
This patch solves this by marking ouself as visited to make sure the
search does not resolve to a self-reference.
2014-05-09 18:58:47 -04:00
Curtis Dunham ad019c5c58 scons: Require SWIG >= 2.0.4 and remove vector typemaps
SWIG commit fd666c1 (*) made it unnecessary for gem5 to have these
typemaps to handle Vector types.

* fd666c1440
2014-05-09 18:58:46 -04:00
Sascha Bischoff 2031c03c09 misc: Proper type check and import for PortRef
Rewriting the type checking around PortRef, which was interacting strangely
with other Python scripts.

Tested-by: stephan.diestelhorst@arm.com
2014-04-23 05:18:25 -04:00
Curtis Dunham fa4a262204 stats: better error message for uninitialized statistic
As suggested by Nathan Binkert in 2008:
http://permalink.gmane.org/gmane.comp.emulators.m5.users/2676
2014-02-10 18:24:20 -06:00
Stan Czerniawski 4f77bc230a misc: Fix -q (quiet) flag
Check the right flag.
2014-03-23 11:11:49 -04:00
Matt Horsnell 739c6df94e base: add support for probe points and common probes
The probe patch is motivated by the desire to move analytical and trace code
away from functional code. This is achieved by the probe interface which is
essentially a glorified observer model.

What this means to users:
* add a probe point and a "notify" call at the source of an "event"
* add an isolated module, that is being used to carry out *your* analysis (e.g. generate a trace)
* register that module as a probe listener
Note: an example is given for reference in src/cpu/o3/simple_trace.[hh|cc] and src/cpu/SimpleTrace.py

What is happening under the hood:
* every SimObject maintains has a ProbeManager.
* during initialization (src/python/m5/simulate.py) first regProbePoints and
  the regProbeListeners is called on each SimObject.  this hooks up the probe
  point notify calls with the listeners.

FAQs:
Why did you develop probe points:
* to remove trace, stats gathering, analytical code out of the functional code.
* the belief that probes could be generically useful.

What is a probe point:
* a probe point is used to notify upon a given event (e.g. cpu commits an instruction)

What is a probe listener:
* a class that handles whatever the user wishes to do when they are notified
  about an event.

What can be passed on notify:
* probe points are templates, and so the user can generate probes that pass any
  type of argument (by const reference) to a listener.

What relationships can be generated (1:1, 1:N, N:M etc):
* there isn't a restriction. You can hook probe points and listeners up in a
  1:1, 1:N, N:M relationship. They become useful when a number of modules
  listen to the same probe points. The idea being that you can add a small
  number of probes into the source code and develop a larger number of useful
  analysis modules that use information passed by the probes.

Can you give examples:
* adding a probe point to the cpu's commit method allows you to build a trace
  module (outputting assembler), you could re-use this to gather instruction
  distribution (arithmetic, load/store, conditional, control flow) stats.

Why is the probe interface currently restricted to passing a const reference:
* the desire, initially at least, is to allow an interface to observe
  functionality, but not to change functionality.
* of course this can be subverted by const-casting.

What is the performance impact of adding probes:
* when nothing is actively listening to the probes they should have a
  relatively minor impact. Profiling has suggested even with a large number of
  probes (60) the impact of them (when not active) is very minimal (<1%).
2014-01-24 15:29:30 -06:00
Andreas Hansson daa781d2db config: Make the Clock a Tick parameter like Latency/Frequency
This patch makes the Clock a TickParamValue just like
Latency/Frequency. There is no longer any need to distinguish it
(originally needed to support multiplication).
2014-01-24 15:29:29 -06:00
Steve Reinhardt d8c9b5431b python: provide better error message for wrapped C++ methods
If you successfully export a C++ SimObject method, but try to
invoke it from Python before the C++ object is created, you
get a confusing error that says the attribute does not exist,
making you question whether you successfully exported the
method at all.  In reality, your only problem is that you're
calling the method too soon.  This patch enhances the error
message to give you a better clue.
2014-01-03 17:08:43 -08:00
Steve Reinhardt ba9ec669bc python: don't die on assignment to cloned object
Updating the SimObject topology of a cloned hierarchy is a little
dangerous, in that cloning is a "deep copy" and the clone does not
inherit SimObject updates the same way it would inherit scalar
variable assignments.

However, because of various SimObject-valued proxy parameters,
like 'memories', 'clk_domain', and 'system', it turns out that
there are a number of implicit topology changes that happen at
instantiation, which means that these changes are impossible to
avoid.  So in order to make cloning systems useful, this error
has to go.  Changing it to a warning produces a lot of noise,
so it seems best just to delete it.
2014-01-03 17:08:42 -08:00
Nilay Vaish 50d250f514 sim: reset stats after startup
Currently statistics are reset after the initial / checkpoint state
has been loaded. But ruby does some checkpoint processing in its
startup() function. So the stats need to be reset after the startup()
function has been called. This patch moves the class to stats.reset()
to achieve this change in functionality.
2013-12-03 10:51:40 -06:00