This patch changes how the embedded swig code is loaded to ensure that
gem5 works with swig 3.0.9. For Python 2.7 and above, swig 3.0.9 now
relies on importlib, and actually looks in the appropriate packages,
even for the wrapped C code. However, the swig wrapper does not
explicitly place the module in the right package (it just calls
Py_InitModule), and we have to take explicit action to ensure that the
swig code can be loaded. This patch adds the information to the
generated wrappers and the appropriate calls to set the context as
part of the swig initialisation.
Previous versions of swig used to fall back on looking in the global
namespace for the wrappers (and still do for Python 2.6), but
technically things should not work without the functionality in this
patch.
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
There is a race between enabling asynchronous IO for a file descriptor
and IO events happening on that descriptor. A SIGIO won't normally be
delivered if an event is pending when asynchronous IO is
enabled. Instead, the signal will be raised the next time there is an
event on the FD. This changeset simulates a SIGIO by setting the
async_io flag when setting up asynchronous IO for an FD. This causes
the main event loop to poll all file descriptors to check for pending
IO. As a consequence of this, the old SIGALRM hack should no longer be
needed and is therefore removed.
The PollEvent class dynamically installs a SIGIO and SIGALRM handler
when a file handler is registered. Most signal handlers currently get
registered in the initSignals() function. This changeset moves the
SIGIO/SIGALRM handlers to initSignals() to live with the other signal
handlers. The original code installs SIGIO and SIGALRM with the
SA_RESTART option to prevent syscalls from returning EINTR. This
changeset consistently uses this flag for all signal handlers to
ensure that other signals that trigger asynchronous behavior (e.g.,
statistics dumping) do not cause undesirable EINTR returns.
This patch adds support for outputting protobuf messages through a
ProtoOutputStream which hides the internal streams used by the
library. The stream is created based on the name of an output file and
optionally includes compression using gzip.
The output stream will start by putting a magic number in the file,
and then for every message that is serialized prepend the size such
that the stream can be written and read incrementally. At this point
this merely serves as a proof of concept.
This patch addresses a number of minor issues that cause problems when
compiling with clang >= 3.0 and gcc >= 4.6. Most importantly, it
avoids using the deprecated ext/hash_map and instead uses
unordered_map (and similarly so for the hash_set). To make use of the
new STL containers, g++ and clang has to be invoked with "-std=c++0x",
and this is now added for all gcc versions >= 4.6, and for clang >=
3.0. For gcc >= 4.3 and <= 4.5 and clang <= 3.0 we use the tr1
unordered_map to avoid the deprecation warning.
The addition of c++0x in turn causes a few problems, as the
compiler is more stringent and adds a number of new warnings. Below,
the most important issues are enumerated:
1) the use of namespaces is more strict, e.g. for isnan, and all
headers opening the entire namespace std are now fixed.
2) another other issue caused by the more stringent compiler is the
narrowing of the embedded python, which used to be a char array,
and is now unsigned char since there were values larger than 128.
3) a particularly odd issue that arose with the new c++0x behaviour is
found in range.hh, where the operator< causes gcc to complain about
the template type parsing (the "<" is interpreted as the beginning
of a template argument), and the problem seems to be related to the
begin/end members introduced for the range-type iteration, which is
a new feature in c++11.
As a minor update, this patch also fixes the build flags for the clang
debug target that used to be shared with gcc and incorrectly use
"-ggdb".
Instead of putting all object files into m5/object/__init__.py, interrogate
the importer to find out what should be imported.
Instead of creating a single file that lists all of the embedded python
modules, use static object construction to put those objects onto a list.
Do something similar for embedded swig (C++) code.
If the user sets the environment variable M5_OVERRIDE_PY_SOURCE to
True, then imports that would normally find python code compiled into
the executable will instead first check in the absolute location where
the code was found during the build of the executable. This only
works for files in the src (or extras) directories, not automatically
generated files.
This is a developer feature!
Targets look like libm5_debug.so. This target can be dynamically
linked into another C++ program and provide just about all of the M5
features. Additionally, this library is a standalone module that can
be imported into python with an "import libm5_debug" type command
line.
This should allow m5 to be more easily embedded into other simulators.
The m5 binary adds a simple main function which then calls into the m5
libarary to start the simulation. In order to make this work
correctly, it was necessary embed python code directly into the
library instead of the zipfile hack. This is because you can't just
append the zipfile to the end of a library the way you can a binary.
As a result, Python files that are part of the m5 simulator are now
compile, marshalled, compressed, and then inserted into the library's
data section with a certain symbol name. Additionally, a new Importer
was needed to allow python to get at the embedded python code.
Small additional changes include:
- Get rid of the PYTHONHOME stuff since I don't think anyone ever used
it, and it just confuses things. Easy enough to add back if I'm wrong.
- Create a few new functions that are key to initializing and running
the simulator: initSignals, initM5Python, m5Main.
The original code for creating libm5 was inspired by a patch Michael
Adler, though the code here was done by me.
