This patch adds limited multithreading support in syscall-emulation
mode, by using the clone system call. The clone system call works
for Alpha, SPARC and x86, and multithreaded applications run
correctly in Alpha and SPARC.
Basically merge it in with Halted.
Also had to get rid of a few other functions that
called ThreadContext::deallocate(), including:
- InOrderCPU's setThreadRescheduleCondition.
- ThreadContext::exit(). This function was there to avoid terminating
simulation when one thread out of a multi-thread workload exits, but we
need to find a better (non-cpu-centric) way.
This is mainly to allow the unit test to run without requiring the standard
M5 stats from being initialized (e.g. sim_seconds, sim_ticks, host_seconds)
Bogus calls to ChunkGenerator with negative size were triggering
a new assertion that was added there.
Also did a little renaming and cleanup in the process.
We need to add a reference when an object is put on the C++ queue, and remove
a reference when the object is removed from the queue. This was not happening
before and caused a memory problem.
the primary identifier for a hardware context should be contextId(). The
concept of threads within a CPU remains, in the form of threadId() because
sometimes you need to know which context within a cpu to manipulate.
SE. Process still keeps track of the tc's it owns, but registration occurs
with the System, this eases the way for system-wide context Ids based on
registration.
across the subclasses. generally make it so that member data is _cpuId and
accessor functions are cpuId(). The ID val comes from the python (default -1 if
none provided), and if it is -1, the index of cpuList will be given. this has
passed util/regress quick and se.py -n4 and fs.py -n4 as well as standard
switch.
Since I never implemented a proper solution, put it back to something that
at least works for now. Once I add more event queues, I'll have to really
fix this though
The major thrust of this change is to limit the amount of code
duplication surrounding the code for these functions. This code also
adds two new message types called info and hack. Info is meant to be
less harsh than warn so people don't get confused and start thinking
that the simulator is broken. Hack is a way for people to add runtime
messages indicating that the simulator just executed a code "hack"
that should probably be fixed. The benefit of knowing about these
code hacks is that it will let people know what sorts of inaccuracies
or potential bugs might be entering their experiments. Finally, I've
added some flags to turn on and off these message types so command
line options can change them.
Make them easier to express by only having the cxx_type parameter which
has the full namespace name, and drop the cxx_namespace thing.
Add support for multiple levels of namespace.
Since the early days of M5, an event needed to know which event queue
it was on, and that data was required at the time of construction of
the event object. In the future parallelized M5, this sort of
requirement does not work well since the proper event queue will not
always be known at the time of construction of an event. Now, events
are created, and the EventQueue itself has the schedule function,
e.g. eventq->schedule(event, when). To simplify the syntax, I created
a class called EventManager which holds a pointer to an EventQueue and
provides the schedule interface that is a proxy for the EventQueue.
The intent is that objects that frequently schedule events can be
derived from EventManager and then they have the schedule interface.
SimObject and Port are examples of objects that will become
EventManagers. The end result is that any SimObject can just call
schedule(event, when) and it will just call that SimObject's
eventq->schedule function. Of course, some objects may have more than
one EventQueue, so this interface might not be perfect for those, but
they should be relatively few.
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.
