A set of patches was recently committed to allow multiple clock domains
in ruby. In those patches, I had inadvertently made an incorrect use of
the clocks. Suppose object A needs to schedule an event on object B. It
was possible that A accesses B's clock to schedule the event. This is not
possible in actual system. Hence, changes are being to the Consumer class
so as to avoid such happenings. Note that in a multi eventq simulation,
this can possibly lead to an incorrect simulation.
There are two functions in the Consumer class that are used for scheduling
events. The first function takes in the relative delay over the current time
as the argument and adds the current time to it for scheduling the event.
The second function takes in the absolute time (in ticks) for scheduling the
event. The first function is now being moved to protected section of the
class so that only objects of the derived classes can use it. All other
objects will have to specify absolute time while scheduling an event
for some consumer.
This patch is as of now the final patch in the series of patches that replace
Time with Cycles.This patch further replaces Time with Cycles in Sequencer,
Profiler, different protocols and related entities.
Though Time has not been completely removed, the places where it is in use
seem benign as of now.
The patch started of with replacing Time with Cycles in the Consumer class.
But to get ruby to compile, the rest of the changes had to be carried out.
Subsequent patches will further this process, till we completely replace
Time with Cycles.
Many Ruby structures inherit from the Consumer, which is used for scheduling
events. The Consumer used to relay on an Event Manager for scheduling events
and on g_system_ptr for time. With this patch, the Consumer will now use a
ClockedObject to schedule events and to query for current time. This resulted
in several structures being converted from SimObjects to ClockedObjects. Also,
the MessageBuffer class now requires a pointer to a ClockedObject so as to
query for time.
In addition to obvious changes, this required a slight change to the slicc
grammar to allow types with :: in them. Otherwise slicc barfs on std::string
which we need for the headers that slicc generates.
This changeset contains a lot of different changes that are too
mingled to separate. They are:
1. Added MOESI_CMP_directory
I made the changes necessary to bring back MOESI_CMP_directory,
including adding a DMA controller. I got rid of MOESI_CMP_directory_m
and made MOESI_CMP_directory use a memory controller. Added a new
configuration for two level protocols in general, and
MOESI_CMP_directory in particular.
2. DMA Sequencer uses a generic SequencerMsg
I will eventually make the cache Sequencer use this type as well. It
doesn't contain an offset field, just a physical address and a length.
MI_example has been updated to deal with this.
3. Parameterized Controllers
SLICC controllers can now take custom parameters to use for mapping,
latencies, etc. Currently, only int parameters are supported.
This basically means changing all #include statements and changing
autogenerated code so that it generates the correct paths. Because
slicc generates #includes, I had to hard code the include paths to
mem/protocol.