ruby: Refactor some Event subclasses to lambdas

Change-Id: I9f47a20a869553515a759d9a29c05f6ce4b42d64
Signed-off-by: Sean Wilson <spwilson2@wisc.edu>
Reviewed-on: https://gem5-review.googlesource.com/3930
Maintainer: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>

ruby: consumer: avoid accessing wakeup times when waking up
Each consumer object maintains a set of tick values when the object is supposed
to wakeup and do some processing. As of now, the object accesses this set both
when scheduling a wakeup event and when the object actually wakes up. The set
is accessed during wakeup to remove the current tick value from the set. This
functionality is now being moved to the scheduling function where ticks are
removed at a later time.

ruby: consumer: avoid using receiver side clock
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.

scons: Fix warnings issued by clang 3.2svn (XCode 4.6)

This patch fixes the warnings that clang3.2svn emit due to the "-Wall"
flag. There is one case of an uninitialised value in the ARM neon ISA
description, and then a whole range of unused private fields that are
pruned.

ruby: replaces Time with Cycles in many places
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.

Ruby: use ClockedObject in Consumer class
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.

ruby: avoid using g_system_ptr for event scheduling
This patch removes the use of g_system_ptr for event scheduling. Each consumer
object now needs to specify upfront an EventManager object it would use for
scheduling events. This makes the ruby memory system more amenable for a
multi-threaded simulation.

Ruby: Remove RubyEventQueue
This patch removes RubyEventQueue. Consumer objects now rely on RubySystem
or themselves for scheduling events.

Ruby: Improve Change PerfectSwitch's wakeup function
Currently the wakeup function for the PerfectSwitch contains three loops -

loop on number of virtual networks
loop on number of incoming links
loop till all messages for this (link, network) have been routed

With an 8 processor mesh network and Hammer protocol, about 11-12% of the
was observed to have been spent in this function, which is the highest
amongst all the functions. It was found that the innermost loop is executed
about 45 times per invocation of the wakeup function, when each invocation
of the wakeup function processes just about one message.

The patch tries to do away with the redundant executions of the innermost
loop. Counters have been added for each virtual network that record the
number of messages that need to be routed for that virtual network. The
inner loops are only executed when the number of messages for that particular
virtual network > 0. This does away with almost 80% of the executions of the
innermost loop. The function now consumes about 5-6% of the total execution
time.

ruby: style pass

ruby: Fix multiple wakeups in Ruby Eventqueue

Fix bug in Ruby Event queue to avoid multiple wakeups of same consumer in
same cycle

ruby: get rid of std-includes.hh
Do not use "using namespace std;" in headers
Include header files as needed

ruby: Removed out_link_vec from Consumer
Removed the out_line_vec data structure from the Consumer. I'm not sure
what this did before, but currently it has no usefulness.

ruby: Import the latest ruby changes from gems.
This was done with an automated process, so there could be things that were
done in this tree in the past that didn't make it. One known regression
is that atomic memory operations do not seem to work properly anymore.

ruby: Make ruby #includes use full paths to the files they're including.
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.

ruby: Renamed Ruby's EventQueue to RubyEventQueue

ruby: Import ruby and slicc from GEMS

We eventually plan to replace the m5 cache hierarchy with the GEMS
hierarchy, but for now we will make both live alongside eachother.