Used cppclean to help identify useless includes and removed them. This
involved erroneously included headers, but also cases where forward
declarations could have been used rather than a full include.
When gem5 is a slave to another simulator and the Python is only used
to initialize the configuration (and not perform actual simulation), a
"debug start" (--debug-start) event will get freed during or immediately
after the initial Python frame's execution rather than remaining in the
event queue. This tricky patch fixes the GC issue causing this.
This patch adds a 'wakeup' member function to EventQueue which should be
called on an event queue whenever an event is scheduled on the event queue
from outside code within the call tree of the gem5 event loop.
This clearly isn't necessary for normal gem5 EventQueue operation but
becomes the minimum necessary interface to allow hosting gem5's event loop
onto other schedulers where there may be calls into gem5 from external
code which schedules events onto an EventQueue between the current time and
the time of the next scheduled event.
The use case I have in mind is a SystemC hosting where the event loop is:
while (more events) {
wait(time_to_next_event or wakeup)
setCurTick
service events at this time
}
where the 'wait' needs to be woken up if time_to_next_event becomes shorter
due to a scheduled event from SystemC arriving in a gem5 object.
Requiring 'wakeup' to be called is a more efficient interface than
requiring all gem5 event scheduling actions to affect the host scheduler.
This interface could be located elsewhere, say on another global object,
or by being passed by the host scheduler to objects which will schedule
such events, but it seems cleanest to put it on EventQueue as it is
actually a signal to the queue.
EventQueue::wakeup is called for async_event events on event queue 0 as
it's only important that *some* queue be triggered for such events.
This patch moves the draining interface from SimObject to a separate
class that can be used by any object needing draining. However,
objects not visible to the Python code (i.e., objects not deriving
from SimObject) still depend on their parents informing them when to
drain. This patch also gets rid of the CountedDrainEvent (which isn't
really an event) and replaces it with a DrainManager.
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.
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.
m5.internal.event.create(). It takes a python object and a
Tick and calls process() when the Tick occurs.
--HG--
extra : convert_revision : 5e4c9728982b206163ff51e6850a1497d85ad7a3
