sim: Move the draining interface into a separate base class

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.

2 files changed, 17 insertions, 17 deletions

diff --git a/src/cpu/o3/cpu.cc b/src/cpu/o3/cpu.cc
index fdd45fdda..bc5f096e6 100644
--- a/src/cpu/o3/cpu.cc
+++ b/src/cpu/o3/cpu.cc
@@ -619,7 +619,7 @@ FullO3CPU<Impl>::tick()
 
     if (!tickEvent.scheduled()) {
         if (_status == SwitchedOut ||
-            getState() == SimObject::Drained) {
+            getDrainState() == Drainable::Drained) {
             DPRINTF(O3CPU, "Switched out!\n");
             // increment stat
             lastRunningCycle = curCycle();
@@ -1077,7 +1077,7 @@ template <class Impl>
 void
 FullO3CPU<Impl>::serialize(std::ostream &os)
 {
-    SimObject::State so_state = SimObject::getState();
+    Drainable::State so_state(getDrainState());
     SERIALIZE_ENUM(so_state);
     BaseCPU::serialize(os);
     nameOut(os, csprintf("%s.tickEvent", name()));
@@ -1100,7 +1100,7 @@ template <class Impl>
 void
 FullO3CPU<Impl>::unserialize(Checkpoint *cp, const std::string &section)
 {
-    SimObject::State so_state;
+    Drainable::State so_state;
     UNSERIALIZE_ENUM(so_state);
     BaseCPU::unserialize(cp, section);
     tickEvent.unserialize(cp, csprintf("%s.tickEvent", section));
@@ -1120,7 +1120,7 @@ FullO3CPU<Impl>::unserialize(Checkpoint *cp, const std::string &section)
 
 template <class Impl>
 unsigned int
-FullO3CPU<Impl>::drain(Event *drain_event)
+FullO3CPU<Impl>::drain(DrainManager *drain_manager)
 {
     DPRINTF(O3CPU, "Switching out\n");
 
@@ -1137,12 +1137,12 @@ FullO3CPU<Impl>::drain(Event *drain_event)
 
     // Wake the CPU and record activity so everything can drain out if
     // the CPU was not able to immediately drain.
-    if (getState() != SimObject::Drained) {
-        // A bit of a hack...set the drainEvent after all the drain()
+    if (getDrainState() != Drainable::Drained) {
+        // A bit of a hack...set the drainManager after all the drain()
         // calls have been made, that way if all of the stages drain
         // immediately, the signalDrained() function knows not to call
         // process on the drain event.
-        drainEvent = drain_event;
+        drainManager = drain_manager;
 
         wakeCPU();
         activityRec.activity();
@@ -1157,7 +1157,7 @@ FullO3CPU<Impl>::drain(Event *drain_event)
 
 template <class Impl>
 void
-FullO3CPU<Impl>::resume()
+FullO3CPU<Impl>::drainResume()
 {
     fetch.resume();
     decode.resume();
@@ -1165,7 +1165,7 @@ FullO3CPU<Impl>::resume()
     iew.resume();
     commit.resume();
 
-    changeState(SimObject::Running);
+    setDrainState(Drainable::Running);
 
     if (_status == SwitchedOut)
         return;
@@ -1185,14 +1185,14 @@ FullO3CPU<Impl>::signalDrained()
         if (tickEvent.scheduled())
             tickEvent.squash();
 
-        changeState(SimObject::Drained);
+        setDrainState(Drainable::Drained);
 
         BaseCPU::switchOut();
 
-        if (drainEvent) {
+        if (drainManager) {
             DPRINTF(Drain, "CPU done draining, processing drain event\n");
-            drainEvent->process();
-            drainEvent = NULL;
+            drainManager->signalDrainDone();
+            drainManager = NULL;
         }
     }
     assert(drainCount <= 5);
diff --git a/src/cpu/o3/cpu.hh b/src/cpu/o3/cpu.hh
index 076cce0fb..1f9a8da6c 100644
--- a/src/cpu/o3/cpu.hh
+++ b/src/cpu/o3/cpu.hh
@@ -431,10 +431,10 @@ class FullO3CPU : public BaseO3CPU
 
     /** Starts draining the CPU's pipeline of all instructions in
      * order to stop all memory accesses. */
-    virtual unsigned int drain(Event *drain_event);
+    unsigned int drain(DrainManager *drain_manager);
 
     /** Resumes execution after a drain. */
-    virtual void resume();
+    void drainResume();
 
     /** Signals to this CPU that a stage has completed switching out. */
     void signalDrained();
@@ -730,8 +730,8 @@ class FullO3CPU : public BaseO3CPU
     /** Pointer to the system. */
     System *system;
 
-    /** Event to call process() on once draining has completed. */
-    Event *drainEvent;
+    /** DrainManager to notify when draining has completed. */
+    DrainManager *drainManager;
 
     /** Counter of how many stages have completed draining. */
     int drainCount;