Clock: Add a Cycles wrapper class and use where applicable

This patch addresses the comments and feedback on the preceding patch
that reworks the clocks and now more clearly shows where cycles
(relative cycle counts) are used to express time.

Instead of bumping the existing patch I chose to make this a separate
patch, merely to try and focus the discussion around a smaller set of
changes. The two patches will be pushed together though.

This changes done as part of this patch are mostly following directly
from the introduction of the wrapper class, and change enough code to
make things compile and run again. There are definitely more places
where int/uint/Tick is still used to represent cycles, and it will
take some time to chase them all down. Similarly, a lot of parameters
should be changed from Param.Tick and Param.Unsigned to
Param.Cycles.

In addition, the use of curTick is questionable as there should not be
an absolute cycle. Potential solutions can be built on top of this
patch. There is a similar situation in the o3 CPU where
lastRunningCycle is currently counting in Cycles, and is still an
absolute time. More discussion to be had in other words.

An additional change that would be appropriate in the future is to
perform a similar wrapping of Tick and probably also introduce a
Ticks class along with suitable operators for all these classes.

1 files changed, 7 insertions, 6 deletions

diff --git a/src/cpu/thread_context.hh b/src/cpu/thread_context.hh
index e186e2f83..e16bc3b39 100644
--- a/src/cpu/thread_context.hh
+++ b/src/cpu/thread_context.hh
@@ -163,13 +163,13 @@ class ThreadContext
 
     /// Set the status to Active.  Optional delay indicates number of
     /// cycles to wait before beginning execution.
-    virtual void activate(int delay = 1) = 0;
+    virtual void activate(Cycles delay = Cycles(1)) = 0;
 
     /// Set the status to Suspended.
-    virtual void suspend(int delay = 0) = 0;
+    virtual void suspend(Cycles delay = Cycles(0)) = 0;
 
     /// Set the status to Halted.
-    virtual void halt(int delay = 0) = 0;
+    virtual void halt(Cycles delay = Cycles(0)) = 0;
 
     virtual void dumpFuncProfile() = 0;
 
@@ -329,13 +329,14 @@ class ProxyThreadContext : public ThreadContext
 
     /// Set the status to Active.  Optional delay indicates number of
     /// cycles to wait before beginning execution.
-    void activate(int delay = 1) { actualTC->activate(delay); }
+    void activate(Cycles delay = Cycles(1))
+    { actualTC->activate(delay); }
 
     /// Set the status to Suspended.
-    void suspend(int delay = 0) { actualTC->suspend(); }
+    void suspend(Cycles delay = Cycles(0)) { actualTC->suspend(); }
 
     /// Set the status to Halted.
-    void halt(int delay = 0) { actualTC->halt(); }
+    void halt(Cycles delay = Cycles(0)) { actualTC->halt(); }
 
     void dumpFuncProfile() { actualTC->dumpFuncProfile(); }