ruby: replace g_ruby_start with per-RubySystem m_start_cycle

This patch begins the process of removing global variables from the Ruby
source with the goal of eventually allowing users to create multiple Ruby
instances in a single simulation.  Currently, users cannot do so because
several global variables and static members are referenced by the RubySystem
object in a way that assumes that there will only ever be a single RubySystem.
These need to be replaced with per-RubySystem equivalents.

This specific patch replaces the global var g_ruby_start, which is used
to calculate throughput statistics for Throttles in simple networks and
links in Garnet networks, with a RubySystem instance var m_start_cycle.

2 files changed, 3 insertions, 1 deletions

diff --git a/src/mem/ruby/system/System.cc b/src/mem/ruby/system/System.cc
index 2f1d9013c..1cdc3879e 100644
--- a/src/mem/ruby/system/System.cc
+++ b/src/mem/ruby/system/System.cc
@@ -338,7 +338,7 @@ RubySystem::RubyEvent::process()
 void
 RubySystem::resetStats()
 {
-    g_ruby_start = curCycle();
+    m_start_cycle = curCycle();
 }
 
 bool
diff --git a/src/mem/ruby/system/System.hh b/src/mem/ruby/system/System.hh
index a59ade398..0030b5033 100644
--- a/src/mem/ruby/system/System.hh
+++ b/src/mem/ruby/system/System.hh
@@ -78,6 +78,7 @@ class RubySystem : public ClockedObject
     static bool getCooldownEnabled() { return m_cooldown_enabled; }
 
     SimpleMemory *getPhysMem() { return m_phys_mem; }
+    Cycles getStartCycle() { return m_start_cycle; }
     const bool getAccessBackingStore() { return m_access_backing_store; }
 
     // Public Methods
@@ -135,6 +136,7 @@ class RubySystem : public ClockedObject
 
     Network* m_network;
     std::vector<AbstractController *> m_abs_cntrl_vec;
+    Cycles m_start_cycle;
 
   public:
     Profiler* m_profiler;