From e9d6bf5e35b732df925f65a7b7adaa746f6a7f3b Mon Sep 17 00:00:00 2001
From: Andreas Sandberg <andreas.sandberg@arm.com>
Date: Fri, 28 Aug 2015 10:58:44 +0100
Subject: [PATCH] ruby: Use the const serialize interface in RubySystem

The new serialization code (kudos to Tim Jones) moves all of the state
mangling in RubySystem to memWriteback. This makes it possible to use
the new const serialization interface.

This changeset moves the cache recorder cleanup from the checkpoint()
method to drainResume() to make checkpointing truly constant and
updates the checkpointing code to use the new interface.
---
 src/mem/ruby/system/System.cc | 15 +++++++++++----
 src/mem/ruby/system/System.hh | 13 +++++++------
 2 files changed, 18 insertions(+), 10 deletions(-)

diff --git a/src/mem/ruby/system/System.cc b/src/mem/ruby/system/System.cc
index c00082010..fd712a47a 100644
--- a/src/mem/ruby/system/System.cc
+++ b/src/mem/ruby/system/System.cc
@@ -235,7 +235,7 @@ RubySystem::writeCompressedTrace(uint8_t *raw_data, string filename,
 }
 
 void
-RubySystem::serializeOld(CheckpointOut &cp)
+RubySystem::serialize(CheckpointOut &cp) const
 {
     // Store the cache-block size, so we are able to restore on systems with a
     // different cache-block size. CacheRecorder depends on the correct
@@ -259,10 +259,17 @@ RubySystem::serializeOld(CheckpointOut &cp)
 
     SERIALIZE_SCALAR(cache_trace_file);
     SERIALIZE_SCALAR(cache_trace_size);
+}
 
-    // Now finished with the cache recorder.
-    delete m_cache_recorder;
-    m_cache_recorder = NULL;
+void
+RubySystem::drainResume()
+{
+    // Delete the cache recorder if it was created in memWriteback()
+    // to checkpoint the current cache state.
+    if (m_cache_recorder) {
+        delete m_cache_recorder;
+        m_cache_recorder = NULL;
+    }
 }
 
 void
diff --git a/src/mem/ruby/system/System.hh b/src/mem/ruby/system/System.hh
index 787e4f4ae..a7afac45c 100644
--- a/src/mem/ruby/system/System.hh
+++ b/src/mem/ruby/system/System.hh
@@ -95,8 +95,9 @@ class RubySystem : public ClockedObject
     void resetStats();
 
     void memWriteback();
-    void serializeOld(CheckpointOut &cp) M5_ATTR_OVERRIDE;
+    void serialize(CheckpointOut &cp) const M5_ATTR_OVERRIDE;
     void unserialize(CheckpointIn &cp) M5_ATTR_OVERRIDE;
+    void drainResume() M5_ATTR_OVERRIDE;
     void process();
     void startup();
     bool functionalRead(Packet *ptr);
@@ -121,11 +122,11 @@ class RubySystem : public ClockedObject
                            uint64 cache_trace_size,
                            uint64 block_size_bytes);
 
-    void readCompressedTrace(std::string filename,
-                             uint8_t *&raw_data,
-                             uint64& uncompressed_trace_size);
-    void writeCompressedTrace(uint8_t *raw_data, std::string file,
-                              uint64 uncompressed_trace_size);
+    static void readCompressedTrace(std::string filename,
+                                    uint8_t *&raw_data,
+                                    uint64& uncompressed_trace_size);
+    static void writeCompressedTrace(uint8_t *raw_data, std::string file,
+                                     uint64 uncompressed_trace_size);
 
   private:
     // configuration parameters