base: Declare a type for context IDs

Context IDs used to be declared as ad hoc (usually as int). This
changeset introduces a typedef for ContextIDs and a constant for
invalid context IDs.

3 files changed, 10 insertions, 9 deletions

diff --git a/src/sim/process.hh b/src/sim/process.hh
index 82a84a935..f509b81c7 100644
--- a/src/sim/process.hh
+++ b/src/sim/process.hh
@@ -75,7 +75,7 @@ class Process : public SimObject
     System *system;
 
     // thread contexts associated with this process
-    std::vector<int> contextIds;
+    std::vector<ContextID> contextIds;
 
     // number of CPUs (esxec contexts, really) assigned to this process.
     unsigned int numCpus() { return contextIds.size(); }
@@ -160,7 +160,7 @@ class Process : public SimObject
 
     // After getting registered with system object, tell process which
     // system-wide context id it is assigned.
-    void assignThreadContext(int context_id)
+    void assignThreadContext(ContextID context_id)
     {
         contextIds.push_back(context_id);
     }
diff --git a/src/sim/system.cc b/src/sim/system.cc
index c5e2e0b96..d0418d99b 100644
--- a/src/sim/system.cc
+++ b/src/sim/system.cc
@@ -209,11 +209,11 @@ bool System::breakpoint()
  */
 int rgdb_wait = -1;
 
-int
-System::registerThreadContext(ThreadContext *tc, int assigned)
+ContextID
+System::registerThreadContext(ThreadContext *tc, ContextID assigned)
 {
     int id;
-    if (assigned == -1) {
+    if (assigned == InvalidContextID) {
         for (id = 0; id < threadContexts.size(); id++) {
             if (!threadContexts[id])
                 break;
@@ -305,7 +305,7 @@ System::initState()
 }
 
 void
-System::replaceThreadContext(ThreadContext *tc, int context_id)
+System::replaceThreadContext(ThreadContext *tc, ContextID context_id)
 {
     if (context_id >= threadContexts.size()) {
         panic("replaceThreadContext: bad id, %d >= %d\n",
diff --git a/src/sim/system.hh b/src/sim/system.hh
index 97d271d3a..634c78a6a 100644
--- a/src/sim/system.hh
+++ b/src/sim/system.hh
@@ -197,7 +197,7 @@ class System : public MemObject
     std::vector<ThreadContext *> threadContexts;
     int _numContexts;
 
-    ThreadContext *getThreadContext(ThreadID tid)
+    ThreadContext *getThreadContext(ContextID tid)
     {
         return threadContexts[tid];
     }
@@ -514,8 +514,9 @@ class System : public MemObject
     /// @return Starting address of first page
     Addr allocPhysPages(int npages);
 
-    int registerThreadContext(ThreadContext *tc, int assigned=-1);
-    void replaceThreadContext(ThreadContext *tc, int context_id);
+    ContextID registerThreadContext(ThreadContext *tc,
+                                    ContextID assigned = InvalidContextID);
+    void replaceThreadContext(ThreadContext *tc, ContextID context_id);
 
     void serialize(CheckpointOut &cp) const M5_ATTR_OVERRIDE;
     void unserialize(CheckpointIn &cp) M5_ATTR_OVERRIDE;