From f63d05eaaf0ef328e745c8a3f802afe2ef9e1cfe Mon Sep 17 00:00:00 2001
From: David Jones <drj@ravenbrook.com>
Date: Mon, 2 Jul 2007 15:43:34 +0100
Subject: [PATCH] Mps: added band field to tracestruct.  unused.

Copied from Perforce
 Change: 162717
 ServerID: perforce.ravenbrook.com
---
 mps/code/mpmst.h |  1 +
 mps/code/trace.c | 50 +++++++++++++++++++++++++++---------------------
 2 files changed, 29 insertions(+), 22 deletions(-)

diff --git a/mps/code/mpmst.h b/mps/code/mpmst.h
index 695bb8c82db..c82325da828 100644
--- a/mps/code/mpmst.h
+++ b/mps/code/mpmst.h
@@ -514,6 +514,7 @@ typedef struct TraceStruct {
   ZoneSet white;                /* zones in the white set */
   ZoneSet mayMove;              /* zones containing possibly moving objs */
   TraceState state;             /* current state of trace */
+  Rank band;                    /* current band */
   Bool emergency;               /* ran out of memory during trace */
   Chain chain;                  /* chain being incrementally collected */
   Size condemned;               /* condemned bytes */
diff --git a/mps/code/trace.c b/mps/code/trace.c
index 36a30274522..961df33fefe 100644
--- a/mps/code/trace.c
+++ b/mps/code/trace.c
@@ -387,36 +387,41 @@ Bool TraceCheck(Trace trace)
   CHECKL(ZoneSetSub(trace->mayMove, trace->white));
   /* Use trace->state to check more invariants. */
   switch(trace->state) {
-  case TraceINIT:
-    /* @@@@ What can be checked here? */
-    break;
+    case TraceINIT:
+      /* @@@@ What can be checked here? */
+      break;
 
-  case TraceUNFLIPPED:
-    CHECKL(!TraceSetIsMember(trace->arena->flippedTraces, trace));
-    /* @@@@ Assert that mutator is grey for trace. */
-    break;
+    case TraceUNFLIPPED:
+      CHECKL(!TraceSetIsMember(trace->arena->flippedTraces, trace));
+      /* @@@@ Assert that mutator is grey for trace. */
+      break;
 
-  case TraceFLIPPED:
-    CHECKL(TraceSetIsMember(trace->arena->flippedTraces, trace));
-    /* @@@@ Assert that mutator is black for trace. */
-    break;
+    case TraceFLIPPED:
+      CHECKL(TraceSetIsMember(trace->arena->flippedTraces, trace));
+      /* @@@@ Assert that mutator is black for trace. */
+      break;
 
-  case TraceRECLAIM:
-    CHECKL(TraceSetIsMember(trace->arena->flippedTraces, trace));
-    /* @@@@ Assert that grey set is empty for trace. */
-    break;
+    case TraceRECLAIM:
+      CHECKL(TraceSetIsMember(trace->arena->flippedTraces, trace));
+      /* @@@@ Assert that grey set is empty for trace. */
+      break;
 
-  case TraceFINISHED:
-    CHECKL(TraceSetIsMember(trace->arena->flippedTraces, trace));
-    /* @@@@ Assert that grey and white sets is empty for trace. */
-    break;
+    case TraceFINISHED:
+      CHECKL(TraceSetIsMember(trace->arena->flippedTraces, trace));
+      /* @@@@ Assert that grey and white sets is empty for trace. */
+      break;
 
-  default:
-    NOTREACHED;
+    default:
+      NOTREACHED;
+  }
+  /* Valid values for band depend on state. */
+  if(trace->state == TraceFLIPPED) {
+    CHECKL(RankCheck(trace->band));
   }
   CHECKL(BoolCheck(trace->emergency));
-  if (trace->chain != NULL)
+  if(trace->chain != NULL) {
     CHECKU(Chain, trace->chain);
+  }
   /* @@@@ checks for counts missing */
   CHECKD(TraceStartMessage, &trace->startMessage);
   return TRUE;
@@ -807,6 +812,7 @@ found:
   trace->mayMove = ZoneSetEMPTY;
   trace->ti = ti;
   trace->state = TraceINIT;
+  trace->band = RankAMBIG;      /* Required to be the earliest rank. */
   trace->emergency = FALSE;
   trace->chain = NULL;
   trace->condemned = (Size)0;   /* nothing condemned yet */