From 9dadfb7444a223cd9eac71b48da00b933db02716 Mon Sep 17 00:00:00 2001
From: Gareth Rees <gdr@ravenbrook.com>
Date: Wed, 4 Jul 2018 16:31:45 +0100
Subject: [PATCH] Mfsextend now takes (base, limit) instead of (base, size) for
 consistency with the rest of the mps.

Copied from Perforce
 Change: 194408
---
 mps/code/arena.c   | 16 +++++++++-------
 mps/code/poolmfs.c | 11 +++++++----
 mps/code/poolmfs.h |  2 +-
 3 files changed, 17 insertions(+), 12 deletions(-)

diff --git a/mps/code/arena.c b/mps/code/arena.c
index 1948e8b4f9c..1ab23d274e0 100644
--- a/mps/code/arena.c
+++ b/mps/code/arena.c
@@ -852,15 +852,16 @@ static void arenaFreePage(Arena arena, Addr base, Pool pool)
 
 static Res arenaExtendCBSBlockPool(Range pageRangeReturn, Arena arena)
 {
-  Addr pageBase;
+  Addr pageBase, pageLimit;
   Res res;
 
   res = arenaAllocPage(&pageBase, arena, ArenaCBSBlockPool(arena));
   if (res != ResOK)
     return res;
-  MFSExtend(ArenaCBSBlockPool(arena), pageBase, ArenaGrainSize(arena));
+  pageLimit = AddrAdd(pageBase, ArenaGrainSize(arena));
+  MFSExtend(ArenaCBSBlockPool(arena), pageBase, pageLimit);
 
-  RangeInitSize(pageRangeReturn, pageBase, ArenaGrainSize(arena));
+  RangeInit(pageRangeReturn, pageBase, pageLimit);
   return ResOK;
 }
 
@@ -940,22 +941,23 @@ static void arenaFreeLandInsertSteal(Range rangeReturn, Arena arena,
   res = arenaFreeLandInsertExtend(rangeReturn, arena, rangeIO);
   
   if (res != ResOK) {
-    Addr pageBase;
+    Addr pageBase, pageLimit;
     Tract tract;
     AVER(ResIsAllocFailure(res));
 
     /* Steal a page from the memory we're about to free. */
     AVER(RangeSize(rangeIO) >= ArenaGrainSize(arena));
     pageBase = RangeBase(rangeIO);
-    RangeInit(rangeIO, AddrAdd(pageBase, ArenaGrainSize(arena)),
-                       RangeLimit(rangeIO));
+    pageLimit = AddrAdd(pageBase, ArenaGrainSize(arena));
+    AVER(pageLimit <= RangeLimit(rangeIO));
+    RangeInit(rangeIO, pageLimit, RangeLimit(rangeIO));
 
     /* Steal the tract from its owning pool. */
     tract = TractOfBaseAddr(arena, pageBase);
     TractFinish(tract);
     TractInit(tract, ArenaCBSBlockPool(arena), pageBase);
   
-    MFSExtend(ArenaCBSBlockPool(arena), pageBase, ArenaGrainSize(arena));
+    MFSExtend(ArenaCBSBlockPool(arena), pageBase, pageLimit);
 
     /* Try again. */
     res = LandInsert(rangeReturn, ArenaFreeLand(arena), rangeIO);
diff --git a/mps/code/poolmfs.c b/mps/code/poolmfs.c
index e7fc4be5c77..21f87ad448a 100644
--- a/mps/code/poolmfs.c
+++ b/mps/code/poolmfs.c
@@ -166,16 +166,18 @@ static void MFSFinish(Inst inst)
 }
 
 
-void MFSExtend(Pool pool, Addr base, Size size)
+void MFSExtend(Pool pool, Addr base, Addr limit)
 {
   MFS mfs = MustBeA(MFSPool, pool);
   Word i, unitsPerExtent;
+  Size size;
   Size unitSize;
   Size ringSize;
   Header header = NULL;
   Ring mfsRing;
 
-  AVER(size == mfs->extendBy);
+  AVER(base < limit);
+  AVER(AddrOffset(base, limit) == mfs->extendBy);
 
   /* Ensure that the memory we're adding belongs to this pool.  This is
      automatic if it was allocated using ArenaAlloc, but if the memory is
@@ -193,7 +195,8 @@ void MFSExtend(Pool pool, Addr base, Size size)
 
   ringSize = SizeAlignUp(sizeof(RingStruct), MPS_PF_ALIGN);
   base = AddrAdd(base, ringSize);
-  size -= ringSize;
+  AVER(base < limit);
+  size = AddrOffset(base, limit);
 
   /* Update accounting */
   mfs->total += size;
@@ -255,7 +258,7 @@ static Res MFSAlloc(Addr *pReturn, Pool pool, Size size)
     if(res != ResOK)
       return res;
 
-    MFSExtend(pool, base, mfs->extendBy);
+    MFSExtend(pool, base, AddrAdd(base, mfs->extendBy));
 
     /* The first unit in the region is now the head of the new free list. */
     f = mfs->freeList;
diff --git a/mps/code/poolmfs.h b/mps/code/poolmfs.h
index 2638e8f92bd..9f112ea80f5 100644
--- a/mps/code/poolmfs.h
+++ b/mps/code/poolmfs.h
@@ -45,7 +45,7 @@ extern const struct mps_key_s _mps_key_MFSExtendSelf;
 #define MFSExtendSelf (&_mps_key_MFSExtendSelf)
 #define MFSExtendSelf_FIELD b
 
-extern void MFSExtend(Pool pool, Addr base, Size size);
+extern void MFSExtend(Pool pool, Addr base, Addr limit);
 
 typedef void MFSExtentVisitor(Pool pool, Addr base, Size size,
                               void *closure);