From c71a9513e0799533d346b95dbfe7466a849b58d9 Mon Sep 17 00:00:00 2001
From: Richard Brooksby <rb@ravenbrook.com>
Date: Fri, 17 Jan 2014 16:15:13 +0000
Subject: [PATCH] Adding a free address space cbs to the arena, initialising
 and finishing it, but not using it yet.

Moved CBSStruct to mpmst.h so that it can be included inline in ArenaStruct without circularity problems.

Copied from Perforce
 Change: 184044
 ServerID: perforce.ravenbrook.com
---
 mps/code/arena.c   | 18 +++++++++++++++++-
 mps/code/cbs.h     | 16 ----------------
 mps/code/mpmst.h   | 24 ++++++++++++++++++++++++
 mps/code/poolmfs.c |  7 +++++--
 4 files changed, 46 insertions(+), 19 deletions(-)

diff --git a/mps/code/arena.c b/mps/code/arena.c
index df709753143..58bd0652e3b 100644
--- a/mps/code/arena.c
+++ b/mps/code/arena.c
@@ -8,6 +8,8 @@
 #include "tract.h"
 #include "poolmv.h"
 #include "mpm.h"
+#include "cbs.h"
+
 
 SRCID(arena, "$Id$");
 
@@ -142,6 +144,9 @@ Bool ArenaCheck(Arena arena)
   CHECKL(RingCheck(&arena->chunkRing));
   /* nothing to check for chunkSerial */
   CHECKD(ChunkCacheEntry, &arena->chunkCache);
+  
+  /* FIXME: Can't check freeCBS until it's initialised */
+  /* CHECKD(CBS, &arena->freeCBS); */
 
   CHECKL(LocusCheck(arena));
   
@@ -183,7 +188,7 @@ Res ArenaInit(Arena arena, ArenaClass class)
   RingInit(&arena->chunkRing);
   arena->chunkSerial = (Serial)0;
   ChunkCacheEntryInit(&arena->chunkCache);
-
+  
   LocusInit(arena);
   
   res = GlobalsInit(ArenaGlobals(arena));
@@ -192,6 +197,14 @@ Res ArenaInit(Arena arena, ArenaClass class)
 
   arena->sig = ArenaSig;
 
+  MPS_ARGS_BEGIN(cbsiArgs) {
+    MPS_ARGS_ADD(cbsiArgs, MPS_KEY_CBS_EXTEND_BY, 0); /* FIXME: explain why we never extend */
+    MPS_ARGS_DONE(cbsiArgs);
+    res = CBSInit(arena, &arena->freeCBS, arena, arena->alignment, TRUE, cbsiArgs);
+  } MPS_ARGS_END(cbsiArgs);
+  if (res != ResOK)
+    goto failCBSInit;
+
   /* initialize the reservoir, <design/reservoir/> */
   res = ReservoirInit(&arena->reservoirStruct, arena);
   if (res != ResOK)
@@ -201,6 +214,8 @@ Res ArenaInit(Arena arena, ArenaClass class)
   return ResOK;
 
 failReservoirInit:
+  CBSFinish(&arena->freeCBS);
+failCBSInit:
   GlobalsFinish(ArenaGlobals(arena));
 failGlobalsInit:
   return res;
@@ -278,6 +293,7 @@ failInit:
 void ArenaFinish(Arena arena)
 {
   ReservoirFinish(ArenaReservoir(arena));
+  CBSFinish(&arena->freeCBS);
   arena->sig = SigInvalid;
   GlobalsFinish(ArenaGlobals(arena));
   LocusFinish(arena);
diff --git a/mps/code/cbs.h b/mps/code/cbs.h
index 78f516727f8..857847816f3 100644
--- a/mps/code/cbs.h
+++ b/mps/code/cbs.h
@@ -10,7 +10,6 @@
 #define cbs_h
 
 #include "arg.h"
-#include "meter.h"
 #include "mpmtypes.h"
 #include "mpmst.h"
 #include "range.h"
@@ -21,21 +20,6 @@ typedef struct CBSStruct *CBS;
 typedef Bool (*CBSIterateMethod)(CBS cbs, Range range,
                                  void *closureP, Size closureS);
 
-
-#define CBSSig ((Sig)0x519CB599) /* SIGnature CBS */
-
-typedef struct CBSStruct {
-  SplayTreeStruct splayTree;
-  Count splayTreeSize;
-  MFSStruct blockPoolStruct;    /* FIXME: ref to why this is inlined */
-  Align alignment;
-  Bool fastFind;
-  Bool inCBS;                   /* prevent reentrance */
-  /* meters for sizes of search structures at each op */
-  METER_DECL(splaySearch);
-  Sig sig; /* sig at end because embeded */
-} CBSStruct;
-
 extern Bool CBSCheck(CBS cbs);
 
 extern Res CBSInit(Arena arena, CBS cbs, void *owner,
diff --git a/mps/code/mpmst.h b/mps/code/mpmst.h
index a95083b32b5..01f0f8e7df8 100644
--- a/mps/code/mpmst.h
+++ b/mps/code/mpmst.h
@@ -27,6 +27,8 @@
 #include "protocol.h"
 #include "ring.h"
 #include "chain.h"
+#include "splay.h"
+#include "meter.h"
 
 
 /* PoolClassStruct -- pool class structure
@@ -600,6 +602,26 @@ typedef struct GlobalsStruct {
 } GlobalsStruct;
 
 
+/* CBSStruct -- coalescing block structure
+ *
+ * See <code/cbs.c>.
+ */
+
+#define CBSSig ((Sig)0x519CB599) /* SIGnature CBS */
+
+typedef struct CBSStruct {
+  SplayTreeStruct splayTree;
+  Count splayTreeSize;
+  MFSStruct blockPoolStruct;    /* FIXME: ref to why this is inlined */
+  Align alignment;
+  Bool fastFind;
+  Bool inCBS;                   /* prevent reentrance */
+  /* meters for sizes of search structures at each op */
+  METER_DECL(splaySearch);
+  Sig sig; /* sig at end because embeded */
+} CBSStruct;
+
+
 /* ArenaStruct -- generic arena
  *
  * See <code/arena.c>.  */
@@ -633,6 +655,8 @@ typedef struct mps_arena_s {
   RingStruct chunkRing;         /* all the chunks */
   Serial chunkSerial;           /* next chunk number */
   ChunkCacheEntryStruct chunkCache; /* just one entry */
+  
+  CBSStruct freeCBS;            /* CBS of free address space */
 
   /* locus fields (<code/locus.c>) */
   GenDescStruct topGen;         /* generation descriptor for dynamic gen */
diff --git a/mps/code/poolmfs.c b/mps/code/poolmfs.c
index 3f596c5d251..accfdabb46f 100644
--- a/mps/code/poolmfs.c
+++ b/mps/code/poolmfs.c
@@ -111,7 +111,7 @@ static Res MFSInit(Pool pool, ArgList args)
       extendBy = unitSize;
   }
 
-  AVER(extendBy >= unitSize);
+  AVER(extendBy == 0 || extendBy >= unitSize);
  
   mfs = PoolPoolMFS(pool);
   arena = PoolArena(pool);
@@ -189,6 +189,9 @@ static Res MFSAlloc(Addr *pReturn, Pool pool, Size size,
     Size unitSize;
     Addr base;
     Header header = NULL, next;
+    
+    if (mfs->extendBy == 0)
+      return ResLIMIT;
 
     /* Create a new region and attach it to the pool. */
     res = ArenaAlloc(&base, SegPrefDefault(), mfs->extendBy, pool,
@@ -322,7 +325,7 @@ Bool MFSCheck(MFS mfs)
   CHECKD(Pool, &mfs->poolStruct);
   CHECKL(mfs->poolStruct.class == EnsureMFSPoolClass());
   CHECKL(mfs->unroundedUnitSize >= UNIT_MIN);
-  CHECKL(mfs->extendBy >= UNIT_MIN);
+  CHECKL(mfs->extendBy == 0 || mfs->extendBy >= UNIT_MIN);
   arena = PoolArena(&mfs->poolStruct);
   CHECKL(SizeIsAligned(mfs->extendBy, ArenaAlign(arena)));
   CHECKL(SizeAlignUp(mfs->unroundedUnitSize, mfs->poolStruct.alignment) ==