From d8d5ebbe9124fe5ff92d30ccb8c8a0e934566a7c Mon Sep 17 00:00:00 2001
From: Richard Brooksby <rptb1+github@pobox.com>
Date: Fri, 12 Feb 2016 15:22:34 +0000
Subject: [PATCH] Separating arenaenter from stack_context_begin and arenaleave
 from stack_context_end as they are not conceptually nested that way.

Copied from Perforce
 Change: 189446
 ServerID: perforce.ravenbrook.com
---
 mps/code/mpsi.c | 18 ++++++++++++++++++
 mps/code/ss.h   | 24 ++++++++++++------------
 2 files changed, 30 insertions(+), 12 deletions(-)

diff --git a/mps/code/mpsi.c b/mps/code/mpsi.c
index eb4bc63a42c..b27f26adafd 100644
--- a/mps/code/mpsi.c
+++ b/mps/code/mpsi.c
@@ -231,9 +231,11 @@ void mps_arena_clamp(mps_arena_t arena)
 
 void mps_arena_release(mps_arena_t arena)
 {
+  ArenaEnter(arena);
   STACK_CONTEXT_BEGIN(arena) {
     ArenaRelease(ArenaGlobals(arena));
   } STACK_CONTEXT_END(arena);
+  ArenaLeave(arena);
 }
 
 
@@ -271,19 +273,23 @@ void mps_arena_unsafe_restore_protection(mps_arena_t arena)
 mps_res_t mps_arena_start_collect(mps_arena_t arena)
 {
   Res res;
+  ArenaEnter(arena);
   STACK_CONTEXT_BEGIN(arena) {
     res = ArenaStartCollect(ArenaGlobals(arena),
                             TraceStartWhyCLIENTFULL_INCREMENTAL);
   } STACK_CONTEXT_END(arena);
+  ArenaLeave(arena);
   return (mps_res_t)res;
 }
 
 mps_res_t mps_arena_collect(mps_arena_t arena)
 {
   Res res;
+  ArenaEnter(arena);
   STACK_CONTEXT_BEGIN(arena) {
     res = ArenaCollect(ArenaGlobals(arena), TraceStartWhyCLIENTFULL_BLOCK);
   } STACK_CONTEXT_END(arena);
+  ArenaLeave(arena);
   return (mps_res_t)res;
 }
 
@@ -292,9 +298,11 @@ mps_bool_t mps_arena_step(mps_arena_t arena,
                           double multiplier)
 {
   Bool b;
+  ArenaEnter(arena);
   STACK_CONTEXT_BEGIN(arena) {
     b = ArenaStep(ArenaGlobals(arena), interval, multiplier);
   } STACK_CONTEXT_END(arena);
+  ArenaLeave(arena);
   return b;
 }
 
@@ -734,6 +742,7 @@ mps_res_t mps_alloc(mps_addr_t *p_o, mps_pool_t pool, size_t size)
   AVER(TESTT(Pool, pool));
   arena = PoolArena(pool);
 
+  ArenaEnter(arena);
   STACK_CONTEXT_BEGIN(arena) {
 
     ArenaPoll(ArenaGlobals(arena)); /* .poll */
@@ -750,6 +759,7 @@ mps_res_t mps_alloc(mps_addr_t *p_o, mps_pool_t pool, size_t size)
     res = PoolAlloc(&p, pool, size, FALSE);
 
   } STACK_CONTEXT_END(arena);
+  ArenaLeave(arena);
 
   if (res != ResOK)
     return (mps_res_t)res;
@@ -1041,6 +1051,7 @@ mps_res_t mps_ap_fill(mps_addr_t *p_o, mps_ap_t mps_ap, size_t size)
   AVER(TESTT(Buffer, buf));
   arena = BufferArena(buf);
 
+  ArenaEnter(arena);
   STACK_CONTEXT_BEGIN(arena) {
 
     ArenaPoll(ArenaGlobals(arena)); /* .poll */
@@ -1053,6 +1064,7 @@ mps_res_t mps_ap_fill(mps_addr_t *p_o, mps_ap_t mps_ap, size_t size)
     res = BufferFill(&p, buf, size, FALSE);
 
   } STACK_CONTEXT_END(arena);
+  ArenaLeave(arena);
 
   if (res != ResOK)
     return (mps_res_t)res;
@@ -1073,6 +1085,7 @@ mps_res_t mps_ap_fill_with_reservoir_permit(mps_addr_t *p_o, mps_ap_t mps_ap,
   AVER(TESTT(Buffer, buf));
   arena = BufferArena(buf);
 
+  ArenaEnter(arena);
   STACK_CONTEXT_BEGIN(arena) {
 
     ArenaPoll(ArenaGlobals(arena)); /* .poll */
@@ -1085,6 +1098,7 @@ mps_res_t mps_ap_fill_with_reservoir_permit(mps_addr_t *p_o, mps_ap_t mps_ap,
     res = BufferFill(&p, buf, size, TRUE);
 
   } STACK_CONTEXT_END(arena);
+  ArenaLeave(arena);
 
   if (res != ResOK)
     return (mps_res_t)res;
@@ -1874,10 +1888,12 @@ mps_res_t mps_ap_alloc_pattern_end(mps_ap_t mps_ap,
 
   arena = BufferArena(BufferOfAP(mps_ap));
 
+  ArenaEnter(arena);
   STACK_CONTEXT_BEGIN(arena) {
     res = BufferRampEnd(BufferOfAP(mps_ap));
     ArenaPoll(ArenaGlobals(arena)); /* .poll */
   } STACK_CONTEXT_END(arena);
+  ArenaLeave(arena);
 
   return (mps_res_t)res;
 }
@@ -1892,10 +1908,12 @@ mps_res_t mps_ap_alloc_pattern_reset(mps_ap_t mps_ap)
 
   arena = BufferArena(BufferOfAP(mps_ap));
 
+  ArenaEnter(arena);
   STACK_CONTEXT_BEGIN(arena) {
     BufferRampReset(BufferOfAP(mps_ap));
     ArenaPoll(ArenaGlobals(arena)); /* .poll */
   } STACK_CONTEXT_END(arena);
+  ArenaLeave(arena);
 
   return MPS_RES_OK;
 }
diff --git a/mps/code/ss.h b/mps/code/ss.h
index ad7ead0c751..7e20c8aac8e 100644
--- a/mps/code/ss.h
+++ b/mps/code/ss.h
@@ -24,23 +24,23 @@ typedef struct StackContextStruct {
 } StackContextStruct;
 
 
-/* STACK_CONTEXT_BEGIN -- enter arena and save context */
+/* STACK_CONTEXT_BEGIN -- save context */
 
-#define STACK_CONTEXT_BEGIN(arena) BEGIN \
-  StackContextStruct _sc; \
-  ArenaEnter(arena); \
-  STACK_CONTEXT_SAVE(&_sc); \
-  AVER(arena->scAtArenaEnter == NULL); \
-  arena->scAtArenaEnter = &_sc; \
-  BEGIN
+#define STACK_CONTEXT_BEGIN(arena) \
+  BEGIN \
+    StackContextStruct _sc; \
+    STACK_CONTEXT_SAVE(&_sc); \
+    AVER(arena->scAtArenaEnter == NULL); \
+    arena->scAtArenaEnter = &_sc; \
+    BEGIN
 
 
 /* STACK_CONTEXT_END -- clear context and leave arena */
 
-#define STACK_CONTEXT_END(arena) END; \
-  AVER(arena->scAtArenaEnter != NULL); \
-  arena->scAtArenaEnter = NULL; \
-  ArenaLeave(arena); \
+#define STACK_CONTEXT_END(arena) \
+    END; \
+    AVER(arena->scAtArenaEnter != NULL); \
+    arena->scAtArenaEnter = NULL; \
   END