From 3cd78358444a437cda53fc8a2f5bc9209441c4f8 Mon Sep 17 00:00:00 2001
From: Gareth Rees <gdr@ravenbrook.com>
Date: Tue, 13 Sep 2016 15:33:31 +0100
Subject: [PATCH] Catch-up merge from custom/cet/branch/2016-09-13/job004006 to
 branch/2016-09-06/job004006.

Copied from Perforce
 Change: 192351
 ServerID: perforce.ravenbrook.com
---
 mps/code/global.c   |  6 +++---
 mps/code/mpm.h      |  1 -
 mps/code/traceanc.c | 12 ++++--------
 3 files changed, 7 insertions(+), 12 deletions(-)

diff --git a/mps/code/global.c b/mps/code/global.c
index b6b57ea5f50..69768a6e5d5 100644
--- a/mps/code/global.c
+++ b/mps/code/global.c
@@ -73,14 +73,14 @@ static void arenaAnnounce(Arena arena)
 }
 
 
-/* ArenaDenounce -- remove an arena from the global ring of arenas
+/* arenaDenounce -- remove an arena from the global ring of arenas
  *
  * After this, no other thread can access the arena through ArenaAccess.
  * On entry, the arena should be locked.  On exit, it will still be, but
  * the lock has been released and reacquired in the meantime, so callers
  * should not assume anything about the state of the arena.  */
 
-void ArenaDenounce(Arena arena)
+static void arenaDenounce(Arena arena)
 {
   Globals arenaGlobals;
 
@@ -403,7 +403,7 @@ void GlobalsPrepareToDestroy(Globals arenaGlobals)
 
   arena = GlobalsArena(arenaGlobals);
 
-  ArenaDenounce(arena);
+  arenaDenounce(arena);
 
   defaultChain = arenaGlobals->defaultChain;
   arenaGlobals->defaultChain = NULL;
diff --git a/mps/code/mpm.h b/mps/code/mpm.h
index cefa9f3e656..e2b99e1fead 100644
--- a/mps/code/mpm.h
+++ b/mps/code/mpm.h
@@ -487,7 +487,6 @@ extern Res ArenaDescribeTracts(Arena arena, mps_lib_FILE *stream, Count depth);
 extern Bool ArenaAccess(Addr addr, AccessSet mode, MutatorFaultContext context);
 extern Res ArenaFreeLandInsert(Arena arena, Addr base, Addr limit);
 extern void ArenaFreeLandDelete(Arena arena, Addr base, Addr limit);
-extern void ArenaDenounce(Arena arena);
 
 extern Bool GlobalsCheck(Globals arena);
 extern Res GlobalsInit(Globals arena);
diff --git a/mps/code/traceanc.c b/mps/code/traceanc.c
index 77054c52d71..a446aa41b67 100644
--- a/mps/code/traceanc.c
+++ b/mps/code/traceanc.c
@@ -637,21 +637,17 @@ void ArenaPostmortem(Globals globals)
     LockReleaseRecursive(globals->lock);
   }
 
-  /* Acquire the lock again so that we can call ArenaDenounce. */
-  ArenaEnter(arena);
-
   /* Remove the arena from the global arena ring so that it no longer
-   * handles protection faults. */
-  ArenaDenounce(arena);
+   * handles protection faults. (Don't call arenaDenounce because that
+   * needs to claim the global ring lock, but that might already be
+   * held, for example if we are inside ArenaAccess.) */
+  RingRemove(&globals->globalRing);
 
   /* Clamp the arena so that ArenaPoll does nothing. */
   ArenaClamp(globals);
 
   /* Remove all protection from mapped pages. */
   arenaExpose(arena);
-
-  /* Release the lock finally. */
-  ArenaLeave(arena);
 }