X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=rts%2FHeapStackCheck.cmm;h=1533ae0617a71361406a33d4b8a1705675940e61;hb=0ee0be109fd00ec629f7a2ad6a597885a0c9d5b4;hp=3980ca2dd10a5d476f51f867f4a17cc809ef5bce;hpb=8f52645bd99ee3e636a34826c0cbfc5939920da1;p=ghc-hetmet.git

diff --git a/rts/HeapStackCheck.cmm b/rts/HeapStackCheck.cmm
index 3980ca2..1533ae0 100644
--- a/rts/HeapStackCheck.cmm
+++ b/rts/HeapStackCheck.cmm
@@ -23,8 +23,11 @@ import LeaveCriticalSection;
  *
  * On discovering that a stack or heap check has failed, we do the following:
  *
- *    - If the context_switch flag is set, indicating that there are more
- *      threads waiting to run, we yield to the scheduler 
+ *    - If HpLim==0, indicating that we should context-switch, we yield
+ *      to the scheduler (return ThreadYielding).
+ *
+ *    - If the context_switch flag is set (the backup plan if setting HpLim
+ *      to 0 didn't trigger a context switch), we yield to the scheduler
  *	(return ThreadYielding).
  *
  *    - If Hp > HpLim, we've had a heap check failure.  This means we've
@@ -61,6 +64,10 @@ import LeaveCriticalSection;
     DEBUG_ONLY(foreign "C" heapCheckFail());			\
     if (Hp > HpLim) {						\
         Hp = Hp - HpAlloc/*in bytes*/;				\
+        if (HpLim == 0) { \
+                R1 = ThreadYielding;				\
+                goto sched;					\
+        }						\
         if (HpAlloc <= BLOCK_SIZE				\
             && bdescr_link(CurrentNursery) != NULL) {		\
             CLOSE_NURSERY();					\
@@ -114,7 +121,7 @@ import LeaveCriticalSection;
    There are canned sequences for 'n' pointer values in registers.
    -------------------------------------------------------------------------- */
 
-INFO_TABLE_RET( stg_enter, RET_SMALL, "ptr" W_ unused)
+INFO_TABLE_RET( stg_enter, RET_SMALL, P_ unused)
 {
     R1 = Sp(1);
     Sp_adj(2);
@@ -444,7 +451,7 @@ INFO_TABLE_RET( stg_gc_void, RET_SMALL)
 
 /*-- R1 is boxed/unpointed -------------------------------------------------- */
 
-INFO_TABLE_RET( stg_gc_unpt_r1, RET_SMALL, "ptr" W_ unused)
+INFO_TABLE_RET( stg_gc_unpt_r1, RET_SMALL, P_ unused)
 {
     R1 = Sp(1);
     Sp_adj(2);
@@ -531,7 +538,7 @@ stg_gc_l1
 
 /*-- Unboxed tuple return, one pointer (unregisterised build only) ---------- */
 
-INFO_TABLE_RET( stg_ut_1_0_unreg, RET_SMALL, "ptr" W_ unused )
+INFO_TABLE_RET( stg_ut_1_0_unreg, RET_SMALL, P_ unused )
 {
     Sp_adj(1);
     // one ptr is on the stack (Sp(0))
@@ -816,7 +823,7 @@ stg_block_1
  * 
  * -------------------------------------------------------------------------- */
 
-INFO_TABLE_RET( stg_block_takemvar, RET_SMALL, "ptr" W_ unused )
+INFO_TABLE_RET( stg_block_takemvar, RET_SMALL, P_ unused )
 {
     R1 = Sp(1);
     Sp_adj(2);
@@ -843,7 +850,7 @@ stg_block_takemvar
     BLOCK_BUT_FIRST(stg_block_takemvar_finally);
 }
 
-INFO_TABLE_RET( stg_block_putmvar, RET_SMALL, "ptr" W_ unused1, "ptr" W_ unused2 )
+INFO_TABLE_RET( stg_block_putmvar, RET_SMALL, P_ unused1, P_ unused2 )
 {
     R2 = Sp(2);
     R1 = Sp(1);
@@ -892,7 +899,7 @@ stg_block_blackhole
     BLOCK_BUT_FIRST(stg_block_blackhole_finally);
 }
 
-INFO_TABLE_RET( stg_block_throwto, RET_SMALL, "ptr" W_ unused, "ptr" W_ unused )
+INFO_TABLE_RET( stg_block_throwto, RET_SMALL, P_ unused, P_ unused )
 {
     R2 = Sp(2);
     R1 = Sp(1);