micro-opt: replace stmGetEnclosingTRec() with a field access

[ghc-hetmet.git] / rts / RaiseAsync.c

diff --git a/rts/RaiseAsync.c b/rts/RaiseAsync.c
index e65cea3..a0f78ee 100644 (file)
--- a/rts/RaiseAsync.c
+++ b/rts/RaiseAsync.c
@@ -8,12 +8,12 @@
 
 #include "PosixSource.h"
 #include "Rts.h"
+
+#include "sm/Storage.h"
 #include "Threads.h"
 #include "Trace.h"
 #include "RaiseAsync.h"
-#include "SMP.h"
 #include "Schedule.h"
-#include "LdvProfile.h"
 #include "Updates.h"
 #include "STM.h"
 #include "Sanity.h"
@@ -161,11 +161,7 @@ throwTo (Capability *cap,  // the Capability we hold
               (unsigned long)source->id, (unsigned long)target->id);
 
 #ifdef DEBUG
-    if (traceClass(DEBUG_sched)) {
-       debugTraceBegin("throwTo: target");
-       printThreadStatus(target);
-       debugTraceEnd();
-    }
+    traceThreadStatus(DEBUG_sched, target);
 #endif
 
     goto check_target;
@@ -264,6 +260,15 @@ check_target:
                target = target->_link;
                goto retry;
            }
+            // check again for ThreadComplete and ThreadKilled.  This
+            // cooperates with scheduleHandleThreadFinished to ensure
+            // that we never miss any threads that are throwing an
+            // exception to a thread in the process of terminating.
+            if (target->what_next == ThreadComplete
+                || target->what_next == ThreadKilled) {
+               unlockTSO(target);
+                return THROWTO_SUCCESS;
+            }
            blockedThrowTo(cap,source,target);
            *out = target;
            return THROWTO_BLOCKED;
@@ -564,12 +569,10 @@ maybePerformBlockedException (Capability *cap, StgTSO *tso)
 void
 awakenBlockedExceptionQueue (Capability *cap, StgTSO *tso)
 {
-    if (tso->blocked_exceptions != END_TSO_QUEUE) {
-       lockTSO(tso);
-       awakenBlockedQueue(cap, tso->blocked_exceptions);
-       tso->blocked_exceptions = END_TSO_QUEUE;
-       unlockTSO(tso);
-    }
+    lockTSO(tso);
+    awakenBlockedQueue(cap, tso->blocked_exceptions);
+    tso->blocked_exceptions = END_TSO_QUEUE;
+    unlockTSO(tso);
 }    
 
 static void
@@ -665,16 +668,7 @@ removeFromQueues(Capability *cap, StgTSO *tso)
   }
 
  done:
-  tso->_link = END_TSO_QUEUE; // no write barrier reqd
-  tso->why_blocked = NotBlocked;
-  tso->block_info.closure = NULL;
-  appendToRunQueue(cap,tso);
-
-  // We might have just migrated this TSO to our Capability:
-  if (tso->bound) {
-      tso->bound->cap = cap;
-  }
-  tso->cap = cap;
+  unblockOne(cap, tso);
 }
 
 /* -----------------------------------------------------------------------------
@@ -729,7 +723,7 @@ raiseAsync(Capability *cap, StgTSO *tso, StgClosure *exception,
 #if defined(PROFILING)
     /* 
      * Debugging tool: on raising an  exception, show where we are.
-     * See also Exception.cmm:raisezh_fast.
+     * See also Exception.cmm:stg_raisezh.
      * This wasn't done for asynchronous exceptions originally; see #1450 
      */
     if (RtsFlags.ProfFlags.showCCSOnException)
@@ -890,9 +884,19 @@ raiseAsync(Capability *cap, StgTSO *tso, StgClosure *exception,
            
        case ATOMICALLY_FRAME:
            if (stop_at_atomically) {
-               ASSERT(stmGetEnclosingTRec(tso->trec) == NO_TREC);
+               ASSERT(tso->trec->enclosing_trec == NO_TREC);
                stmCondemnTransaction(cap, tso -> trec);
-               tso->sp = frame;
+               tso->sp = frame - 2;
+                // The ATOMICALLY_FRAME expects to be returned a
+                // result from the transaction, which it stores in the
+                // stack frame.  Hence we arrange to return a dummy
+                // result, so that the GC doesn't get upset (#3578).
+                // Perhaps a better way would be to have a different
+                // ATOMICALLY_FRAME instance for condemned
+                // transactions, but I don't fully understand the
+                // interaction with STM invariants.
+                tso->sp[1] = (W_)&stg_NO_TREC_closure;
+                tso->sp[0] = (W_)&stg_gc_unpt_r1_info;
                tso->what_next = ThreadRunGHC;
                return;
            }
@@ -910,7 +914,7 @@ raiseAsync(Capability *cap, StgTSO *tso, StgClosure *exception,
 
                {
             StgTRecHeader *trec = tso -> trec;
-            StgTRecHeader *outer = stmGetEnclosingTRec(trec);
+            StgTRecHeader *outer = trec -> enclosing_trec;
            debugTrace(DEBUG_stm, 
                       "found atomically block delivering async exception");
             stmAbortTransaction(cap, trec);