NCG: Fix validate

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

diff --git a/rts/Schedule.c b/rts/Schedule.c
index 7c453d7..978adb8 100644 (file)
--- a/rts/Schedule.c
+++ b/rts/Schedule.c
@@ -32,6 +32,7 @@
 #include "Proftimer.h"
 #include "ProfHeap.h"
 #include "GC.h"
+#include "Weak.h"
 
 /* PARALLEL_HASKELL includes go here */
 
@@ -281,6 +282,12 @@ schedule (Capability *initialCapability, Task *task)
              "### NEW SCHEDULER LOOP (task: %p, cap: %p)",
              task, initialCapability);
 
+  if (running_finalizers) {
+      errorBelch("error: a C finalizer called back into Haskell.\n"
+                 "   use Foreign.Concurrent.newForeignPtr for Haskell finalizers.");
+      stg_exit(EXIT_FAILURE);
+  }
+
   schedulePreLoop();
 
   // -----------------------------------------------------------
@@ -1403,10 +1410,9 @@ scheduleHandleThreadFinished (Capability *cap STG_UNUSED, Task *task, StgTSO *t)
               (unsigned long)t->id, whatNext_strs[t->what_next]);
 
     // blocked exceptions can now complete, even if the thread was in
-    // blocked mode (see #2910).  The thread is already marked
-    // ThreadComplete, so any further throwTos will complete
-    // immediately and we don't need to worry about synchronising with
-    // those.
+    // blocked mode (see #2910).  This unconditionally calls
+    // lockTSO(), which ensures that we don't miss any threads that
+    // are engaged in throwTo() with this thread as a target.
     awakenBlockedExceptionQueue (cap, t);
 
       //
@@ -1599,6 +1605,21 @@ delete_threads_and_gc:
     
     heap_census = scheduleNeedHeapProfile(rtsTrue);
 
+    if (recent_activity == ACTIVITY_INACTIVE && force_major)
+    {
+        // We are doing a GC because the system has been idle for a
+        // timeslice and we need to check for deadlock.  Record the
+        // fact that we've done a GC and turn off the timer signal;
+        // it will get re-enabled if we run any threads after the GC.
+        //
+        // Note: this is done before GC, because after GC there might
+        // be threads already running (GarbageCollect() releases the
+        // GC threads when it completes), so we risk turning off the
+        // timer signal when it should really be on.
+        recent_activity = ACTIVITY_DONE_GC;
+        stopTimer();
+    }
+
 #if defined(THREADED_RTS)
     debugTrace(DEBUG_sched, "doing GC");
     // reset waiting_for_gc *before* GC, so that when the GC threads
@@ -1640,16 +1661,6 @@ delete_threads_and_gc:
     balanceSparkPoolsCaps(n_capabilities, capabilities);
 #endif
 
-    if (force_major)
-    {
-        // We've just done a major GC and we don't need the timer
-        // signal turned on any more (#1623).
-        // NB. do this *before* releasing the Capabilities, to avoid
-        // deadlocks!
-        recent_activity = ACTIVITY_DONE_GC;
-        stopTimer();
-    }
-
 #if defined(THREADED_RTS)
     if (gc_type == PENDING_GC_SEQ) {
         // release our stash of capabilities.
@@ -1983,7 +1994,10 @@ resumeThread (void *task_)
     debugTrace(DEBUG_sched, "thread %lu: re-entering RTS", (unsigned long)tso->id);
     
     if (tso->why_blocked == BlockedOnCCall) {
-       awakenBlockedExceptionQueue(cap,tso);
+        // avoid locking the TSO if we don't have to
+        if (tso->blocked_exceptions != END_TSO_QUEUE) {
+            awakenBlockedExceptionQueue(cap,tso);
+        }
        tso->flags &= ~(TSO_BLOCKEX | TSO_INTERRUPTIBLE);
     }