MERGE: Fix a few uses of the wrong return convention for the scheduler
[ghc-hetmet.git] / rts / Exception.cmm
index 5c2ee95..8ed83b3 100644 (file)
 INFO_TABLE_RET( stg_unblockAsyncExceptionszh_ret,
                0/*framesize*/, 0/*bitmap*/, RET_SMALL )
 {
+    CInt r;
+
     // Not true: see comments above
     // ASSERT(StgTSO_blocked_exceptions(CurrentTSO) != NULL);
 
-    foreign "C" awakenBlockedExceptionQueue(MyCapability() "ptr", 
-                                           CurrentTSO "ptr") [R1];
-
     StgTSO_flags(CurrentTSO) = StgTSO_flags(CurrentTSO) & 
        ~(TSO_BLOCKEX::I32|TSO_INTERRUPTIBLE::I32);
 
+    /* Eagerly raise a blocked exception, if there is one */
+    if (StgTSO_blocked_exceptions(CurrentTSO) != END_TSO_QUEUE) {
+        /* 
+         * We have to be very careful here, as in killThread#, since
+         * we are about to raise an async exception in the current
+         * thread, which might result in the thread being killed.
+         */
+
+#ifndef REG_R1
+        /*
+         * raiseAsync assumes that the stack is in ThreadRunGHC state,
+         * i.e. with a return address on the top.  In unreg mode, the
+         * return value for IO is on top of the return address, so we
+         * need to make a small adjustment here.
+         */
+        Sp_adj(1);
+#endif
+        SAVE_THREAD_STATE();
+        r = foreign "C" maybePerformBlockedException (MyCapability() "ptr", 
+                                                     CurrentTSO "ptr") [R1];
+
+        if (r != 0::CInt) {
+            if (StgTSO_what_next(CurrentTSO) == ThreadKilled::I16) {
+                jump stg_threadFinished;
+            } else {
+                LOAD_THREAD_STATE();
+                ASSERT(StgTSO_what_next(CurrentTSO) == ThreadRunGHC::I16);
+                jump %ENTRY_CODE(Sp(0));
+            }
+        }
+#ifndef REG_R1
+        /* 
+         * Readjust stack in unregisterised mode if we didn't raise an
+         * exception, see above
+         */
+        else {
+            Sp_adj(-1);
+        }
+#endif
+    }
+
 #ifdef REG_R1
     Sp_adj(1);
     jump %ENTRY_CODE(Sp(0));
@@ -116,12 +156,37 @@ blockAsyncExceptionszh_fast
 
 unblockAsyncExceptionszh_fast
 {
+    CInt r;
+
     /* Args: R1 :: IO a */
     STK_CHK_GEN( WDS(2), R1_PTR, unblockAsyncExceptionszh_fast);
 
     if ((TO_W_(StgTSO_flags(CurrentTSO)) & TSO_BLOCKEX) != 0) {
-       foreign "C" awakenBlockedExceptionQueue(MyCapability() "ptr", 
-                                               CurrentTSO "ptr") [R1];
+
+       StgTSO_flags(CurrentTSO) = StgTSO_flags(CurrentTSO) & 
+          ~(TSO_BLOCKEX::I32|TSO_INTERRUPTIBLE::I32);
+
+        /* Eagerly raise a blocked exception, if there is one */
+        if (StgTSO_blocked_exceptions(CurrentTSO) != END_TSO_QUEUE) {
+            /* 
+             * We have to be very careful here, as in killThread#, since
+             * we are about to raise an async exception in the current
+             * thread, which might result in the thread being killed.
+             */
+            SAVE_THREAD_STATE();
+            r = foreign "C" maybePerformBlockedException (MyCapability() "ptr", 
+                                                     CurrentTSO "ptr") [R1];
+
+            if (r != 0::CInt) {
+                if (StgTSO_what_next(CurrentTSO) == ThreadKilled::I16) {
+                    jump stg_threadFinished;
+               } else {
+                   LOAD_THREAD_STATE();
+                   ASSERT(StgTSO_what_next(CurrentTSO) == ThreadRunGHC::I16);
+                   jump %ENTRY_CODE(Sp(0));
+               }
+            }
+        }
 
        /* avoid growing the stack unnecessarily */
        if (Sp(0) == stg_unblockAsyncExceptionszh_ret_info) {
@@ -162,8 +227,7 @@ killThreadzh_fast
        foreign "C" throwToSingleThreaded(MyCapability() "ptr", 
                                          target "ptr", exception "ptr")[R1,R2];
        if (StgTSO_what_next(CurrentTSO) == ThreadKilled::I16) {
-           R1 = ThreadFinished;
-           jump StgReturn;
+            jump stg_threadFinished;
        } else {
            LOAD_THREAD_STATE();
            ASSERT(StgTSO_what_next(CurrentTSO) == ThreadRunGHC::I16);
@@ -200,43 +264,11 @@ killThreadzh_fast
    -------------------------------------------------------------------------- */
 
 #ifdef REG_R1
-#define CATCH_FRAME_ENTRY_TEMPLATE(label,ret)  \
-   label                                       \
-   {                                           \
-      Sp = Sp + SIZEOF_StgCatchFrame;          \
-      jump ret;                                        \
-   }
-#else
-#define CATCH_FRAME_ENTRY_TEMPLATE(label,ret)  \
-   label                                       \
-   {                                           \
-      W_ rval;                                 \
-      rval = Sp(0);                            \
-      Sp = Sp + SIZEOF_StgCatchFrame;          \
-      Sp(0) = rval;                            \
-      jump ret;                                        \
-   }
-#endif
-
-#ifdef REG_R1
 #define SP_OFF 0
 #else
 #define SP_OFF 1
 #endif
 
-CATCH_FRAME_ENTRY_TEMPLATE(stg_catch_frame_0_ret,%RET_VEC(Sp(SP_OFF),0))
-CATCH_FRAME_ENTRY_TEMPLATE(stg_catch_frame_1_ret,%RET_VEC(Sp(SP_OFF),1))
-CATCH_FRAME_ENTRY_TEMPLATE(stg_catch_frame_2_ret,%RET_VEC(Sp(SP_OFF),2))
-CATCH_FRAME_ENTRY_TEMPLATE(stg_catch_frame_3_ret,%RET_VEC(Sp(SP_OFF),3))
-CATCH_FRAME_ENTRY_TEMPLATE(stg_catch_frame_4_ret,%RET_VEC(Sp(SP_OFF),4))
-CATCH_FRAME_ENTRY_TEMPLATE(stg_catch_frame_5_ret,%RET_VEC(Sp(SP_OFF),5))
-CATCH_FRAME_ENTRY_TEMPLATE(stg_catch_frame_6_ret,%RET_VEC(Sp(SP_OFF),6))
-CATCH_FRAME_ENTRY_TEMPLATE(stg_catch_frame_7_ret,%RET_VEC(Sp(SP_OFF),7))
-
-#if MAX_VECTORED_RTN > 8
-#error MAX_VECTORED_RTN has changed: please modify stg_catch_frame too.
-#endif
-
 #if defined(PROFILING)
 #define CATCH_FRAME_BITMAP 7
 #define CATCH_FRAME_WORDS  4
@@ -252,16 +284,21 @@ CATCH_FRAME_ENTRY_TEMPLATE(stg_catch_frame_7_ret,%RET_VEC(Sp(SP_OFF),7))
 
 INFO_TABLE_RET(stg_catch_frame,
               CATCH_FRAME_WORDS, CATCH_FRAME_BITMAP,
-              CATCH_FRAME,
-              stg_catch_frame_0_ret,
-              stg_catch_frame_1_ret,
-              stg_catch_frame_2_ret,
-              stg_catch_frame_3_ret,
-              stg_catch_frame_4_ret,
-              stg_catch_frame_5_ret,
-              stg_catch_frame_6_ret,
-              stg_catch_frame_7_ret)
-CATCH_FRAME_ENTRY_TEMPLATE(,%ENTRY_CODE(Sp(SP_OFF)))
+              CATCH_FRAME)
+#ifdef REG_R1
+   {
+      Sp = Sp + SIZEOF_StgCatchFrame;
+      jump %ENTRY_CODE(Sp(SP_OFF));
+   }
+#else
+   {
+      W_ rval;
+      rval = Sp(0);
+      Sp = Sp + SIZEOF_StgCatchFrame;
+      Sp(0) = rval;
+      jump %ENTRY_CODE(Sp(SP_OFF));
+   }
+#endif
 
 /* -----------------------------------------------------------------------------
  * The catch infotable
@@ -329,10 +366,13 @@ raisezh_fast
     /* ToDo: currently this is a hack.  Would be much better if
      * the info was only displayed for an *uncaught* exception.
      */
-    if (RtsFlags_ProfFlags_showCCSOnException(RtsFlags)) {
+    if (RtsFlags_ProfFlags_showCCSOnException(RtsFlags) != 0::I32) {
       foreign "C" fprintCCS_stderr(W_[CCCS] "ptr");
     }
 #endif
+    
+    /* Inform the Hpc that an exception has been thrown */
+    foreign "C" hs_hpc_raise_event(CurrentTSO "ptr");
 
 retry_pop_stack:
     StgTSO_sp(CurrentTSO) = Sp;
@@ -341,14 +381,27 @@ retry_pop_stack:
     if (frame_type == ATOMICALLY_FRAME) {
       /* The exception has reached the edge of a memory transaction.  Check that 
        * the transaction is valid.  If not then perhaps the exception should
-       * not have been thrown: re-run the transaction */
-      W_ trec;
+       * not have been thrown: re-run the transaction.  "trec" will either be
+       * a top-level transaction running the atomic block, or a nested 
+       * transaction running an invariant check.  In the latter case we
+       * abort and de-allocate the top-level transaction that encloses it
+       * as well (we could just abandon its transaction record, but this makes
+       * sure it's marked as aborted and available for re-use). */
+      W_ trec, outer;
       W_ r;
       trec = StgTSO_trec(CurrentTSO);
       r = foreign "C" stmValidateNestOfTransactions(trec "ptr");
+      "ptr" outer = foreign "C" stmGetEnclosingTRec(trec "ptr") [];
       foreign "C" stmAbortTransaction(MyCapability() "ptr", trec "ptr");
+      foreign "C" stmFreeAbortedTRec(MyCapability() "ptr", trec "ptr");
+
+      if (outer != NO_TREC) {
+        foreign "C" stmAbortTransaction(MyCapability() "ptr", outer "ptr");
+        foreign "C" stmFreeAbortedTRec(MyCapability() "ptr", outer "ptr");
+      }
+
       StgTSO_trec(CurrentTSO) = NO_TREC;
-      if (r) {
+      if (r != 0) {
         // Transaction was valid: continue searching for a catch frame
         Sp = Sp + SIZEOF_StgAtomicallyFrame;
         goto retry_pop_stack;
@@ -375,11 +428,7 @@ retry_pop_stack:
        StgTSO_what_next(CurrentTSO) = ThreadKilled::I16;
        SAVE_THREAD_STATE();    /* inline! */
 
-       /* The return code goes in BaseReg->rRet, and BaseReg is returned in R1 */
-       StgRegTable_rRet(BaseReg) = ThreadFinished;
-       R1 = BaseReg;
-
-       jump StgReturn;
+        jump stg_threadFinished;
     }
 
     /* Ok, Sp points to the enclosing CATCH_FRAME or CATCH_STM_FRAME.  Pop everything
@@ -397,6 +446,9 @@ retry_pop_stack:
      * If exceptions were unblocked, arrange that they are unblocked
      * again after executing the handler by pushing an
      * unblockAsyncExceptions_ret stack frame.
+     *
+     * If we've reached an STM catch frame then roll back the nested
+     * transaction we were using.
      */
     W_ frame;
     frame = Sp;
@@ -407,6 +459,12 @@ retry_pop_stack:
         Sp(0) = stg_unblockAsyncExceptionszh_ret_info;
       }
     } else {
+      W_ trec, outer;
+      trec = StgTSO_trec(CurrentTSO);
+      "ptr" outer = foreign "C" stmGetEnclosingTRec(trec "ptr") [];
+      foreign "C" stmAbortTransaction(MyCapability() "ptr", trec "ptr") [];
+      foreign "C" stmFreeAbortedTRec(MyCapability() "ptr", trec "ptr") [];
+      StgTSO_trec(CurrentTSO) = outer;
       Sp = Sp + SIZEOF_StgCatchSTMFrame;
     }