--- Coro/Coro/State.xs	2008/11/10 00:02:29	1.259
+++ Coro/Coro/State.xs	2008/11/10 04:37:23	1.260
@@ -183,7 +183,12 @@
 static JMPENV *main_top_env;
 static HV *coro_state_stash, *coro_stash;
 static volatile SV *coro_mortal; /* will be freed/thrown after next transfer */
-static volatile char next_has_throw; /* speedup flag for next->throw check */
+static volatile struct coro *transfer_next;
+
+struct transfer_args
+{
+  struct coro *prev, *next;
+};
 
 static GV *irsgv;    /* $/ */
 static GV *stdoutgv; /* *STDOUT */
@@ -837,9 +842,9 @@
 
   {
     dSP;
-    LOGOP myop;
+    UNOP myop;
 
-    Zero (&myop, 1, LOGOP);
+    Zero (&myop, 1, UNOP);
     myop.op_next = Nullop;
     myop.op_flags = OPf_WANT_VOID;
 
@@ -854,7 +859,7 @@
   /* this newly created coroutine might be run on an existing cctx which most
    * likely was suspended in set_stacklevel, called from entersub.
    * set_stacklevl doesn't do anything on return, but entersub does LEAVE,
-   * so we ENTER here for symmetry
+   * so we ENTER here for symmetry.
    */
   ENTER;
 }
@@ -1029,6 +1034,13 @@
   return 0;
 }
 
+static void
+prepare_set_stacklevel (struct transfer_args *ta, struct coro_cctx *cctx)
+{
+  ta->prev  = (struct coro *)cctx;
+  ta->next  = 0;
+}
+
 /* inject a fake call to Coro::State::_cctx_init into the execution */
 /* _cctx_init should be careful, as it could be called at almost any time */
 /* during execution of a perl program */
@@ -1037,20 +1049,20 @@
 cctx_prepare (pTHX_ coro_cctx *cctx)
 {
   dSP;
-  LOGOP myop;
+  UNOP myop;
 
   PL_top_env = &PL_start_env;
 
   if (cctx->flags & CC_TRACE)
     PL_runops = runops_trace;
 
-  Zero (&myop, 1, LOGOP);
-  myop.op_next = PL_op;
+  Zero (&myop, 1, UNOP);
+  myop.op_next  = PL_op;
   myop.op_flags = OPf_WANT_VOID | OPf_STACKED;
 
   PUSHMARK (SP);
   EXTEND (SP, 2);
-  PUSHs (sv_2mortal (newSViv (PTR2IV (cctx))));
+  PUSHs (sv_2mortal (newSViv ((IV)cctx)));
   PUSHs ((SV *)get_cv ("Coro::State::_cctx_init", FALSE));
   PUTBACK;
   PL_op = (OP *)&myop;
@@ -1062,19 +1074,20 @@
 static void
 transfer_tail (void)
 {
+  struct coro *next = (struct coro *)transfer_next;
+  transfer_next = 0; //D for temporary assertion in transfer
+  assert (("FATAL ERROR: internal error 1067 in Coro module, please report", next));//D
+
+  free_coro_mortal (aTHX);
   UNLOCK;
 
-  if (expect_false (next_has_throw))
+  if (expect_false (next->throw))
     {
-      struct coro *coro = SvSTATE (coro_current);
+      SV *exception = sv_2mortal (next->throw);
 
-      if (coro->throw)
-        {
-          SV *exception = coro->throw;
-          coro->throw = 0;
-          sv_setsv (ERRSV, exception);
-          croak (0);
-        }
+      next->throw = 0;
+      sv_setsv (ERRSV, exception);
+      croak (0);
     }
 }
 
@@ -1092,13 +1105,16 @@
   {
     dTHX;
 
-    /* we now skip the entersub that lead to transfer () */
+    /* entersub called ENTER, but we never 'returned', undo that here */
+    LEAVE;
+
+    /* we now skip the entersub that did lead to transfer() */
     PL_op = PL_op->op_next;
 
     /* inject a fake subroutine call to cctx_init */
     cctx_prepare (aTHX_ (coro_cctx *)arg);
 
-    /* cctx_run is the alternative tail of transfer () */
+    /* cctx_run is the alternative tail of transfer() */
     transfer_tail ();
 
     /* somebody or something will hit me for both perl_run and PL_restartop */
@@ -1127,7 +1143,7 @@
 
   cctx->gen     = cctx_gen;
   cctx->flags   = 0;
-  cctx->idle_sp = 0; /* can be accessed by transfer between cctx_run and set_stacklevel */
+  cctx->idle_sp = 0; /* can be accessed by transfer between cctx_run and set_stacklevel, on throw */
 
   return cctx;
 }
@@ -1323,8 +1339,6 @@
 
       prev__cctx = prev->cctx;
 
-      if (prev__cctx->idle_sp == STACKLEVEL) asm volatile("");//D
-
       /* possibly "free" the cctx */
       if (expect_true (
             prev__cctx->idle_sp == STACKLEVEL
@@ -1351,7 +1365,8 @@
       if (expect_true (!next->cctx))
         next->cctx = cctx_get (aTHX);
 
-      next_has_throw = !!next->throw;
+      assert (("FATAL ERROR: internal error 1352 in Coro, please report", !transfer_next));//D
+      transfer_next = next;
 
       if (expect_false (prev__cctx != next->cctx))
         {
@@ -1360,18 +1375,10 @@
           coro_transfer (&prev__cctx->cctx, &next->cctx->cctx);
         }
 
-      free_coro_mortal (aTHX);
-      UNLOCK;
-
       transfer_tail ();
     }
 }
 
-struct transfer_args
-{
-  struct coro *prev, *next;
-};
-
 #define TRANSFER(ta, force_cctx) transfer (aTHX_ (ta).prev, (ta).next, (force_cctx))
 #define TRANSFER_CHECK(ta) transfer_check (aTHX_ (ta).prev, (ta).next)
 
@@ -1592,7 +1599,7 @@
         {
           UNLOCK;
           SvREFCNT_dec (next_sv);
-          /* coro_nready is already taken care of by destroy */
+          /* coro_nready has already been taken care of by destroy */
           continue;
         }
 
@@ -1899,8 +1906,7 @@
         switch (ix)
           {
             case 0:
-              ta.prev  = (struct coro *)INT2PTR (coro_cctx *, SvIV (ST (0)));
-              ta.next  = 0;
+              prepare_set_stacklevel (&ta, (struct coro_cctx *)SvIV (ST (0)));
               break;
 
             case 1:
@@ -2051,6 +2057,13 @@
         RETVAL
 
 void
+throw (Coro::State self, SV *throw = &PL_sv_undef)
+	PROTOTYPE: $;$
+        CODE:
+        SvREFCNT_dec (self->throw);
+        self->throw = SvOK (throw) ? newSVsv (throw) : 0;
+
+void
 api_trace (SV *coro, int flags = CC_TRACE | CC_TRACE_SUB)
 
 SV *
@@ -2202,13 +2215,6 @@
 	OUTPUT:
         RETVAL
 
-void
-throw (Coro::State self, SV *throw = &PL_sv_undef)
-	PROTOTYPE: $;$
-        CODE:
-        SvREFCNT_dec (self->throw);
-        self->throw = SvOK (throw) ? newSVsv (throw) : 0;
-
 # for async_pool speedup
 void
 _pool_1 (SV *cb)