From: Simon Marlow <marlowsd@gmail.com>
Date: Sat, 25 Sep 2010 19:33:17 +0000 (+0000)
Subject: interruptible FFI: more robust handling of the exception case in the interpreter
X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=commitdiff_plain;h=11fbcd763a9ab7b4135693c510b8bb4e4709a438

interruptible FFI: more robust handling of the exception case in the interpreter
---

diff --git a/rts/Interpreter.c b/rts/Interpreter.c
index 58ffd25..fa4a46f 100644
--- a/rts/Interpreter.c
+++ b/rts/Interpreter.c
@@ -1454,11 +1454,12 @@ run_BCO:
 	    cap = (Capability *)((void *)((unsigned char*)resumeThread(tok) - STG_FIELD_OFFSET(Capability,r)));
 	    LOAD_STACK_POINTERS;
 
-            if (Sp[0] == (W_)&stg_enter_info) {
-                // Sp got clobbered due to an exception; so we should
-                // go run it instead.
-                Sp++;
-                goto eval;
+            if (Sp[0] != (W_)&stg_gc_gen_info) {
+                // the stack is not how we left it.  This probably
+                // means that an exception got raised on exit from the
+                // foreign call, so we should just continue with
+                // whatever is on top of the stack now.
+                RETURN_TO_SCHEDULER_NO_PAUSE(ThreadRunGHC, ThreadYielding);
             }
 
             // Re-load the pointer to the BCO from the RET_DYN frame,