CInt r;
/* Args: R1 :: IO a */
- STK_CHK_GEN( WDS(2), R1_PTR, unblockAsyncExceptionszh_fast);
+ STK_CHK_GEN( WDS(4), R1_PTR, unblockAsyncExceptionszh_fast);
+ /* 4 words: one for the unblock frame, 3 for setting up the
+ * stack to call maybePerformBlockedException() below.
+ */
+ /* If exceptions are already unblocked, there's nothing to do */
if ((TO_W_(StgTSO_flags(CurrentTSO)) & TSO_BLOCKEX) != 0) {
StgTSO_flags(CurrentTSO) = StgTSO_flags(CurrentTSO) &
~(TSO_BLOCKEX::I32|TSO_INTERRUPTIBLE::I32);
+ /* avoid growing the stack unnecessarily */
+ if (Sp(0) == stg_unblockAsyncExceptionszh_ret_info) {
+ Sp_adj(1);
+ } else {
+ Sp_adj(-1);
+ Sp(0) = stg_blockAsyncExceptionszh_ret_info;
+ }
+
/* 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.
+ *
+ * Now, if we are to raise an exception in the current
+ * thread, there might be an update frame above us on the
+ * stack due to unsafePerformIO. Hence, the stack must
+ * make sense, because it is about to be snapshotted into
+ * an AP_STACK.
*/
+ Sp_adj(-3);
+ Sp(2) = stg_ap_v_info;
+ Sp(1) = R1;
+ Sp(0) = stg_enter_info;
+
SAVE_THREAD_STATE();
(r) = foreign "C" maybePerformBlockedException (MyCapability() "ptr",
CurrentTSO "ptr") [R1];
ASSERT(StgTSO_what_next(CurrentTSO) == ThreadRunGHC::I16);
jump %ENTRY_CODE(Sp(0));
}
+ } else {
+ /* we'll just call R1 directly, below */
+ Sp_adj(3);
}
}
- /* avoid growing the stack unnecessarily */
- if (Sp(0) == stg_unblockAsyncExceptionszh_ret_info) {
- Sp_adj(1);
- } else {
- Sp_adj(-1);
- Sp(0) = stg_blockAsyncExceptionszh_ret_info;
- }
}
TICK_UNKNOWN_CALL();
TICK_SLOW_CALL_v();
target = R1;
exception = R2;
+ /* Needs 3 words because throwToSingleThreaded uses some stack */
STK_CHK_GEN( WDS(3), R1_PTR & R2_PTR, killThreadzh_fast);
/*
goto loop;
}
if (target == CurrentTSO) {
+ /*
+ * So what should happen if a thread calls "throwTo self" inside
+ * unsafePerformIO, and later the closure is evaluated by another
+ * thread? Presumably it should behave as if throwTo just returned,
+ * and then continue from there. See #3279, #3288. This is what
+ * happens: on resumption, we will just jump to the next frame on
+ * the stack, which is the return point for killThreadzh_fast.
+ */
SAVE_THREAD_STATE();
/* ToDo: what if the current thread is blocking exceptions? */
foreign "C" throwToSingleThreaded(MyCapability() "ptr",
} else {
W_ out;
W_ retcode;
- out = BaseReg + OFFSET_StgRegTable_rmp_tmp_w;
-
+ out = Sp - WDS(1); /* ok to re-use stack space here */
+
(retcode) = foreign "C" throwTo(MyCapability() "ptr",
CurrentTSO "ptr",
target "ptr",
#if defined(PROFILING)
W_ unused1, W_ unused2,
#endif
- W_ unused3, "ptr" W_ unused4)
+ W_ unused3, P_ unused4)
{
Sp = Sp + SIZEOF_StgCatchFrame;
jump %ENTRY_CODE(Sp(SP_OFF));
no_break_on_exception: W_[1];
}
-INFO_TABLE_RET(stg_raise_ret, RET_SMALL, "ptr" W_ arg1)
+INFO_TABLE_RET(stg_raise_ret, RET_SMALL, P_ arg1)
{
R1 = Sp(1);
Sp = Sp + WDS(2);