-------------------------------------------------------------------------- */
+STRING(stg_unblockAsync_err_str, "unblockAsyncExceptions#_ret")
+
INFO_TABLE_RET( stg_unblockAsyncExceptionszh_ret, RET_SMALL )
{
CInt r;
jump %ENTRY_CODE(Sp(0));
}
}
+ else {
+ /*
+ the thread might have been removed from the
+ blocked_exception list by someone else in the meantime.
+ Just restore the stack pointer and continue.
+ */
+ Sp_adj(2);
+ }
}
Sp_adj(1);
jump %ENTRY_CODE(Sp(0));
}
-blockAsyncExceptionszh_fast
+stg_blockAsyncExceptionszh
{
/* Args: R1 :: IO a */
- STK_CHK_GEN( WDS(2)/* worst case */, R1_PTR, blockAsyncExceptionszh_fast);
+ STK_CHK_GEN( WDS(2)/* worst case */, R1_PTR, stg_blockAsyncExceptionszh);
if ((TO_W_(StgTSO_flags(CurrentTSO)) & TSO_BLOCKEX) == 0) {
jump stg_ap_v_fast;
}
-unblockAsyncExceptionszh_fast
+stg_unblockAsyncExceptionszh
{
CInt r;
/* Args: R1 :: IO a */
- STK_CHK_GEN( WDS(2), R1_PTR, unblockAsyncExceptionszh_fast);
+ STK_CHK_GEN( WDS(4), R1_PTR, stg_unblockAsyncExceptionszh);
+ /* 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();
jump stg_ap_v_fast;
}
-asyncExceptionsBlockedzh_fast
+stg_asyncExceptionsBlockedzh
{
/* args: none */
if ((TO_W_(StgTSO_flags(CurrentTSO)) & TSO_BLOCKEX) != 0) {
}
}
-killThreadzh_fast
+stg_killThreadzh
{
/* args: R1 = TSO to kill, R2 = Exception */
exception = R2;
/* Needs 3 words because throwToSingleThreaded uses some stack */
- STK_CHK_GEN( WDS(3), R1_PTR & R2_PTR, killThreadzh_fast);
+ STK_CHK_GEN( WDS(3), R1_PTR & R2_PTR, stg_killThreadzh);
/*
* We might have killed ourselves. In which case, better be *very*
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 stg_killThreadzh.
+ */
SAVE_THREAD_STATE();
/* ToDo: what if the current thread is blocking exceptions? */
foreign "C" throwToSingleThreaded(MyCapability() "ptr",
{
R2 = StgClosure_payload(R1,1); /* h */
R1 = StgClosure_payload(R1,0); /* x */
- jump catchzh_fast;
+ jump stg_catchzh;
}
-catchzh_fast
+stg_catchzh
{
/* args: R1 = m :: IO a, R2 = handler :: Exception -> IO a */
- STK_CHK_GEN(SIZEOF_StgCatchFrame + WDS(1), R1_PTR & R2_PTR, catchzh_fast);
+ STK_CHK_GEN(SIZEOF_StgCatchFrame + WDS(1), R1_PTR & R2_PTR, stg_catchzh);
/* Set up the catch frame */
Sp = Sp - SIZEOF_StgCatchFrame;
*
* raise = {err} \n {} -> raise#{err}
*
- * It is used in raisezh_fast to update thunks on the update list
+ * It is used in stg_raisezh to update thunks on the update list
* -------------------------------------------------------------------------- */
INFO_TABLE(stg_raise,1,0,THUNK_1_0,"raise","raise")
{
R1 = StgThunk_payload(R1,0);
- jump raisezh_fast;
+ jump stg_raisezh;
}
section "data" {
R1 = Sp(1);
Sp = Sp + WDS(2);
W_[no_break_on_exception] = 1;
- jump raisezh_fast;
+ jump stg_raisezh;
}
-raisezh_fast
+stg_raisezh
{
W_ handler;
W_ frame_type;
W_ r;
trec = StgTSO_trec(CurrentTSO);
(r) = foreign "C" stmValidateNestOfTransactions(trec "ptr") [];
- ("ptr" outer) = foreign "C" stmGetEnclosingTRec(trec "ptr") [];
+ outer = StgTRecHeader_enclosing_trec(trec);
foreign "C" stmAbortTransaction(MyCapability() "ptr", trec "ptr") [];
foreign "C" stmFreeAbortedTRec(MyCapability() "ptr", trec "ptr") [];
// deadlock if an exception is raised in InteractiveUI,
// for exmplae. Perhaps the stop_on_exception flag should
// be per-thread.
- W_[rts_stop_on_exception] = 0;
+ CInt[rts_stop_on_exception] = 0;
("ptr" ioAction) = foreign "C" deRefStablePtr (W_[rts_breakpoint_io_action] "ptr") [];
Sp = Sp - WDS(7);
Sp(6) = exception;
} else {
W_ trec, outer;
trec = StgTSO_trec(CurrentTSO);
- ("ptr" outer) = foreign "C" stmGetEnclosingTRec(trec "ptr") [];
+ outer = StgTRecHeader_enclosing_trec(trec);
foreign "C" stmAbortTransaction(MyCapability() "ptr", trec "ptr") [];
foreign "C" stmFreeAbortedTRec(MyCapability() "ptr", trec "ptr") [];
StgTSO_trec(CurrentTSO) = outer;
jump RET_LBL(stg_ap_pv);
}
-raiseIOzh_fast
+stg_raiseIOzh
{
/* Args :: R1 :: Exception */
- jump raisezh_fast;
+ jump stg_raisezh;
}