#include "Cmm.h"
#include "RaiseAsync.h"
+import ghczmprim_GHCziBool_True_closure;
+
/* -----------------------------------------------------------------------------
Exception Primitives
unsafePerformIO thunk will be updated with a stack object
containing the unblockAsyncExceptions_ret frame. Later, when
someone else evaluates this thunk, the blocked exception state is
- not restored, and the result is that unblockAsyncExceptions_ret
- will attempt to unblock exceptions in the current thread, but it'll
- find that the CurrentTSO->blocked_exceptions is NULL. Hence, we
- work around this by checking for NULL in awakenBlockedQueue().
+ not restored.
-------------------------------------------------------------------------- */
-INFO_TABLE_RET( stg_unblockAsyncExceptionszh_ret,
- 0/*framesize*/, 0/*bitmap*/, RET_SMALL )
+STRING(stg_unblockAsync_err_str, "unblockAsyncExceptions#_ret")
+
+INFO_TABLE_RET( stg_unblockAsyncExceptionszh_ret, RET_SMALL )
{
CInt r;
- // Not true: see comments above
- // ASSERT(StgTSO_blocked_exceptions(CurrentTSO) != NULL);
-
StgTSO_flags(CurrentTSO) = StgTSO_flags(CurrentTSO) &
~(TSO_BLOCKEX::I32|TSO_INTERRUPTIBLE::I32);
* 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
+ STK_CHK_GEN( WDS(2), R1_PTR, stg_unblockAsyncExceptionszh_ret_info);
+ Sp_adj(-2);
+ Sp(1) = R1;
+ Sp(0) = stg_gc_unpt_r1_info;
SAVE_THREAD_STATE();
- r = foreign "C" maybePerformBlockedException (MyCapability() "ptr",
+ (r) = foreign "C" maybePerformBlockedException (MyCapability() "ptr",
CurrentTSO "ptr") [R1];
if (r != 0::CInt) {
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);
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);
+ /*
+ 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);
}
-#endif
}
-#ifdef REG_R1
Sp_adj(1);
jump %ENTRY_CODE(Sp(0));
-#else
- Sp(1) = Sp(0);
- Sp_adj(1);
- jump %ENTRY_CODE(Sp(1));
-#endif
}
-INFO_TABLE_RET( stg_blockAsyncExceptionszh_ret,
- 0/*framesize*/, 0/*bitmap*/, RET_SMALL )
+INFO_TABLE_RET( stg_blockAsyncExceptionszh_ret, RET_SMALL )
{
- // Not true: see comments above
- // ASSERT(StgTSO_blocked_exceptions(CurrentTSO) == NULL);
-
StgTSO_flags(CurrentTSO) =
StgTSO_flags(CurrentTSO) | TSO_BLOCKEX::I32 | TSO_INTERRUPTIBLE::I32;
-#ifdef REG_R1
Sp_adj(1);
jump %ENTRY_CODE(Sp(0));
-#else
- Sp(1) = Sp(0);
- Sp_adj(1);
- jump %ENTRY_CODE(Sp(1));
-#endif
}
-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",
+ (r) = foreign "C" maybePerformBlockedException (MyCapability() "ptr",
CurrentTSO "ptr") [R1];
if (r != 0::CInt) {
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);
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;
}
+stg_asyncExceptionsBlockedzh
+{
+ /* args: none */
+ if ((TO_W_(StgTSO_flags(CurrentTSO)) & TSO_BLOCKEX) != 0) {
+ RET_N(1);
+ } else {
+ RET_N(0);
+ }
+}
-killThreadzh_fast
+stg_killThreadzh
{
/* args: R1 = TSO to kill, R2 = Exception */
target = R1;
exception = R2;
- STK_CHK_GEN( WDS(3), R1_PTR & R2_PTR, killThreadzh_fast);
+ /* Needs 3 words because throwToSingleThreaded uses some stack */
+ STK_CHK_GEN( WDS(3), R1_PTR & R2_PTR, stg_killThreadzh);
/*
* We might have killed ourselves. In which case, better be *very*
* If the exception went to a catch frame, we'll just continue from
* the handler.
*/
+ loop:
+ if (StgTSO_what_next(target) == ThreadRelocated::I16) {
+ target = StgTSO__link(target);
+ 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",
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);
} else {
W_ out;
W_ retcode;
- out = BaseReg + OFFSET_StgRegTable_rmp_tmp_w;
-
- retcode = foreign "C" throwTo(MyCapability() "ptr",
+ out = Sp - WDS(1); /* ok to re-use stack space here */
+
+ (retcode) = foreign "C" throwTo(MyCapability() "ptr",
CurrentTSO "ptr",
target "ptr",
exception "ptr",
Catch frames
-------------------------------------------------------------------------- */
-#ifdef REG_R1
#define SP_OFF 0
-#else
-#define SP_OFF 1
-#endif
-
-#if defined(PROFILING)
-#define CATCH_FRAME_BITMAP 7
-#define CATCH_FRAME_WORDS 4
-#else
-#define CATCH_FRAME_BITMAP 1
-#define CATCH_FRAME_WORDS 2
-#endif
/* Catch frames are very similar to update frames, but when entering
* one we just pop the frame off the stack and perform the correct
* kind of return to the activation record underneath us on the stack.
*/
-INFO_TABLE_RET(stg_catch_frame,
- CATCH_FRAME_WORDS, CATCH_FRAME_BITMAP,
- CATCH_FRAME)
-#ifdef REG_R1
- {
- Sp = Sp + SIZEOF_StgCatchFrame;
- jump %ENTRY_CODE(Sp(SP_OFF));
- }
-#else
+INFO_TABLE_RET(stg_catch_frame, CATCH_FRAME,
+#if defined(PROFILING)
+ W_ unused1, W_ unused2,
+#endif
+ W_ unused3, P_ unused4)
{
- W_ rval;
- rval = Sp(0);
Sp = Sp + SIZEOF_StgCatchFrame;
- Sp(0) = rval;
jump %ENTRY_CODE(Sp(SP_OFF));
}
-#endif
/* -----------------------------------------------------------------------------
* The catch infotable
{
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" {
+ no_break_on_exception: W_[1];
}
-raisezh_fast
+INFO_TABLE_RET(stg_raise_ret, RET_SMALL, P_ arg1)
+{
+ R1 = Sp(1);
+ Sp = Sp + WDS(2);
+ W_[no_break_on_exception] = 1;
+ jump stg_raisezh;
+}
+
+stg_raisezh
{
W_ handler;
- W_ raise_closure;
W_ frame_type;
+ W_ exception;
/* args : R1 :: Exception */
+ exception = R1;
#if defined(PROFILING)
/* Debugging tool: on raising an exception, show where we are. */
* the info was only displayed for an *uncaught* exception.
*/
if (RtsFlags_ProfFlags_showCCSOnException(RtsFlags) != 0::I32) {
- foreign "C" fprintCCS_stderr(W_[CCCS] "ptr");
+ 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;
- frame_type = foreign "C" raiseExceptionHelper(BaseReg "ptr", CurrentTSO "ptr", R1 "ptr");
+ (frame_type) = foreign "C" raiseExceptionHelper(BaseReg "ptr", CurrentTSO "ptr", exception "ptr") [];
Sp = StgTSO_sp(CurrentTSO);
if (frame_type == ATOMICALLY_FRAME) {
/* The exception has reached the edge of a memory transaction. Check that
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");
+ (r) = foreign "C" stmValidateNestOfTransactions(trec "ptr") [];
+ outer = StgTRecHeader_enclosing_trec(trec);
+ 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");
+ foreign "C" stmAbortTransaction(MyCapability() "ptr", outer "ptr") [];
+ foreign "C" stmFreeAbortedTRec(MyCapability() "ptr", outer "ptr") [];
}
StgTSO_trec(CurrentTSO) = NO_TREC;
} else {
// Transaction was not valid: we retry the exception (otherwise continue
// with a further call to raiseExceptionHelper)
- "ptr" trec = foreign "C" stmStartTransaction(MyCapability() "ptr", NO_TREC "ptr");
+ ("ptr" trec) = foreign "C" stmStartTransaction(MyCapability() "ptr", NO_TREC "ptr") [];
StgTSO_trec(CurrentTSO) = trec;
R1 = StgAtomicallyFrame_code(Sp);
jump stg_ap_v_fast;
}
}
+ // After stripping the stack, see whether we should break here for
+ // GHCi (c.f. the -fbreak-on-exception flag). We do this after
+ // stripping the stack for a reason: we'll be inspecting values in
+ // GHCi, and it helps if all the thunks under evaluation have
+ // already been updated with the exception, rather than being left
+ // as blackholes.
+ if (W_[no_break_on_exception] != 0) {
+ W_[no_break_on_exception] = 0;
+ } else {
+ if (TO_W_(CInt[rts_stop_on_exception]) != 0) {
+ W_ ioAction;
+ // we don't want any further exceptions to be caught,
+ // until GHCi is ready to handle them. This prevents
+ // deadlock if an exception is raised in InteractiveUI,
+ // for exmplae. Perhaps the stop_on_exception flag should
+ // be per-thread.
+ CInt[rts_stop_on_exception] = 0;
+ ("ptr" ioAction) = foreign "C" deRefStablePtr (W_[rts_breakpoint_io_action] "ptr") [];
+ Sp = Sp - WDS(7);
+ Sp(6) = exception;
+ Sp(5) = stg_raise_ret_info;
+ Sp(4) = stg_noforceIO_info; // required for unregisterised
+ Sp(3) = exception; // the AP_STACK
+ Sp(2) = ghczmprim_GHCziBool_True_closure; // dummy breakpoint info
+ Sp(1) = ghczmprim_GHCziBool_True_closure; // True <=> a breakpoint
+ R1 = ioAction;
+ jump RET_LBL(stg_ap_pppv);
+ }
+ }
+
if (frame_type == STOP_FRAME) {
/*
* We've stripped the entire stack, the thread is now dead.
*/
Sp = CurrentTSO + TSO_OFFSET_StgTSO_stack
+ WDS(TO_W_(StgTSO_stack_size(CurrentTSO))) - WDS(2);
- Sp(1) = R1; /* save the exception */
+ Sp(1) = exception; /* save the exception */
Sp(0) = stg_enter_info; /* so that GC can traverse this 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
} 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;
* token as arguments.
*/
Sp_adj(-1);
- Sp(0) = R1;
+ Sp(0) = exception;
R1 = handler;
Sp_adj(-1);
TICK_UNKNOWN_CALL();
jump RET_LBL(stg_ap_pv);
}
-raiseIOzh_fast
+stg_raiseIOzh
{
/* Args :: R1 :: Exception */
- jump raisezh_fast;
+ jump stg_raisezh;
}
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