#include "Cmm.h"
#include "RaiseAsync.h"
-#ifdef __PIC__
-import ghczmprim_GHCziBool_True_closure;
-#endif
+import ghczmprim_GHCziTypes_True_closure;
/* -----------------------------------------------------------------------------
Exception Primitives
A thread can request that asynchronous exceptions not be delivered
("blocked") for the duration of an I/O computation. The primitive
- blockAsyncExceptions# :: IO a -> IO a
+ maskAsyncExceptions# :: IO a -> IO a
is used for this purpose. During a blocked section, asynchronous
exceptions may be unblocked again temporarily:
- unblockAsyncExceptions# :: IO a -> IO a
+ unmaskAsyncExceptions# :: IO a -> IO a
Furthermore, asynchronous exceptions are blocked automatically during
the execution of an exception handler. Both of these primitives
the threads waiting to deliver exceptions to that thread.
NB. there's a bug in here. If a thread is inside an
- unsafePerformIO, and inside blockAsyncExceptions# (there is an
- unblockAsyncExceptions_ret on the stack), and it is blocked in an
+ unsafePerformIO, and inside maskAsyncExceptions# (there is an
+ unmaskAsyncExceptions_ret on the stack), and it is blocked in an
interruptible operation, and it receives an exception, then the
unsafePerformIO thunk will be updated with a stack object
- containing the unblockAsyncExceptions_ret frame. Later, when
+ containing the unmaskAsyncExceptions_ret frame. Later, when
someone else evaluates this thunk, the blocked exception state is
not restored.
-------------------------------------------------------------------------- */
-INFO_TABLE_RET( stg_unblockAsyncExceptionszh_ret, RET_SMALL )
+
+INFO_TABLE_RET(stg_unmaskAsyncExceptionszh_ret, RET_SMALL)
{
CInt r;
- StgTSO_flags(CurrentTSO) = StgTSO_flags(CurrentTSO) &
- ~(TSO_BLOCKEX::I32|TSO_INTERRUPTIBLE::I32);
+ StgTSO_flags(CurrentTSO) = %lobits32(
+ TO_W_(StgTSO_flags(CurrentTSO)) & ~(TSO_BLOCKEX|TSO_INTERRUPTIBLE));
/* Eagerly raise a blocked exception, if there is one */
if (StgTSO_blocked_exceptions(CurrentTSO) != END_TSO_QUEUE) {
+
+ STK_CHK_GEN( WDS(2), R1_PTR, stg_unmaskAsyncExceptionszh_ret_info);
/*
* 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.
*/
-
-#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
+ Sp_adj(-2);
+ Sp(1) = R1;
+ Sp(0) = stg_gc_unpt_r1_info;
SAVE_THREAD_STATE();
(r) = foreign "C" maybePerformBlockedException (MyCapability() "ptr",
CurrentTSO "ptr") [R1];
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, RET_SMALL )
+INFO_TABLE_RET(stg_maskAsyncExceptionszh_ret, RET_SMALL)
{
StgTSO_flags(CurrentTSO) =
- StgTSO_flags(CurrentTSO) | TSO_BLOCKEX::I32 | TSO_INTERRUPTIBLE::I32;
+ %lobits32(
+ TO_W_(StgTSO_flags(CurrentTSO))
+ | TSO_BLOCKEX | TSO_INTERRUPTIBLE
+ );
-#ifdef REG_R1
Sp_adj(1);
jump %ENTRY_CODE(Sp(0));
-#else
- Sp(1) = Sp(0);
+}
+
+INFO_TABLE_RET(stg_maskUninterruptiblezh_ret, RET_SMALL)
+{
+ StgTSO_flags(CurrentTSO) =
+ %lobits32(
+ (TO_W_(StgTSO_flags(CurrentTSO))
+ | TSO_BLOCKEX)
+ & ~TSO_INTERRUPTIBLE
+ );
+
Sp_adj(1);
- jump %ENTRY_CODE(Sp(1));
-#endif
+ jump %ENTRY_CODE(Sp(0));
}
-blockAsyncExceptionszh_fast
+stg_maskAsyncExceptionszh
{
/* Args: R1 :: IO a */
- STK_CHK_GEN( WDS(2)/* worst case */, R1_PTR, blockAsyncExceptionszh_fast);
+ STK_CHK_GEN( WDS(1)/* worst case */, R1_PTR, stg_maskAsyncExceptionszh);
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_maskAsyncExceptionszh_ret_info) {
+ Sp_adj(1);
+ } else {
+ Sp_adj(-1);
+ Sp(0) = stg_unmaskAsyncExceptionszh_ret_info;
+ }
+ } else {
+ if ((TO_W_(StgTSO_flags(CurrentTSO)) & TSO_INTERRUPTIBLE) == 0) {
+ Sp_adj(-1);
+ Sp(0) = stg_maskUninterruptiblezh_ret_info;
+ }
+ }
- /* avoid growing the stack unnecessarily */
- if (Sp(0) == stg_blockAsyncExceptionszh_ret_info) {
- Sp_adj(1);
- } else {
- Sp_adj(-1);
- Sp(0) = stg_unblockAsyncExceptionszh_ret_info;
- }
+ StgTSO_flags(CurrentTSO) = %lobits32(
+ TO_W_(StgTSO_flags(CurrentTSO)) | TSO_BLOCKEX | TSO_INTERRUPTIBLE);
+
+ TICK_UNKNOWN_CALL();
+ TICK_SLOW_CALL_v();
+ jump stg_ap_v_fast;
+}
+
+stg_maskUninterruptiblezh
+{
+ /* Args: R1 :: IO a */
+ STK_CHK_GEN( WDS(1)/* worst case */, R1_PTR, stg_maskAsyncExceptionszh);
+
+ if ((TO_W_(StgTSO_flags(CurrentTSO)) & TSO_BLOCKEX) == 0) {
+ /* avoid growing the stack unnecessarily */
+ if (Sp(0) == stg_maskUninterruptiblezh_ret_info) {
+ Sp_adj(1);
+ } else {
+ Sp_adj(-1);
+ Sp(0) = stg_unmaskAsyncExceptionszh_ret_info;
+ }
+ } else {
+ if ((TO_W_(StgTSO_flags(CurrentTSO)) & TSO_INTERRUPTIBLE) != 0) {
+ Sp_adj(-1);
+ Sp(0) = stg_maskAsyncExceptionszh_ret_info;
+ }
}
+
+ StgTSO_flags(CurrentTSO) = %lobits32(
+ (TO_W_(StgTSO_flags(CurrentTSO)) | TSO_BLOCKEX) & ~TSO_INTERRUPTIBLE);
+
TICK_UNKNOWN_CALL();
TICK_SLOW_CALL_v();
jump stg_ap_v_fast;
}
-unblockAsyncExceptionszh_fast
+stg_unmaskAsyncExceptionszh
{
CInt r;
+ W_ level;
/* Args: R1 :: IO a */
- STK_CHK_GEN( WDS(2), R1_PTR, unblockAsyncExceptionszh_fast);
+ STK_CHK_GEN( WDS(4), R1_PTR, stg_unmaskAsyncExceptionszh);
+ /* 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_unmaskAsyncExceptionszh_ret_info) {
+ Sp_adj(1);
+ } else {
+ Sp_adj(-1);
+ if ((TO_W_(StgTSO_flags(CurrentTSO)) & TSO_INTERRUPTIBLE) != 0) {
+ Sp(0) = stg_maskAsyncExceptionszh_ret_info;
+ } else {
+ Sp(0) = stg_maskUninterruptiblezh_ret_info;
+ }
+ }
+
+ StgTSO_flags(CurrentTSO) = %lobits32(
+ TO_W_(StgTSO_flags(CurrentTSO)) & ~(TSO_BLOCKEX|TSO_INTERRUPTIBLE));
/* 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();
}
-killThreadzh_fast
+stg_getMaskingStatezh
+{
+ /* args: none */
+ /*
+ returns: 0 == unmasked,
+ 1 == masked, non-interruptible,
+ 2 == masked, interruptible
+ */
+ RET_N(((TO_W_(StgTSO_flags(CurrentTSO)) & TSO_BLOCKEX) != 0) +
+ ((TO_W_(StgTSO_flags(CurrentTSO)) & TSO_INTERRUPTIBLE) != 0));
+}
+
+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 call allocate in throwTo(), so better check for GC */
+ MAYBE_GC(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",
}
} else {
W_ out;
- W_ retcode;
- out = BaseReg + OFFSET_StgRegTable_rmp_tmp_w;
-
- (retcode) = foreign "C" throwTo(MyCapability() "ptr",
- CurrentTSO "ptr",
- target "ptr",
- exception "ptr",
- out "ptr") [R1,R2];
-
- switch [THROWTO_SUCCESS .. THROWTO_BLOCKED] (retcode) {
+ W_ msg;
+ out = Sp - WDS(1); /* ok to re-use stack space here */
- case THROWTO_SUCCESS: {
+ (msg) = foreign "C" throwTo(MyCapability() "ptr",
+ CurrentTSO "ptr",
+ target "ptr",
+ exception "ptr") [R1,R2];
+
+ if (msg == NULL) {
jump %ENTRY_CODE(Sp(0));
- }
-
- case THROWTO_BLOCKED: {
- R3 = W_[out];
- // we must block, and call throwToReleaseTarget() before returning
+ } else {
+ StgTSO_why_blocked(CurrentTSO) = BlockedOnMsgThrowTo;
+ StgTSO_block_info(CurrentTSO) = msg;
+ // we must block, and unlock the message before returning
jump stg_block_throwto;
}
- }
}
}
Catch frames
-------------------------------------------------------------------------- */
-#ifdef REG_R1
#define SP_OFF 0
-#else
-#define SP_OFF 1
-#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
#if defined(PROFILING)
W_ unused1, W_ unused2,
#endif
- W_ unused3, "ptr" W_ unused4)
-#ifdef REG_R1
+ W_ unused3, P_ unused4)
{
Sp = Sp + SIZEOF_StgCatchFrame;
jump %ENTRY_CODE(Sp(SP_OFF));
}
-#else
- {
- 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;
SET_HDR(Sp,stg_catch_frame_info,W_[CCCS]);
StgCatchFrame_handler(Sp) = R2;
- StgCatchFrame_exceptions_blocked(Sp) = TO_W_(StgTSO_flags(CurrentTSO)) & TSO_BLOCKEX;
+ StgCatchFrame_exceptions_blocked(Sp) =
+ TO_W_(StgTSO_flags(CurrentTSO)) & (TSO_BLOCKEX | TSO_INTERRUPTIBLE);
TICK_CATCHF_PUSHED();
/* Apply R1 to the realworld token */
*
* 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];
}
-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);
W_[no_break_on_exception] = 1;
- jump raisezh_fast;
+ jump stg_raisezh;
}
-raisezh_fast
+stg_raisezh
{
W_ handler;
W_ frame_type;
#endif
retry_pop_stack:
- StgTSO_sp(CurrentTSO) = Sp;
+ SAVE_THREAD_STATE();
(frame_type) = foreign "C" raiseExceptionHelper(BaseReg "ptr", CurrentTSO "ptr", exception "ptr") [];
- Sp = StgTSO_sp(CurrentTSO);
+ LOAD_THREAD_STATE();
if (frame_type == ATOMICALLY_FRAME) {
/* The exception has reached the edge of a memory transaction. Check that
* the transaction is valid. If not then perhaps the exception should
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;
- Sp(5) = stg_raise_ret_info;
- Sp(4) = stg_noforceIO_info; // required for unregisterised
+ Sp = Sp - WDS(6);
+ Sp(5) = exception;
+ Sp(4) = stg_raise_ret_info;
Sp(3) = exception; // the AP_STACK
- Sp(2) = ghczmprim_GHCziBool_True_closure; // dummy breakpoint info
- Sp(1) = ghczmprim_GHCziBool_True_closure; // True <=> a breakpoint
+ Sp(2) = ghczmprim_GHCziTypes_True_closure; // dummy breakpoint info
+ Sp(1) = ghczmprim_GHCziTypes_True_closure; // True <=> a breakpoint
R1 = ioAction;
jump RET_LBL(stg_ap_pppv);
}
* We will leave the stack in a GC'able state, see the stg_stop_thread
* entry code in StgStartup.cmm.
*/
- Sp = CurrentTSO + TSO_OFFSET_StgTSO_stack
- + WDS(TO_W_(StgTSO_stack_size(CurrentTSO))) - WDS(2);
+ W_ stack;
+ stack = StgTSO_stackobj(CurrentTSO);
+ Sp = stack + OFFSET_StgStack_stack
+ + WDS(TO_W_(StgStack_stack_size(stack))) - WDS(2);
Sp(1) = exception; /* save the exception */
Sp(0) = stg_enter_info; /* so that GC can traverse this stack */
StgTSO_what_next(CurrentTSO) = ThreadKilled::I16;
*
* If exceptions were unblocked, arrange that they are unblocked
* again after executing the handler by pushing an
- * unblockAsyncExceptions_ret stack frame.
+ * unmaskAsyncExceptions_ret stack frame.
*
* If we've reached an STM catch frame then roll back the nested
* transaction we were using.
frame = Sp;
if (frame_type == CATCH_FRAME) {
Sp = Sp + SIZEOF_StgCatchFrame;
- if (StgCatchFrame_exceptions_blocked(frame) == 0) {
- Sp_adj(-1);
- Sp(0) = stg_unblockAsyncExceptionszh_ret_info;
+ if ((StgCatchFrame_exceptions_blocked(frame) & TSO_BLOCKEX) == 0) {
+ Sp_adj(-1);
+ Sp(0) = stg_unmaskAsyncExceptionszh_ret_info;
}
} 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;
}
/* Ensure that async excpetions are blocked when running the handler.
+ * The interruptible state is inherited from the context of the
+ * catch frame.
*/
- StgTSO_flags(CurrentTSO) =
- StgTSO_flags(CurrentTSO) | TSO_BLOCKEX::I32 | TSO_INTERRUPTIBLE::I32;
+ StgTSO_flags(CurrentTSO) = %lobits32(
+ TO_W_(StgTSO_flags(CurrentTSO)) | TSO_BLOCKEX);
+ if ((StgCatchFrame_exceptions_blocked(frame) & TSO_INTERRUPTIBLE) == 0) {
+ StgTSO_flags(CurrentTSO) = %lobits32(
+ TO_W_(StgTSO_flags(CurrentTSO)) & ~TSO_INTERRUPTIBLE);
+ } else {
+ StgTSO_flags(CurrentTSO) = %lobits32(
+ TO_W_(StgTSO_flags(CurrentTSO)) | TSO_INTERRUPTIBLE);
+ }
/* Call the handler, passing the exception value and a realworld
* token as arguments.
jump RET_LBL(stg_ap_pv);
}
-raiseIOzh_fast
+stg_raiseIOzh
{
/* Args :: R1 :: Exception */
- jump raisezh_fast;
+ jump stg_raisezh;
}
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