#include "Cmm.h"
#include "RaiseAsync.h"
-import ghczmprim_GHCziTypes_True_closure;
+import CLOSURE 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
-
- maskAsyncExceptions# :: IO a -> IO a
+ ("masked") for the duration of an I/O computation. The primitives
- is used for this purpose. During a blocked section, asynchronous
- exceptions may be unblocked again temporarily:
+ maskAsyncExceptions# :: IO a -> IO a
- unmaskAsyncExceptions# :: IO a -> IO a
+ and
- Furthermore, asynchronous exceptions are blocked automatically during
- the execution of an exception handler. Both of these primitives
+ maskUninterruptible# :: IO a -> IO a
+
+ are used for this purpose. During a masked section, asynchronous
+ exceptions may be unmasked again temporarily:
+
+ unmaskAsyncExceptions# :: IO a -> IO a
+
+ Furthermore, asynchronous exceptions are masked automatically during
+ the execution of an exception handler. All three of these primitives
leave a continuation on the stack which reverts to the previous
- state (blocked or unblocked) on exit.
+ state (masked interruptible, masked non-interruptible, or unmasked)
+ on exit.
A thread which wants to raise an exception in another thread (using
killThread#) must block until the target thread is ready to receive
- it. The action of unblocking exceptions in a thread will release all
+ it. The action of unmasking exceptions in a thread will release all
the threads waiting to deliver exceptions to that thread.
NB. there's a bug in here. If a thread is inside an
interruptible operation, and it receives an exception, then the
unsafePerformIO thunk will be updated with a stack object
containing the unmaskAsyncExceptions_ret frame. Later, when
- someone else evaluates this thunk, the blocked exception state is
+ someone else evaluates this thunk, the original masking state is
not restored.
-------------------------------------------------------------------------- */
INFO_TABLE_RET(stg_unmaskAsyncExceptionszh_ret, RET_SMALL, W_ info_ptr)
/* explicit stack */
{
+ unwind Sp = Sp + WDS(1);
CInt r;
P_ ret;
StgTSO_flags(CurrentTSO) = %lobits32(
TO_W_(StgTSO_flags(CurrentTSO)) & ~(TSO_BLOCKEX|TSO_INTERRUPTIBLE));
- /* Eagerly raise a blocked exception, if there is one */
+ /* Eagerly raise a masked exception, if there is one */
if (StgTSO_blocked_exceptions(CurrentTSO) != END_TSO_QUEUE) {
- STK_CHK_P (WDS(2), stg_unmaskAsyncExceptionszh_ret_info, R1);
- /*
+ STK_CHK_P_LL (WDS(2), stg_unmaskAsyncExceptionszh_ret_info, R1);
+ /*
* 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.
/*
the thread might have been removed from the
blocked_exception list by someone else in the meantime.
- Just restore the stack pointer and continue.
- */
+ Just restore the stack pointer and continue.
+ */
Sp_adj(2);
}
}
INFO_TABLE_RET(stg_maskAsyncExceptionszh_ret, RET_SMALL, W_ info_ptr)
return (P_ ret)
{
- StgTSO_flags(CurrentTSO) =
+ unwind Sp = Sp + WDS(1);
+ StgTSO_flags(CurrentTSO) =
%lobits32(
- TO_W_(StgTSO_flags(CurrentTSO))
+ TO_W_(StgTSO_flags(CurrentTSO))
| TSO_BLOCKEX | TSO_INTERRUPTIBLE
);
INFO_TABLE_RET(stg_maskUninterruptiblezh_ret, RET_SMALL, W_ info_ptr)
return (P_ ret)
{
- StgTSO_flags(CurrentTSO) =
+ unwind Sp = Sp + WDS(1);
+ StgTSO_flags(CurrentTSO) =
%lobits32(
- (TO_W_(StgTSO_flags(CurrentTSO))
+ (TO_W_(StgTSO_flags(CurrentTSO))
| TSO_BLOCKEX)
& ~TSO_INTERRUPTIBLE
);
stg_maskAsyncExceptionszh /* explicit stack */
{
/* Args: R1 :: IO a */
- STK_CHK_P( WDS(1)/* worst case */, stg_maskAsyncExceptionszh, R1);
+ STK_CHK_P_LL (WDS(1)/* worst case */, stg_maskAsyncExceptionszh, R1);
if ((TO_W_(StgTSO_flags(CurrentTSO)) & TSO_BLOCKEX) == 0) {
/* avoid growing the stack unnecessarily */
TO_W_(StgTSO_flags(CurrentTSO)) | TSO_BLOCKEX | TSO_INTERRUPTIBLE);
TICK_UNKNOWN_CALL();
- TICK_SLOW_CALL_v();
+ TICK_SLOW_CALL_fast_v();
jump stg_ap_v_fast [R1];
}
stg_maskUninterruptiblezh /* explicit stack */
{
/* Args: R1 :: IO a */
- STK_CHK_P( WDS(1)/* worst case */, stg_maskAsyncExceptionszh, R1);
+ STK_CHK_P_LL (WDS(1)/* worst case */, stg_maskUninterruptiblezh, R1);
if ((TO_W_(StgTSO_flags(CurrentTSO)) & TSO_BLOCKEX) == 0) {
/* avoid growing the stack unnecessarily */
(TO_W_(StgTSO_flags(CurrentTSO)) | TSO_BLOCKEX) & ~TSO_INTERRUPTIBLE);
TICK_UNKNOWN_CALL();
- TICK_SLOW_CALL_v();
+ TICK_SLOW_CALL_fast_v();
jump stg_ap_v_fast [R1];
}
P_ io;
io = R1;
- STK_CHK_P (WDS(4), stg_unmaskAsyncExceptionszh, io);
- /* 4 words: one for the unblock frame, 3 for setting up the
+ STK_CHK_P_LL (WDS(4), stg_unmaskAsyncExceptionszh, io);
+ /* 4 words: one for the unmask frame, 3 for setting up the
* stack to call maybePerformBlockedException() below.
*/
- /* If exceptions are already unblocked, there's nothing to do */
+ /* If exceptions are already unmasked, there's nothing to do */
if ((TO_W_(StgTSO_flags(CurrentTSO)) & TSO_BLOCKEX) != 0) {
- /* avoid growing the stack unnecessarily */
- if (Sp(0) == stg_unmaskAsyncExceptionszh_ret_info) {
- Sp_adj(1);
- } else {
- Sp_adj(-1);
+ /* 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(
+ StgTSO_flags(CurrentTSO) = %lobits32(
TO_W_(StgTSO_flags(CurrentTSO)) & ~(TSO_BLOCKEX|TSO_INTERRUPTIBLE));
- /* Eagerly raise a blocked exception, if there is one */
+ /* Eagerly raise a masked 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.
if (r != 0::CInt) {
if (StgTSO_what_next(CurrentTSO) == ThreadKilled::I16) {
jump stg_threadFinished [];
- } else {
- LOAD_THREAD_STATE();
- ASSERT(StgTSO_what_next(CurrentTSO) == ThreadRunGHC::I16);
+ } else {
+ LOAD_THREAD_STATE();
+ ASSERT(StgTSO_what_next(CurrentTSO) == ThreadRunGHC::I16);
R1 = io;
jump %ENTRY_CODE(Sp(0)) [R1];
- }
+ }
} else {
/* we'll just call R1 directly, below */
Sp_adj(3);
}
TICK_UNKNOWN_CALL();
- TICK_SLOW_CALL_v();
+ TICK_SLOW_CALL_fast_v();
R1 = io;
jump stg_ap_v_fast [R1];
}
stg_getMaskingStatezh ()
{
/* args: none */
- /*
+ /*
returns: 0 == unmasked,
1 == masked, non-interruptible,
2 == masked, interruptible
/* We call allocate in throwTo(), so better check for GC */
MAYBE_GC_PP (stg_killThreadzh, target, exception);
- /*
+ /*
* We might have killed ourselves. In which case, better be *very*
* careful. If the exception killed us, then return to the scheduler.
* If the exception went to a catch frame, we'll just continue from
} else {
W_ msg;
- (msg) = ccall throwTo(MyCapability() "ptr",
+ ("ptr" msg) = ccall throwTo(MyCapability() "ptr",
CurrentTSO "ptr",
target "ptr",
exception "ptr");
-
+
if (msg == NULL) {
return ();
} else {
StgTSO_why_blocked(CurrentTSO) = BlockedOnMsgThrowTo;
StgTSO_block_info(CurrentTSO) = msg;
- // we must block, and unlock the message before returning
+ // we must block, and unlock the message before returning
jump stg_block_throwto (target, exception);
- }
+ }
}
}
exception = R2;
SAVE_THREAD_STATE();
- /* ToDo: what if the current thread is blocking exceptions? */
- ccall throwToSingleThreaded(MyCapability() "ptr",
+ /* ToDo: what if the current thread is masking exceptions? */
+ ccall throwToSingleThreaded(MyCapability() "ptr",
target "ptr", exception "ptr");
if (StgTSO_what_next(CurrentTSO) == ThreadKilled::I16) {
jump stg_threadFinished [];
exceptions_blocked,handler))
return (P_ ret)
{
+ unwind Sp = Sp + SIZEOF_StgCatchFrame;
return (ret);
}
W_ exceptions_blocked;
STK_CHK_GEN();
-
+
exceptions_blocked =
TO_W_(StgTSO_flags(CurrentTSO)) & (TSO_BLOCKEX | TSO_INTERRUPTIBLE);
TICK_CATCHF_PUSHED();
/* Apply R1 to the realworld token */
TICK_UNKNOWN_CALL();
- TICK_SLOW_CALL_v();
+ TICK_SLOW_CALL_fast_v();
jump stg_ap_v_fast
(CATCH_FRAME_FIELDS(,,stg_catch_frame_info, CCCS, 0,
/* -----------------------------------------------------------------------------
* The raise infotable
- *
+ *
* This should be exactly the same as would be generated by this STG code
*
* raise = {err} \n {} -> raise#{err}
INFO_TABLE_RET(stg_raise_ret, RET_SMALL, W_ info_ptr, P_ exception)
return (P_ ret)
{
+ unwind Sp = Sp + WDS(2);
W_[no_break_on_exception] = 1;
jump stg_raisezh (exception);
}
/* ToDo: currently this is a hack. Would be much better if
* the info was only displayed for an *uncaught* exception.
*/
- if (RtsFlags_ProfFlags_showCCSOnException(RtsFlags) != 0::I32) {
+ if (RtsFlags_ProfFlags_showCCSOnException(RtsFlags) != 0::CBool) {
SAVE_THREAD_STATE();
ccall fprintCCS_stderr(CCCS "ptr",
exception "ptr",
LOAD_THREAD_STATE();
}
#endif
-
+
retry_pop_stack:
SAVE_THREAD_STATE();
(frame_type) = ccall raiseExceptionHelper(BaseReg "ptr", CurrentTSO "ptr", exception "ptr");
LOAD_THREAD_STATE();
if (frame_type == ATOMICALLY_FRAME) {
- /* The exception has reached the edge of a memory transaction. Check that
+ /* The exception has reached the edge of a memory transaction. Check that
* the transaction is valid. If not then perhaps the exception should
* not have been thrown: re-run the transaction. "trec" will either be
- * a top-level transaction running the atomic block, or a nested
+ * a top-level transaction running the atomic block, or a nested
* transaction running an invariant check. In the latter case we
* abort and de-allocate the top-level transaction that encloses it
* as well (we could just abandon its transaction record, but this makes
W_ trec, outer;
W_ r;
trec = StgTSO_trec(CurrentTSO);
- (r) = ccall stmValidateNestOfTransactions(trec "ptr");
+ (r) = ccall stmValidateNestOfTransactions(MyCapability() "ptr", trec "ptr");
outer = StgTRecHeader_enclosing_trec(trec);
ccall stmAbortTransaction(MyCapability() "ptr", trec "ptr");
ccall stmFreeAbortedTRec(MyCapability() "ptr", trec "ptr");
StgTSO_trec(CurrentTSO) = trec;
R1 = StgAtomicallyFrame_code(Sp);
jump stg_ap_v_fast [R1];
- }
+ }
}
// After stripping the stack, see whether we should break here for
// be per-thread.
CInt[rts_stop_on_exception] = 0;
("ptr" ioAction) = ccall deRefStablePtr (W_[rts_breakpoint_io_action] "ptr");
- Sp = Sp - WDS(6);
- Sp(5) = exception;
- Sp(4) = stg_raise_ret_info;
- Sp(3) = exception; // the AP_STACK
- Sp(2) = ghczmprim_GHCziTypes_True_closure; // dummy breakpoint info
- Sp(1) = ghczmprim_GHCziTypes_True_closure; // True <=> a breakpoint
+ Sp = Sp - WDS(9);
+ Sp(8) = exception;
+ Sp(7) = stg_raise_ret_info;
+ Sp(6) = exception;
+ Sp(5) = ghczmprim_GHCziTypes_True_closure; // True <=> a breakpoint
+ Sp(4) = stg_ap_ppv_info;
+ Sp(3) = 0;
+ Sp(2) = stg_ap_n_info;
+ Sp(1) = 0;
R1 = ioAction;
- jump RET_LBL(stg_ap_pppv) [R1];
+ jump RET_LBL(stg_ap_n) [R1];
}
}
if (frame_type == STOP_FRAME) {
- /*
- * We've stripped the entire stack, the thread is now dead.
- * We will leave the stack in a GC'able state, see the stg_stop_thread
- * entry code in StgStartup.cmm.
- */
+ /*
+ * We've stripped the entire stack, the thread is now dead.
+ * We will leave the stack in a GC'able state, see the stg_stop_thread
+ * entry code in StgStartup.cmm.
+ */
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;
- SAVE_THREAD_STATE(); /* inline! */
+ 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! */
jump stg_threadFinished [];
}
handler = StgCatchSTMFrame_handler(Sp);
}
- /* Restore the blocked/unblocked state for asynchronous exceptions
- * at the CATCH_FRAME.
+ /* Restore the masked/unmasked state for asynchronous exceptions
+ * at the CATCH_FRAME.
*
- * If exceptions were unblocked, arrange that they are unblocked
+ * If exceptions were unmasked, arrange that they are unmasked
* again after executing the handler by pushing an
* unmaskAsyncExceptions_ret stack frame.
*
Sp(0) = stg_unmaskAsyncExceptionszh_ret_info;
}
- /* Ensure that async excpetions are blocked when running the handler.
+ /* Ensure that async exceptions are masked when running the handler.
*/
StgTSO_flags(CurrentTSO) = %lobits32(
TO_W_(StgTSO_flags(CurrentTSO)) | TSO_BLOCKEX | TSO_INTERRUPTIBLE);
R1 = handler;
Sp_adj(-1);
TICK_UNKNOWN_CALL();
- TICK_SLOW_CALL_pv();
+ TICK_SLOW_CALL_fast_pv();
jump RET_LBL(stg_ap_pv) [R1];
}
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