X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=rts%2FException.cmm;h=75f2c15d93c301b4627a2bb0c23f9d9ad7e63e00;hp=0c1b6648d5c89c5bf1313f4ee3343b55bdd4bfe1;hb=842e9d6628a27cf1f420d53f6a5901935dc50c54;hpb=45c35148be308b3290f1c14240d406f1cb1af166 diff --git a/rts/Exception.cmm b/rts/Exception.cmm index 0c1b664..75f2c15 100644 --- a/rts/Exception.cmm +++ b/rts/Exception.cmm @@ -13,6 +13,8 @@ #include "Cmm.h" #include "RaiseAsync.h" +import ghczmprim_GHCziBool_True_closure; + /* ----------------------------------------------------------------------------- Exception Primitives @@ -43,25 +45,66 @@ 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 ) +INFO_TABLE_RET( stg_unblockAsyncExceptionszh_ret, RET_SMALL ) { - // Not true: see comments above - // ASSERT(StgTSO_blocked_exceptions(CurrentTSO) != NULL); - - foreign "C" awakenBlockedExceptionQueue(MyCapability() "ptr", - CurrentTSO "ptr") [R1]; + CInt r; StgTSO_flags(CurrentTSO) = StgTSO_flags(CurrentTSO) & ~(TSO_BLOCKEX::I32|TSO_INTERRUPTIBLE::I32); + /* 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. + */ + +#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; +#ifdef REG_R1 + Sp(0) = stg_gc_unpt_r1_info; +#else + Sp(0) = stg_ut_1_0_unreg_info; +#endif + SAVE_THREAD_STATE(); + (r) = foreign "C" maybePerformBlockedException (MyCapability() "ptr", + CurrentTSO "ptr") [R1]; + + 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); + 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); + } +#endif + } + #ifdef REG_R1 Sp_adj(1); jump %ENTRY_CODE(Sp(0)); @@ -72,12 +115,8 @@ INFO_TABLE_RET( stg_unblockAsyncExceptionszh_ret, #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; @@ -116,16 +155,38 @@ blockAsyncExceptionszh_fast unblockAsyncExceptionszh_fast { + CInt r; + /* Args: R1 :: IO a */ STK_CHK_GEN( WDS(2), R1_PTR, unblockAsyncExceptionszh_fast); if ((TO_W_(StgTSO_flags(CurrentTSO)) & TSO_BLOCKEX) != 0) { - foreign "C" awakenBlockedExceptionQueue(MyCapability() "ptr", - CurrentTSO "ptr") [R1]; StgTSO_flags(CurrentTSO) = StgTSO_flags(CurrentTSO) & ~(TSO_BLOCKEX::I32|TSO_INTERRUPTIBLE::I32); + /* 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. + */ + SAVE_THREAD_STATE(); + (r) = foreign "C" maybePerformBlockedException (MyCapability() "ptr", + CurrentTSO "ptr") [R1]; + + 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); + jump %ENTRY_CODE(Sp(0)); + } + } + } + /* avoid growing the stack unnecessarily */ if (Sp(0) == stg_unblockAsyncExceptionszh_ret_info) { Sp_adj(1); @@ -159,14 +220,18 @@ killThreadzh_fast * 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) { 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); @@ -177,7 +242,7 @@ killThreadzh_fast W_ retcode; out = BaseReg + OFFSET_StgRegTable_rmp_tmp_w; - retcode = foreign "C" throwTo(MyCapability() "ptr", + (retcode) = foreign "C" throwTo(MyCapability() "ptr", CurrentTSO "ptr", target "ptr", exception "ptr", @@ -203,68 +268,35 @@ killThreadzh_fast -------------------------------------------------------------------------- */ #ifdef REG_R1 -#define CATCH_FRAME_ENTRY_TEMPLATE(label,ret) \ - label \ - { \ - Sp = Sp + SIZEOF_StgCatchFrame; \ - jump ret; \ - } -#else -#define CATCH_FRAME_ENTRY_TEMPLATE(label,ret) \ - label \ - { \ - W_ rval; \ - rval = Sp(0); \ - Sp = Sp + SIZEOF_StgCatchFrame; \ - Sp(0) = rval; \ - jump ret; \ - } -#endif - -#ifdef REG_R1 #define SP_OFF 0 #else #define SP_OFF 1 #endif -CATCH_FRAME_ENTRY_TEMPLATE(stg_catch_frame_0_ret,%RET_VEC(Sp(SP_OFF),0)) -CATCH_FRAME_ENTRY_TEMPLATE(stg_catch_frame_1_ret,%RET_VEC(Sp(SP_OFF),1)) -CATCH_FRAME_ENTRY_TEMPLATE(stg_catch_frame_2_ret,%RET_VEC(Sp(SP_OFF),2)) -CATCH_FRAME_ENTRY_TEMPLATE(stg_catch_frame_3_ret,%RET_VEC(Sp(SP_OFF),3)) -CATCH_FRAME_ENTRY_TEMPLATE(stg_catch_frame_4_ret,%RET_VEC(Sp(SP_OFF),4)) -CATCH_FRAME_ENTRY_TEMPLATE(stg_catch_frame_5_ret,%RET_VEC(Sp(SP_OFF),5)) -CATCH_FRAME_ENTRY_TEMPLATE(stg_catch_frame_6_ret,%RET_VEC(Sp(SP_OFF),6)) -CATCH_FRAME_ENTRY_TEMPLATE(stg_catch_frame_7_ret,%RET_VEC(Sp(SP_OFF),7)) - -#if MAX_VECTORED_RTN > 8 -#error MAX_VECTORED_RTN has changed: please modify stg_catch_frame too. -#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, - stg_catch_frame_0_ret, - stg_catch_frame_1_ret, - stg_catch_frame_2_ret, - stg_catch_frame_3_ret, - stg_catch_frame_4_ret, - stg_catch_frame_5_ret, - stg_catch_frame_6_ret, - stg_catch_frame_7_ret) -CATCH_FRAME_ENTRY_TEMPLATE(,%ENTRY_CODE(Sp(SP_OFF))) +INFO_TABLE_RET(stg_catch_frame, CATCH_FRAME, +#if defined(PROFILING) + W_ unused1, W_ unused2, +#endif + W_ unused3, "ptr" W_ unused4) +#ifdef REG_R1 + { + 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 @@ -318,13 +350,26 @@ INFO_TABLE(stg_raise,1,0,THUNK_1_0,"raise","raise") jump raisezh_fast; } +section "data" { + no_break_on_exception: W_[1]; +} + +INFO_TABLE_RET(stg_raise_ret, RET_SMALL, "ptr" W_ arg1) +{ + R1 = Sp(1); + Sp = Sp + WDS(2); + W_[no_break_on_exception] = 1; + jump raisezh_fast; +} + raisezh_fast { 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. */ @@ -333,23 +378,36 @@ raisezh_fast * 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 - + 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 * the transaction is valid. If not then perhaps the exception should - * not have been thrown: re-run the transaction */ - W_ trec; + * not have been thrown: re-run the transaction. "trec" will either be + * 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 + * sure it's marked as aborted and available for re-use). */ + W_ trec, outer; W_ r; trec = StgTSO_trec(CurrentTSO); - r = foreign "C" stmValidateNestOfTransactions(trec "ptr"); - foreign "C" stmAbortTransaction(MyCapability() "ptr", trec "ptr"); + (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") []; + + if (outer != NO_TREC) { + foreign "C" stmAbortTransaction(MyCapability() "ptr", outer "ptr") []; + foreign "C" stmFreeAbortedTRec(MyCapability() "ptr", outer "ptr") []; + } + StgTSO_trec(CurrentTSO) = NO_TREC; if (r != 0) { // Transaction was valid: continue searching for a catch frame @@ -358,13 +416,43 @@ retry_pop_stack: } 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. + W_[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. @@ -373,16 +461,12 @@ retry_pop_stack: */ 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 @@ -400,6 +484,9 @@ retry_pop_stack: * If exceptions were unblocked, arrange that they are unblocked * again after executing the handler by pushing an * unblockAsyncExceptions_ret stack frame. + * + * If we've reached an STM catch frame then roll back the nested + * transaction we were using. */ W_ frame; frame = Sp; @@ -410,6 +497,12 @@ retry_pop_stack: Sp(0) = stg_unblockAsyncExceptionszh_ret_info; } } else { + W_ trec, outer; + trec = StgTSO_trec(CurrentTSO); + ("ptr" outer) = foreign "C" stmGetEnclosingTRec(trec "ptr") []; + foreign "C" stmAbortTransaction(MyCapability() "ptr", trec "ptr") []; + foreign "C" stmFreeAbortedTRec(MyCapability() "ptr", trec "ptr") []; + StgTSO_trec(CurrentTSO) = outer; Sp = Sp + SIZEOF_StgCatchSTMFrame; } @@ -422,7 +515,7 @@ retry_pop_stack: * token as arguments. */ Sp_adj(-1); - Sp(0) = R1; + Sp(0) = exception; R1 = handler; Sp_adj(-1); TICK_UNKNOWN_CALL();