X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=rts%2FException.cmm;h=24da1c690e50784451e5f144edce893029cb6f2c;hp=5f6bd0703df0b2e2e521e640be937b6b99531a88;hb=e5c3b478b3cd1707cf122833822f44b2ac09b8e9;hpb=1fb4c716c901f08b185439521f91f8cf552797c3 diff --git a/rts/Exception.cmm b/rts/Exception.cmm index 5f6bd07..24da1c6 100644 --- a/rts/Exception.cmm +++ b/rts/Exception.cmm @@ -13,18 +13,20 @@ #include "Cmm.h" #include "RaiseAsync.h" +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 @@ -37,43 +39,38 @@ 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, - 0/*framesize*/, 0/*bitmap*/, 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", + (r) = foreign "C" maybePerformBlockedException (MyCapability() "ptr", CurrentTSO "ptr") [R1]; if (r != 0::CInt) { @@ -85,77 +82,129 @@ INFO_TABLE_RET( stg_unblockAsyncExceptionszh_ret, 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_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) { @@ -163,9 +212,20 @@ unblockAsyncExceptionszh_fast * 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) { @@ -176,16 +236,12 @@ unblockAsyncExceptionszh_fast 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(); @@ -193,7 +249,19 @@ unblockAsyncExceptionszh_fast } -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 */ @@ -204,7 +272,10 @@ killThreadzh_fast 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* @@ -213,6 +284,14 @@ killThreadzh_fast * the handler. */ 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", @@ -226,27 +305,22 @@ killThreadzh_fast } } 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; } - } } } @@ -254,42 +328,22 @@ killThreadzh_fast 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 @@ -305,20 +359,21 @@ INFO_TABLE(stg_catch,2,0,FUN,"catch","catch") { 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 */ @@ -334,28 +389,28 @@ catchzh_fast * * 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, 1, 0, RET_SMALL) +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; @@ -375,13 +430,10 @@ raisezh_fast } #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", exception "ptr") []; - Sp = StgTSO_sp(CurrentTSO); + SAVE_THREAD_STATE(); + (frame_type) = foreign "C" 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 transaction is valid. If not then perhaps the exception should @@ -394,8 +446,8 @@ retry_pop_stack: W_ trec, outer; W_ r; trec = StgTSO_trec(CurrentTSO); - r = foreign "C" stmValidateNestOfTransactions(trec "ptr") []; - "ptr" outer = foreign "C" stmGetEnclosingTRec(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") []; @@ -412,7 +464,7 @@ 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; @@ -435,16 +487,16 @@ retry_pop_stack: // 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") []; + CInt[rts_stop_on_exception] = 0; + ("ptr" ioAction) = foreign "C" 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) = base_GHCziBase_True_closure; // dummy breakpoint info - Sp(1) = base_GHCziBase_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 stg_ap_pppv_info; + jump RET_LBL(stg_ap_pppv); } } @@ -454,8 +506,10 @@ retry_pop_stack: * 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; @@ -478,7 +532,7 @@ retry_pop_stack: * * 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. @@ -487,14 +541,14 @@ retry_pop_stack: 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; @@ -502,9 +556,18 @@ retry_pop_stack: } /* 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. @@ -518,8 +581,8 @@ retry_pop_stack: jump RET_LBL(stg_ap_pv); } -raiseIOzh_fast +stg_raiseIOzh { /* Args :: R1 :: Exception */ - jump raisezh_fast; + jump stg_raisezh; }