X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=rts%2FException.cmm;h=6c887c22dc3cbbba9579db78788541e368e2f28b;hb=6cf8982ac30be6836a0cdd8be5a6ac1a1a144213;hp=15b2c64d4fb0be10cf9e1cfef37f946ee0f3c37d;hpb=17f848e12faf8cf51aa58918522b6abe1e75dc51;p=ghc-hetmet.git diff --git a/rts/Exception.cmm b/rts/Exception.cmm index 15b2c64..6c887c2 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 @@ -43,21 +45,16 @@ 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); @@ -69,17 +66,12 @@ INFO_TABLE_RET( stg_unblockAsyncExceptionszh_ret, * 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) { @@ -91,50 +83,33 @@ 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_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) { @@ -154,27 +129,50 @@ blockAsyncExceptionszh_fast 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) { @@ -185,24 +183,29 @@ 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(); 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 */ @@ -213,7 +216,8 @@ 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 might have killed ourselves. In which case, better be *very* @@ -221,7 +225,20 @@ 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) { + /* + * 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", @@ -236,9 +253,9 @@ killThreadzh_fast } 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", @@ -263,42 +280,22 @@ 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 @@ -314,13 +311,13 @@ 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; @@ -343,28 +340,28 @@ 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; @@ -384,35 +381,9 @@ raisezh_fast } #endif - 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(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 - R1 = ioAction; - jump stg_ap_pppv_info; - } - } - - /* 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") []; + (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 @@ -426,8 +397,8 @@ 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") []; @@ -444,13 +415,43 @@ 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. + 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. @@ -497,7 +498,7 @@ retry_pop_stack: } 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; @@ -521,8 +522,8 @@ retry_pop_stack: jump RET_LBL(stg_ap_pv); } -raiseIOzh_fast +stg_raiseIOzh { /* Args :: R1 :: Exception */ - jump raisezh_fast; + jump stg_raisezh; }