X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=rts%2FException.cmm;h=55c79cede7890d08b5d41d17e3a00eebf95a7c9e;hp=cf24ef5b497359d0e6aa38d2e6dd5727e554689f;hb=7408b39235bccdcde48df2a73337ff976fbc09b7;hpb=c9acb4de50dd2b7f7ece5491f60598f0a4815e75 diff --git a/rts/Exception.cmm b/rts/Exception.cmm index cf24ef5..55c79ce 100644 --- a/rts/Exception.cmm +++ b/rts/Exception.cmm @@ -49,12 +49,14 @@ import ghczmprim_GHCziBool_True_closure; -------------------------------------------------------------------------- */ +STRING(stg_unblockAsync_err_str, "unblockAsyncExceptions#_ret") + INFO_TABLE_RET( stg_unblockAsyncExceptionszh_ret, RET_SMALL ) { CInt r; StgTSO_flags(CurrentTSO) = StgTSO_flags(CurrentTSO) & - ~(TSO_BLOCKEX::I32|TSO_INTERRUPTIBLE::I32); + %lobits32(~(TSO_BLOCKEX|TSO_INTERRUPTIBLE)); /* Eagerly raise a blocked exception, if there is one */ if (StgTSO_blocked_exceptions(CurrentTSO) != END_TSO_QUEUE) { @@ -81,6 +83,14 @@ INFO_TABLE_RET( stg_unblockAsyncExceptionszh_ret, RET_SMALL ) jump %ENTRY_CODE(Sp(0)); } } + else { + /* + 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); + } } Sp_adj(1); @@ -89,22 +99,22 @@ INFO_TABLE_RET( stg_unblockAsyncExceptionszh_ret, RET_SMALL ) INFO_TABLE_RET( stg_blockAsyncExceptionszh_ret, RET_SMALL ) { - 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); Sp_adj(1); jump %ENTRY_CODE(Sp(0)); } -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) { - 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); /* avoid growing the stack unnecessarily */ if (Sp(0) == stg_blockAsyncExceptionszh_ret_info) { @@ -119,17 +129,29 @@ 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); + StgTSO_flags(CurrentTSO) = %lobits32( + TO_W_(StgTSO_flags(CurrentTSO)) & ~(TSO_BLOCKEX|TSO_INTERRUPTIBLE)); + + /* 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) { @@ -137,7 +159,18 @@ 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", CurrentTSO "ptr") [R1]; @@ -150,23 +183,19 @@ 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; } -asyncExceptionsBlockedzh_fast +stg_asyncExceptionsBlockedzh { /* args: none */ if ((TO_W_(StgTSO_flags(CurrentTSO)) & TSO_BLOCKEX) != 0) { @@ -176,7 +205,7 @@ asyncExceptionsBlockedzh_fast } } -killThreadzh_fast +stg_killThreadzh { /* args: R1 = TSO to kill, R2 = Exception */ @@ -188,7 +217,7 @@ killThreadzh_fast exception = R2; /* Needs 3 words because throwToSingleThreaded uses some stack */ - STK_CHK_GEN( WDS(3), R1_PTR & R2_PTR, killThreadzh_fast); + STK_CHK_GEN( WDS(3), R1_PTR & R2_PTR, stg_killThreadzh); /* * We might have killed ourselves. In which case, better be *very* @@ -202,6 +231,14 @@ killThreadzh_fast 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", @@ -215,27 +252,22 @@ killThreadzh_fast } } else { W_ out; - W_ retcode; + W_ msg; out = Sp - WDS(1); /* ok to re-use stack space here */ - (retcode) = foreign "C" throwTo(MyCapability() "ptr", - CurrentTSO "ptr", - target "ptr", - exception "ptr", - out "ptr") [R1,R2]; + (msg) = foreign "C" throwTo(MyCapability() "ptr", + CurrentTSO "ptr", + target "ptr", + exception "ptr") [R1,R2]; - switch [THROWTO_SUCCESS .. THROWTO_BLOCKED] (retcode) { - - case THROWTO_SUCCESS: { + 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; } - } } } @@ -274,13 +306,13 @@ 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; @@ -303,13 +335,13 @@ 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" { @@ -321,10 +353,10 @@ 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; @@ -361,7 +393,7 @@ retry_pop_stack: 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") []; @@ -401,7 +433,7 @@ 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; + CInt[rts_stop_on_exception] = 0; ("ptr" ioAction) = foreign "C" deRefStablePtr (W_[rts_breakpoint_io_action] "ptr") []; Sp = Sp - WDS(7); Sp(6) = exception; @@ -461,7 +493,7 @@ 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; @@ -470,8 +502,8 @@ retry_pop_stack: /* Ensure that async excpetions are blocked when running the handler. */ - 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); /* Call the handler, passing the exception value and a realworld * token as arguments. @@ -485,8 +517,8 @@ retry_pop_stack: jump RET_LBL(stg_ap_pv); } -raiseIOzh_fast +stg_raiseIOzh { /* Args :: R1 :: Exception */ - jump raisezh_fast; + jump stg_raisezh; }