X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=rts%2FException.cmm;h=6c887c22dc3cbbba9579db78788541e368e2f28b;hb=6cf8982ac30be6836a0cdd8be5a6ac1a1a144213;hp=43f53c7ad31f86b2e58b0a0b933d89cb0b612556;hpb=176fa33f17dd78355cc572e006d2ab26898e2c69;p=ghc-hetmet.git diff --git a/rts/Exception.cmm b/rts/Exception.cmm index 43f53c7..6c887c2 100644 --- a/rts/Exception.cmm +++ b/rts/Exception.cmm @@ -49,6 +49,8 @@ import ghczmprim_GHCziBool_True_closure; -------------------------------------------------------------------------- */ +STRING(stg_unblockAsync_err_str, "unblockAsyncExceptions#_ret") + INFO_TABLE_RET( stg_unblockAsyncExceptionszh_ret, RET_SMALL ) { CInt r; @@ -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); @@ -96,10 +106,10 @@ INFO_TABLE_RET( stg_blockAsyncExceptionszh_ret, RET_SMALL ) 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) { @@ -119,25 +129,48 @@ 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", 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 */ @@ -187,7 +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* @@ -201,6 +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", @@ -215,8 +253,8 @@ killThreadzh_fast } else { W_ out; W_ retcode; - out = BaseReg + OFFSET_StgRegTable_rmp_tmp_w; - + out = Sp - WDS(1); /* ok to re-use stack space here */ + (retcode) = foreign "C" throwTo(MyCapability() "ptr", CurrentTSO "ptr", target "ptr", @@ -273,13 +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; @@ -302,13 +340,13 @@ 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" { @@ -320,10 +358,10 @@ 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; @@ -360,7 +398,7 @@ 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") []; @@ -400,7 +438,7 @@ 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; @@ -460,7 +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; @@ -484,8 +522,8 @@ retry_pop_stack: jump RET_LBL(stg_ap_pv); } -raiseIOzh_fast +stg_raiseIOzh { /* Args :: R1 :: Exception */ - jump raisezh_fast; + jump stg_raisezh; }