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
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.
-------------------------------------------------------------------------- */
-STRING(stg_unblockAsync_err_str, "unblockAsyncExceptions#_ret")
-INFO_TABLE_RET( stg_unblockAsyncExceptionszh_ret, RET_SMALL )
+INFO_TABLE_RET(stg_unmaskAsyncExceptionszh_ret, RET_SMALL)
{
CInt r;
- StgTSO_flags(CurrentTSO) = StgTSO_flags(CurrentTSO) &
- %lobits32(~(TSO_BLOCKEX|TSO_INTERRUPTIBLE));
+ 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.
*/
-
- STK_CHK_GEN( WDS(2), R1_PTR, stg_unblockAsyncExceptionszh_ret_info);
Sp_adj(-2);
Sp(1) = R1;
Sp(0) = stg_gc_unpt_r1_info;
jump %ENTRY_CODE(Sp(0));
}
-INFO_TABLE_RET( stg_blockAsyncExceptionszh_ret, RET_SMALL )
+INFO_TABLE_RET(stg_maskAsyncExceptionszh_ret, RET_SMALL)
{
- StgTSO_flags(CurrentTSO) = %lobits32(
- TO_W_(StgTSO_flags(CurrentTSO)) | TSO_BLOCKEX | TSO_INTERRUPTIBLE);
+ StgTSO_flags(CurrentTSO) =
+ %lobits32(
+ TO_W_(StgTSO_flags(CurrentTSO))
+ | TSO_BLOCKEX | TSO_INTERRUPTIBLE
+ );
Sp_adj(1);
jump %ENTRY_CODE(Sp(0));
}
-stg_blockAsyncExceptionszh
+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(0));
+}
+
+stg_maskAsyncExceptionszh
{
/* Args: R1 :: IO a */
- STK_CHK_GEN( WDS(2)/* worst case */, R1_PTR, stg_blockAsyncExceptionszh);
+ STK_CHK_GEN( WDS(1)/* worst case */, R1_PTR, stg_maskAsyncExceptionszh);
if ((TO_W_(StgTSO_flags(CurrentTSO)) & TSO_BLOCKEX) == 0) {
-
- StgTSO_flags(CurrentTSO) = %lobits32(
- TO_W_(StgTSO_flags(CurrentTSO)) | TSO_BLOCKEX | TSO_INTERRUPTIBLE);
+ /* 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;
}
-stg_unblockAsyncExceptionszh
+stg_unmaskAsyncExceptionszh
{
CInt r;
+ W_ level;
/* Args: R1 :: IO a */
- STK_CHK_GEN( WDS(4), R1_PTR, stg_unblockAsyncExceptionszh);
+ 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) = %lobits32(
- TO_W_(StgTSO_flags(CurrentTSO)) & ~(TSO_BLOCKEX|TSO_INTERRUPTIBLE));
-
/* avoid growing the stack unnecessarily */
- if (Sp(0) == stg_unblockAsyncExceptionszh_ret_info) {
+ if (Sp(0) == stg_unmaskAsyncExceptionszh_ret_info) {
Sp_adj(1);
} else {
Sp_adj(-1);
- Sp(0) = stg_blockAsyncExceptionszh_ret_info;
+ 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) {
/*
jump stg_ap_v_fast;
}
-stg_asyncExceptionsBlockedzh
+
+stg_getMaskingStatezh
{
/* args: none */
- if ((TO_W_(StgTSO_flags(CurrentTSO)) & TSO_BLOCKEX) != 0) {
- RET_N(1);
- } else {
- RET_N(0);
- }
+ /*
+ 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
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 */
*
* 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.
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;
}
/* 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) = %lobits32(
- TO_W_(StgTSO_flags(CurrentTSO)) | TSO_BLOCKEX | TSO_INTERRUPTIBLE);
+ 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.
projects / ghc-hetmet.git / blobdiff