1 /* -----------------------------------------------------------------------------
3 * (c) The GHC Team, 1998-2004
5 * Out-of-line primitive operations
7 * This file contains the implementations of all the primitive
8 * operations ("primops") which are not expanded inline. See
9 * ghc/compiler/prelude/primops.txt.pp for a list of all the primops;
10 * this file contains code for most of those with the attribute
13 * Entry convention: the entry convention for a primop is that all the
14 * args are in Stg registers (R1, R2, etc.). This is to make writing
15 * the primops easier. (see compiler/codeGen/CgCallConv.hs).
17 * Return convention: results from a primop are generally returned
18 * using the ordinary unboxed tuple return convention. The C-- parser
19 * implements the RET_xxxx() macros to perform unboxed-tuple returns
20 * based on the prevailing return convention.
22 * This file is written in a subset of C--, extended with various
23 * features specific to GHC. It is compiled by GHC directly. For the
24 * syntax of .cmm files, see the parser in ghc/compiler/cmm/CmmParse.y.
26 * ---------------------------------------------------------------------------*/
31 import pthread_mutex_lock;
32 import pthread_mutex_unlock;
34 import base_ControlziExceptionziBase_nestedAtomically_closure;
35 import EnterCriticalSection;
36 import LeaveCriticalSection;
37 import ghczmprim_GHCziBool_False_closure;
38 #if !defined(mingw32_HOST_OS)
42 /*-----------------------------------------------------------------------------
45 Basically just new*Array - the others are all inline macros.
47 The size arg is always passed in R1, and the result returned in R1.
49 The slow entry point is for returning from a heap check, the saved
50 size argument must be re-loaded from the stack.
51 -------------------------------------------------------------------------- */
53 /* for objects that are *less* than the size of a word, make sure we
54 * round up to the nearest word for the size of the array.
59 W_ words, payload_words, n, p;
60 MAYBE_GC(NO_PTRS,stg_newByteArrayzh);
62 payload_words = ROUNDUP_BYTES_TO_WDS(n);
63 words = BYTES_TO_WDS(SIZEOF_StgArrWords) + payload_words;
64 ("ptr" p) = foreign "C" allocate(MyCapability() "ptr",words) [];
65 TICK_ALLOC_PRIM(SIZEOF_StgArrWords,WDS(payload_words),0);
66 SET_HDR(p, stg_ARR_WORDS_info, W_[CCCS]);
67 StgArrWords_bytes(p) = n;
72 #define BA_MASK (BA_ALIGN-1)
74 stg_newPinnedByteArrayzh
76 W_ words, n, bytes, payload_words, p;
78 MAYBE_GC(NO_PTRS,stg_newPinnedByteArrayzh);
81 /* payload_words is what we will tell the profiler we had to allocate */
82 payload_words = ROUNDUP_BYTES_TO_WDS(bytes);
83 /* When we actually allocate memory, we need to allow space for the
85 bytes = bytes + SIZEOF_StgArrWords;
86 /* And we want to align to BA_ALIGN bytes, so we need to allow space
87 to shift up to BA_ALIGN - 1 bytes: */
88 bytes = bytes + BA_ALIGN - 1;
89 /* Now we convert to a number of words: */
90 words = ROUNDUP_BYTES_TO_WDS(bytes);
92 ("ptr" p) = foreign "C" allocatePinned(MyCapability() "ptr", words) [];
93 TICK_ALLOC_PRIM(SIZEOF_StgArrWords,WDS(payload_words),0);
95 /* Now we need to move p forward so that the payload is aligned
97 p = p + ((-p - SIZEOF_StgArrWords) & BA_MASK);
99 SET_HDR(p, stg_ARR_WORDS_info, W_[CCCS]);
100 StgArrWords_bytes(p) = n;
104 stg_newAlignedPinnedByteArrayzh
106 W_ words, n, bytes, payload_words, p, alignment;
108 MAYBE_GC(NO_PTRS,stg_newAlignedPinnedByteArrayzh);
112 /* we always supply at least word-aligned memory, so there's no
113 need to allow extra space for alignment if the requirement is less
114 than a word. This also prevents mischief with alignment == 0. */
115 if (alignment <= SIZEOF_W) { alignment = 1; }
119 /* payload_words is what we will tell the profiler we had to allocate */
120 payload_words = ROUNDUP_BYTES_TO_WDS(bytes);
122 /* When we actually allocate memory, we need to allow space for the
124 bytes = bytes + SIZEOF_StgArrWords;
125 /* And we want to align to <alignment> bytes, so we need to allow space
126 to shift up to <alignment - 1> bytes: */
127 bytes = bytes + alignment - 1;
128 /* Now we convert to a number of words: */
129 words = ROUNDUP_BYTES_TO_WDS(bytes);
131 ("ptr" p) = foreign "C" allocatePinned(MyCapability() "ptr", words) [];
132 TICK_ALLOC_PRIM(SIZEOF_StgArrWords,WDS(payload_words),0);
134 /* Now we need to move p forward so that the payload is aligned
135 to <alignment> bytes. Note that we are assuming that
136 <alignment> is a power of 2, which is technically not guaranteed */
137 p = p + ((-p - SIZEOF_StgArrWords) & (alignment - 1));
139 SET_HDR(p, stg_ARR_WORDS_info, W_[CCCS]);
140 StgArrWords_bytes(p) = n;
146 W_ words, n, init, arr, p, size;
147 /* Args: R1 = words, R2 = initialisation value */
150 MAYBE_GC(R2_PTR,stg_newArrayzh);
152 // the mark area contains one byte for each 2^MUT_ARR_PTRS_CARD_BITS words
153 // in the array, making sure we round up, and then rounding up to a whole
155 size = n + mutArrPtrsCardWords(n);
156 words = BYTES_TO_WDS(SIZEOF_StgMutArrPtrs) + size;
157 ("ptr" arr) = foreign "C" allocate(MyCapability() "ptr",words) [R2];
158 TICK_ALLOC_PRIM(SIZEOF_StgMutArrPtrs, WDS(n), 0);
160 SET_HDR(arr, stg_MUT_ARR_PTRS_DIRTY_info, W_[CCCS]);
161 StgMutArrPtrs_ptrs(arr) = n;
162 StgMutArrPtrs_size(arr) = size;
164 // Initialise all elements of the the array with the value in R2
166 p = arr + SIZEOF_StgMutArrPtrs;
168 if (p < arr + WDS(words)) {
173 // Initialise the mark bits with 0
175 if (p < arr + WDS(size)) {
184 stg_unsafeThawArrayzh
186 // SUBTLETY TO DO WITH THE OLD GEN MUTABLE LIST
188 // A MUT_ARR_PTRS lives on the mutable list, but a MUT_ARR_PTRS_FROZEN
189 // normally doesn't. However, when we freeze a MUT_ARR_PTRS, we leave
190 // it on the mutable list for the GC to remove (removing something from
191 // the mutable list is not easy).
193 // So that we can tell whether a MUT_ARR_PTRS_FROZEN is on the mutable list,
194 // when we freeze it we set the info ptr to be MUT_ARR_PTRS_FROZEN0
195 // to indicate that it is still on the mutable list.
197 // So, when we thaw a MUT_ARR_PTRS_FROZEN, we must cope with two cases:
198 // either it is on a mut_list, or it isn't. We adopt the convention that
199 // the closure type is MUT_ARR_PTRS_FROZEN0 if it is on the mutable list,
200 // and MUT_ARR_PTRS_FROZEN otherwise. In fact it wouldn't matter if
201 // we put it on the mutable list more than once, but it would get scavenged
202 // multiple times during GC, which would be unnecessarily slow.
204 if (StgHeader_info(R1) != stg_MUT_ARR_PTRS_FROZEN0_info) {
205 SET_INFO(R1,stg_MUT_ARR_PTRS_DIRTY_info);
206 recordMutable(R1, R1);
207 // must be done after SET_INFO, because it ASSERTs closure_MUTABLE()
210 SET_INFO(R1,stg_MUT_ARR_PTRS_DIRTY_info);
215 /* -----------------------------------------------------------------------------
217 -------------------------------------------------------------------------- */
222 /* Args: R1 = initialisation value */
224 ALLOC_PRIM( SIZEOF_StgMutVar, R1_PTR, stg_newMutVarzh);
226 mv = Hp - SIZEOF_StgMutVar + WDS(1);
227 SET_HDR(mv,stg_MUT_VAR_DIRTY_info,W_[CCCS]);
228 StgMutVar_var(mv) = R1;
233 stg_atomicModifyMutVarzh
235 W_ mv, f, z, x, y, r, h;
236 /* Args: R1 :: MutVar#, R2 :: a -> (a,b) */
238 /* If x is the current contents of the MutVar#, then
239 We want to make the new contents point to
243 and the return value is
247 obviously we can share (f x).
249 z = [stg_ap_2 f x] (max (HS + 2) MIN_UPD_SIZE)
250 y = [stg_sel_0 z] (max (HS + 1) MIN_UPD_SIZE)
251 r = [stg_sel_1 z] (max (HS + 1) MIN_UPD_SIZE)
255 #define THUNK_1_SIZE (SIZEOF_StgThunkHeader + WDS(MIN_UPD_SIZE))
256 #define TICK_ALLOC_THUNK_1() TICK_ALLOC_UP_THK(WDS(1),WDS(MIN_UPD_SIZE-1))
258 #define THUNK_1_SIZE (SIZEOF_StgThunkHeader + WDS(1))
259 #define TICK_ALLOC_THUNK_1() TICK_ALLOC_UP_THK(WDS(1),0)
263 #define THUNK_2_SIZE (SIZEOF_StgThunkHeader + WDS(MIN_UPD_SIZE))
264 #define TICK_ALLOC_THUNK_2() TICK_ALLOC_UP_THK(WDS(2),WDS(MIN_UPD_SIZE-2))
266 #define THUNK_2_SIZE (SIZEOF_StgThunkHeader + WDS(2))
267 #define TICK_ALLOC_THUNK_2() TICK_ALLOC_UP_THK(WDS(2),0)
270 #define SIZE (THUNK_2_SIZE + THUNK_1_SIZE + THUNK_1_SIZE)
272 HP_CHK_GEN_TICKY(SIZE, R1_PTR & R2_PTR, stg_atomicModifyMutVarzh);
277 TICK_ALLOC_THUNK_2();
278 CCCS_ALLOC(THUNK_2_SIZE);
279 z = Hp - THUNK_2_SIZE + WDS(1);
280 SET_HDR(z, stg_ap_2_upd_info, W_[CCCS]);
281 LDV_RECORD_CREATE(z);
282 StgThunk_payload(z,0) = f;
284 TICK_ALLOC_THUNK_1();
285 CCCS_ALLOC(THUNK_1_SIZE);
286 y = z - THUNK_1_SIZE;
287 SET_HDR(y, stg_sel_0_upd_info, W_[CCCS]);
288 LDV_RECORD_CREATE(y);
289 StgThunk_payload(y,0) = z;
291 TICK_ALLOC_THUNK_1();
292 CCCS_ALLOC(THUNK_1_SIZE);
293 r = y - THUNK_1_SIZE;
294 SET_HDR(r, stg_sel_1_upd_info, W_[CCCS]);
295 LDV_RECORD_CREATE(r);
296 StgThunk_payload(r,0) = z;
299 x = StgMutVar_var(mv);
300 StgThunk_payload(z,1) = x;
302 (h) = foreign "C" cas(mv + SIZEOF_StgHeader + OFFSET_StgMutVar_var, x, y) [];
303 if (h != x) { goto retry; }
305 StgMutVar_var(mv) = y;
308 if (GET_INFO(mv) == stg_MUT_VAR_CLEAN_info) {
309 foreign "C" dirty_MUT_VAR(BaseReg "ptr", mv "ptr") [];
315 /* -----------------------------------------------------------------------------
316 Weak Pointer Primitives
317 -------------------------------------------------------------------------- */
319 STRING(stg_weak_msg,"New weak pointer at %p\n")
325 R3 = finalizer (or NULL)
330 R3 = stg_NO_FINALIZER_closure;
333 ALLOC_PRIM( SIZEOF_StgWeak, R1_PTR & R2_PTR & R3_PTR, stg_mkWeakzh );
335 w = Hp - SIZEOF_StgWeak + WDS(1);
336 SET_HDR(w, stg_WEAK_info, W_[CCCS]);
338 // We don't care about cfinalizer here.
339 // Should StgWeak_cfinalizer(w) be stg_NO_FINALIZER_closure or
343 StgWeak_value(w) = R2;
344 StgWeak_finalizer(w) = R3;
345 StgWeak_cfinalizer(w) = stg_NO_FINALIZER_closure;
347 ACQUIRE_LOCK(sm_mutex);
348 StgWeak_link(w) = W_[weak_ptr_list];
349 W_[weak_ptr_list] = w;
350 RELEASE_LOCK(sm_mutex);
352 IF_DEBUG(weak, foreign "C" debugBelch(stg_weak_msg,w) []);
357 stg_mkWeakForeignEnvzh
363 R5 = has environment (0 or 1)
366 W_ w, payload_words, words, p;
368 W_ key, val, fptr, ptr, flag, eptr;
377 ALLOC_PRIM( SIZEOF_StgWeak, R1_PTR & R2_PTR, stg_mkWeakForeignEnvzh );
379 w = Hp - SIZEOF_StgWeak + WDS(1);
380 SET_HDR(w, stg_WEAK_info, W_[CCCS]);
383 words = BYTES_TO_WDS(SIZEOF_StgArrWords) + payload_words;
384 ("ptr" p) = foreign "C" allocate(MyCapability() "ptr", words) [];
386 TICK_ALLOC_PRIM(SIZEOF_StgArrWords,WDS(payload_words),0);
387 SET_HDR(p, stg_ARR_WORDS_info, W_[CCCS]);
389 StgArrWords_bytes(p) = WDS(payload_words);
390 StgArrWords_payload(p,0) = fptr;
391 StgArrWords_payload(p,1) = ptr;
392 StgArrWords_payload(p,2) = eptr;
393 StgArrWords_payload(p,3) = flag;
395 // We don't care about the value here.
396 // Should StgWeak_value(w) be stg_NO_FINALIZER_closure or something else?
398 StgWeak_key(w) = key;
399 StgWeak_value(w) = val;
400 StgWeak_finalizer(w) = stg_NO_FINALIZER_closure;
401 StgWeak_cfinalizer(w) = p;
403 ACQUIRE_LOCK(sm_mutex);
404 StgWeak_link(w) = W_[weak_ptr_list];
405 W_[weak_ptr_list] = w;
406 RELEASE_LOCK(sm_mutex);
408 IF_DEBUG(weak, foreign "C" debugBelch(stg_weak_msg,w) []);
422 if (GET_INFO(w) == stg_DEAD_WEAK_info) {
423 RET_NP(0,stg_NO_FINALIZER_closure);
429 // A weak pointer is inherently used, so we do not need to call
430 // LDV_recordDead_FILL_SLOP_DYNAMIC():
431 // LDV_recordDead_FILL_SLOP_DYNAMIC((StgClosure *)w);
432 // or, LDV_recordDead():
433 // LDV_recordDead((StgClosure *)w, sizeofW(StgWeak) - sizeofW(StgProfHeader));
434 // Furthermore, when PROFILING is turned on, dead weak pointers are exactly as
435 // large as weak pointers, so there is no need to fill the slop, either.
436 // See stg_DEAD_WEAK_info in StgMiscClosures.hc.
440 // Todo: maybe use SET_HDR() and remove LDV_recordCreate()?
442 SET_INFO(w,stg_DEAD_WEAK_info);
443 LDV_RECORD_CREATE(w);
445 f = StgWeak_finalizer(w);
446 arr = StgWeak_cfinalizer(w);
448 StgDeadWeak_link(w) = StgWeak_link(w);
450 if (arr != stg_NO_FINALIZER_closure) {
451 foreign "C" runCFinalizer(StgArrWords_payload(arr,0),
452 StgArrWords_payload(arr,1),
453 StgArrWords_payload(arr,2),
454 StgArrWords_payload(arr,3)) [];
457 /* return the finalizer */
458 if (f == stg_NO_FINALIZER_closure) {
459 RET_NP(0,stg_NO_FINALIZER_closure);
471 if (GET_INFO(w) == stg_WEAK_info) {
473 val = StgWeak_value(w);
481 /* -----------------------------------------------------------------------------
482 Floating point operations.
483 -------------------------------------------------------------------------- */
485 stg_decodeFloatzuIntzh
492 STK_CHK_GEN( WDS(2), NO_PTRS, stg_decodeFloatzuIntzh );
494 mp_tmp1 = Sp - WDS(1);
495 mp_tmp_w = Sp - WDS(2);
497 /* arguments: F1 = Float# */
500 /* Perform the operation */
501 foreign "C" __decodeFloat_Int(mp_tmp1 "ptr", mp_tmp_w "ptr", arg) [];
503 /* returns: (Int# (mantissa), Int# (exponent)) */
504 RET_NN(W_[mp_tmp1], W_[mp_tmp_w]);
507 stg_decodeDoublezu2Intzh
516 STK_CHK_GEN( WDS(4), NO_PTRS, stg_decodeDoublezu2Intzh );
518 mp_tmp1 = Sp - WDS(1);
519 mp_tmp2 = Sp - WDS(2);
520 mp_result1 = Sp - WDS(3);
521 mp_result2 = Sp - WDS(4);
523 /* arguments: D1 = Double# */
526 /* Perform the operation */
527 foreign "C" __decodeDouble_2Int(mp_tmp1 "ptr", mp_tmp2 "ptr",
528 mp_result1 "ptr", mp_result2 "ptr",
532 (Int# (mant sign), Word# (mant high), Word# (mant low), Int# (expn)) */
533 RET_NNNN(W_[mp_tmp1], W_[mp_tmp2], W_[mp_result1], W_[mp_result2]);
536 /* -----------------------------------------------------------------------------
537 * Concurrency primitives
538 * -------------------------------------------------------------------------- */
542 /* args: R1 = closure to spark */
544 MAYBE_GC(R1_PTR, stg_forkzh);
550 ("ptr" threadid) = foreign "C" createIOThread( MyCapability() "ptr",
551 RtsFlags_GcFlags_initialStkSize(RtsFlags),
554 /* start blocked if the current thread is blocked */
555 StgTSO_flags(threadid) = %lobits16(
556 TO_W_(StgTSO_flags(threadid)) |
557 TO_W_(StgTSO_flags(CurrentTSO)) & (TSO_BLOCKEX | TSO_INTERRUPTIBLE));
559 foreign "C" scheduleThread(MyCapability() "ptr", threadid "ptr") [];
561 // context switch soon, but not immediately: we don't want every
562 // forkIO to force a context-switch.
563 Capability_context_switch(MyCapability()) = 1 :: CInt;
570 /* args: R1 = cpu, R2 = closure to spark */
572 MAYBE_GC(R2_PTR, stg_forkOnzh);
580 ("ptr" threadid) = foreign "C" createIOThread( MyCapability() "ptr",
581 RtsFlags_GcFlags_initialStkSize(RtsFlags),
584 /* start blocked if the current thread is blocked */
585 StgTSO_flags(threadid) = %lobits16(
586 TO_W_(StgTSO_flags(threadid)) |
587 TO_W_(StgTSO_flags(CurrentTSO)) & (TSO_BLOCKEX | TSO_INTERRUPTIBLE));
589 foreign "C" scheduleThreadOn(MyCapability() "ptr", cpu, threadid "ptr") [];
591 // context switch soon, but not immediately: we don't want every
592 // forkIO to force a context-switch.
593 Capability_context_switch(MyCapability()) = 1 :: CInt;
600 jump stg_yield_noregs;
615 foreign "C" labelThread(R1 "ptr", R2 "ptr") [];
617 jump %ENTRY_CODE(Sp(0));
620 stg_isCurrentThreadBoundzh
624 (r) = foreign "C" isThreadBound(CurrentTSO) [];
630 /* args: R1 :: ThreadId# */
638 if (TO_W_(StgTSO_what_next(tso)) == ThreadRelocated) {
639 tso = StgTSO__link(tso);
643 what_next = TO_W_(StgTSO_what_next(tso));
644 why_blocked = TO_W_(StgTSO_why_blocked(tso));
645 // Note: these two reads are not atomic, so they might end up
646 // being inconsistent. It doesn't matter, since we
647 // only return one or the other. If we wanted to return the
648 // contents of block_info too, then we'd have to do some synchronisation.
650 if (what_next == ThreadComplete) {
651 ret = 16; // NB. magic, matches up with GHC.Conc.threadStatus
653 if (what_next == ThreadKilled) {
662 /* -----------------------------------------------------------------------------
664 * -------------------------------------------------------------------------- */
668 // Catch retry frame ------------------------------------------------------------
670 INFO_TABLE_RET(stg_catch_retry_frame, CATCH_RETRY_FRAME,
671 #if defined(PROFILING)
672 W_ unused1, W_ unused2,
674 W_ unused3, P_ unused4, P_ unused5)
676 W_ r, frame, trec, outer;
679 trec = StgTSO_trec(CurrentTSO);
680 outer = StgTRecHeader_enclosing_trec(trec);
681 (r) = foreign "C" stmCommitNestedTransaction(MyCapability() "ptr", trec "ptr") [];
683 /* Succeeded (either first branch or second branch) */
684 StgTSO_trec(CurrentTSO) = outer;
685 Sp = Sp + SIZEOF_StgCatchRetryFrame;
686 jump %ENTRY_CODE(Sp(SP_OFF));
688 /* Did not commit: re-execute */
690 ("ptr" new_trec) = foreign "C" stmStartTransaction(MyCapability() "ptr", outer "ptr") [];
691 StgTSO_trec(CurrentTSO) = new_trec;
692 if (StgCatchRetryFrame_running_alt_code(frame) != 0::I32) {
693 R1 = StgCatchRetryFrame_alt_code(frame);
695 R1 = StgCatchRetryFrame_first_code(frame);
702 // Atomically frame ------------------------------------------------------------
704 INFO_TABLE_RET(stg_atomically_frame, ATOMICALLY_FRAME,
705 #if defined(PROFILING)
706 W_ unused1, W_ unused2,
708 P_ code, P_ next_invariant_to_check, P_ result)
710 W_ frame, trec, valid, next_invariant, q, outer;
713 trec = StgTSO_trec(CurrentTSO);
715 outer = StgTRecHeader_enclosing_trec(trec);
717 if (outer == NO_TREC) {
718 /* First time back at the atomically frame -- pick up invariants */
719 ("ptr" q) = foreign "C" stmGetInvariantsToCheck(MyCapability() "ptr", trec "ptr") [];
720 StgAtomicallyFrame_next_invariant_to_check(frame) = q;
721 StgAtomicallyFrame_result(frame) = result;
724 /* Second/subsequent time back at the atomically frame -- abort the
725 * tx that's checking the invariant and move on to the next one */
726 StgTSO_trec(CurrentTSO) = outer;
727 q = StgAtomicallyFrame_next_invariant_to_check(frame);
728 StgInvariantCheckQueue_my_execution(q) = trec;
729 foreign "C" stmAbortTransaction(MyCapability() "ptr", trec "ptr") [];
730 /* Don't free trec -- it's linked from q and will be stashed in the
731 * invariant if we eventually commit. */
732 q = StgInvariantCheckQueue_next_queue_entry(q);
733 StgAtomicallyFrame_next_invariant_to_check(frame) = q;
737 q = StgAtomicallyFrame_next_invariant_to_check(frame);
739 if (q != END_INVARIANT_CHECK_QUEUE) {
740 /* We can't commit yet: another invariant to check */
741 ("ptr" trec) = foreign "C" stmStartTransaction(MyCapability() "ptr", trec "ptr") [];
742 StgTSO_trec(CurrentTSO) = trec;
744 next_invariant = StgInvariantCheckQueue_invariant(q);
745 R1 = StgAtomicInvariant_code(next_invariant);
750 /* We've got no more invariants to check, try to commit */
751 (valid) = foreign "C" stmCommitTransaction(MyCapability() "ptr", trec "ptr") [];
753 /* Transaction was valid: commit succeeded */
754 StgTSO_trec(CurrentTSO) = NO_TREC;
755 R1 = StgAtomicallyFrame_result(frame);
756 Sp = Sp + SIZEOF_StgAtomicallyFrame;
757 jump %ENTRY_CODE(Sp(SP_OFF));
759 /* Transaction was not valid: try again */
760 ("ptr" trec) = foreign "C" stmStartTransaction(MyCapability() "ptr", NO_TREC "ptr") [];
761 StgTSO_trec(CurrentTSO) = trec;
762 StgAtomicallyFrame_next_invariant_to_check(frame) = END_INVARIANT_CHECK_QUEUE;
763 R1 = StgAtomicallyFrame_code(frame);
769 INFO_TABLE_RET(stg_atomically_waiting_frame, ATOMICALLY_FRAME,
770 #if defined(PROFILING)
771 W_ unused1, W_ unused2,
773 P_ code, P_ next_invariant_to_check, P_ result)
775 W_ frame, trec, valid;
779 /* The TSO is currently waiting: should we stop waiting? */
780 (valid) = foreign "C" stmReWait(MyCapability() "ptr", CurrentTSO "ptr") [];
782 /* Previous attempt is still valid: no point trying again yet */
783 jump stg_block_noregs;
785 /* Previous attempt is no longer valid: try again */
786 ("ptr" trec) = foreign "C" stmStartTransaction(MyCapability() "ptr", NO_TREC "ptr") [];
787 StgTSO_trec(CurrentTSO) = trec;
788 StgHeader_info(frame) = stg_atomically_frame_info;
789 R1 = StgAtomicallyFrame_code(frame);
794 // STM catch frame --------------------------------------------------------------
798 /* Catch frames are very similar to update frames, but when entering
799 * one we just pop the frame off the stack and perform the correct
800 * kind of return to the activation record underneath us on the stack.
803 INFO_TABLE_RET(stg_catch_stm_frame, CATCH_STM_FRAME,
804 #if defined(PROFILING)
805 W_ unused1, W_ unused2,
807 P_ unused3, P_ unused4)
809 W_ r, frame, trec, outer;
811 trec = StgTSO_trec(CurrentTSO);
812 outer = StgTRecHeader_enclosing_trec(trec);
813 (r) = foreign "C" stmCommitNestedTransaction(MyCapability() "ptr", trec "ptr") [];
815 /* Commit succeeded */
816 StgTSO_trec(CurrentTSO) = outer;
817 Sp = Sp + SIZEOF_StgCatchSTMFrame;
822 ("ptr" new_trec) = foreign "C" stmStartTransaction(MyCapability() "ptr", outer "ptr") [];
823 StgTSO_trec(CurrentTSO) = new_trec;
824 R1 = StgCatchSTMFrame_code(frame);
830 // Primop definition ------------------------------------------------------------
838 // stmStartTransaction may allocate
839 MAYBE_GC (R1_PTR, stg_atomicallyzh);
841 /* Args: R1 = m :: STM a */
842 STK_CHK_GEN(SIZEOF_StgAtomicallyFrame + WDS(1), R1_PTR, stg_atomicallyzh);
844 old_trec = StgTSO_trec(CurrentTSO);
846 /* Nested transactions are not allowed; raise an exception */
847 if (old_trec != NO_TREC) {
848 R1 = base_ControlziExceptionziBase_nestedAtomically_closure;
852 /* Set up the atomically frame */
853 Sp = Sp - SIZEOF_StgAtomicallyFrame;
856 SET_HDR(frame,stg_atomically_frame_info, W_[CCCS]);
857 StgAtomicallyFrame_code(frame) = R1;
858 StgAtomicallyFrame_result(frame) = NO_TREC;
859 StgAtomicallyFrame_next_invariant_to_check(frame) = END_INVARIANT_CHECK_QUEUE;
861 /* Start the memory transcation */
862 ("ptr" new_trec) = foreign "C" stmStartTransaction(MyCapability() "ptr", old_trec "ptr") [R1];
863 StgTSO_trec(CurrentTSO) = new_trec;
865 /* Apply R1 to the realworld token */
874 /* Args: R1 :: STM a */
875 /* Args: R2 :: Exception -> STM a */
876 STK_CHK_GEN(SIZEOF_StgCatchSTMFrame + WDS(1), R1_PTR & R2_PTR, stg_catchSTMzh);
878 /* Set up the catch frame */
879 Sp = Sp - SIZEOF_StgCatchSTMFrame;
882 SET_HDR(frame, stg_catch_stm_frame_info, W_[CCCS]);
883 StgCatchSTMFrame_handler(frame) = R2;
884 StgCatchSTMFrame_code(frame) = R1;
886 /* Start a nested transaction to run the body of the try block in */
889 cur_trec = StgTSO_trec(CurrentTSO);
890 ("ptr" new_trec) = foreign "C" stmStartTransaction(MyCapability() "ptr", cur_trec "ptr");
891 StgTSO_trec(CurrentTSO) = new_trec;
893 /* Apply R1 to the realworld token */
904 // stmStartTransaction may allocate
905 MAYBE_GC (R1_PTR & R2_PTR, stg_catchRetryzh);
907 /* Args: R1 :: STM a */
908 /* Args: R2 :: STM a */
909 STK_CHK_GEN(SIZEOF_StgCatchRetryFrame + WDS(1), R1_PTR & R2_PTR, stg_catchRetryzh);
911 /* Start a nested transaction within which to run the first code */
912 trec = StgTSO_trec(CurrentTSO);
913 ("ptr" new_trec) = foreign "C" stmStartTransaction(MyCapability() "ptr", trec "ptr") [R1,R2];
914 StgTSO_trec(CurrentTSO) = new_trec;
916 /* Set up the catch-retry frame */
917 Sp = Sp - SIZEOF_StgCatchRetryFrame;
920 SET_HDR(frame, stg_catch_retry_frame_info, W_[CCCS]);
921 StgCatchRetryFrame_running_alt_code(frame) = 0 :: CInt; // false;
922 StgCatchRetryFrame_first_code(frame) = R1;
923 StgCatchRetryFrame_alt_code(frame) = R2;
925 /* Apply R1 to the realworld token */
938 MAYBE_GC (NO_PTRS, stg_retryzh); // STM operations may allocate
940 // Find the enclosing ATOMICALLY_FRAME or CATCH_RETRY_FRAME
942 StgTSO_sp(CurrentTSO) = Sp;
943 (frame_type) = foreign "C" findRetryFrameHelper(CurrentTSO "ptr") [];
944 Sp = StgTSO_sp(CurrentTSO);
946 trec = StgTSO_trec(CurrentTSO);
947 outer = StgTRecHeader_enclosing_trec(trec);
949 if (frame_type == CATCH_RETRY_FRAME) {
950 // The retry reaches a CATCH_RETRY_FRAME before the atomic frame
951 ASSERT(outer != NO_TREC);
952 // Abort the transaction attempting the current branch
953 foreign "C" stmAbortTransaction(MyCapability() "ptr", trec "ptr") [];
954 foreign "C" stmFreeAbortedTRec(MyCapability() "ptr", trec "ptr") [];
955 if (!StgCatchRetryFrame_running_alt_code(frame) != 0::I32) {
956 // Retry in the first branch: try the alternative
957 ("ptr" trec) = foreign "C" stmStartTransaction(MyCapability() "ptr", outer "ptr") [];
958 StgTSO_trec(CurrentTSO) = trec;
959 StgCatchRetryFrame_running_alt_code(frame) = 1 :: CInt; // true;
960 R1 = StgCatchRetryFrame_alt_code(frame);
963 // Retry in the alternative code: propagate the retry
964 StgTSO_trec(CurrentTSO) = outer;
965 Sp = Sp + SIZEOF_StgCatchRetryFrame;
966 goto retry_pop_stack;
970 // We've reached the ATOMICALLY_FRAME: attempt to wait
971 ASSERT(frame_type == ATOMICALLY_FRAME);
972 if (outer != NO_TREC) {
973 // We called retry while checking invariants, so abort the current
974 // invariant check (merging its TVar accesses into the parents read
975 // set so we'll wait on them)
976 foreign "C" stmAbortTransaction(MyCapability() "ptr", trec "ptr") [];
977 foreign "C" stmFreeAbortedTRec(MyCapability() "ptr", trec "ptr") [];
979 StgTSO_trec(CurrentTSO) = trec;
980 outer = StgTRecHeader_enclosing_trec(trec);
982 ASSERT(outer == NO_TREC);
984 (r) = foreign "C" stmWait(MyCapability() "ptr", CurrentTSO "ptr", trec "ptr") [];
986 // Transaction was valid: stmWait put us on the TVars' queues, we now block
987 StgHeader_info(frame) = stg_atomically_waiting_frame_info;
989 // Fix up the stack in the unregisterised case: the return convention is different.
990 R3 = trec; // passing to stmWaitUnblock()
991 jump stg_block_stmwait;
993 // Transaction was not valid: retry immediately
994 ("ptr" trec) = foreign "C" stmStartTransaction(MyCapability() "ptr", outer "ptr") [];
995 StgTSO_trec(CurrentTSO) = trec;
996 R1 = StgAtomicallyFrame_code(frame);
1007 /* Args: R1 = invariant closure */
1008 MAYBE_GC (R1_PTR, stg_checkzh);
1010 trec = StgTSO_trec(CurrentTSO);
1012 foreign "C" stmAddInvariantToCheck(MyCapability() "ptr",
1016 jump %ENTRY_CODE(Sp(0));
1025 /* Args: R1 = initialisation value */
1027 MAYBE_GC (R1_PTR, stg_newTVarzh);
1029 ("ptr" tv) = foreign "C" stmNewTVar(MyCapability() "ptr", new_value "ptr") [];
1040 /* Args: R1 = TVar closure */
1042 MAYBE_GC (R1_PTR, stg_readTVarzh); // Call to stmReadTVar may allocate
1043 trec = StgTSO_trec(CurrentTSO);
1045 ("ptr" result) = foreign "C" stmReadTVar(MyCapability() "ptr", trec "ptr", tvar "ptr") [];
1055 result = StgTVar_current_value(R1);
1056 if (%INFO_PTR(result) == stg_TREC_HEADER_info) {
1068 /* Args: R1 = TVar closure */
1069 /* R2 = New value */
1071 MAYBE_GC (R1_PTR & R2_PTR, stg_writeTVarzh); // Call to stmWriteTVar may allocate
1072 trec = StgTSO_trec(CurrentTSO);
1075 foreign "C" stmWriteTVar(MyCapability() "ptr", trec "ptr", tvar "ptr", new_value "ptr") [];
1077 jump %ENTRY_CODE(Sp(0));
1081 /* -----------------------------------------------------------------------------
1084 * take & putMVar work as follows. Firstly, an important invariant:
1086 * If the MVar is full, then the blocking queue contains only
1087 * threads blocked on putMVar, and if the MVar is empty then the
1088 * blocking queue contains only threads blocked on takeMVar.
1091 * MVar empty : then add ourselves to the blocking queue
1092 * MVar full : remove the value from the MVar, and
1093 * blocking queue empty : return
1094 * blocking queue non-empty : perform the first blocked putMVar
1095 * from the queue, and wake up the
1096 * thread (MVar is now full again)
1098 * putMVar is just the dual of the above algorithm.
1100 * How do we "perform a putMVar"? Well, we have to fiddle around with
1101 * the stack of the thread waiting to do the putMVar. See
1102 * stg_block_putmvar and stg_block_takemvar in HeapStackCheck.c for
1103 * the stack layout, and the PerformPut and PerformTake macros below.
1105 * It is important that a blocked take or put is woken up with the
1106 * take/put already performed, because otherwise there would be a
1107 * small window of vulnerability where the thread could receive an
1108 * exception and never perform its take or put, and we'd end up with a
1111 * -------------------------------------------------------------------------- */
1115 /* args: R1 = MVar closure */
1117 if (StgMVar_value(R1) == stg_END_TSO_QUEUE_closure) {
1129 ALLOC_PRIM ( SIZEOF_StgMVar, NO_PTRS, stg_newMVarzh );
1131 mvar = Hp - SIZEOF_StgMVar + WDS(1);
1132 SET_HDR(mvar,stg_MVAR_DIRTY_info,W_[CCCS]);
1133 // MVARs start dirty: generation 0 has no mutable list
1134 StgMVar_head(mvar) = stg_END_TSO_QUEUE_closure;
1135 StgMVar_tail(mvar) = stg_END_TSO_QUEUE_closure;
1136 StgMVar_value(mvar) = stg_END_TSO_QUEUE_closure;
1141 #define PerformTake(tso, value) \
1142 W_[StgTSO_sp(tso) + WDS(1)] = value; \
1143 W_[StgTSO_sp(tso) + WDS(0)] = stg_gc_unpt_r1_info;
1145 #define PerformPut(tso,lval) \
1146 StgTSO_sp(tso) = StgTSO_sp(tso) + WDS(3); \
1147 lval = W_[StgTSO_sp(tso) - WDS(1)];
1151 W_ mvar, val, info, tso, q;
1153 /* args: R1 = MVar closure */
1156 #if defined(THREADED_RTS)
1157 ("ptr" info) = foreign "C" lockClosure(mvar "ptr") [];
1159 info = GET_INFO(mvar);
1162 if (info == stg_MVAR_CLEAN_info) {
1163 foreign "C" dirty_MVAR(BaseReg "ptr", mvar "ptr") [];
1166 /* If the MVar is empty, put ourselves on its blocking queue,
1167 * and wait until we're woken up.
1169 if (StgMVar_value(mvar) == stg_END_TSO_QUEUE_closure) {
1171 // Note [mvar-heap-check] We want to do the heap check in the
1172 // branch here, to avoid the conditional in the common case.
1173 // However, we've already locked the MVar above, so we better
1174 // be careful to unlock it again if the the heap check fails.
1175 // Unfortunately we don't have an easy way to inject any code
1176 // into the heap check generated by the code generator, so we
1177 // have to do it in stg_gc_gen (see HeapStackCheck.cmm).
1178 HP_CHK_GEN_TICKY(SIZEOF_StgMVarTSOQueue, R1_PTR, stg_takeMVarzh);
1180 q = Hp - SIZEOF_StgMVarTSOQueue + WDS(1);
1182 SET_HDR(q, stg_MVAR_TSO_QUEUE_info, CCS_SYSTEM);
1183 StgMVarTSOQueue_link(q) = END_TSO_QUEUE;
1184 StgMVarTSOQueue_tso(q) = CurrentTSO;
1186 if (StgMVar_head(mvar) == stg_END_TSO_QUEUE_closure) {
1187 StgMVar_head(mvar) = q;
1189 StgMVarTSOQueue_link(StgMVar_tail(mvar)) = q;
1190 foreign "C" recordClosureMutated(MyCapability() "ptr",
1191 StgMVar_tail(mvar)) [];
1193 StgTSO__link(CurrentTSO) = q;
1194 StgTSO_block_info(CurrentTSO) = mvar;
1195 StgTSO_why_blocked(CurrentTSO) = BlockedOnMVar::I16;
1196 StgMVar_tail(mvar) = q;
1199 jump stg_block_takemvar;
1202 /* we got the value... */
1203 val = StgMVar_value(mvar);
1205 q = StgMVar_head(mvar);
1207 if (q == stg_END_TSO_QUEUE_closure) {
1208 /* No further putMVars, MVar is now empty */
1209 StgMVar_value(mvar) = stg_END_TSO_QUEUE_closure;
1210 unlockClosure(mvar, stg_MVAR_DIRTY_info);
1213 if (StgHeader_info(q) == stg_IND_info ||
1214 StgHeader_info(q) == stg_MSG_NULL_info) {
1215 q = StgInd_indirectee(q);
1219 // There are putMVar(s) waiting... wake up the first thread on the queue
1221 tso = StgMVarTSOQueue_tso(q);
1222 StgMVar_head(mvar) = StgMVarTSOQueue_link(q);
1223 if (StgMVar_head(mvar) == stg_END_TSO_QUEUE_closure) {
1224 StgMVar_tail(mvar) = stg_END_TSO_QUEUE_closure;
1228 if (TO_W_(StgTSO_what_next(tso)) == ThreadRelocated) {
1229 tso = StgTSO__link(tso);
1233 ASSERT(StgTSO_why_blocked(tso) == BlockedOnMVar::I16);
1234 ASSERT(StgTSO_block_info(tso) == mvar);
1236 // actually perform the putMVar for the thread that we just woke up
1237 PerformPut(tso,StgMVar_value(mvar));
1239 // indicate that the MVar operation has now completed.
1240 StgTSO__link(tso) = stg_END_TSO_QUEUE_closure;
1242 // no need to mark the TSO dirty, we have only written END_TSO_QUEUE.
1244 foreign "C" tryWakeupThread_(MyCapability() "ptr", tso) [];
1246 unlockClosure(mvar, stg_MVAR_DIRTY_info);
1253 W_ mvar, val, info, tso, q;
1255 /* args: R1 = MVar closure */
1258 #if defined(THREADED_RTS)
1259 ("ptr" info) = foreign "C" lockClosure(mvar "ptr") [];
1261 info = GET_INFO(mvar);
1264 /* If the MVar is empty, put ourselves on its blocking queue,
1265 * and wait until we're woken up.
1267 if (StgMVar_value(mvar) == stg_END_TSO_QUEUE_closure) {
1268 #if defined(THREADED_RTS)
1269 unlockClosure(mvar, info);
1271 /* HACK: we need a pointer to pass back,
1272 * so we abuse NO_FINALIZER_closure
1274 RET_NP(0, stg_NO_FINALIZER_closure);
1277 if (info == stg_MVAR_CLEAN_info) {
1278 foreign "C" dirty_MVAR(BaseReg "ptr", mvar "ptr") [];
1281 /* we got the value... */
1282 val = StgMVar_value(mvar);
1284 q = StgMVar_head(mvar);
1286 if (q == stg_END_TSO_QUEUE_closure) {
1287 /* No further putMVars, MVar is now empty */
1288 StgMVar_value(mvar) = stg_END_TSO_QUEUE_closure;
1289 unlockClosure(mvar, stg_MVAR_DIRTY_info);
1292 if (StgHeader_info(q) == stg_IND_info ||
1293 StgHeader_info(q) == stg_MSG_NULL_info) {
1294 q = StgInd_indirectee(q);
1298 // There are putMVar(s) waiting... wake up the first thread on the queue
1300 tso = StgMVarTSOQueue_tso(q);
1301 StgMVar_head(mvar) = StgMVarTSOQueue_link(q);
1302 if (StgMVar_head(mvar) == stg_END_TSO_QUEUE_closure) {
1303 StgMVar_tail(mvar) = stg_END_TSO_QUEUE_closure;
1307 if (TO_W_(StgTSO_what_next(tso)) == ThreadRelocated) {
1308 tso = StgTSO__link(tso);
1312 ASSERT(StgTSO_why_blocked(tso) == BlockedOnMVar::I16);
1313 ASSERT(StgTSO_block_info(tso) == mvar);
1315 // actually perform the putMVar for the thread that we just woke up
1316 PerformPut(tso,StgMVar_value(mvar));
1318 // indicate that the MVar operation has now completed.
1319 StgTSO__link(tso) = stg_END_TSO_QUEUE_closure;
1321 // no need to mark the TSO dirty, we have only written END_TSO_QUEUE.
1323 foreign "C" tryWakeupThread_(MyCapability() "ptr", tso) [];
1325 unlockClosure(mvar, stg_MVAR_DIRTY_info);
1332 W_ mvar, val, info, tso, q;
1334 /* args: R1 = MVar, R2 = value */
1338 #if defined(THREADED_RTS)
1339 ("ptr" info) = foreign "C" lockClosure(mvar "ptr") [];
1341 info = GET_INFO(mvar);
1344 if (info == stg_MVAR_CLEAN_info) {
1345 foreign "C" dirty_MVAR(BaseReg "ptr", mvar "ptr");
1348 if (StgMVar_value(mvar) != stg_END_TSO_QUEUE_closure) {
1350 // see Note [mvar-heap-check] above
1351 HP_CHK_GEN_TICKY(SIZEOF_StgMVarTSOQueue, R1_PTR & R2_PTR, stg_putMVarzh);
1353 q = Hp - SIZEOF_StgMVarTSOQueue + WDS(1);
1355 SET_HDR(q, stg_MVAR_TSO_QUEUE_info, CCS_SYSTEM);
1356 StgMVarTSOQueue_link(q) = END_TSO_QUEUE;
1357 StgMVarTSOQueue_tso(q) = CurrentTSO;
1359 if (StgMVar_head(mvar) == stg_END_TSO_QUEUE_closure) {
1360 StgMVar_head(mvar) = q;
1362 StgMVarTSOQueue_link(StgMVar_tail(mvar)) = q;
1363 foreign "C" recordClosureMutated(MyCapability() "ptr",
1364 StgMVar_tail(mvar)) [];
1366 StgTSO__link(CurrentTSO) = q;
1367 StgTSO_block_info(CurrentTSO) = mvar;
1368 StgTSO_why_blocked(CurrentTSO) = BlockedOnMVar::I16;
1369 StgMVar_tail(mvar) = q;
1373 jump stg_block_putmvar;
1376 q = StgMVar_head(mvar);
1378 if (q == stg_END_TSO_QUEUE_closure) {
1379 /* No further takes, the MVar is now full. */
1380 StgMVar_value(mvar) = val;
1381 unlockClosure(mvar, stg_MVAR_DIRTY_info);
1382 jump %ENTRY_CODE(Sp(0));
1384 if (StgHeader_info(q) == stg_IND_info ||
1385 StgHeader_info(q) == stg_MSG_NULL_info) {
1386 q = StgInd_indirectee(q);
1390 // There are takeMVar(s) waiting: wake up the first one
1392 tso = StgMVarTSOQueue_tso(q);
1393 StgMVar_head(mvar) = StgMVarTSOQueue_link(q);
1394 if (StgMVar_head(mvar) == stg_END_TSO_QUEUE_closure) {
1395 StgMVar_tail(mvar) = stg_END_TSO_QUEUE_closure;
1399 if (TO_W_(StgTSO_what_next(tso)) == ThreadRelocated) {
1400 tso = StgTSO__link(tso);
1404 ASSERT(StgTSO_why_blocked(tso) == BlockedOnMVar::I16);
1405 ASSERT(StgTSO_block_info(tso) == mvar);
1407 // actually perform the takeMVar
1408 PerformTake(tso, val);
1410 // indicate that the MVar operation has now completed.
1411 StgTSO__link(tso) = stg_END_TSO_QUEUE_closure;
1413 if (TO_W_(StgTSO_dirty(tso)) == 0) {
1414 foreign "C" dirty_TSO(MyCapability() "ptr", tso "ptr") [];
1417 foreign "C" tryWakeupThread_(MyCapability() "ptr", tso) [];
1419 unlockClosure(mvar, stg_MVAR_DIRTY_info);
1420 jump %ENTRY_CODE(Sp(0));
1426 W_ mvar, val, info, tso, q;
1428 /* args: R1 = MVar, R2 = value */
1432 #if defined(THREADED_RTS)
1433 ("ptr" info) = foreign "C" lockClosure(mvar "ptr") [];
1435 info = GET_INFO(mvar);
1438 if (info == stg_MVAR_CLEAN_info) {
1439 foreign "C" dirty_MVAR(BaseReg "ptr", mvar "ptr");
1442 if (StgMVar_value(mvar) != stg_END_TSO_QUEUE_closure) {
1443 #if defined(THREADED_RTS)
1444 unlockClosure(mvar, info);
1449 q = StgMVar_head(mvar);
1451 if (q == stg_END_TSO_QUEUE_closure) {
1452 /* No further takes, the MVar is now full. */
1453 StgMVar_value(mvar) = val;
1454 unlockClosure(mvar, stg_MVAR_DIRTY_info);
1455 jump %ENTRY_CODE(Sp(0));
1457 if (StgHeader_info(q) == stg_IND_info ||
1458 StgHeader_info(q) == stg_MSG_NULL_info) {
1459 q = StgInd_indirectee(q);
1463 // There are takeMVar(s) waiting: wake up the first one
1465 tso = StgMVarTSOQueue_tso(q);
1466 StgMVar_head(mvar) = StgMVarTSOQueue_link(q);
1467 if (StgMVar_head(mvar) == stg_END_TSO_QUEUE_closure) {
1468 StgMVar_tail(mvar) = stg_END_TSO_QUEUE_closure;
1472 if (TO_W_(StgTSO_what_next(tso)) == ThreadRelocated) {
1473 tso = StgTSO__link(tso);
1477 ASSERT(StgTSO_why_blocked(tso) == BlockedOnMVar::I16);
1478 ASSERT(StgTSO_block_info(tso) == mvar);
1480 // actually perform the takeMVar
1481 PerformTake(tso, val);
1483 // indicate that the MVar operation has now completed.
1484 StgTSO__link(tso) = stg_END_TSO_QUEUE_closure;
1486 if (TO_W_(StgTSO_dirty(tso)) == 0) {
1487 foreign "C" dirty_TSO(MyCapability() "ptr", tso "ptr") [];
1490 foreign "C" tryWakeupThread_(MyCapability() "ptr", tso) [];
1492 unlockClosure(mvar, stg_MVAR_DIRTY_info);
1493 jump %ENTRY_CODE(Sp(0));
1497 /* -----------------------------------------------------------------------------
1498 Stable pointer primitives
1499 ------------------------------------------------------------------------- */
1501 stg_makeStableNamezh
1505 ALLOC_PRIM( SIZEOF_StgStableName, R1_PTR, stg_makeStableNamezh );
1507 (index) = foreign "C" lookupStableName(R1 "ptr") [];
1509 /* Is there already a StableName for this heap object?
1510 * stable_ptr_table is a pointer to an array of snEntry structs.
1512 if ( snEntry_sn_obj(W_[stable_ptr_table] + index*SIZEOF_snEntry) == NULL ) {
1513 sn_obj = Hp - SIZEOF_StgStableName + WDS(1);
1514 SET_HDR(sn_obj, stg_STABLE_NAME_info, W_[CCCS]);
1515 StgStableName_sn(sn_obj) = index;
1516 snEntry_sn_obj(W_[stable_ptr_table] + index*SIZEOF_snEntry) = sn_obj;
1518 sn_obj = snEntry_sn_obj(W_[stable_ptr_table] + index*SIZEOF_snEntry);
1529 MAYBE_GC(R1_PTR, stg_makeStablePtrzh);
1530 ("ptr" sp) = foreign "C" getStablePtr(R1 "ptr") [];
1534 stg_deRefStablePtrzh
1536 /* Args: R1 = the stable ptr */
1539 r = snEntry_addr(W_[stable_ptr_table] + sp*SIZEOF_snEntry);
1543 /* -----------------------------------------------------------------------------
1544 Bytecode object primitives
1545 ------------------------------------------------------------------------- */
1555 W_ bco, bitmap_arr, bytes, words;
1559 words = BYTES_TO_WDS(SIZEOF_StgBCO) + BYTE_ARR_WDS(bitmap_arr);
1562 ALLOC_PRIM( bytes, R1_PTR&R2_PTR&R3_PTR&R5_PTR, stg_newBCOzh );
1564 bco = Hp - bytes + WDS(1);
1565 SET_HDR(bco, stg_BCO_info, W_[CCCS]);
1567 StgBCO_instrs(bco) = R1;
1568 StgBCO_literals(bco) = R2;
1569 StgBCO_ptrs(bco) = R3;
1570 StgBCO_arity(bco) = HALF_W_(R4);
1571 StgBCO_size(bco) = HALF_W_(words);
1573 // Copy the arity/bitmap info into the BCO
1577 if (i < BYTE_ARR_WDS(bitmap_arr)) {
1578 StgBCO_bitmap(bco,i) = StgArrWords_payload(bitmap_arr,i);
1589 // R1 = the BCO# for the AP
1593 // This function is *only* used to wrap zero-arity BCOs in an
1594 // updatable wrapper (see ByteCodeLink.lhs). An AP thunk is always
1595 // saturated and always points directly to a FUN or BCO.
1596 ASSERT(%INFO_TYPE(%GET_STD_INFO(R1)) == HALF_W_(BCO) &&
1597 StgBCO_arity(R1) == HALF_W_(0));
1599 HP_CHK_GEN_TICKY(SIZEOF_StgAP, R1_PTR, stg_mkApUpd0zh);
1600 TICK_ALLOC_UP_THK(0, 0);
1601 CCCS_ALLOC(SIZEOF_StgAP);
1603 ap = Hp - SIZEOF_StgAP + WDS(1);
1604 SET_HDR(ap, stg_AP_info, W_[CCCS]);
1606 StgAP_n_args(ap) = HALF_W_(0);
1614 /* args: R1 = closure to analyze */
1615 // TODO: Consider the absence of ptrs or nonptrs as a special case ?
1617 W_ info, ptrs, nptrs, p, ptrs_arr, nptrs_arr;
1618 info = %GET_STD_INFO(UNTAG(R1));
1620 // Some closures have non-standard layout, so we omit those here.
1622 type = TO_W_(%INFO_TYPE(info));
1623 switch [0 .. N_CLOSURE_TYPES] type {
1624 case THUNK_SELECTOR : {
1629 case THUNK, THUNK_1_0, THUNK_0_1, THUNK_2_0, THUNK_1_1,
1630 THUNK_0_2, THUNK_STATIC, AP, PAP, AP_STACK, BCO : {
1636 ptrs = TO_W_(%INFO_PTRS(info));
1637 nptrs = TO_W_(%INFO_NPTRS(info));
1642 W_ ptrs_arr_sz, ptrs_arr_cards, nptrs_arr_sz;
1643 nptrs_arr_sz = SIZEOF_StgArrWords + WDS(nptrs);
1644 ptrs_arr_cards = mutArrPtrsCardWords(ptrs);
1645 ptrs_arr_sz = SIZEOF_StgMutArrPtrs + WDS(ptrs) + WDS(ptrs_arr_cards);
1647 ALLOC_PRIM (ptrs_arr_sz + nptrs_arr_sz, R1_PTR, stg_unpackClosurezh);
1652 ptrs_arr = Hp - nptrs_arr_sz - ptrs_arr_sz + WDS(1);
1653 nptrs_arr = Hp - nptrs_arr_sz + WDS(1);
1655 SET_HDR(ptrs_arr, stg_MUT_ARR_PTRS_FROZEN_info, W_[CCCS]);
1656 StgMutArrPtrs_ptrs(ptrs_arr) = ptrs;
1657 StgMutArrPtrs_size(ptrs_arr) = ptrs + ptrs_arr_cards;
1662 W_[ptrs_arr + SIZEOF_StgMutArrPtrs + WDS(p)] = StgClosure_payload(clos,p);
1666 /* We can leave the card table uninitialised, since the array is
1667 allocated in the nursery. The GC will fill it in if/when the array
1670 SET_HDR(nptrs_arr, stg_ARR_WORDS_info, W_[CCCS]);
1671 StgArrWords_bytes(nptrs_arr) = WDS(nptrs);
1675 W_[BYTE_ARR_CTS(nptrs_arr) + WDS(p)] = StgClosure_payload(clos, p+ptrs);
1679 RET_NPP(info, ptrs_arr, nptrs_arr);
1682 /* -----------------------------------------------------------------------------
1683 Thread I/O blocking primitives
1684 -------------------------------------------------------------------------- */
1686 /* Add a thread to the end of the blocked queue. (C-- version of the C
1687 * macro in Schedule.h).
1689 #define APPEND_TO_BLOCKED_QUEUE(tso) \
1690 ASSERT(StgTSO__link(tso) == END_TSO_QUEUE); \
1691 if (W_[blocked_queue_hd] == END_TSO_QUEUE) { \
1692 W_[blocked_queue_hd] = tso; \
1694 foreign "C" setTSOLink(MyCapability() "ptr", W_[blocked_queue_tl] "ptr", tso) []; \
1696 W_[blocked_queue_tl] = tso;
1702 foreign "C" barf("waitRead# on threaded RTS") never returns;
1705 ASSERT(StgTSO_why_blocked(CurrentTSO) == NotBlocked::I16);
1706 StgTSO_why_blocked(CurrentTSO) = BlockedOnRead::I16;
1707 StgTSO_block_info(CurrentTSO) = R1;
1708 // No locking - we're not going to use this interface in the
1709 // threaded RTS anyway.
1710 APPEND_TO_BLOCKED_QUEUE(CurrentTSO);
1711 jump stg_block_noregs;
1719 foreign "C" barf("waitWrite# on threaded RTS") never returns;
1722 ASSERT(StgTSO_why_blocked(CurrentTSO) == NotBlocked::I16);
1723 StgTSO_why_blocked(CurrentTSO) = BlockedOnWrite::I16;
1724 StgTSO_block_info(CurrentTSO) = R1;
1725 // No locking - we're not going to use this interface in the
1726 // threaded RTS anyway.
1727 APPEND_TO_BLOCKED_QUEUE(CurrentTSO);
1728 jump stg_block_noregs;
1733 STRING(stg_delayzh_malloc_str, "stg_delayzh")
1736 #ifdef mingw32_HOST_OS
1744 foreign "C" barf("delay# on threaded RTS") never returns;
1747 /* args: R1 (microsecond delay amount) */
1748 ASSERT(StgTSO_why_blocked(CurrentTSO) == NotBlocked::I16);
1749 StgTSO_why_blocked(CurrentTSO) = BlockedOnDelay::I16;
1751 #ifdef mingw32_HOST_OS
1753 /* could probably allocate this on the heap instead */
1754 ("ptr" ares) = foreign "C" stgMallocBytes(SIZEOF_StgAsyncIOResult,
1755 stg_delayzh_malloc_str);
1756 (reqID) = foreign "C" addDelayRequest(R1);
1757 StgAsyncIOResult_reqID(ares) = reqID;
1758 StgAsyncIOResult_len(ares) = 0;
1759 StgAsyncIOResult_errCode(ares) = 0;
1760 StgTSO_block_info(CurrentTSO) = ares;
1762 /* Having all async-blocked threads reside on the blocked_queue
1763 * simplifies matters, so change the status to OnDoProc put the
1764 * delayed thread on the blocked_queue.
1766 StgTSO_why_blocked(CurrentTSO) = BlockedOnDoProc::I16;
1767 APPEND_TO_BLOCKED_QUEUE(CurrentTSO);
1768 jump stg_block_async_void;
1774 (time) = foreign "C" getourtimeofday() [R1];
1775 divisor = TO_W_(RtsFlags_MiscFlags_tickInterval(RtsFlags));
1779 divisor = divisor * 1000;
1780 target = ((R1 + divisor - 1) / divisor) /* divide rounding up */
1781 + time + 1; /* Add 1 as getourtimeofday rounds down */
1782 StgTSO_block_info(CurrentTSO) = target;
1784 /* Insert the new thread in the sleeping queue. */
1786 t = W_[sleeping_queue];
1788 if (t != END_TSO_QUEUE && StgTSO_block_info(t) < target) {
1790 t = StgTSO__link(t);
1794 StgTSO__link(CurrentTSO) = t;
1796 W_[sleeping_queue] = CurrentTSO;
1798 foreign "C" setTSOLink(MyCapability() "ptr", prev "ptr", CurrentTSO) [];
1800 jump stg_block_noregs;
1802 #endif /* !THREADED_RTS */
1806 #ifdef mingw32_HOST_OS
1807 STRING(stg_asyncReadzh_malloc_str, "stg_asyncReadzh")
1814 foreign "C" barf("asyncRead# on threaded RTS") never returns;
1817 /* args: R1 = fd, R2 = isSock, R3 = len, R4 = buf */
1818 ASSERT(StgTSO_why_blocked(CurrentTSO) == NotBlocked::I16);
1819 StgTSO_why_blocked(CurrentTSO) = BlockedOnRead::I16;
1821 /* could probably allocate this on the heap instead */
1822 ("ptr" ares) = foreign "C" stgMallocBytes(SIZEOF_StgAsyncIOResult,
1823 stg_asyncReadzh_malloc_str)
1825 (reqID) = foreign "C" addIORequest(R1, 0/*FALSE*/,R2,R3,R4 "ptr") [];
1826 StgAsyncIOResult_reqID(ares) = reqID;
1827 StgAsyncIOResult_len(ares) = 0;
1828 StgAsyncIOResult_errCode(ares) = 0;
1829 StgTSO_block_info(CurrentTSO) = ares;
1830 APPEND_TO_BLOCKED_QUEUE(CurrentTSO);
1831 jump stg_block_async;
1835 STRING(stg_asyncWritezh_malloc_str, "stg_asyncWritezh")
1842 foreign "C" barf("asyncWrite# on threaded RTS") never returns;
1845 /* args: R1 = fd, R2 = isSock, R3 = len, R4 = buf */
1846 ASSERT(StgTSO_why_blocked(CurrentTSO) == NotBlocked::I16);
1847 StgTSO_why_blocked(CurrentTSO) = BlockedOnWrite::I16;
1849 ("ptr" ares) = foreign "C" stgMallocBytes(SIZEOF_StgAsyncIOResult,
1850 stg_asyncWritezh_malloc_str)
1852 (reqID) = foreign "C" addIORequest(R1, 1/*TRUE*/,R2,R3,R4 "ptr") [];
1854 StgAsyncIOResult_reqID(ares) = reqID;
1855 StgAsyncIOResult_len(ares) = 0;
1856 StgAsyncIOResult_errCode(ares) = 0;
1857 StgTSO_block_info(CurrentTSO) = ares;
1858 APPEND_TO_BLOCKED_QUEUE(CurrentTSO);
1859 jump stg_block_async;
1863 STRING(stg_asyncDoProczh_malloc_str, "stg_asyncDoProczh")
1870 foreign "C" barf("asyncDoProc# on threaded RTS") never returns;
1873 /* args: R1 = proc, R2 = param */
1874 ASSERT(StgTSO_why_blocked(CurrentTSO) == NotBlocked::I16);
1875 StgTSO_why_blocked(CurrentTSO) = BlockedOnDoProc::I16;
1877 /* could probably allocate this on the heap instead */
1878 ("ptr" ares) = foreign "C" stgMallocBytes(SIZEOF_StgAsyncIOResult,
1879 stg_asyncDoProczh_malloc_str)
1881 (reqID) = foreign "C" addDoProcRequest(R1 "ptr",R2 "ptr") [];
1882 StgAsyncIOResult_reqID(ares) = reqID;
1883 StgAsyncIOResult_len(ares) = 0;
1884 StgAsyncIOResult_errCode(ares) = 0;
1885 StgTSO_block_info(CurrentTSO) = ares;
1886 APPEND_TO_BLOCKED_QUEUE(CurrentTSO);
1887 jump stg_block_async;
1892 /* -----------------------------------------------------------------------------
1895 * noDuplicate# tries to ensure that none of the thunks under
1896 * evaluation by the current thread are also under evaluation by
1897 * another thread. It relies on *both* threads doing noDuplicate#;
1898 * the second one will get blocked if they are duplicating some work.
1900 * The idea is that noDuplicate# is used within unsafePerformIO to
1901 * ensure that the IO operation is performed at most once.
1902 * noDuplicate# calls threadPaused which acquires an exclusive lock on
1903 * all the thunks currently under evaluation by the current thread.
1905 * Consider the following scenario. There is a thunk A, whose
1906 * evaluation requires evaluating thunk B, where thunk B is an
1907 * unsafePerformIO. Two threads, 1 and 2, bother enter A. Thread 2
1908 * is pre-empted before it enters B, and claims A by blackholing it
1909 * (in threadPaused). Thread 1 now enters B, and calls noDuplicate#.
1912 * +-----------+ +---------------+
1913 * | -------+-----> A <-------+------- |
1914 * | update | BLACKHOLE | marked_update |
1915 * +-----------+ +---------------+
1918 * | | +---------------+
1921 * | update | BLACKHOLE
1924 * At this point: A is a blackhole, owned by thread 2. noDuplicate#
1925 * calls threadPaused, which walks up the stack and
1926 * - claims B on behalf of thread 1
1927 * - then it reaches the update frame for A, which it sees is already
1928 * a BLACKHOLE and is therefore owned by another thread. Since
1929 * thread 1 is duplicating work, the computation up to the update
1930 * frame for A is suspended, including thunk B.
1931 * - thunk B, which is an unsafePerformIO, has now been reverted to
1932 * an AP_STACK which could be duplicated - BAD!
1933 * - The solution is as follows: before calling threadPaused, we
1934 * leave a frame on the stack (stg_noDuplicate_info) that will call
1935 * noDuplicate# again if the current computation is suspended and
1938 * See the test program in concurrent/prog003 for a way to demonstrate
1939 * this. It needs to be run with +RTS -N3 or greater, and the bug
1940 * only manifests occasionally (once very 10 runs or so).
1941 * -------------------------------------------------------------------------- */
1943 INFO_TABLE_RET(stg_noDuplicate, RET_SMALL)
1946 jump stg_noDuplicatezh;
1951 STK_CHK_GEN( WDS(1), NO_PTRS, stg_noDuplicatezh );
1952 // leave noDuplicate frame in case the current
1953 // computation is suspended and restarted (see above).
1955 Sp(0) = stg_noDuplicate_info;
1957 SAVE_THREAD_STATE();
1958 ASSERT(StgTSO_what_next(CurrentTSO) == ThreadRunGHC::I16);
1959 foreign "C" threadPaused (MyCapability() "ptr", CurrentTSO "ptr") [];
1961 if (StgTSO_what_next(CurrentTSO) == ThreadKilled::I16) {
1962 jump stg_threadFinished;
1964 LOAD_THREAD_STATE();
1965 ASSERT(StgTSO_what_next(CurrentTSO) == ThreadRunGHC::I16);
1966 // remove the stg_noDuplicate frame if it is still there.
1967 if (Sp(0) == stg_noDuplicate_info) {
1970 jump %ENTRY_CODE(Sp(0));
1974 /* -----------------------------------------------------------------------------
1976 -------------------------------------------------------------------------- */
1980 W_ ap_stack, offset, val, ok;
1982 /* args: R1 = AP_STACK, R2 = offset */
1986 if (%INFO_PTR(ap_stack) == stg_AP_STACK_info) {
1988 val = StgAP_STACK_payload(ap_stack,offset);
1996 // Write the cost center stack of the first argument on stderr; return
1997 // the second. Possibly only makes sense for already evaluated
2004 ccs = StgHeader_ccs(UNTAG(R1));
2005 foreign "C" fprintCCS_stderr(ccs "ptr") [R2];
2016 #ifndef THREADED_RTS
2017 RET_NP(0,ghczmprim_GHCziBool_False_closure);
2019 (spark) = foreign "C" findSpark(MyCapability());
2023 RET_NP(0,ghczmprim_GHCziBool_False_closure);
2032 (n) = foreign "C" dequeElements(Capability_sparks(MyCapability()));
2044 #if defined(TRACING) || defined(DEBUG)
2046 foreign "C" traceUserMsg(MyCapability() "ptr", msg "ptr") [];
2048 #elif defined(DTRACE)
2052 // We should go through the macro HASKELLEVENT_USER_MSG_ENABLED from
2053 // RtsProbes.h, but that header file includes unistd.h, which doesn't
2055 (enabled) = foreign "C" __dtrace_isenabled$HaskellEvent$user__msg$v1() [];
2057 foreign "C" dtraceUserMsgWrapper(MyCapability() "ptr", msg "ptr") [];
2061 jump %ENTRY_CODE(Sp(0));