X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fincludes%2FClosures.h;h=3df208cd09f2f25ee90df5605ae14f010f9818a8;hb=c137ecd7e6e83d0f9c39b15ccdb9f2355f243c91;hp=93fadd2122bce820040bd7e49c42895f2bd9e6cf;hpb=6a02dd25682e76484d2505ec7139948e6a32b9ee;p=ghc-hetmet.git diff --git a/ghc/includes/Closures.h b/ghc/includes/Closures.h index 93fadd2..3df208c 100644 --- a/ghc/includes/Closures.h +++ b/ghc/includes/Closures.h @@ -1,7 +1,6 @@ /* ---------------------------------------------------------------------------- - * $Id: Closures.h,v 1.34 2003/11/14 09:27:00 stolz Exp $ * - * (c) The GHC Team, 1998-1999 + * (c) The GHC Team, 1998-2004 * * Closures * @@ -36,6 +35,23 @@ typedef struct { } StgGranHeader; /* ----------------------------------------------------------------------------- + The SMP header + + A thunk has a padding word to take the updated value. This is so + that the update doesn't overwrite the payload, so we can avoid + needing to lock the thunk during entry and update. + + Note: this doesn't apply to THUNK_STATICs, which have no payload. + + Note: we leave this padding word in all ways, rather than just SMP, + so that we don't have to recompile all our libraries for SMP. + -------------------------------------------------------------------------- */ + +typedef struct { + StgWord pad; +} StgSMPThunkHeader; + +/* ----------------------------------------------------------------------------- The full fixed-size closure header The size of the fixed header is the sum of the optional parts plus a single @@ -43,16 +59,27 @@ typedef struct { -------------------------------------------------------------------------- */ typedef struct { - const struct _StgInfoTable* info; + const struct _StgInfoTable* info; #ifdef PROFILING - StgProfHeader prof; + StgProfHeader prof; #endif #ifdef GRAN - StgGranHeader gran; + StgGranHeader gran; #endif } StgHeader; -#define FIXED_HS (sizeof(StgHeader)) +typedef struct { + const struct _StgInfoTable* info; +#ifdef PROFILING + StgProfHeader prof; +#endif +#ifdef GRAN + StgGranHeader gran; +#endif + StgSMPThunkHeader smp; +} StgThunkHeader; + +#define THUNK_EXTRA_HEADER_W (sizeofW(StgThunkHeader)-sizeofW(StgHeader)) /* ----------------------------------------------------------------------------- Closure Types @@ -69,21 +96,13 @@ struct StgClosure_ { struct StgClosure_ *payload[FLEXIBLE_ARRAY]; }; -/* What a stroke of luck - all our mutable closures follow the same - * basic layout, with the mutable link field as the second field after - * the header. This means the following structure is the supertype of - * mutable closures. - */ - -typedef struct StgMutClosure_ { - StgHeader header; - StgWord padding; - struct StgMutClosure_ *mut_link; +typedef struct { + StgThunkHeader header; struct StgClosure_ *payload[FLEXIBLE_ARRAY]; -} StgMutClosure; +} StgThunk; typedef struct { - StgHeader header; + StgThunkHeader header; StgClosure *selectee; } StgSelector; @@ -95,11 +114,16 @@ typedef struct { StgClosure *payload[FLEXIBLE_ARRAY]; } StgPAP; -/* AP closures have the same layout, for convenience */ -typedef StgPAP StgAP; +typedef struct { + StgThunkHeader header; + StgHalfWord arity; /* zero if it is an AP */ + StgHalfWord n_args; + StgClosure *fun; /* really points to a fun */ + StgClosure *payload[FLEXIBLE_ARRAY]; +} StgAP; typedef struct { - StgHeader header; + StgThunkHeader header; StgWord size; /* number of words in payload */ StgClosure *fun; StgClosure *payload[FLEXIBLE_ARRAY]; /* contains a chunk of *stack* */ @@ -111,12 +135,6 @@ typedef struct { } StgInd; typedef struct { - StgHeader header; - StgClosure *indirectee; - StgMutClosure *mut_link; -} StgIndOldGen; - -typedef struct { StgHeader header; StgClosure *indirectee; StgClosure *static_link; @@ -132,14 +150,12 @@ typedef struct { typedef struct { StgHeader header; StgWord ptrs; - StgMutClosure *mut_link; /* mutable list */ StgClosure *payload[FLEXIBLE_ARRAY]; } StgMutArrPtrs; typedef struct { StgHeader header; StgClosure *var; - StgMutClosure *mut_link; } StgMutVar; typedef struct _StgUpdateFrame { @@ -172,11 +188,6 @@ typedef struct { StgHeader header; } StgRetry; -typedef struct _StgForeignObj { - StgHeader header; - StgAddr data; /* pointer to data in non-haskell-land */ -} StgForeignObj; - typedef struct _StgStableName { StgHeader header; StgWord sn; @@ -233,11 +244,53 @@ typedef struct { #define BCO_BITMAP_SIZEW(bco) ((BCO_BITMAP_SIZE(bco) + BITS_IN(StgWord) - 1) \ / BITS_IN(StgWord)) -/* Dynamic stack frames - these have a liveness mask in the object - * itself, rather than in the info table. Useful for generic heap - * check code. See StgMacros.h, HEAP_CHK_GEN(). - */ - +/* ----------------------------------------------------------------------------- + Dynamic stack frames for generic heap checks. + + These generic heap checks are slow, but have the advantage of being + usable in a variety of situations. + + The one restriction is that any relevant SRTs must already be pointed + to from the stack. The return address doesn't need to have an info + table attached: hence it can be any old code pointer. + + The liveness mask contains a 1 at bit n, if register Rn contains a + non-pointer. The contents of all 8 vanilla registers are always saved + on the stack; the liveness mask tells the GC which ones contain + pointers. + + Good places to use a generic heap check: + + - case alternatives (the return address with an SRT is already + on the stack). + + - primitives (no SRT required). + + The stack frame layout for a RET_DYN is like this: + + some pointers |-- RET_DYN_PTRS(liveness) words + some nonpointers |-- RET_DYN_NONPTRS(liveness) words + + L1 \ + D1-2 |-- RET_DYN_NONPTR_REGS_SIZE words + F1-4 / + + R1-8 |-- RET_DYN_BITMAP_SIZE words + + return address \ + liveness mask |-- StgRetDyn structure + stg_gen_chk_info / + + we assume that the size of a double is always 2 pointers (wasting a + word when it is only one pointer, but avoiding lots of #ifdefs). + + See Liveness.h for the macros (RET_DYN_PTRS() etc.). + + NOTE: if you change the layout of RET_DYN stack frames, then you + might also need to adjust the value of RESERVED_STACK_WORDS in + Constants.h. + -------------------------------------------------------------------------- */ + typedef struct { const struct _StgInfoTable* info; StgWord liveness; @@ -264,19 +317,110 @@ typedef struct { typedef struct { StgHeader header; struct StgTSO_ *head; - StgMutClosure *mut_link; struct StgTSO_ *tail; StgClosure* value; } StgMVar; + +/* STM data structures + * + * StgTVar defines the only type that can be updated through the STM + * interface. + * + * Note that various optimisations may be possible in order to use less + * space for these data structures at the cost of more complexity in the + * implementation: + * + * - In StgTVar, current_value and first_wait_queue_entry could be held in + * the same field: if any thread is waiting then its expected_value for + * the tvar is the current value. + * + * - In StgTRecHeader, it might be worthwhile having separate chunks + * of read-only and read-write locations. This would save a + * new_value field in the read-only locations. + * + * - In StgAtomicallyFrame, we could combine the waiting bit into + * the header (maybe a different info tbl for a waiting transaction). + * This means we can specialise the code for the atomically frame + * (it immediately switches on frame->waiting anyway). + */ + +typedef struct StgTVarWaitQueue_ { + StgHeader header; + struct StgTSO_ *waiting_tso; + struct StgTVarWaitQueue_ *next_queue_entry; + struct StgTVarWaitQueue_ *prev_queue_entry; +} StgTVarWaitQueue; + +typedef struct { + StgHeader header; + StgClosure *volatile current_value; + StgTVarWaitQueue *volatile first_wait_queue_entry; +#if defined(THREADED_RTS) + StgInt volatile num_updates; +#endif +} StgTVar; + +/* new_value == expected_value for read-only accesses */ +/* new_value is a StgTVarWaitQueue entry when trec in state TREC_WAITING */ +typedef struct { + StgTVar *tvar; + StgClosure *expected_value; + StgClosure *new_value; +#if defined(THREADED_RTS) + StgInt num_updates; +#endif +} TRecEntry; + +#define TREC_CHUNK_NUM_ENTRIES 16 + +typedef struct StgTRecChunk_ { + StgHeader header; + struct StgTRecChunk_ *prev_chunk; + StgWord next_entry_idx; + TRecEntry entries[TREC_CHUNK_NUM_ENTRIES]; +} StgTRecChunk; + +typedef enum { + TREC_ACTIVE, /* Transaction in progress, outcome undecided */ + TREC_CONDEMNED, /* Transaction in progress, inconsistent / out of date reads */ + TREC_COMMITTED, /* Transaction has committed, now updating tvars */ + TREC_ABORTED, /* Transaction has aborted, now reverting tvars */ + TREC_WAITING, /* Transaction currently waiting */ +} TRecState; + +typedef struct StgTRecHeader_ { + StgHeader header; + TRecState state; + struct StgTRecHeader_ *enclosing_trec; + StgTRecChunk *current_chunk; +} StgTRecHeader; + +typedef struct { + StgHeader header; + StgClosure *code; +} StgAtomicallyFrame; + +typedef struct { + StgHeader header; + StgClosure *handler; +} StgCatchSTMFrame; + +typedef struct { + StgHeader header; + StgBool running_alt_code; + StgClosure *first_code; + StgClosure *alt_code; + StgTRecHeader *first_code_trec; +} StgCatchRetryFrame; + #if defined(PAR) || defined(GRAN) /* StgBlockingQueueElement is a ``collective type'' representing the types of closures that can be found on a blocking queue: StgTSO, StgRBHSave, StgBlockedFetch. (StgRBHSave can only appear at the end of a blocking queue). Logically, this is a union type, but defining another struct - with a common layout is easier to handle in the code (same as for - StgMutClosures). + with a common layout is easier to handle in the code. Note that in the standard setup only StgTSOs can be on a blocking queue. This is one of the main reasons for slightly different code in files such as Schedule.c. @@ -284,7 +428,6 @@ typedef struct { typedef struct StgBlockingQueueElement_ { StgHeader header; struct StgBlockingQueueElement_ *link; /* next elem in BQ */ - StgMutClosure *mut_link; /* next elem in mutable list */ struct StgClosure_ *payload[FLEXIBLE_ARRAY];/* contents of the closure */ } StgBlockingQueueElement; @@ -292,7 +435,6 @@ typedef struct StgBlockingQueueElement_ { typedef struct StgBlockingQueue_ { StgHeader header; struct StgBlockingQueueElement_ *blocking_queue; /* start of the BQ */ - StgMutClosure *mut_link; /* next elem in mutable list */ } StgBlockingQueue; /* this closure is hanging at the end of a blocking queue in (see RBH.c) */ @@ -304,17 +446,8 @@ typedef struct StgRBHSave_ { typedef struct StgRBH_ { StgHeader header; struct StgBlockingQueueElement_ *blocking_queue; /* start of the BQ */ - StgMutClosure *mut_link; /* next elem in mutable list */ } StgRBH; -#else - -typedef struct StgBlockingQueue_ { - StgHeader header; - struct StgTSO_ *blocking_queue; - StgMutClosure *mut_link; -} StgBlockingQueue; - #endif #if defined(PAR) @@ -322,14 +455,12 @@ typedef struct StgBlockingQueue_ { typedef struct StgFetchMe_ { StgHeader header; globalAddr *ga; /* ptr to unique id for a closure */ - StgMutClosure *mut_link; /* next elem in mutable list */ } StgFetchMe; /* same contents as an ordinary StgBlockingQueue */ typedef struct StgFetchMeBlockingQueue_ { StgHeader header; struct StgBlockingQueueElement_ *blocking_queue; /* start of the BQ */ - StgMutClosure *mut_link; /* next elem in mutable list */ } StgFetchMeBlockingQueue; /* This is an entry in a blocking queue. It indicates a fetch request from a @@ -341,7 +472,6 @@ typedef struct StgFetchMeBlockingQueue_ { typedef struct StgBlockedFetch_ { StgHeader header; struct StgBlockingQueueElement_ *link; /* next elem in the BQ */ - StgMutClosure *mut_link; /* next elem in mutable list */ StgClosure *node; /* node to fetch */ globalAddr ga; /* where to send the result to */ } StgBlockedFetch; /* NB: not just a ptr to a GA */