typedef struct {
CostCentreStack *ccs;
union {
- struct _RetainerSet *rs; // Retainer Set
- StgWord ldvw; // Lag/Drag/Void Word
+ struct _RetainerSet *rs; /* Retainer Set */
+ StgWord ldvw; /* Lag/Drag/Void Word */
} hp;
} StgProfHeader;
} 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
-------------------------------------------------------------------------- */
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;
+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
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;
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;
- StgWord size; // number of words in payload
+ StgThunkHeader header;
+ StgWord size; /* number of words in payload */
StgClosure *fun;
- StgClosure *payload[FLEXIBLE_ARRAY]; // contains a chunk of *stack*
+ StgClosure *payload[FLEXIBLE_ARRAY]; /* contains a chunk of *stack* */
} StgAP_STACK;
typedef struct {
} StgInd;
typedef struct {
- StgHeader header;
- StgClosure *indirectee;
- StgMutClosure *mut_link;
-} StgIndOldGen;
-
-typedef struct {
StgHeader header;
StgClosure *indirectee;
StgClosure *static_link;
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 {
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;
typedef struct {
StgHeader header;
- StgArrWords *instrs; // a pointer to an ArrWords
- StgArrWords *literals; // a pointer to an ArrWords
- StgMutArrPtrs *ptrs; // a pointer to a MutArrPtrs
- StgArrWords *itbls; // a pointer to an ArrWords
- StgHalfWord arity; // arity of this BCO
- StgHalfWord size; // size of this BCO (in words)
- StgWord bitmap[FLEXIBLE_ARRAY]; // an StgLargeBitmap
+ StgArrWords *instrs; /* a pointer to an ArrWords */
+ StgArrWords *literals; /* a pointer to an ArrWords */
+ StgMutArrPtrs *ptrs; /* a pointer to a MutArrPtrs */
+ StgArrWords *itbls; /* a pointer to an ArrWords */
+ StgHalfWord arity; /* arity of this BCO */
+ StgHalfWord size; /* size of this BCO (in words) */
+ StgWord bitmap[FLEXIBLE_ARRAY]; /* an StgLargeBitmap */
} StgBCO;
#define BCO_BITMAP(bco) ((StgLargeBitmap *)((StgBCO *)(bco))->bitmap)
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.
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;
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) */
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)
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
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 */