/* -----------------------------------------------------------------------------
- * $Id: Storage.h,v 1.4 1999/01/18 15:21:40 simonm Exp $
+ * $Id: Storage.h,v 1.39 2002/02/01 10:50:35 simonmar Exp $
+ *
+ * (c) The GHC Team, 1998-1999
*
* External Storage Manger Interface
*
#define STORAGE_H
#include "Block.h"
+#include "MBlock.h"
#include "BlockAlloc.h"
#include "StoragePriv.h"
+#ifdef PROFILING
+#include "LdvProfile.h"
+#endif
/* -----------------------------------------------------------------------------
Initialisation / De-initialisation
/* -----------------------------------------------------------------------------
Generic allocation
- StgPtr allocate(int n) Allocates a chunk of contiguous store
+ StgPtr allocate(nat n) Allocates a chunk of contiguous store
n words long, returning a pointer to
the first word. Always succeeds.
+
+ StgPtr allocatePinned(nat n) Allocates a chunk of contiguous store
+ n words long, which is at a fixed
+ address (won't be moved by GC).
+ Returns a pointer to the first word.
+ Always succeeds.
+
+ NOTE: the GC can't in general handle
+ pinned objects, so allocatePinned()
+ can only be used for ByteArrays at the
+ moment.
+
+ Don't forget to TICK_ALLOC_XXX(...)
+ after calling allocate or
+ allocatePinned, for the
+ benefit of the ticky-ticky profiler.
rtsBool doYouWantToGC(void) Returns True if the storage manager is
ready to perform a GC, False otherwise.
lnat allocated_bytes(void) Returns the number of bytes allocated
via allocate() since the last GC.
Used in the reoprting of statistics.
+
+ SMP: allocate and doYouWantToGC can be used from STG code, they are
+ surrounded by a mutex.
-------------------------------------------------------------------------- */
-extern StgPtr allocate(nat n);
-static inline rtsBool doYouWantToGC(void)
+extern StgPtr allocate ( nat n );
+extern StgPtr allocatePinned ( nat n );
+extern lnat allocated_bytes ( void );
+
+static inline rtsBool
+doYouWantToGC( void )
{
return (alloc_blocks >= alloc_blocks_lim);
}
-extern lnat allocated_bytes(void);
/* -----------------------------------------------------------------------------
ExtendNursery(hp,hplim) When hplim is reached, try to grab
-------------------------------------------------------------------------- */
#define ExtendNursery(hp,hplim) \
- (current_nursery->free = (P_)(hp)+1, \
- current_nursery->link == NULL ? rtsFalse : \
- (current_nursery = current_nursery->link, \
+ (CurrentNursery->free = (P_)(hp)+1, \
+ CurrentNursery->link == NULL ? rtsFalse : \
+ (CurrentNursery = CurrentNursery->link, \
OpenNursery(hp,hplim), \
rtsTrue))
MarkRoot(StgClosure *p) Returns the new location of the root.
-------------------------------------------------------------------------- */
-extern void GarbageCollect(void (*get_roots)(void));
-extern StgClosure *MarkRoot(StgClosure *p);
+extern void GarbageCollect(void (*get_roots)(evac_fn),rtsBool force_major_gc);
/* -----------------------------------------------------------------------------
Generational garbage collection support
- RecordMutable(StgPtr p) Informs the garbage collector that a
+ recordMutable(StgPtr p) Informs the garbage collector that a
previously immutable object has
become (permanently) mutable. Used
by thawArray and similar.
- UpdateWithIndirection(p1,p2) Updates the object at p1 with an
+ updateWithIndirection(p1,p2) Updates the object at p1 with an
indirection pointing to p2. This is
normally called for objects in an old
generation (>0) when they are updated.
+ updateWithPermIndirection(p1,p2) As above but uses a permanent indir.
+
-------------------------------------------------------------------------- */
-extern void recordMutable(StgMutClosure *p);
+/*
+ * Storage manager mutex
+ */
+#ifdef SMP
+extern pthread_mutex_t sm_mutex;
+#endif
+
+/* ToDo: shouldn't recordMutable and recordOldToNewPtrs acquire some
+ * kind of lock in the SMP case?
+ */
+static inline void
+recordMutable(StgMutClosure *p)
+{
+ bdescr *bd;
+
+#ifdef SMP
+ ASSERT(p->header.info == &stg_WHITEHOLE_info || closure_MUTABLE(p));
+#else
+ ASSERT(closure_MUTABLE(p));
+#endif
+
+ bd = Bdescr((P_)p);
+ if (bd->gen_no > 0) {
+ p->mut_link = generations[bd->gen_no].mut_list;
+ generations[bd->gen_no].mut_list = p;
+ }
+}
+
+static inline void
+recordOldToNewPtrs(StgMutClosure *p)
+{
+ bdescr *bd;
+
+ bd = Bdescr((P_)p);
+ if (bd->gen_no > 0) {
+ p->mut_link = generations[bd->gen_no].mut_once_list;
+ generations[bd->gen_no].mut_once_list = p;
+ }
+}
+
+// @LDV profiling
+// We zero out the slop when PROFILING is on.
+// #ifndef DEBUG
+#if !defined(DEBUG) && !defined(PROFILING)
+#define updateWithIndirection(info, p1, p2) \
+ { \
+ bdescr *bd; \
+ \
+ bd = Bdescr((P_)p1); \
+ if (bd->gen_no == 0) { \
+ ((StgInd *)p1)->indirectee = p2; \
+ SET_INFO(p1,&stg_IND_info); \
+ TICK_UPD_NEW_IND(); \
+ } else { \
+ ((StgIndOldGen *)p1)->indirectee = p2; \
+ if (info != &stg_BLACKHOLE_BQ_info) { \
+ ACQUIRE_LOCK(&sm_mutex); \
+ ((StgIndOldGen *)p1)->mut_link = generations[bd->gen_no].mut_once_list; \
+ generations[bd->gen_no].mut_once_list = (StgMutClosure *)p1; \
+ RELEASE_LOCK(&sm_mutex); \
+ } \
+ SET_INFO(p1,&stg_IND_OLDGEN_info); \
+ TICK_UPD_OLD_IND(); \
+ } \
+ }
+#elif defined(PROFILING)
+// @LDV profiling
+// We call LDV_recordDead_FILL_SLOP_DYNAMIC(p1) regardless of the generation in
+// which p1 resides.
+//
+// Note:
+// After all, we do *NOT* need to call LDV_recordCreate() for both IND and
+// IND_OLDGEN closures because they are inherently used. But, it corrupts
+// the invariants that every closure keeps its creation time in the profiling
+// field. So, we call LDV_recordCreate().
+
+#define updateWithIndirection(info, p1, p2) \
+ { \
+ bdescr *bd; \
+ \
+ LDV_recordDead_FILL_SLOP_DYNAMIC((p1)); \
+ bd = Bdescr((P_)p1); \
+ if (bd->gen_no == 0) { \
+ ((StgInd *)p1)->indirectee = p2; \
+ SET_INFO(p1,&stg_IND_info); \
+ LDV_recordCreate((p1)); \
+ TICK_UPD_NEW_IND(); \
+ } else { \
+ ((StgIndOldGen *)p1)->indirectee = p2; \
+ if (info != &stg_BLACKHOLE_BQ_info) { \
+ ACQUIRE_LOCK(&sm_mutex); \
+ ((StgIndOldGen *)p1)->mut_link = generations[bd->gen_no].mut_once_list; \
+ generations[bd->gen_no].mut_once_list = (StgMutClosure *)p1; \
+ RELEASE_LOCK(&sm_mutex); \
+ } \
+ SET_INFO(p1,&stg_IND_OLDGEN_info); \
+ LDV_recordCreate((p1)); \
+ } \
+ }
+
+#else
-#ifdef TICKY_TICKY
-#error updateWithIndirection: maybe permanent indirection?
-# define Ind_info_TO_USE ((AllFlags.doUpdEntryCounts) ? &IND_PERM_info : &IND_info
-)
+/* In the DEBUG case, we also zero out the slop of the old closure,
+ * so that the sanity checker can tell where the next closure is.
+ *
+ * Two important invariants: we should never try to update a closure
+ * to point to itself, and the closure being updated should not
+ * already have been updated (the mutable list will get messed up
+ * otherwise).
+ */
+#define updateWithIndirection(info, p1, p2) \
+ { \
+ bdescr *bd; \
+ \
+ ASSERT( p1 != p2 && !closure_IND(p1) ); \
+ bd = Bdescr((P_)p1); \
+ if (bd->gen_no == 0) { \
+ ((StgInd *)p1)->indirectee = p2; \
+ SET_INFO(p1,&stg_IND_info); \
+ TICK_UPD_NEW_IND(); \
+ } else { \
+ if (info != &stg_BLACKHOLE_BQ_info) { \
+ { \
+ StgInfoTable *inf = get_itbl(p1); \
+ nat np = inf->layout.payload.ptrs, \
+ nw = inf->layout.payload.nptrs, i; \
+ if (inf->type != THUNK_SELECTOR) { \
+ for (i = np; i < np + nw; i++) { \
+ ((StgClosure *)p1)->payload[i] = 0; \
+ } \
+ } \
+ } \
+ ACQUIRE_LOCK(&sm_mutex); \
+ ((StgIndOldGen *)p1)->mut_link = generations[bd->gen_no].mut_once_list; \
+ generations[bd->gen_no].mut_once_list = (StgMutClosure *)p1; \
+ RELEASE_LOCK(&sm_mutex); \
+ } \
+ ((StgIndOldGen *)p1)->indirectee = p2; \
+ SET_INFO(p1,&stg_IND_OLDGEN_info); \
+ TICK_UPD_OLD_IND(); \
+ } \
+ }
#endif
+/* Static objects all live in the oldest generation
+ */
+#define updateWithStaticIndirection(info, p1, p2) \
+ { \
+ ASSERT( p1 != p2 && !closure_IND(p1) ); \
+ ASSERT( ((StgMutClosure*)p1)->mut_link == NULL ); \
+ \
+ ACQUIRE_LOCK(&sm_mutex); \
+ ((StgMutClosure *)p1)->mut_link = oldest_gen->mut_once_list; \
+ oldest_gen->mut_once_list = (StgMutClosure *)p1; \
+ RELEASE_LOCK(&sm_mutex); \
+ \
+ ((StgInd *)p1)->indirectee = p2; \
+ SET_INFO((StgInd *)p1, &stg_IND_STATIC_info); \
+ TICK_UPD_STATIC_IND(); \
+ }
+
+#if defined(TICKY_TICKY) || defined(PROFILING)
static inline void
-updateWithIndirection(StgClosure *p1, StgClosure *p2)
+updateWithPermIndirection(const StgInfoTable *info, StgClosure *p1, StgClosure *p2)
{
bdescr *bd;
+ ASSERT( p1 != p2 && !closure_IND(p1) );
+
+#ifdef PROFILING
+ // @LDV profiling
+ // Destroy the old closure.
+ // Nb: LDV_* stuff cannot mix with ticky-ticky
+ LDV_recordDead_FILL_SLOP_DYNAMIC(p1);
+#endif
bd = Bdescr((P_)p1);
- if (bd->gen->no == 0) {
- SET_INFO(p1,&IND_info);
+ if (bd->gen_no == 0) {
((StgInd *)p1)->indirectee = p2;
+ SET_INFO(p1,&stg_IND_PERM_info);
+#ifdef PROFILING
+ // @LDV profiling
+ // We have just created a new closure.
+ LDV_recordCreate(p1);
+#endif
+ TICK_UPD_NEW_PERM_IND(p1);
} else {
- SET_INFO(p1,&IND_OLDGEN_info);
((StgIndOldGen *)p1)->indirectee = p2;
- ((StgIndOldGen *)p1)->mut_link = bd->gen->mut_list;
- bd->gen->mut_list = (StgMutClosure *)p1;
+ if (info != &stg_BLACKHOLE_BQ_info) {
+ ACQUIRE_LOCK(&sm_mutex);
+ ((StgIndOldGen *)p1)->mut_link = generations[bd->gen_no].mut_once_list;
+ generations[bd->gen_no].mut_once_list = (StgMutClosure *)p1;
+ RELEASE_LOCK(&sm_mutex);
+ }
+ SET_INFO(p1,&stg_IND_OLDGEN_PERM_info);
+#ifdef PROFILING
+ // @LDV profiling
+ // We have just created a new closure.
+ LDV_recordCreate(p1);
+#endif
+ TICK_UPD_OLD_PERM_IND();
}
}
+#endif
/* -----------------------------------------------------------------------------
- The CAF list - used to let us revert CAFs
+ The CAF table - used to let us revert CAFs
+ -------------------------------------------------------------------------- */
+
+void revertCAFs( void );
+
+#if defined(DEBUG)
+void printMutOnceList(generation *gen);
+void printMutableList(generation *gen);
+#endif /* DEBUG */
+
+/* --------------------------------------------------------------------------
+ Address space layout macros
+ --------------------------------------------------------------------------
+
+ Here are the assumptions GHC makes about address space layout.
+ Broadly, it thinks there are three sections:
+
+ CODE Read-only. Contains code and read-only data (such as
+ info tables)
+ Also called "text"
+
+ DATA Read-write data. Contains static closures (and on some
+ architectures, info tables too)
+
+ HEAP Dynamically-allocated closures
+
+ USER None of the above. The only way USER things arise right
+ now is when GHCi allocates a constructor info table, which
+ it does by mallocing them.
+
+ Three macros identify these three areas:
+ IS_DATA(p), HEAP_ALLOCED(p)
+
+ HEAP_ALLOCED is called FOR EVERY SINGLE CLOSURE during GC.
+ It needs to be FAST.
+
+ Implementation of HEAP_ALLOCED
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ Concerning HEAP, most of the time (certainly under [Static] and [GHCi],
+ we ensure that the heap is allocated above some fixed address HEAP_BASE
+ (defined in MBlock.h). In this case we set TEXT_BEFORE_HEAP, and we
+ get a nice fast test.
+
+ Sometimes we can't be quite sure. For example in Windows, we can't
+ fix where our heap address space comes from. In this case we un-set
+ TEXT_BEFORE_HEAP. That makes it more expensive to test whether a pointer
+ comes from the HEAP section, because we need to look at the allocator's
+ address maps (see HEAP_ALLOCED macro)
+
+ Implementation of CODE and DATA
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ Concerning CODE and DATA, there are three main regimes:
+
+ [Static] Totally The segments are contiguous, and laid out
+ statically linked exactly as above
+
+ [GHCi] Static, GHCi may load new modules, but it knows the
+ except for GHCi address map, so for any given address it can
+ still tell which section it belongs to
+ [DLL] OS-supported Chunks of CODE and DATA may be mixed in
+ dynamic loading the address space, and we can't tell how
+
+
+ For the [Static] case, we assume memory is laid out like this
+ (in order of increasing addresses)
+
+ Start of memory
+ CODE section
+ TEXT_SECTION_END_MARKER (usually _etext)
+ DATA section
+ DATA_SECTION_END_MARKER (usually _end)
+ USER section
+ HEAP_BASE
+ HEAP section
+
+ For the [GHCi] case, we have to consult GHCi's dynamic linker's
+ address maps, which is done by macros
+ is_dynamically_loaded_code_or_rodata_ptr
+ is_dynamically_loaded_code_or_rwdata_ptr
+
+ For the [DLL] case, IS_DATA is really not usable at all.
+ */
+
+
+#undef TEXT_BEFORE_HEAP
+#ifndef mingw32_TARGET_OS
+#define TEXT_BEFORE_HEAP 1
+#endif
+
+extern void* TEXT_SECTION_END_MARKER_DECL;
+extern void* DATA_SECTION_END_MARKER_DECL;
+
+/* Take into account code sections in dynamically loaded object files. */
+#define IS_DATA_PTR(p) ( ((P_)(p) >= (P_)&TEXT_SECTION_END_MARKER && \
+ (P_)(p) < (P_)&DATA_SECTION_END_MARKER) \
+ || is_dynamically_loaded_rwdata_ptr((char *)p) )
+#define IS_USER_PTR(p) ( ((P_)(p) >= (P_)&DATA_SECTION_END_MARKER) \
+ && is_not_dynamically_loaded_ptr((char *)p) )
+
+/* The HEAP_ALLOCED test below is called FOR EVERY SINGLE CLOSURE
+ * during GC. It needs to be FAST.
+ *
+ * BEWARE: when we're dynamically loading code (for GHCi), make sure
+ * that we don't load any code above HEAP_BASE, or this test won't work.
+ */
+#ifdef TEXT_BEFORE_HEAP
+# define HEAP_ALLOCED(x) ((StgPtr)(x) >= (StgPtr)(HEAP_BASE))
+#else
+extern int is_heap_alloced(const void* x);
+# define HEAP_ALLOCED(x) (is_heap_alloced(x))
+#endif
+
+
+/* --------------------------------------------------------------------------
+ Macros for distinguishing data pointers from code pointers
+ --------------------------------------------------------------------------
+
+ Specification
+ ~~~~~~~~~~~~~
+ The garbage collector needs to make some critical distinctions between pointers.
+ In particular we need
+
+ LOOKS_LIKE_GHC_INFO(p) p points to an info table
+
+ For both of these macros, p is
+ *either* a pointer to a closure (static or heap allocated)
+ *or* a return address on the (Haskell) stack
+
+ (Return addresses are in fact info-pointers, so that the Haskell stack
+ looks very like a chunk of heap.)
+
+ The garbage collector uses LOOKS_LIKE_GHC_INFO when walking the stack, as it
+ walks over the "pending arguments" on its way to the next return address.
+ It is called moderately often, but not as often as HEAP_ALLOCED
+
+ ToDo: LOOKS_LIKE_GHC_INFO(p) does not return True when p points to a
+ constructor info table allocated by GHCi. We should really rename
+ LOOKS_LIKE_GHC_INFO to LOOKS_LIKE_GHC_RETURN_INFO.
+
+ Implementation
+ ~~~~~~~~~~~~~~
+ LOOKS_LIKE_GHC_INFO is more complicated because of the need to distinguish
+ between static closures and info tables. It's a known portability problem.
+ We have three approaches:
+
+ Plan A: Address-space partitioning.
+ keep static closures in the (single, contiguous) data segment: IS_DATA_PTR(p)
+
+ Plan A can fail for two reasons:
+ * In many environments (eg. dynamic loading),
+ text and data aren't in a single contiguous range.
+ * When we compile through vanilla C (no mangling) we sometimes
+ can't guaranteee to put info tables in the text section. This
+ happens eg. on MacOS where the C compiler refuses to put const
+ data in the text section if it has any code pointers in it
+ (which info tables do *only* when we're compiling without
+ TABLES_NEXT_TO_CODE).
+
+ Hence, Plan B: (compile-via-C-with-mangling, or native code generation)
+ Put a zero word before each static closure.
+ When compiling to native code, or via C-with-mangling, info tables
+ are laid out "backwards" from the address specified in the info pointer
+ (the entry code goes forward from the info pointer). Hence, the word
+ before the one referenced the info pointer is part of the info table,
+ and is guaranteed non-zero.
+
+ For reasons nobody seems to fully understand, the statically-allocated tables
+ of INTLIKE and CHARLIKE closures can't have this zero word, so we
+ have to test separately for them.
+
+ Plan B fails altogether for the compile-through-vanilla-C route, because
+ info tables aren't laid out backwards.
+
+
+ Hence, Plan C: (unregisterised, compile-through-vanilla-C route only)
+ If we didn't manage to get info tables into the text section, then
+ we can distinguish between a static closure pointer and an info
+ pointer as follows: the first word of an info table is a code pointer,
+ and therefore in text space, whereas the first word of a closure pointer
+ is an info pointer, and therefore not. Shazam!
+*/
+
+
+/* When working with Win32 DLLs, static closures are identified by
+ being prefixed with a zero word. This is needed so that we can
+ distinguish between pointers to static closures and (reversed!)
+ info tables.
+
+ This 'scheme' breaks down for closure tables such as CHARLIKE,
+ so we catch these separately.
+
+ LOOKS_LIKE_STATIC_CLOSURE()
+ - discriminates between static closures and info tbls
+ (needed by LOOKS_LIKE_GHC_INFO() below - [Win32 DLLs only.])
+ LOOKS_LIKE_STATIC()
+ - distinguishes between static and heap allocated data.
+ */
+#if defined(ENABLE_WIN32_DLL_SUPPORT)
+ /* definitely do not enable for mingw DietHEP */
+#define LOOKS_LIKE_STATIC(r) (!(HEAP_ALLOCED(r)))
+
+/* Tiresome predicates needed to check for pointers into the closure tables */
+#define IS_CHARLIKE_CLOSURE(p) \
+ ( (P_)(p) >= (P_)stg_CHARLIKE_closure && \
+ (char*)(p) <= ((char*)stg_CHARLIKE_closure + \
+ (MAX_CHARLIKE-MIN_CHARLIKE) * sizeof(StgIntCharlikeClosure)) )
+#define IS_INTLIKE_CLOSURE(p) \
+ ( (P_)(p) >= (P_)stg_INTLIKE_closure && \
+ (char*)(p) <= ((char*)stg_INTLIKE_closure + \
+ (MAX_INTLIKE-MIN_INTLIKE) * sizeof(StgIntCharlikeClosure)) )
+
+#define LOOKS_LIKE_STATIC_CLOSURE(r) (((*(((unsigned long *)(r))-1)) == 0) || IS_CHARLIKE_CLOSURE(r) || IS_INTLIKE_CLOSURE(r))
+#else
+#define LOOKS_LIKE_STATIC(r) IS_DATA_PTR(r)
+#define LOOKS_LIKE_STATIC_CLOSURE(r) IS_DATA_PTR(r)
+#endif
+
+
+/* -----------------------------------------------------------------------------
+ Macros for distinguishing infotables from closures.
+
+ You'd think it'd be easy to tell an info pointer from a closure pointer:
+ closures live on the heap and infotables are in read only memory. Right?
+ Wrong! Static closures live in read only memory and Hugs allocates
+ infotables for constructors on the (writable) C heap.
-------------------------------------------------------------------------- */
-extern StgCAF* enteredCAFs;
+/* not accurate by any means, but stops the assertions failing... */
+/* TODO TODO TODO TODO TODO TODO TODO TODO TODO TODO TODO TODO */
+#define IS_HUGS_CONSTR_INFO(info) IS_USER_PTR(info)
+
+/* LOOKS_LIKE_GHC_INFO is called moderately often during GC, but
+ * Certainly not as often as HEAP_ALLOCED.
+ */
+#define LOOKS_LIKE_GHC_INFO(info) (!HEAP_ALLOCED(info) \
+ && !LOOKS_LIKE_STATIC_CLOSURE(info))
+
+/* -----------------------------------------------------------------------------
+ Macros for calculating how big a closure will be (used during allocation)
+ -------------------------------------------------------------------------- */
+
+static __inline__ StgOffset AP_sizeW ( nat n_args )
+{ return sizeofW(StgAP_UPD) + n_args; }
+
+static __inline__ StgOffset PAP_sizeW ( nat n_args )
+{ return sizeofW(StgPAP) + n_args; }
+
+static __inline__ StgOffset CONSTR_sizeW( nat p, nat np )
+{ return sizeofW(StgHeader) + p + np; }
+
+static __inline__ StgOffset THUNK_SELECTOR_sizeW ( void )
+{ return sizeofW(StgHeader) + MIN_UPD_SIZE; }
+
+static __inline__ StgOffset BLACKHOLE_sizeW ( void )
+{ return sizeofW(StgHeader) + MIN_UPD_SIZE; }
+
+/* --------------------------------------------------------------------------
+ * Sizes of closures
+ * ------------------------------------------------------------------------*/
+
+static __inline__ StgOffset sizeW_fromITBL( const StgInfoTable* itbl )
+{ return sizeofW(StgClosure)
+ + sizeofW(StgPtr) * itbl->layout.payload.ptrs
+ + sizeofW(StgWord) * itbl->layout.payload.nptrs; }
+
+static __inline__ StgOffset pap_sizeW( StgPAP* x )
+{ return PAP_sizeW(x->n_args); }
+
+static __inline__ StgOffset arr_words_sizeW( StgArrWords* x )
+{ return sizeofW(StgArrWords) + x->words; }
+
+static __inline__ StgOffset mut_arr_ptrs_sizeW( StgMutArrPtrs* x )
+{ return sizeofW(StgMutArrPtrs) + x->ptrs; }
+
+static __inline__ StgWord tso_sizeW ( StgTSO *tso )
+{ return TSO_STRUCT_SIZEW + tso->stack_size; }
-#endif STORAGE_H
+#endif /* STORAGE_H */