X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fincludes%2FStgStorage.h;h=5c0ca12a5160ee574aab1ab150e26f50d3f92299;hb=1c82b947f92da21c57dcec6c65b570871e938f4c;hp=6c9b0d350344ceaf26cf6e10ee3cef9b238b6ea7;hpb=f6692611aad945e46ffb615bde1df7def3fc742f;p=ghc-hetmet.git diff --git a/ghc/includes/StgStorage.h b/ghc/includes/StgStorage.h index 6c9b0d3..5c0ca12 100644 --- a/ghc/includes/StgStorage.h +++ b/ghc/includes/StgStorage.h @@ -1,15 +1,93 @@ /* ----------------------------------------------------------------------------- - * $Id: StgStorage.h,v 1.5 1999/11/02 15:05:53 simonmar Exp $ + * $Id: StgStorage.h,v 1.12 2003/03/26 17:40:58 sof Exp $ * * (c) The GHC Team, 1998-1999 * - * STG Storage Manger Interface + * STG Storage Manager Interface * * ---------------------------------------------------------------------------*/ #ifndef STGSTORAGE_H #define STGSTORAGE_H +/* GENERATION GC NOTES + * + * We support an arbitrary number of generations, with an arbitrary number + * of steps per generation. Notes (in no particular order): + * + * - all generations except the oldest should have two steps. This gives + * objects a decent chance to age before being promoted, and in + * particular will ensure that we don't end up with too many + * thunks being updated in older generations. + * + * - the oldest generation has one step. There's no point in aging + * objects in the oldest generation. + * + * - generation 0, step 0 (G0S0) is the allocation area. It is given + * a fixed set of blocks during initialisation, and these blocks + * are never freed. + * + * - during garbage collection, each step which is an evacuation + * destination (i.e. all steps except G0S0) is allocated a to-space. + * evacuated objects are allocated into the step's to-space until + * GC is finished, when the original step's contents may be freed + * and replaced by the to-space. + * + * - the mutable-list is per-generation (not per-step). G0 doesn't + * have one (since every garbage collection collects at least G0). + * + * - block descriptors contain pointers to both the step and the + * generation that the block belongs to, for convenience. + * + * - static objects are stored in per-generation lists. See GC.c for + * details of how we collect CAFs in the generational scheme. + * + * - large objects are per-step, and are promoted in the same way + * as small objects, except that we may allocate large objects into + * generation 1 initially. + */ + +typedef struct _step { + unsigned int no; /* step number */ + bdescr * blocks; /* blocks in this step */ + unsigned int n_blocks; /* number of blocks */ + struct _step * to; /* destination step for live objects */ + struct _generation * gen; /* generation this step belongs to */ + unsigned int gen_no; /* generation number (cached) */ + bdescr * large_objects; /* large objects (doubly linked) */ + unsigned int n_large_blocks; /* no. of blocks used by large objs */ + int is_compacted; /* compact this step? (old gen only) */ + + /* temporary use during GC: */ + StgPtr hp; /* next free locn in to-space */ + StgPtr hpLim; /* end of current to-space block */ + bdescr * hp_bd; /* bdescr of current to-space block */ + bdescr * to_blocks; /* bdescr of first to-space block */ + unsigned int n_to_blocks; /* number of blocks in to-space */ + bdescr * scan_bd; /* block currently being scanned */ + StgPtr scan; /* scan pointer in current block */ + bdescr * new_large_objects; /* large objects collected so far */ + bdescr * scavenged_large_objects; /* live large objs after GC (d-link) */ + unsigned int n_scavenged_large_blocks;/* size of above */ + bdescr * bitmap; /* bitmap for compacting collection */ +} step; + +typedef struct _generation { + unsigned int no; /* generation number */ + step * steps; /* steps */ + unsigned int n_steps; /* number of steps */ + unsigned int max_blocks; /* max blocks in step 0 */ + StgMutClosure *mut_list; /* mut objects in this gen (not G0)*/ + StgMutClosure *mut_once_list; /* objects that point to younger gens */ + + /* temporary use during GC: */ + StgMutClosure * saved_mut_list; + + /* stats information */ + unsigned int collections; + unsigned int failed_promotions; +} generation; + /* ----------------------------------------------------------------------------- Allocation area for compiled code @@ -18,23 +96,26 @@ CloseNursery(hp) Closes the allocation area. - PleaseStopAllocating(void) Arranges that the next call to - ExtendNursery() will fail, triggering - a return to the scheduler. This is - useful for asynchronous interupts etc. -------------------------------------------------------------------------- */ #define OpenNursery(hp,hplim) \ (hp = CurrentNursery->free-1, \ - hplim = CurrentNursery->start + BLOCK_SIZE_W - 1) + hplim = CurrentNursery->start + CurrentNursery->blocks*BLOCK_SIZE_W - 1) #define CloseNursery(hp) (CurrentNursery->free = (P_)(hp)+1) /* ----------------------------------------------------------------------------- + Prototype for an evacuate-like function + -------------------------------------------------------------------------- */ + +typedef void (*evac_fn)(StgClosure **); + +/* ----------------------------------------------------------------------------- Trigger a GC from Haskell land. -------------------------------------------------------------------------- */ extern void performGC(void); -extern void performGCWithRoots(void (*get_roots)(void)); +extern void performMajorGC(void); +extern void performGCWithRoots(void (*get_roots)(evac_fn)); #endif /* STGSTORAGE_H */