HCoop / hcoop / debian / mlton.git / blame
| Commit | Line | Data |
|---|---|---|
| 7f918cf1 CE |
1 | /* Copyright (C) 1999-2007 Henry Cejtin, Matthew Fluet, Suresh |
| 2 | * Jagannathan, and Stephen Weeks. | |
| 3 | * Copyright (C) 1997-2000 NEC Research Institute. | |
| 4 | * | |
| 5 | * MLton is released under a BSD-style license. | |
| 6 | * See the file MLton-LICENSE for details. | |
| 7 | */ | |
| 8 | ||
| 9 | #if (defined (MLTON_GC_INTERNAL_TYPES)) | |
| 10 | ||
| 11 | /* | |
| 12 | * Weak objects have the following layout: | |
| 13 | * | |
| 14 | * header :: | |
| 15 | * padding :: | |
| 16 | * link (native-pointer) :: | |
| 17 | * objptr (object-pointer) | |
| 18 | * | |
| 19 | * The object type indexed by the header determines whether the weak | |
| 20 | * is valid or not. If the type has numObjptrs == 1, then the weak | |
| 21 | * pointer is valid. Otherwise, the type has numObjptrs == 0 and the | |
| 22 | * weak pointer is not valid. | |
| 23 | * | |
| 24 | * There may be zero or more bytes of padding for alignment purposes. | |
| 25 | * | |
| 26 | * The link native-pointer is used to chain the live weaks together | |
| 27 | * during a copying/mark-compact gc and is otherwise unused. | |
| 28 | * | |
| 29 | * The final component is the weak object-pointer. | |
| 30 | * | |
| 31 | * Note that the order of the fields is important. The non-objptr | |
| 32 | * field must be first, because a weak object is sometimes treated as | |
| 33 | * a normal object. | |
| 34 | */ | |
| 35 | typedef struct GC_weak { | |
| 36 | struct GC_weak *link; | |
| 37 | objptr objptr; | |
| 38 | } __attribute__ ((packed)) *GC_weak; | |
| 39 | ||
| 40 | COMPILE_TIME_ASSERT(GC_weak__packed, | |
| 41 | sizeof(struct GC_weak) == | |
| 42 | sizeof(struct GC_weak*) | |
| 43 | + sizeof(objptr)); | |
| 44 | ||
| 45 | #endif /* (defined (MLTON_GC_INTERNAL_TYPES)) */ | |
| 46 | ||
| 47 | #if (defined (MLTON_GC_INTERNAL_FUNCS)) | |
| 48 | ||
| 49 | static inline size_t sizeofWeak (GC_state s); | |
| 50 | static inline size_t offsetofWeak (GC_state s); | |
| 51 | ||
| 52 | #endif /* (defined (MLTON_GC_INTERNAL_FUNCS)) */ | |
| 53 | ||
| 54 | #if (defined (MLTON_GC_INTERNAL_BASIS)) | |
| 55 | ||
| 56 | PRIVATE uint32_t GC_weakCanGet (GC_state s, pointer p); | |
| 57 | PRIVATE pointer GC_weakGet (GC_state s, pointer p); | |
| 58 | PRIVATE pointer GC_weakNew (GC_state s, GC_header header, pointer p); | |
| 59 | ||
| 60 | #endif /* (defined (MLTON_GC_INTERNAL_BASIS)) */ |