diff options
| -rw-r--r-- | includes/rts/ForeignExports.h | 2 | ||||
| -rw-r--r-- | rts/ForeignExports.c | 53 | ||||
| -rw-r--r-- | rts/Linker.c | 18 | ||||
| -rw-r--r-- | rts/LinkerInternals.h | 14 |
4 files changed, 50 insertions, 37 deletions
diff --git a/includes/rts/ForeignExports.h b/includes/rts/ForeignExports.h index f8828e59d4..aeb524aebf 100644 --- a/includes/rts/ForeignExports.h +++ b/includes/rts/ForeignExports.h @@ -29,6 +29,8 @@ struct ForeignExportsList { /* if the RTS linker loaded the module, * this points to an array of length ->n_entries * recording the StablePtr for each export. */ + StgStablePtr **stable_ptrs; + /* the exported closures. of length ->exports. */ StgPtr exports[]; }; diff --git a/rts/ForeignExports.c b/rts/ForeignExports.c index 3195b6e779..e218281b51 100644 --- a/rts/ForeignExports.c +++ b/rts/ForeignExports.c @@ -48,12 +48,14 @@ static ObjectCode *loading_obj = NULL; * For instance, doing exactly this resulted in #18548. * * Another consideration here is that the linker needs to know which - * `StablePtr`s belong to each `ObjectCode` it loads for the sake of unloading. - * For this reason, the linker informs us when it is loading an object by calling - * `foreignExportsLoadingObject` and `foreignExportsFinishedLoadingObject`. We - * take note of the `ObjectCode*` we are loading in `loading_obj` such that we - * can associate the `StablePtr` with the `ObjectCode` in - * `processForeignExports`. + * `StablePtr`s belong to each `ObjectCode` so it can free them when the module is + * unloaded. For this reason, the linker informs us when it is loading an + * object by calling `foreignExportsLoadingObject` and + * `foreignExportsFinishedLoadingObject`. We take note of the `ObjectCode*` we + * are loading in `loading_obj` such that we can associate the `ForeignExportsList` with + * the `ObjectCode` in `processForeignExports`. We then record each of the + * StablePtrs we create in the ->stable_ptrs array of ForeignExportsList so + * they can be enumerated during unloading. * */ @@ -94,20 +96,35 @@ void foreignExportsFinishedLoadingObject() void processForeignExports() { while (pending) { - for (int i=0; i < pending->n_entries; i++) { - StgPtr p = pending->exports[i]; - StgStablePtr *sptr = getStablePtr(p); + struct ForeignExportsList *cur = pending; + pending = cur->next; - if (loading_obj != NULL) { - ForeignExportStablePtr *fe_sptr = (ForeignExportStablePtr *) - stgMallocBytes(sizeof(ForeignExportStablePtr), - "foreignExportStablePtr"); - fe_sptr->stable_ptr = sptr; - fe_sptr->next = loading_obj->stable_ptrs; - pending->oc->stable_ptrs = fe_sptr; + /* sanity check */ + ASSERT(cur->stable_ptrs == NULL); + + /* N.B. We only need to populate the ->stable_ptrs + * array if the object might later be unloaded. + */ + if (cur->oc != NULL) { + cur->stable_ptrs = + stgMallocBytes(sizeof(StgStablePtr*) * cur->n_entries, + "foreignExportStablePtr"); + + for (int i=0; i < cur->n_entries; i++) { + StgStablePtr *sptr = getStablePtr(cur->exports[i]); + + if (cur->oc != NULL) { + cur->stable_ptrs[i] = sptr; + } + } + cur->next = cur->oc->foreign_exports; + cur->oc->foreign_exports = cur; + } else { + /* can't be unloaded, don't bother populating + * ->stable_ptrs array. */ + for (int i=0; i < cur->n_entries; i++) { + getStablePtr(cur->exports[i]); } } - - pending = pending->next; } } diff --git a/rts/Linker.c b/rts/Linker.c index fa38480fb6..2d54c29196 100644 --- a/rts/Linker.c +++ b/rts/Linker.c @@ -1239,14 +1239,18 @@ static void freeOcStablePtrs (ObjectCode *oc) { // Release any StablePtrs that were created when this // object module was initialized. - ForeignExportStablePtr *fe_ptr, *next; + struct ForeignExportsList *exports, *next; - for (fe_ptr = oc->stable_ptrs; fe_ptr != NULL; fe_ptr = next) { - next = fe_ptr->next; - freeStablePtr(fe_ptr->stable_ptr); - stgFree(fe_ptr); + for (exports = oc->foreign_exports; exports != NULL; exports = next) { + next = exports->next; + for (int i = 0; i < exports->n_entries; i++) { + freeStablePtr(exports->stable_ptrs[i]); + } + stgFree(exports->stable_ptrs); + exports->stable_ptrs = NULL; + exports->next = NULL; } - oc->stable_ptrs = NULL; + oc->foreign_exports = NULL; } static void @@ -1404,7 +1408,7 @@ mkOc( pathchar *path, char *image, int imageSize, oc->n_segments = 0; oc->segments = NULL; oc->proddables = NULL; - oc->stable_ptrs = NULL; + oc->foreign_exports = NULL; #if defined(NEED_SYMBOL_EXTRAS) oc->symbol_extras = NULL; #endif diff --git a/rts/LinkerInternals.h b/rts/LinkerInternals.h index 1f63f0c485..2e76a888e4 100644 --- a/rts/LinkerInternals.h +++ b/rts/LinkerInternals.h @@ -135,17 +135,6 @@ typedef struct _Segment { int n_sections; } Segment; -/* - * We must keep track of the StablePtrs that are created for foreign - * exports by constructor functions when the module is loaded, so that - * we can free them again when the module is unloaded. If we don't do - * this, then the StablePtr will keep the module alive indefinitely. - */ -typedef struct ForeignExportStablePtr_ { - StgStablePtr stable_ptr; - struct ForeignExportStablePtr_ *next; -} ForeignExportStablePtr; - #if defined(powerpc_HOST_ARCH) || defined(x86_64_HOST_ARCH) #define NEED_SYMBOL_EXTRAS 1 #endif @@ -240,7 +229,8 @@ typedef struct _ObjectCode { char* bssBegin; char* bssEnd; - ForeignExportStablePtr *stable_ptrs; + /* a list of all ForeignExportsLists owned by this object */ + struct ForeignExportsList *foreign_exports; /* Holds the list of symbols in the .o file which require extra information.*/ |