#include "genesis/primitive-objects.h"
#include "genesis/static-symbols.h"
#include "genesis/layout.h"
+#include "genesis/hash-table.h"
#include "gc-internal.h"
#ifdef LISP_FEATURE_SPARC
#endif
#endif
+size_t dynamic_space_size = DEFAULT_DYNAMIC_SPACE_SIZE;
+
inline static boolean
forwarding_pointer_p(lispobj *pointer) {
lispobj first_word=*pointer;
scavenge(&function_ptr->name, 1);
scavenge(&function_ptr->arglist, 1);
scavenge(&function_ptr->type, 1);
+ scavenge(&function_ptr->xrefs, 1);
}
return n_words;
}
}
+\f
+/* Hash tables */
+
+#if N_WORD_BITS == 32
+#define EQ_HASH_MASK 0x1fffffff
+#elif N_WORD_BITS == 64
+#define EQ_HASH_MASK 0x1fffffffffffffff
+#endif
+
+/* Compute the EQ-hash of KEY. This must match POINTER-HASH in
+ * target-hash-table.lisp. */
+#define EQ_HASH(key) ((key) & EQ_HASH_MASK)
+
+/* List of weak hash tables chained through their NEXT-WEAK-HASH-TABLE
+ * slot. Set to NULL at the end of a collection.
+ *
+ * This is not optimal because, when a table is tenured, it won't be
+ * processed automatically; only the yougest generation is GC'd by
+ * default. On the other hand, all applications will need an
+ * occasional full GC anyway, so it's not that bad either. */
+struct hash_table *weak_hash_tables = NULL;
+
+/* Return true if OBJ has already survived the current GC. */
+static inline int
+survived_gc_yet (lispobj obj)
+{
+ return (!is_lisp_pointer(obj) || !from_space_p(obj) ||
+ forwarding_pointer_p(native_pointer(obj)));
+}
+
+static inline int
+weak_hash_entry_alivep (lispobj weakness, lispobj key, lispobj value)
+{
+ switch (weakness) {
+ case KEY:
+ return survived_gc_yet(key);
+ case VALUE:
+ return survived_gc_yet(value);
+ case KEY_OR_VALUE:
+ return (survived_gc_yet(key) || survived_gc_yet(value));
+ case KEY_AND_VALUE:
+ return (survived_gc_yet(key) && survived_gc_yet(value));
+ default:
+ gc_assert(0);
+ /* Shut compiler up. */
+ return 0;
+ }
+}
+
+/* Return the beginning of data in ARRAY (skipping the header and the
+ * length) or NULL if it isn't an array of the specified widetag after
+ * all. */
+static inline lispobj *
+get_array_data (lispobj array, int widetag, unsigned long *length)
+{
+ if (is_lisp_pointer(array) &&
+ (widetag_of(*(lispobj *)native_pointer(array)) == widetag)) {
+ if (length != NULL)
+ *length = fixnum_value(((lispobj *)native_pointer(array))[1]);
+ return ((lispobj *)native_pointer(array)) + 2;
+ } else {
+ return NULL;
+ }
+}
+
+/* Only need to worry about scavenging the _real_ entries in the
+ * table. Phantom entries such as the hash table itself at index 0 and
+ * the empty marker at index 1 were scavenged by scav_vector that
+ * either called this function directly or arranged for it to be
+ * called later by pushing the hash table onto weak_hash_tables. */
+static void
+scav_hash_table_entries (struct hash_table *hash_table)
+{
+ lispobj *kv_vector;
+ unsigned long kv_length;
+ lispobj *index_vector;
+ unsigned long length;
+ lispobj *next_vector;
+ unsigned long next_vector_length;
+ lispobj *hash_vector;
+ unsigned long hash_vector_length;
+ lispobj empty_symbol;
+ lispobj weakness = hash_table->weakness;
+ long i;
+
+ kv_vector = get_array_data(hash_table->table,
+ SIMPLE_VECTOR_WIDETAG, &kv_length);
+ if (kv_vector == NULL)
+ lose("invalid kv_vector %x\n", hash_table->table);
+
+ index_vector = get_array_data(hash_table->index_vector,
+ SIMPLE_ARRAY_WORD_WIDETAG, &length);
+ if (index_vector == NULL)
+ lose("invalid index_vector %x\n", hash_table->index_vector);
+
+ next_vector = get_array_data(hash_table->next_vector,
+ SIMPLE_ARRAY_WORD_WIDETAG,
+ &next_vector_length);
+ if (next_vector == NULL)
+ lose("invalid next_vector %x\n", hash_table->next_vector);
+
+ hash_vector = get_array_data(hash_table->hash_vector,
+ SIMPLE_ARRAY_WORD_WIDETAG,
+ &hash_vector_length);
+ if (hash_vector != NULL)
+ gc_assert(hash_vector_length == next_vector_length);
+
+ /* These lengths could be different as the index_vector can be a
+ * different length from the others, a larger index_vector could
+ * help reduce collisions. */
+ gc_assert(next_vector_length*2 == kv_length);
+
+ empty_symbol = kv_vector[1];
+ /* fprintf(stderr,"* empty_symbol = %x\n", empty_symbol);*/
+ if (widetag_of(*(lispobj *)native_pointer(empty_symbol)) !=
+ SYMBOL_HEADER_WIDETAG) {
+ lose("not a symbol where empty-hash-table-slot symbol expected: %x\n",
+ *(lispobj *)native_pointer(empty_symbol));
+ }
+
+ /* Work through the KV vector. */
+ for (i = 1; i < next_vector_length; i++) {
+ lispobj old_key = kv_vector[2*i];
+ lispobj value = kv_vector[2*i+1];
+ if ((weakness == NIL) ||
+ weak_hash_entry_alivep(weakness, old_key, value)) {
+
+ /* Scavenge the key and value. */
+ scavenge(&kv_vector[2*i],2);
+
+ /* Rehashing of EQ based keys. */
+ if ((!hash_vector) ||
+ (hash_vector[i] == MAGIC_HASH_VECTOR_VALUE)) {
+#ifndef LISP_FEATURE_GENCGC
+ /* For GENCGC scav_hash_table_entries only rehashes
+ * the entries whose keys were moved. Cheneygc always
+ * moves the objects so here we let the lisp side know
+ * that rehashing is needed for the whole table. */
+ *(kv_vector - 2) = (subtype_VectorMustRehash<<N_WIDETAG_BITS) |
+ SIMPLE_VECTOR_WIDETAG;
+#else
+ unsigned long old_index = EQ_HASH(old_key)%length;
+ lispobj new_key = kv_vector[2*i];
+ unsigned long new_index = EQ_HASH(new_key)%length;
+ /* Check whether the key has moved. */
+ if ((old_index != new_index) &&
+ (new_key != empty_symbol)) {
+ gc_assert(kv_vector[2*i+1] != empty_symbol);
+
+ /*FSHOW((stderr,
+ "* EQ key %d moved from %x to %x; index %d to %d\n",
+ i, old_key, new_key, old_index, new_index));*/
+
+ /* Unlink the key from the old_index chain. */
+ if (!index_vector[old_index]) {
+ /* It's not here, must be on the
+ * needing_rehash chain. */
+ } else if (index_vector[old_index] == i) {
+ /*FSHOW((stderr, "/P2a %d\n", next_vector[i]));*/
+ index_vector[old_index] = next_vector[i];
+ /* Link it into the needing rehash chain. */
+ next_vector[i] =
+ fixnum_value(hash_table->needing_rehash);
+ hash_table->needing_rehash = make_fixnum(i);
+ /*SHOW("P2");*/
+ } else {
+ unsigned long prior = index_vector[old_index];
+ unsigned long next = next_vector[prior];
+
+ /*FSHOW((stderr, "/P3a %d %d\n", prior, next));*/
+
+ while (next != 0) {
+ /*FSHOW((stderr, "/P3b %d %d\n", prior, next));*/
+ if (next == i) {
+ /* Unlink it. */
+ next_vector[prior] = next_vector[next];
+ /* Link it into the needing rehash
+ * chain. */
+ next_vector[next] =
+ fixnum_value(hash_table->needing_rehash);
+ hash_table->needing_rehash = make_fixnum(next);
+ /*SHOW("/P3");*/
+ break;
+ }
+ prior = next;
+ next = next_vector[next];
+ }
+ }
+ }
+#endif
+ }
+ }
+ }
+}
+
+long
+scav_vector (lispobj *where, lispobj object)
+{
+ unsigned long kv_length;
+ lispobj *kv_vector;
+ struct hash_table *hash_table;
+
+ /* SB-VM:VECTOR-VALID-HASHING-SUBTYPE is set for EQ-based and weak
+ * hash tables in the Lisp HASH-TABLE code to indicate need for
+ * special GC support. */
+ if (HeaderValue(object) == subtype_VectorNormal)
+ return 1;
+
+ kv_length = fixnum_value(where[1]);
+ kv_vector = where + 2; /* Skip the header and length. */
+ /*FSHOW((stderr,"/kv_length = %d\n", kv_length));*/
+
+ /* Scavenge element 0, which may be a hash-table structure. */
+ scavenge(where+2, 1);
+ if (!is_lisp_pointer(where[2])) {
+ lose("no pointer at %x in hash table\n", where[2]);
+ }
+ hash_table = (struct hash_table *)native_pointer(where[2]);
+ /*FSHOW((stderr,"/hash_table = %x\n", hash_table));*/
+ if (widetag_of(hash_table->header) != INSTANCE_HEADER_WIDETAG) {
+ lose("hash table not instance (%x at %x)\n",
+ hash_table->header,
+ hash_table);
+ }
+
+ /* Scavenge element 1, which should be some internal symbol that
+ * the hash table code reserves for marking empty slots. */
+ scavenge(where+3, 1);
+ if (!is_lisp_pointer(where[3])) {
+ lose("not empty-hash-table-slot symbol pointer: %x\n", where[3]);
+ }
+
+ /* Scavenge hash table, which will fix the positions of the other
+ * needed objects. */
+ scavenge((lispobj *)hash_table,
+ sizeof(struct hash_table) / sizeof(lispobj));
+
+ /* Cross-check the kv_vector. */
+ if (where != (lispobj *)native_pointer(hash_table->table)) {
+ lose("hash_table table!=this table %x\n", hash_table->table);
+ }
+
+ if (hash_table->weakness == NIL) {
+ scav_hash_table_entries(hash_table);
+ } else {
+ /* Delay scavenging of this table by pushing it onto
+ * weak_hash_tables (if it's not there already) for the weak
+ * object phase. */
+ if (hash_table->next_weak_hash_table == NIL) {
+ hash_table->next_weak_hash_table = (lispobj)weak_hash_tables;
+ weak_hash_tables = hash_table;
+ }
+ }
+
+ return (CEILING(kv_length + 2, 2));
+}
+
+void
+scav_weak_hash_tables (void)
+{
+ struct hash_table *table;
+
+ /* Scavenge entries whose triggers are known to survive. */
+ for (table = weak_hash_tables; table != NULL;
+ table = (struct hash_table *)table->next_weak_hash_table) {
+ scav_hash_table_entries(table);
+ }
+}
+
+/* Walk through the chain whose first element is *FIRST and remove
+ * dead weak entries. */
+static inline void
+scan_weak_hash_table_chain (struct hash_table *hash_table, lispobj *prev,
+ lispobj *kv_vector, lispobj *index_vector,
+ lispobj *next_vector, lispobj *hash_vector,
+ lispobj empty_symbol, lispobj weakness)
+{
+ unsigned index = *prev;
+ while (index) {
+ unsigned next = next_vector[index];
+ lispobj key = kv_vector[2 * index];
+ lispobj value = kv_vector[2 * index + 1];
+ gc_assert(key != empty_symbol);
+ gc_assert(value != empty_symbol);
+ if (!weak_hash_entry_alivep(weakness, key, value)) {
+ unsigned count = fixnum_value(hash_table->number_entries);
+ gc_assert(count > 0);
+ *prev = next;
+ hash_table->number_entries = make_fixnum(count - 1);
+ next_vector[index] = fixnum_value(hash_table->next_free_kv);
+ hash_table->next_free_kv = make_fixnum(index);
+ kv_vector[2 * index] = empty_symbol;
+ kv_vector[2 * index + 1] = empty_symbol;
+ if (hash_vector)
+ hash_vector[index] = MAGIC_HASH_VECTOR_VALUE;
+ } else {
+ prev = &next_vector[index];
+ }
+ index = next;
+ }
+}
+
+static void
+scan_weak_hash_table (struct hash_table *hash_table)
+{
+ lispobj *kv_vector;
+ lispobj *index_vector;
+ unsigned long length = 0; /* prevent warning */
+ lispobj *next_vector;
+ unsigned long next_vector_length = 0; /* prevent warning */
+ lispobj *hash_vector;
+ lispobj empty_symbol;
+ lispobj weakness = hash_table->weakness;
+ long i;
+
+ kv_vector = get_array_data(hash_table->table,
+ SIMPLE_VECTOR_WIDETAG, NULL);
+ index_vector = get_array_data(hash_table->index_vector,
+ SIMPLE_ARRAY_WORD_WIDETAG, &length);
+ next_vector = get_array_data(hash_table->next_vector,
+ SIMPLE_ARRAY_WORD_WIDETAG,
+ &next_vector_length);
+ hash_vector = get_array_data(hash_table->hash_vector,
+ SIMPLE_ARRAY_WORD_WIDETAG, NULL);
+ empty_symbol = kv_vector[1];
+
+ for (i = 0; i < length; i++) {
+ scan_weak_hash_table_chain(hash_table, &index_vector[i],
+ kv_vector, index_vector, next_vector,
+ hash_vector, empty_symbol, weakness);
+ }
+ {
+ lispobj first = fixnum_value(hash_table->needing_rehash);
+ scan_weak_hash_table_chain(hash_table, &first,
+ kv_vector, index_vector, next_vector,
+ hash_vector, empty_symbol, weakness);
+ hash_table->needing_rehash = make_fixnum(first);
+ }
+}
+
+/* Remove dead entries from weak hash tables. */
+void
+scan_weak_hash_tables (void)
+{
+ struct hash_table *table, *next;
+
+ for (table = weak_hash_tables; table != NULL; table = next) {
+ next = (struct hash_table *)table->next_weak_hash_table;
+ table->next_weak_hash_table = NIL;
+ scan_weak_hash_table(table);
+ }
+
+ weak_hash_tables = NULL;
+}
\f
/*
scavtab[SIMPLE_FUN_HEADER_WIDETAG] = scav_fun_header;
scavtab[RETURN_PC_HEADER_WIDETAG] = scav_return_pc_header;
#endif
+ scavtab[FUNCALLABLE_INSTANCE_HEADER_WIDETAG] = scav_boxed;
#if defined(LISP_FEATURE_X86) || defined(LISP_FEATURE_X86_64)
scavtab[CLOSURE_HEADER_WIDETAG] = scav_closure_header;
- scavtab[FUNCALLABLE_INSTANCE_HEADER_WIDETAG] = scav_closure_header;
#else
scavtab[CLOSURE_HEADER_WIDETAG] = scav_boxed;
- scavtab[FUNCALLABLE_INSTANCE_HEADER_WIDETAG] = scav_boxed;
#endif
scavtab[VALUE_CELL_HEADER_WIDETAG] = scav_boxed;
scavtab[SYMBOL_HEADER_WIDETAG] = scav_boxed;
#else
scavtab[FDEFN_WIDETAG] = scav_fdefn;
#endif
+ scavtab[SIMPLE_VECTOR_WIDETAG] = scav_vector;
/* transport other table, initialized same way as scavtab */
for (i = 0; i < ((sizeof transother)/(sizeof transother[0])); i++)
}
return (NULL);
}
+
+boolean
+maybe_gc(os_context_t *context)
+{
+#ifndef LISP_FEATURE_WIN32
+ struct thread *thread = arch_os_get_current_thread();
+#endif
+
+ fake_foreign_function_call(context);
+ /* SUB-GC may return without GCing if *GC-INHIBIT* is set, in
+ * which case we will be running with no gc trigger barrier
+ * thing for a while. But it shouldn't be long until the end
+ * of WITHOUT-GCING.
+ *
+ * FIXME: It would be good to protect the end of dynamic space for
+ * CheneyGC and signal a storage condition from there.
+ */
+
+ /* Restore the signal mask from the interrupted context before
+ * calling into Lisp if interrupts are enabled. Why not always?
+ *
+ * Suppose there is a WITHOUT-INTERRUPTS block far, far out. If an
+ * interrupt hits while in SUB-GC, it is deferred and the
+ * os_context_sigmask of that interrupt is set to block further
+ * deferrable interrupts (until the first one is
+ * handled). Unfortunately, that context refers to this place and
+ * when we return from here the signals will not be blocked.
+ *
+ * A kludgy alternative is to propagate the sigmask change to the
+ * outer context.
+ */
+#ifndef LISP_FEATURE_WIN32
+ if(SymbolValue(INTERRUPTS_ENABLED,thread)!=NIL) {
+ sigset_t *context_sigmask = os_context_sigmask_addr(context);
+ /* What if the context we'd like to restore has GC signals
+ * blocked? Just skip the GC: we can't set GC_PENDING, because
+ * that would block the next attempt, and we don't know when
+ * we'd next check for it -- and it's hard to be sure that
+ * unblocking would be safe. */
+ if (sigismember(context_sigmask,SIG_STOP_FOR_GC)) {
+ undo_fake_foreign_function_call(context);
+ return 1;
+ }
+ thread_sigmask(SIG_SETMASK, context_sigmask, 0);
+ }
+ else
+ unblock_gc_signals();
+#endif
+ funcall0(SymbolFunction(SUB_GC));
+ undo_fake_foreign_function_call(context);
+ return 1;
+}
projects / sbcl.git / blobdiff