/* Sparse Arrays for Objective C dispatch tables
- Copyright (C) 1993, 1995 Free Software Foundation, Inc.
+ Copyright (C) 1993, 1995, 1996 Free Software Foundation, Inc.
This file is part of GNU CC.
the executable file might be covered by the GNU General Public License. */
#include "objc/sarray.h"
+#include "objc/runtime.h"
#include <stdio.h>
#include "assert.h"
-int nbuckets = 0;
-int nindices = 0;
-int narrays = 0;
-int idxsize = 0;
+int nbuckets = 0; /* !T:MUTEX */
+int nindices = 0; /* !T:MUTEX */
+int narrays = 0; /* !T:MUTEX */
+int idxsize = 0; /* !T:MUTEX */
+
+static void * first_free_data = NULL; /* !T:MUTEX */
#ifdef OBJC_SPARSE2
const char* __objc_sparse2_id = "2 level sparse indices";
void free (const void*);
#endif
+/* This function removes any structures left over from free operations
+ that were not safe in a multi-threaded environment. */
+void
+sarray_remove_garbage(void)
+{
+ void **vp;
+ void *np;
+
+ objc_mutex_lock(__objc_runtime_mutex);
+
+ vp = first_free_data;
+ first_free_data = NULL;
+
+ while (vp) {
+ np = *vp;
+ free(vp);
+ vp = np;
+ }
+
+ objc_mutex_unlock(__objc_runtime_mutex);
+}
+
+/* Free a block of dynamically allocated memory. If we are in multi-threaded
+ mode, it is ok to free it. If not, we add it to the garbage heap to be
+ freed later. */
+
+static void
+sarray_free_garbage(void *vp)
+{
+ objc_mutex_lock(__objc_runtime_mutex);
+
+ if (__objc_runtime_threads_alive == 1) {
+ free(vp);
+ if (first_free_data)
+ sarray_remove_garbage();
+ }
+ else {
+ *(void **)vp = first_free_data;
+ first_free_data = vp;
+ }
+
+ objc_mutex_unlock(__objc_runtime_mutex);
+}
+
+/* sarray_at_put : copies data in such a way as to be thread reader safe. */
void
sarray_at_put(struct sarray* array, sidx index, void* element)
{
#ifdef OBJC_SPARSE3
struct sindex** the_index;
+ struct sindex* new_index;
#endif
struct sbucket** the_bucket;
+ struct sbucket* new_bucket;
#ifdef OBJC_SPARSE3
size_t ioffset;
#endif
if ((*the_index) == array->empty_index) {
/* The index was previously empty, allocate a new */
- *the_index = (struct sindex*)__objc_xmalloc(sizeof(struct sindex));
- memcpy(*the_index, array->empty_index, sizeof(struct sindex));
- (*the_index)->version = array->version;
+ new_index = (struct sindex*)__objc_xmalloc(sizeof(struct sindex));
+ memcpy(new_index, array->empty_index, sizeof(struct sindex));
+ new_index->version.version = array->version.version;
+ *the_index = new_index; /* Prepared for install. */
the_bucket = &((*the_index)->buckets[boffset]);
- nindices += 1;
- } else if ((*the_index)->version != array->version) {
+ nindices += 1;
+ } else if ((*the_index)->version.version != array->version.version) {
/* This index must be lazy copied */
struct sindex* old_index = *the_index;
- *the_index = (struct sindex*)__objc_xmalloc(sizeof(struct sindex));
- memcpy( *the_index,old_index, sizeof(struct sindex));
- (*the_index)->version = array->version;
+ new_index = (struct sindex*)__objc_xmalloc(sizeof(struct sindex));
+ memcpy( new_index, old_index, sizeof(struct sindex));
+ new_index->version.version = array->version.version;
+ *the_index = new_index; /* Prepared for install. */
the_bucket = &((*the_index)->buckets[boffset]);
- nindices += 1;
+ nindices += 1;
}
#endif /* OBJC_SPARSE3 */
/* The bucket was previously empty (or something like that), */
/* allocate a new. This is the effect of `lazy' allocation */
- *the_bucket = (struct sbucket*)__objc_xmalloc(sizeof(struct sbucket));
- memcpy((void *) *the_bucket, (const void*)array->empty_bucket, sizeof(struct sbucket));
- (*the_bucket)->version = array->version;
+ new_bucket = (struct sbucket*)__objc_xmalloc(sizeof(struct sbucket));
+ memcpy((void *) new_bucket, (const void*)array->empty_bucket, sizeof(struct sbucket));
+ new_bucket->version.version = array->version.version;
+ *the_bucket = new_bucket; /* Prepared for install. */
+
nbuckets += 1;
- } else if ((*the_bucket)->version != array->version) {
+ } else if ((*the_bucket)->version.version != array->version.version) {
/* Perform lazy copy. */
struct sbucket* old_bucket = *the_bucket;
- *the_bucket = (struct sbucket*)__objc_xmalloc(sizeof(struct sbucket));
- memcpy( *the_bucket,old_bucket, sizeof(struct sbucket));
- (*the_bucket)->version = array->version;
+ new_bucket = (struct sbucket*)__objc_xmalloc(sizeof(struct sbucket));
+ memcpy( new_bucket, old_bucket, sizeof(struct sbucket));
+ new_bucket->version.version = array->version.version;
+ *the_bucket = new_bucket; /* Prepared for install. */
+
nbuckets += 1;
}
struct sarray*
sarray_new (int size, void* default_element)
{
+ struct sarray* arr;
#ifdef OBJC_SPARSE3
size_t num_indices = ((size-1)/(INDEX_CAPACITY))+1;
+ struct sindex ** new_indices;
#else /* OBJC_SPARSE2 */
size_t num_indices = ((size-1)/BUCKET_SIZE)+1;
+ struct sbucket ** new_buckets;
#endif
int counter;
- struct sarray* arr;
assert(size > 0);
/* Allocate core array */
arr = (struct sarray*) __objc_xmalloc(sizeof(struct sarray));
- arr->version = 0;
- narrays += 1;
+ arr->version.version = 0;
/* Initialize members */
#ifdef OBJC_SPARSE3
arr->capacity = num_indices*INDEX_CAPACITY;
- arr->indices = (struct sindex**)
+ new_indices = (struct sindex**)
__objc_xmalloc(sizeof(struct sindex*)*num_indices);
- idxsize += num_indices;
arr->empty_index = (struct sindex*) __objc_xmalloc(sizeof(struct sindex));
- arr->empty_index->version = 0;
+ arr->empty_index->version.version = 0;
+
+ narrays += 1;
+ idxsize += num_indices;
nindices += 1;
#else /* OBJC_SPARSE2 */
arr->capacity = num_indices*BUCKET_SIZE;
- arr->buckets = (struct sbucket**)
+ new_buckets = (struct sbucket**)
__objc_xmalloc(sizeof(struct sbucket*)*num_indices);
+
+ narrays += 1;
idxsize += num_indices;
#endif
arr->empty_bucket = (struct sbucket*) __objc_xmalloc(sizeof(struct sbucket));
- arr->empty_bucket->version = 0;
+ arr->empty_bucket->version.version = 0;
+
nbuckets += 1;
arr->ref_count = 1;
arr->empty_index->buckets[counter] = arr->empty_bucket;
for (counter=0; counter<num_indices; counter++)
- arr->indices[counter] = arr->empty_index;
+ new_indices[counter] = arr->empty_index;
#else /* OBJC_SPARSE2 */
for (counter=0; counter<num_indices; counter++)
- arr->buckets[counter] = arr->empty_bucket;
+ new_buckets[counter] = arr->empty_bucket;
#endif
-
+
+#ifdef OBJC_SPARSE3
+ arr->indices = new_indices;
+#else /* OBJC_SPARSE2 */
+ arr->buckets = new_buckets;
+#endif
+
return arr;
}
\f
-/* Reallocate the sparse array to hold `newsize' entries */
+/* Reallocate the sparse array to hold `newsize' entries
+ Note: We really allocate and then free. We have to do this to ensure that
+ any concurrent readers notice the update. */
void
sarray_realloc(struct sarray* array, int newsize)
size_t new_max_index = ((newsize-1)/INDEX_CAPACITY);
size_t rounded_size = (new_max_index+1)*INDEX_CAPACITY;
+ struct sindex ** new_indices;
+ struct sindex ** old_indices;
+
#else /* OBJC_SPARSE2 */
size_t old_max_index = (array->capacity-1)/BUCKET_SIZE;
size_t new_max_index = ((newsize-1)/BUCKET_SIZE);
size_t rounded_size = (new_max_index+1)*BUCKET_SIZE;
+ struct sbucket ** new_buckets;
+ struct sbucket ** old_buckets;
+
#endif
int counter;
assert(newsize > 0);
/* The size is the same, just ignore the request */
- if(rounded_size == array->capacity)
+ if(rounded_size <= array->capacity)
return;
assert(array->ref_count == 1); /* stop if lazy copied... */
- if(rounded_size < array->capacity)
+ /* We are asked to extend the array -- allocate new bucket table, */
+ /* and insert empty_bucket in newly allocated places. */
+ if(rounded_size > array->capacity)
{
+
+#ifdef OBJC_SPARSE3
+ new_max_index += 4;
+ rounded_size = (new_max_index+1)*INDEX_CAPACITY;
+
+#else /* OBJC_SPARSE2 */
+ new_max_index += 4;
+ rounded_size = (new_max_index+1)*BUCKET_SIZE;
+#endif
+
/* update capacity */
array->capacity = rounded_size;
- /* free buckets above new_max_index */
- for(counter = old_max_index; counter > new_max_index; counter-- ) {
#ifdef OBJC_SPARSE3
- struct sindex* idx = array->indices[counter];
- if((idx != array->empty_index) && (idx->version == array->version)) {
- int c2;
- for(c2=0; c2<INDEX_SIZE; c2++) {
- struct sbucket* bkt = idx->buckets[c2];
- if((bkt != array->empty_bucket) && (bkt->version == array->version))
- {
- free(bkt);
- nbuckets -= 1;
- }
- }
- free(idx);
- nindices -= 1;
- }
+ /* alloc to force re-read by any concurrent readers. */
+ old_indices = array->indices;
+ new_indices = (struct sindex**)
+ __objc_xmalloc((new_max_index+1)*sizeof(struct sindex*));
#else /* OBJC_SPARSE2 */
- struct sbucket* bkt = array->buckets[counter];
- if ((bkt != array->empty_bucket) && (bkt->version == array->version))
- {
- free(bkt);
- nbuckets -= 1;
- }
+ old_buckets = array->buckets;
+ new_buckets = (struct sbucket**)
+ __objc_xmalloc((new_max_index+1)*sizeof(struct sbucket*));
#endif
- }
-
+
+ /* copy buckets below old_max_index (they are still valid) */
+ for(counter = 0; counter <= old_max_index; counter++ ) {
#ifdef OBJC_SPARSE3
- /* realloc to free the space above new_max_index */
- array->indices = (struct sindex**)
- __objc_xrealloc(array->indices,
- (new_max_index+1)*sizeof(struct sindex*));
+ new_indices[counter] = old_indices[counter];
#else /* OBJC_SPARSE2 */
- array->buckets = (struct sbucket**)
- __objc_xrealloc(array->buckets,
- (new_max_index+1)*sizeof(struct sbucket*));
-#endif
- idxsize -= (old_max_index-new_max_index);
-
- return;
- }
-
- /* We are asked to extend the array -- reallocate the bucket table, */
- /* and insert empty_bucket in newly allocated places. */
- if(rounded_size > array->capacity)
- {
- /* update capacity */
- array->capacity = rounded_size;
+ new_buckets[counter] = old_buckets[counter];
+#endif
+ }
#ifdef OBJC_SPARSE3
- /* realloc to make room in table above old_max_index */
- array->indices = (struct sindex**)
- __objc_xrealloc(array->indices,
- (new_max_index+1)*sizeof(struct sindex*));
-
/* reset entries above old_max_index to empty_bucket */
for(counter = old_max_index+1; counter <= new_max_index; counter++)
- array->indices[counter] = array->empty_index;
-
+ new_indices[counter] = array->empty_index;
#else /* OBJC_SPARSE2 */
-
- /* realloc to make room in table above old_max_index */
- array->buckets = (struct sbucket**)
- __objc_xrealloc(array->buckets,
- (new_max_index+1)*sizeof(struct sbucket*));
-
/* reset entries above old_max_index to empty_bucket */
for(counter = old_max_index+1; counter <= new_max_index; counter++)
- array->buckets[counter] = array->empty_bucket;
+ new_buckets[counter] = array->empty_bucket;
+#endif
+
+#ifdef OBJC_SPARSE3
+ /* install the new indices */
+ array->indices = new_indices;
+#else /* OBJC_SPARSE2 */
+ array->buckets = new_buckets;
+#endif
+#ifdef OBJC_SPARSE3
+ /* free the old indices */
+ sarray_free_garbage(old_indices);
+#else /* OBJC_SPARSE2 */
+ sarray_free_garbage(old_buckets);
#endif
+
idxsize += (new_max_index-old_max_index);
return;
}
void
sarray_free(struct sarray* array) {
+
#ifdef OBJC_SPARSE3
size_t old_max_index = (array->capacity-1)/INDEX_CAPACITY;
+ struct sindex ** old_indices;
#else
size_t old_max_index = (array->capacity-1)/BUCKET_SIZE;
+ struct sbucket ** old_buckets;
#endif
int counter = 0;
if(--(array->ref_count) != 0) /* There exists copies of me */
return;
+#ifdef OBJC_SPARSE3
+ old_indices = array->indices;
+#else
+ old_buckets = array->buckets;
+#endif
+
if((array->is_copy_of) && ((array->is_copy_of->ref_count - 1) == 0))
sarray_free(array->is_copy_of);
/* Free all entries that do not point to empty_bucket */
for(counter = 0; counter <= old_max_index; counter++ ) {
#ifdef OBJC_SPARSE3
- struct sindex* idx = array->indices[counter];
- if((idx != array->empty_index) && (idx->version == array->version)) {
+ struct sindex* idx = old_indices[counter];
+ if((idx != array->empty_index) &&
+ (idx->version.version == array->version.version)) {
int c2;
for(c2=0; c2<INDEX_SIZE; c2++) {
struct sbucket* bkt = idx->buckets[c2];
- if((bkt != array->empty_bucket) && (bkt->version == array->version))
+ if((bkt != array->empty_bucket) &&
+ (bkt->version.version == array->version.version))
{
- free(bkt);
+ sarray_free_garbage(bkt);
nbuckets -= 1;
}
}
- free(idx);
+ sarray_free_garbage(idx);
nindices -= 1;
}
#else /* OBJC_SPARSE2 */
struct sbucket* bkt = array->buckets[counter];
- if ((bkt != array->empty_bucket) && (bkt->version == array->version))
+ if ((bkt != array->empty_bucket) &&
+ (bkt->version.version == array->version.version))
{
- free(bkt);
+ sarray_free_garbage(bkt);
nbuckets -= 1;
}
#endif
#ifdef OBJC_SPARSE3
/* free empty_index */
- if(array->empty_index->version == array->version) {
- free(array->empty_index);
+ if(array->empty_index->version.version == array->version.version) {
+ sarray_free_garbage(array->empty_index);
nindices -= 1;
}
#endif
/* free empty_bucket */
- if(array->empty_bucket->version == array->version) {
- free(array->empty_bucket);
+ if(array->empty_bucket->version.version == array->version.version) {
+ sarray_free_garbage(array->empty_bucket);
nbuckets -= 1;
}
+ idxsize -= (old_max_index+1);
+ narrays -= 1;
#ifdef OBJC_SPARSE3
/* free bucket table */
- free(array->indices);
- idxsize -= (old_max_index+1);
+ sarray_free_garbage(array->indices);
#else
/* free bucket table */
- free(array->buckets);
- idxsize -= (old_max_index+1);
+ sarray_free_garbage(array->buckets);
#endif
-
+
/* free array */
- free(array);
- narrays -= 1;
+ sarray_free_garbage(array);
}
/* This is a lazy copy. Only the core of the structure is actually */
struct sarray*
sarray_lazy_copy(struct sarray* oarr)
{
+ struct sarray* arr;
+
#ifdef OBJC_SPARSE3
size_t num_indices = ((oarr->capacity-1)/INDEX_CAPACITY)+1;
+ struct sindex ** new_indices;
#else /* OBJC_SPARSE2 */
size_t num_indices = ((oarr->capacity-1)/BUCKET_SIZE)+1;
+ struct sbucket ** new_buckets;
#endif
- struct sarray* arr;
/* Allocate core array */
- arr = (struct sarray*) __objc_xmalloc(sizeof(struct sarray));
- memcpy( arr,oarr, sizeof(struct sarray));
- arr->version = oarr->version + 1;
- arr->is_copy_of = oarr;
- oarr->ref_count += 1;
+ arr = (struct sarray*) __objc_xmalloc(sizeof(struct sarray)); /* !!! */
+ arr->version.version = oarr->version.version + 1;
+#ifdef OBJC_SPARSE3
+ arr->empty_index = oarr->empty_index;
+#endif
+ arr->empty_bucket = oarr->empty_bucket;
arr->ref_count = 1;
+ oarr->ref_count += 1;
+ arr->is_copy_of = oarr;
+ arr->capacity = oarr->capacity;
#ifdef OBJC_SPARSE3
/* Copy bucket table */
- arr->indices = (struct sindex**)
+ new_indices = (struct sindex**)
__objc_xmalloc(sizeof(struct sindex*)*num_indices);
- memcpy( arr->indices,oarr->indices,
+ memcpy( new_indices,oarr->indices,
sizeof(struct sindex*)*num_indices);
+ arr->indices = new_indices;
#else
/* Copy bucket table */
- arr->buckets = (struct sbucket**)
+ new_buckets = (struct sbucket**)
__objc_xmalloc(sizeof(struct sbucket*)*num_indices);
- memcpy( arr->buckets,oarr->buckets,
+ memcpy( new_buckets,oarr->buckets,
sizeof(struct sbucket*)*num_indices);
+ arr->buckets = new_buckets;
#endif
idxsize += num_indices;
narrays += 1;
-
+
return arr;
}
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