From: Richard Kenner Date: Tue, 5 Mar 1996 14:10:50 +0000 (-0500) Subject: (sarray_{remove,free}_garbage): New functions. X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=1ebb5fcc6471f5eb9003e615e1bb686b71a0b036;p=gcc.git (sarray_{remove,free}_garbage): New functions. (sarray_at_put, sarray_new, sarray_lazy_copy): Modify/copy sarray structure/data in a thread-safe manner (sarray_{realloc,free}): Reallocate/free sarray structure/data in a thread-safe manner. From-SVN: r11445 --- diff --git a/gcc/objc/sarray.c b/gcc/objc/sarray.c index 9ed219681c8..fc7323a2442 100644 --- a/gcc/objc/sarray.c +++ b/gcc/objc/sarray.c @@ -1,5 +1,5 @@ /* 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. @@ -25,13 +25,16 @@ Boston, MA 02111-1307, USA. */ the executable file might be covered by the GNU General Public License. */ #include "objc/sarray.h" +#include "objc/runtime.h" #include #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"; @@ -46,13 +49,60 @@ const void *memcpy (void*, const void*, size_t); 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 @@ -96,22 +146,24 @@ sarray_at_put(struct sarray* array, sidx index, void* element) 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 */ @@ -122,18 +174,22 @@ sarray_at_put(struct sarray* array, sidx index, void* element) /* 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; } @@ -151,42 +207,48 @@ sarray_at_put_safe(struct sarray* array, sidx index, void* element) 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; @@ -200,20 +262,28 @@ sarray_new (int size, void* default_element) arr->empty_index->buckets[counter] = arr->empty_bucket; for (counter=0; counterindices[counter] = arr->empty_index; + new_indices[counter] = arr->empty_index; #else /* OBJC_SPARSE2 */ for (counter=0; counterbuckets[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; } -/* 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) @@ -223,11 +293,17 @@ 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; @@ -235,87 +311,72 @@ sarray_realloc(struct sarray* array, int newsize) 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; c2buckets[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; } @@ -326,10 +387,13 @@ sarray_realloc(struct sarray* array, int newsize) 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; @@ -338,31 +402,40 @@ sarray_free(struct sarray* array) { 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; c2buckets[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 @@ -370,33 +443,32 @@ sarray_free(struct sarray* array) { #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 */ @@ -405,37 +477,46 @@ sarray_free(struct sarray* array) { 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; }