diff options
Diffstat (limited to 'src/common')
| -rw-r--r-- | src/common/libkogata/slab_alloc.c | 92 |
1 files changed, 48 insertions, 44 deletions
diff --git a/src/common/libkogata/slab_alloc.c b/src/common/libkogata/slab_alloc.c index 714c49f..6d0b9d6 100644 --- a/src/common/libkogata/slab_alloc.c +++ b/src/common/libkogata/slab_alloc.c @@ -45,12 +45,12 @@ struct mem_allocator { // Helper functions for the manipulation of lists // // ============================================== // -static void add_free_descriptor(mem_allocator_t *a, descriptor_t *c) { +void add_free_descriptor(mem_allocator_t *a, descriptor_t *c) { c->next_free = a->first_free_descriptor; a->first_free_descriptor = c; } -static descriptor_t *take_descriptor(mem_allocator_t *a) { +descriptor_t *take_descriptor(mem_allocator_t *a) { if (a->first_free_descriptor == 0) { void* p = a->alloc_fun(PAGE_SIZE); if (p == 0) return 0; @@ -119,7 +119,7 @@ mem_allocator_t* create_slab_allocator(const slab_type_t *types, page_alloc_fun_ return a; } -static void stack_and_destroy_regions(page_free_fun_t ff, region_t *r) { +void stack_and_destroy_regions(page_free_fun_t ff, region_t *r) { if (r == 0) return; void* addr = r->region_addr; ASSERT(r != r->next_region); @@ -151,53 +151,57 @@ void destroy_slab_allocator(mem_allocator_t *a) { void* slab_alloc(mem_allocator_t* a, size_t sz) { for (int i = 0; a->types[i].obj_size != 0; i++) { const size_t obj_size = a->types[i].obj_size; - if (sz <= obj_size) { - // find a cache with free space - cache_t *fc = a->slabs[i].first_cache; - while (fc != 0 && fc->n_free_objs == 0) { - ASSERT(fc->first_free_obj == 0); // make sure n_free == 0 iff no object in the free stack - fc = fc->next_cache; - } - // if none found, try to allocate a new one - if (fc == 0) { - descriptor_t *fcd = take_descriptor(a); - if (fcd == 0) return 0; - - fc = &fcd->c; - ASSERT((descriptor_t*)fc == fcd); - - const size_t cache_size = a->types[i].pages_per_cache * PAGE_SIZE; - fc->region_addr = a->alloc_fun(cache_size); - if (fc->region_addr == 0) { - add_free_descriptor(a, fcd); - return 0; - } - fc->n_free_objs = 0; - fc->first_free_obj = 0; - for (void* p = fc->region_addr; p + obj_size <= fc->region_addr + cache_size; p += obj_size) { - object_t *x = (object_t*)p; - x->next = fc->first_free_obj; - fc->first_free_obj = x; - fc->n_free_objs++; - } - ASSERT(fc->n_free_objs == cache_size / obj_size); + if (sz > obj_size) continue; - fc->next_cache = a->slabs[i].first_cache; - a->slabs[i].first_cache = fc; + // find a cache with free space + cache_t *fc = a->slabs[i].first_cache; + while (fc != 0 && fc->n_free_objs == 0) { + // make sure n_free == 0 iff no object in the free stack + ASSERT((fc->first_free_obj == 0) == (fc->n_free_objs == 0)); + fc = fc->next_cache; + } + // if none found, try to allocate a new one + if (fc == 0) { + descriptor_t *fcd = take_descriptor(a); + if (fcd == 0) return 0; + + fc = &fcd->c; + ASSERT((descriptor_t*)fc == fcd); + + const size_t cache_size = a->types[i].pages_per_cache * PAGE_SIZE; + fc->region_addr = a->alloc_fun(cache_size); + if (fc->region_addr == 0) { + add_free_descriptor(a, fcd); + return 0; } - // allocate on fc - ASSERT(fc != 0 && fc->n_free_objs > 0); - - object_t *x = fc->first_free_obj; - fc->first_free_obj = x->next; - fc->n_free_objs--; - ASSERT((fc->n_free_objs == 0) == (fc->first_free_obj == 0)); + fc->n_free_objs = 0; + fc->first_free_obj = 0; + for (void* p = fc->region_addr; p + obj_size <= fc->region_addr + cache_size; p += obj_size) { + object_t *x = (object_t*)p; + x->next = fc->first_free_obj; + fc->first_free_obj = x; + fc->n_free_objs++; + } + ASSERT(fc->n_free_objs == cache_size / obj_size); - // TODO : if fc is full, put it at the end - return x; + fc->next_cache = a->slabs[i].first_cache; + a->slabs[i].first_cache = fc; } + // allocate on fc + ASSERT(fc != 0); + ASSERT(fc->n_free_objs > 0); + ASSERT(fc->first_free_obj != 0); + + object_t *x = fc->first_free_obj; + fc->first_free_obj = x->next; + fc->n_free_objs--; + + ASSERT((fc->n_free_objs == 0) == (fc->first_free_obj == 0)); + + // TODO : if fc is full, put it at the end + return x; } // otherwise directly allocate using a->alloc_fun |