diff options
Diffstat (limited to 'upb/env.c')
| -rw-r--r-- | upb/env.c | 67 |
1 files changed, 36 insertions, 31 deletions
@@ -21,18 +21,17 @@ static void *seeded_alloc(void *ud, void *ptr, size_t oldsize, size_t size); /* Default allocator **********************************************************/ -// Just use realloc, keeping all allocated blocks in a linked list to destroy at -// the end. +/* Just use realloc, keeping all allocated blocks in a linked list to destroy at + * the end. */ typedef struct mem_block { - // List is doubly-linked, because in cases where realloc() moves an existing - // block, we need to be able to remove the old pointer from the list - // efficiently. + /* List is doubly-linked, because in cases where realloc() moves an existing + * block, we need to be able to remove the old pointer from the list + * efficiently. */ struct mem_block *prev, *next; #ifndef NDEBUG - size_t size; // Doesn't include mem_block structure. + size_t size; /* Doesn't include mem_block structure. */ #endif - char data[]; } mem_block; typedef struct { @@ -40,10 +39,12 @@ typedef struct { } default_alloc_ud; static void *default_alloc(void *_ud, void *ptr, size_t oldsize, size_t size) { - UPB_UNUSED(oldsize); default_alloc_ud *ud = _ud; + mem_block *from, *block; + void *ret; + UPB_UNUSED(oldsize); - mem_block *from = ptr ? (void*)((char*)ptr - sizeof(mem_block)) : NULL; + from = ptr ? (void*)((char*)ptr - sizeof(mem_block)) : NULL; #ifndef NDEBUG if (from) { @@ -51,8 +52,11 @@ static void *default_alloc(void *_ud, void *ptr, size_t oldsize, size_t size) { } #endif - mem_block *block = realloc(from, size + sizeof(mem_block)); + /* TODO(haberman): we probably need to provide even better alignment here, + * like 16-byte alignment of the returned data pointer. */ + block = realloc(from, size + sizeof(mem_block)); if (!block) return NULL; + ret = (char*)block + sizeof(*block); #ifndef NDEBUG block->size = size; @@ -60,20 +64,20 @@ static void *default_alloc(void *_ud, void *ptr, size_t oldsize, size_t size) { if (from) { if (block != from) { - // The block was moved, so pointers in next and prev blocks must be - // updated to its new location. + /* The block was moved, so pointers in next and prev blocks must be + * updated to its new location. */ if (block->next) block->next->prev = block; if (block->prev) block->prev->next = block; } } else { - // Insert at head of linked list. + /* Insert at head of linked list. */ block->prev = NULL; block->next = ud->head; if (block->next) block->next->prev = block; ud->head = block; } - return &block->data; + return ret; } static void default_alloc_cleanup(void *_ud) { @@ -106,14 +110,14 @@ static bool write_err_to(void *ud, const upb_status *status) { /* upb_env ********************************************************************/ void upb_env_init(upb_env *e) { + default_alloc_ud *ud = (default_alloc_ud*)&e->default_alloc_ud; e->ok_ = true; e->bytes_allocated = 0; e->cleanup_head = NULL; - default_alloc_ud *ud = (default_alloc_ud*)&e->default_alloc_ud; ud->head = NULL; - // Set default functions. + /* Set default functions. */ upb_env_setallocfunc(e, default_alloc, ud); upb_env_seterrorfunc(e, default_err, NULL); } @@ -126,8 +130,8 @@ void upb_env_uninit(upb_env *e) { ent = ent->next; } - // Must do this after running cleanup functions, because this will delete - // the memory we store our cleanup entries in! + /* Must do this after running cleanup functions, because this will delete + the memory we store our cleanup entries in! */ if (e->alloc == default_alloc) { default_alloc_cleanup(e->alloc_ud); } @@ -174,8 +178,8 @@ bool upb_env_addcleanup(upb_env *e, upb_cleanup_func *func, void *ud) { void *upb_env_malloc(upb_env *e, size_t size) { e->bytes_allocated += size; if (e->alloc == seeded_alloc) { - // This is equivalent to the next branch, but allows inlining for a - // measurable perf benefit. + /* This is equivalent to the next branch, but allows inlining for a + * measurable perf benefit. */ return seeded_alloc(e->alloc_ud, NULL, 0, size); } else { return e->alloc(e->alloc_ud, NULL, 0, size); @@ -183,12 +187,13 @@ void *upb_env_malloc(upb_env *e, size_t size) { } void *upb_env_realloc(upb_env *e, void *ptr, size_t oldsize, size_t size) { + char *ret; assert(oldsize <= size); - char *ret = e->alloc(e->alloc_ud, ptr, oldsize, size); + ret = e->alloc(e->alloc_ud, ptr, oldsize, size); #ifndef NDEBUG - // Overwrite non-preserved memory to ensure callers are passing the oldsize - // that they truly require. + /* Overwrite non-preserved memory to ensure callers are passing the oldsize + * that they truly require. */ memset(ret + oldsize, 0xff, size - oldsize); #endif @@ -202,7 +207,7 @@ size_t upb_env_bytesallocated(const upb_env *e) { /* upb_seededalloc ************************************************************/ -// Be conservative and choose 16 in case anyone is using SSE. +/* Be conservative and choose 16 in case anyone is using SSE. */ static const size_t maxalign = 16; static size_t align_up(size_t size) { @@ -211,24 +216,24 @@ static size_t align_up(size_t size) { UPB_FORCEINLINE static void *seeded_alloc(void *ud, void *ptr, size_t oldsize, size_t size) { + upb_seededalloc *a = ud; UPB_UNUSED(ptr); - upb_seededalloc *a = ud; size = align_up(size); assert(a->mem_limit >= a->mem_ptr); if (oldsize == 0 && size <= (size_t)(a->mem_limit - a->mem_ptr)) { - // Fast path: we can satisfy from the initial allocation. + /* Fast path: we can satisfy from the initial allocation. */ void *ret = a->mem_ptr; a->mem_ptr += size; return ret; } else { - // Slow path: fallback to other allocator. - a->need_cleanup = true; - // Is `ptr` part of the user-provided initial block? Don't pass it to the - // default allocator if so; otherwise, it may try to realloc() the block. char *chptr = ptr; + /* Slow path: fallback to other allocator. */ + a->need_cleanup = true; + /* Is `ptr` part of the user-provided initial block? Don't pass it to the + * default allocator if so; otherwise, it may try to realloc() the block. */ if (chptr >= a->mem_base && chptr < a->mem_limit) { return a->alloc(a->alloc_ud, NULL, 0, size); } else { @@ -238,13 +243,13 @@ UPB_FORCEINLINE static void *seeded_alloc(void *ud, void *ptr, size_t oldsize, } void upb_seededalloc_init(upb_seededalloc *a, void *mem, size_t len) { + default_alloc_ud *ud = (default_alloc_ud*)&a->default_alloc_ud; a->mem_base = mem; a->mem_ptr = mem; a->mem_limit = (char*)mem + len; a->need_cleanup = false; a->returned_allocfunc = false; - default_alloc_ud *ud = (default_alloc_ud*)&a->default_alloc_ud; ud->head = NULL; upb_seededalloc_setfallbackalloc(a, default_alloc, ud); |