Re: [libvirt] [PATCH 1/1] Implement variable length structure allocator

On 04/05/2010 11:21 AM, David Allan wrote: > +int virAllocVar(void *ptrptr, size_t struct_size, size_t element_size, size_t count) Shouldn't that be void **ptrptr - that is, the caller passes in the address of a void* that we then modify? > +{ > + size_t alloc_size = 0; > + > +#if TEST_OOM > + if (virAllocTestFail()) > + return -1; > +#endif > + > + if (VIR_ALLOC_VAR_OVERSIZED(struct_size, count, element_size)) { > + errno = ENOMEM; > + return -1; > + } > + > + alloc_size = struct_size + (element_size * count); > + *(void **)ptrptr = calloc(1, alloc_size); > + if (*(void **)ptrptr == NULL) Especially since typing it correctly to begin with would avoid these ugly type-punning casts? > +++ b/src/util/memory.h > @@ -48,6 +48,10 @@ > int virAlloc(void *ptrptr, size_t size) ATTRIBUTE_RETURN_CHECK; > int virAllocN(void *ptrptr, size_t size, size_t count) ATTRIBUTE_RETURN_CHECK; > int virReallocN(void *ptrptr, size_t size, size_t count) ATTRIBUTE_RETURN_CHECK; > +int virAllocVar(void *ptrptr, > + size_t struct_size, > + size_t element_size, > + size_t count) ATTRIBUTE_RETURN_CHECK; Then again, fixing the type for your new method would imply fixing the typing of virAlloc and friends as well.

> +#define VIR_ALLOC_VAR(ptr, type, count) virAllocVar(&(ptr), sizeof(*ptr), sizeof(type), (count)) Should that second argument be sizeof(*(ptr)) for safety? On the other hand, the parenthesis around count are redundant, if you want to strip them.