diff options
| -rw-r--r-- | src/slibc-alloc.c | 114 |
1 files changed, 72 insertions, 42 deletions
diff --git a/src/slibc-alloc.c b/src/slibc-alloc.c index a7ae30a..5ae9cbd 100644 --- a/src/slibc-alloc.c +++ b/src/slibc-alloc.c @@ -403,6 +403,51 @@ void* naive_extalloc(void* ptr, size_t size) } +/** + * Reallocation procedure for `falloc`. + * + * @param ptr The old pointer. + * @param ptrshift Pointer that is used to keep track of the pointer's + * shift for alignment. + * @param alignment The aligment of both the new and old pointer. + * @param old_size The old allocation size. + * @param new_size The new allocation size. + * @param mode `FALLOC_CLEAR`, `FALLOC_INIT`, or `FALLOC_MEMCPY`, or + * both or neither. + * @return The new pointer, or the old pointer if it was reallocated + * without creating a new allocation. `NULL` is returned + * on error (errno is set to describe the error.) + * + * @throws ENOMEM The process cannot allocate more memory. + */ +__GCC_ONLY(__attribute__((nonnull))) +static inline void* falloc_realloc(void* ptr, size_t* ptrshift, size_t alignment, + size_t old_size, size_t new_size, enum falloc_mode mode) +{ + void* new_ptr = NULL; + size_t shift = *ptrshift; + + if ((mode & FALLOC_CLEAR) && (old_size > new_size)) + explicit_bzero(ptr + new_size, old_size - new_size); + + new_ptr = falloc_extalloc(ptr - shift, old_size + shift, new_size + shift); + if ((new_ptr == NULL) && (errno == 0)) + { + new_ptr = falloc_malloc(new_size + alignment - 1); + if (new_ptr != NULL) + { + if ((size_t)new_ptr % alignment) + shift = alignment - ((size_t)new_ptr % alignment); + *ptrshift = shift; + new_ptr = (void*)((char*)new_ptr + shift); + if (mode & FALLOC_MEMCPY) + memcpy(new_ptr, ptr, old_size); + } + } + + return new_ptr; +} + /** * Allocates, deallocates, or reallocates memory without @@ -460,55 +505,27 @@ void* naive_extalloc(void* ptr, size_t size) void* falloc(void* ptr, size_t* ptrshift, size_t alignment, size_t old_size, size_t new_size, enum falloc_mode mode) { + /* TODO implement falloc_malloc, falloc_free, and falloc_extalloc */ + + size_t shift = 0, _ptrshift = 0; void* new_ptr = NULL; - size_t shift = 0; if (mode & (enum falloc_mode)~(FALLOC_CLEAR | FALLOC_INIT | FALLOC_MEMCPY)) - return errno = EINVAL, NULL; - - alignment = alignment ? alignment : 1; + goto invalid; if (new_size && old_size && ptr) { - shift = ptrshift == NULL ? *ptrshift : 0; - if ((alignment > 1) && (ptrshift == NULL)) - return errno = EINVAL, NULL; - if ((mode & FALLOC_CLEAR) && (old_size > new_size)) - explicit_bzero(ptr + new_size, old_size - new_size); - new_ptr = falloc_extalloc(ptr - shift, old_size + shift, new_size + shift); - if ((new_ptr == NULL) && (errno == 0)) - { - new_ptr = falloc_malloc(new_size + alignment - 1); - if (new_ptr != NULL) - { - if ((size_t)new_ptr % alignment) - shift = alignment - ((size_t)new_ptr % alignment); - if (ptrshift != NULL) - *ptrshift = shift; - new_ptr = (void*)((char*)new_ptr + shift); - if (mode & FALLOC_MEMCPY) - memcpy(new_ptr, ptr, old_size); - } - } - } - else if (new_size && (old_size || ptr)) - return errno = EINVAL, NULL; - else if (new_size) - new_ptr = falloc_malloc(new_size); - else if (old_size && ptr) - { - shift = ptrshift == NULL ? *ptrshift : 0; - if ((alignment > 1) && (ptrshift == NULL)) - return errno = EINVAL, NULL; - if (mode & FALLOC_CLEAR) - explicit_bzero(ptr, old_size); - falloc_free(ptr - shift); - return errno = 0, NULL; + if ((alignment > 1) && !ptrshift) goto invalid; + new_ptr = falloc_realloc(ptr, ptrshift ? ptrshift : &_ptrshift, + alignment ? alignment : 1, + old_size, new_size, mode, &shift); + shift = ptrshift ? *ptrshift : _ptrshift; } - else if (old_size || !ptr) - return errno = 0, NULL; - else - return errno = EINVAL, NULL; + else if (new_size && (old_size || ptr)) goto invalid; + else if (new_size) new_ptr = falloc_malloc(new_size); + else if (old_size && ptr) goto deallocate; + else if (old_size || !ptr) goto return_null; + else goto invalid; if (new_ptr != NULL) { @@ -528,5 +545,18 @@ void* falloc(void* ptr, size_t* ptrshift, size_t alignment, } return errno = 0, new_ptr; + + deallocate: + shift = ptrshift == NULL ? *ptrshift : 0; + if ((alignment > 1) && (ptrshift == NULL)) + goto invalid; + if (mode & FALLOC_CLEAR) + explicit_bzero(ptr, old_size); + falloc_free(ptr - shift); + return_null: + return errno = 0, NULL; + + invalid: + return errno = EINVAL, NULL; } |