[FFmpeg-cvslog] avutil/mem: fix doc for reallocs
Zhao Zhili
git at videolan.org
Thu May 26 12:19:43 EEST 2022
ffmpeg | branch: master | Zhao Zhili <quinkblack at foxmail.com> | Sat Apr 2 01:05:37 2022 +0800| [5d8d3c1ac211c3b13a2dcce5214dcf250c6c61f2] | committer: Zhao Zhili
avutil/mem: fix doc for reallocs
The doc says those function are like av_free if size or nmemb is
zero. It doesn't match the code. av_realloc() realloc one byte if
size is zero, which was added by 91ff05f6ac5 ten years ago.
realloc() itself in C is implementation-dependent. Make the doc
match the longstanding behaviour.
Signed-off-by: Zhao Zhili <zhilizhao at tencent.com>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=5d8d3c1ac211c3b13a2dcce5214dcf250c6c61f2
---
libavutil/mem.h | 23 +++++++++++------------
1 file changed, 11 insertions(+), 12 deletions(-)
diff --git a/libavutil/mem.h b/libavutil/mem.h
index b9fe80738c..d91174196c 100644
--- a/libavutil/mem.h
+++ b/libavutil/mem.h
@@ -250,8 +250,7 @@ void *av_mallocz_array(size_t nmemb, size_t size) av_malloc_attrib av_alloc_size
/**
* Allocate, reallocate, or free a block of memory.
*
- * If `ptr` is `NULL` and `size` > 0, allocate a new block. If `size` is
- * zero, free the memory block pointed to by `ptr`. Otherwise, expand or
+ * If `ptr` is `NULL` and `size` > 0, allocate a new block. Otherwise, expand or
* shrink that block of memory according to `size`.
*
* @param ptr Pointer to a memory block already allocated with
@@ -260,10 +259,11 @@ void *av_mallocz_array(size_t nmemb, size_t size) av_malloc_attrib av_alloc_size
* reallocated
*
* @return Pointer to a newly-reallocated block or `NULL` if the block
- * cannot be reallocated or the function is used to free the memory block
+ * cannot be reallocated
*
* @warning Unlike av_malloc(), the returned pointer is not guaranteed to be
- * correctly aligned.
+ * correctly aligned. The returned pointer must be freed after even
+ * if size is zero.
* @see av_fast_realloc()
* @see av_reallocp()
*/
@@ -311,8 +311,7 @@ void *av_realloc_f(void *ptr, size_t nelem, size_t elsize);
/**
* Allocate, reallocate, or free an array.
*
- * If `ptr` is `NULL` and `nmemb` > 0, allocate a new block. If
- * `nmemb` is zero, free the memory block pointed to by `ptr`.
+ * If `ptr` is `NULL` and `nmemb` > 0, allocate a new block.
*
* @param ptr Pointer to a memory block already allocated with
* av_realloc() or `NULL`
@@ -320,19 +319,19 @@ void *av_realloc_f(void *ptr, size_t nelem, size_t elsize);
* @param size Size of the single element of the array
*
* @return Pointer to a newly-reallocated block or NULL if the block
- * cannot be reallocated or the function is used to free the memory block
+ * cannot be reallocated
*
* @warning Unlike av_malloc(), the allocated memory is not guaranteed to be
- * correctly aligned.
+ * correctly aligned. The returned pointer must be freed after even if
+ * nmemb is zero.
* @see av_reallocp_array()
*/
av_alloc_size(2, 3) void *av_realloc_array(void *ptr, size_t nmemb, size_t size);
/**
- * Allocate, reallocate, or free an array through a pointer to a pointer.
+ * Allocate, reallocate an array through a pointer to a pointer.
*
- * If `*ptr` is `NULL` and `nmemb` > 0, allocate a new block. If `nmemb` is
- * zero, free the memory block pointed to by `*ptr`.
+ * If `*ptr` is `NULL` and `nmemb` > 0, allocate a new block.
*
* @param[in,out] ptr Pointer to a pointer to a memory block already
* allocated with av_realloc(), or a pointer to `NULL`.
@@ -343,7 +342,7 @@ av_alloc_size(2, 3) void *av_realloc_array(void *ptr, size_t nmemb, size_t size)
* @return Zero on success, an AVERROR error code on failure
*
* @warning Unlike av_malloc(), the allocated memory is not guaranteed to be
- * correctly aligned.
+ * correctly aligned. *ptr must be freed after even if nmemb is zero.
*/
int av_reallocp_array(void *ptr, size_t nmemb, size_t size);
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