alex/esp-idf
alex/esp-idf
1
0
Fork 0
mirror of https://github.com/espressif/esp-idf.git synced 2024-10-05 20:47:46 -04:00
Code Issues Actions 2 Packages Projects Releases Wiki Activity

heap: remove misleading info about malloc being equivalent to heap_caps_malloc(p, MALLOC_CAP_8BIT)

Browse Source 
The actual memory allocated for malloc() depends on a lot of factors, see heap_caps_malloc_default()

Closes https://github.com/espressif/esp-idf/issues/7659
This commit is contained in:
Marius Vikhammer 2022-09-01 10:23:15 +08:00
parent 5a35714f2e
commit e1f27cf31b
2 changed files with 3 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
components/heap/include/esp_heap_caps.h
View File

@ -58,8 +58,6 @@ esp_err_t heap_caps_register_failed_alloc_callback(esp_alloc_failed_hook_t callb
*
* Equivalent semantics to libc malloc(), for capability-aware memory.
*
* In IDF, ``malloc(p)`` is equivalent to ``heap_caps_malloc(p, MALLOC_CAP_8BIT)``.
*
* @param size Size, in bytes, of the amount of memory to allocate
* @param caps Bitwise OR of MALLOC_CAP_* flags indicating the type
* of memory to be returned

4
docs/en/api-reference/system/mem_alloc.rst
View File

@ -30,7 +30,9 @@ For more details on these internal memory types, see :ref:`memory-layout`.
It's also possible to connect external SPI RAM to the {IDF_TARGET_NAME} - :doc:`external RAM </api-guides/external-ram>` can be integrated into the {IDF_TARGET_NAME}'s memory map using the flash cache, and accessed similarly to DRAM.
DRAM uses capability ``MALLOC_CAP_8BIT`` (accessible in single byte reads and writes). When calling ``malloc()``, the ESP-IDF ``malloc()`` implementation internally calls ``heap_caps_malloc(size, MALLOC_CAP_8BIT)`` in order to allocate DRAM that is byte-addressable. To test the free DRAM heap size at runtime, call cpp:func:`heap_caps_get_free_size(MALLOC_CAP_8BIT)`.
DRAM uses capability ``MALLOC_CAP_8BIT`` (accessible in single byte reads and writes). To test the free DRAM heap size at runtime, call cpp:func:`heap_caps_get_free_size(MALLOC_CAP_8BIT)`.
When calling ``malloc()``, the ESP-IDF ``malloc()`` implementation internally calls cpp:func:`heap_caps_malloc_default(size)`. This will allocate memory with capability ``MALLOC_CAP_DEFAULT``, which is byte-addressable.
Because malloc uses the capabilities-based allocation system, memory allocated using :cpp:func:`heap_caps_malloc` can be freed by calling
the standard ``free()`` function.