Collaboration diagram for Heap and memory pools:
Macros | |
| #define | MEM_SIZE 1600 |
| #define | MEMP_OVERFLOW_CHECK 0 |
| #define | MEMP_SANITY_CHECK 0 |
| #define | MEM_USE_POOLS 0 |
| #define | MEM_USE_POOLS_TRY_BIGGER_POOL 0 |
| #define | MEMP_USE_CUSTOM_POOLS 0 |
| #define | LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT 0 |
Detailed Description
Macro Definition Documentation
| #define LWIP_ALLOW_MEM_FREE_FROM_OTHER_CONTEXT 0 |
Set this to 1 if you want to free PBUF_RAM pbufs (or call mem_free()) from interrupt context (or another context that doesn't allow waiting for a semaphore). If set to 1, mem_malloc will be protected by a semaphore and SYS_ARCH_PROTECT, while mem_free will only use SYS_ARCH_PROTECT. mem_malloc SYS_ARCH_UNPROTECTs with each loop so that mem_free can run.
ATTENTION: As you can see from the above description, this leads to dis-/ enabling interrupts often, which can be slow! Also, on low memory, mem_malloc can need longer.
If you don't want that, at least for NO_SYS=0, you can still use the following functions to enqueue a deallocation call which then runs in the tcpip_thread context:
- pbuf_free_callback(p);
- mem_free_callback(m);
| #define MEM_SIZE 1600 |
MEM_LIBC_MALLOC==1: Use malloc/free/realloc provided by your C-library instead of the lwip internal allocator. Can save code size if you already use it. MEMP_MEM_MALLOC==1: Use mem_malloc/mem_free instead of the lwip pool allocator. Especially useful with MEM_LIBC_MALLOC but handle with care regarding execution speed (heap alloc can be much slower than pool alloc) and usage from interrupts (especially if your netif driver allocates PBUF_POOL pbufs for received frames from interrupt)! ATTENTION: Currently, this uses the heap for ALL pools (also for private pools, not only for internal pools defined in memp_std.h)! MEM_ALIGNMENT: should be set to the alignment of the CPU 4 byte alignment -> #define MEM_ALIGNMENT 4 2 byte alignment -> #define MEM_ALIGNMENT 2 MEM_SIZE: the size of the heap memory. If the application will send a lot of data that needs to be copied, this should be set high.
| #define MEM_USE_POOLS 0 |
MEM_USE_POOLS==1: Use an alternative to malloc() by allocating from a set of memory pools of various sizes. When mem_malloc is called, an element of the smallest pool that can provide the length needed is returned. To use this, MEMP_USE_CUSTOM_POOLS also has to be enabled.
| #define MEM_USE_POOLS_TRY_BIGGER_POOL 0 |
| #define MEMP_OVERFLOW_CHECK 0 |
MEMP_OVERFLOW_CHECK: memp overflow protection reserves a configurable amount of bytes before and after each memp element in every pool and fills it with a prominent default value. MEMP_OVERFLOW_CHECK == 0 no checking MEMP_OVERFLOW_CHECK == 1 checks each element when it is freed MEMP_OVERFLOW_CHECK >= 2 checks each element in every pool every time memp_malloc() or memp_free() is called (useful but slow!)
Definition at line 288 of file opt.h.
Referenced by memp_init_pool().
| #define MEMP_SANITY_CHECK 0 |
MEMP_SANITY_CHECK==1: run a sanity check after each memp_free() to make sure that there are no cycles in the linked lists.
