stm32 lwip mqtt 修改发送接收长度和内存优化

mqtt的长度限制：

mqtt_opt.h(配置文件)

/**
 * Output ring-buffer size, must be able to fit largest outgoing publish message topic+payloads
 */
#ifndef MQTT_OUTPUT_RINGBUF_SIZE
#define MQTT_OUTPUT_RINGBUF_SIZE 256*4
#endif

/**
 * Number of bytes in receive buffer, must be at least the size of the longest incoming topic + 8
 * If one wants to avoid fragmented incoming publish, set length to max incoming topic length + max payload length + 8
 */
#ifndef MQTT_VAR_HEADER_BUFFER_LEN
#define MQTT_VAR_HEADER_BUFFER_LEN 128*4
#endif

lwip长度限制修改：

opt.h文件

/**
 * 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.
 */
#if !defined MEM_SIZE || defined __DOXYGEN__
#define MEM_SIZE                        1024*10
#endif

基于freertos优化lwip的pools

不单独开辟数组内存，直接通过frertos的内存申请释放，统一管理内存。

opt.h

/**
 * 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.
 */
#if !defined MEM_LIBC_MALLOC || defined __DOXYGEN__
#define MEM_LIBC_MALLOC                 1
#endif

mem.c

/* in case C library malloc() needs extra protection,
 * allow these defines to be overridden.
 */
//#ifndef mem_clib_free
//#define mem_clib_free free
//#endif
//#ifndef mem_clib_malloc
//#define mem_clib_malloc malloc
//#endif
//#ifndef mem_clib_calloc
//#define mem_clib_calloc calloc
//#endif
#ifndef mem_clib_free
#define mem_clib_free vPortFree  //(void * pv)
#endif
#ifndef mem_clib_malloc
#define mem_clib_malloc pvPortMalloc  //(size_t xWantedSize)
#endif
void* vPortcalloc(unsigned int num , unsigned int size)
{
    void *p;
    p = pvPortMalloc(num*size);
    if(p != NULL){
        memset(p,0,num*size);
    }
    return p;
}
#ifndef mem_clib_calloc
#define mem_clib_calloc vPortcalloc
#endif