Re: [lwip-users] lwip: Scan through the heap searching for a free block that is big enough, beginning with the lowest free block.

[address@hidden]

Am 25.03.2019 um 10:52 schrieb vrnud:
> Hi,
>
> I am trying to impelement modbus over TCPIP.
> I am using FreeRTOS + lwip +STM32f4 (cube Mx generated code).
> Lwip version is 2.0.0.
> Freertos version 9.0.0.
> heap 4 is used. is it ok?
>
> TCPIP echo server application is used.
> while trying to connect from Modscan utility program stucks in
> mem.c file . function mem_malloc.

What does "stuck" mean? Endless loop in mem_malloc? If so, that's an
indication that the list is broken, which in turn is an indication for
violating lwIP's threading rules.

Regards,
Simon

>     /* Scan through the heap searching for a free block that is big enough,
> modbus_connect_problem.pcap
> <http://lwip.100.n7.nabble.com/file/t2188/modbus_connect_problem.pcap>
>       * beginning with the lowest free block.
>       */
> under this loop.
>   for (ptr = (mem_size_t)((u8_t *)lfree - ram); ptr < MEM_SIZE_ALIGNED -
> size;
>           ptr = ((struct mem *)(void *)&ram[ptr])->next) {
> }
>
> I have enabled the modbus_connect_problem.pcap
> <http://lwip.100.n7.nabble.com/file/t2188/modbus_connect_problem.pcap>
> CHECKSUM_GEN_IP 1
> CHECKSUM_GEN_TCP 1
> I have attached the wireshark report.
>
>
> Kindly guide.