lwip: fix socket memory leak issue
1. Add socket memory leak debug counter
2. Fix TCP PCB leak issue
Currently ESP32 support maximum 16 TCP PCBs and all TCP PCB are allocated from heap memory. In some scenario, we may
have memory leak issue, for example, the application already created 16 TCP PCB, then it close 5 of them, because the TCP
state machine, the LWIP core may not free all the 5 TCP PCB immediately, maybe some is in TIME_WAIT status, some is in
FIN_WAIT_1 etc. Then the application try to malloc 17th TCP PCB (the application think they just create 12 because they already
close 5), memp_malloc() will return true because the heap is not out of memory, but actually we got 17 TCP PCB. When the
scenario repeat again and again (in our Audio application, it repeat more than 10000 times), more and more TCP PCB will be
created in the system, each TCP PCB require 200B, then memory leak happen (In Audio application, I saw more than 26 TCP PCB
are created, and 10*200=2K memory are leaked).
See merge request !223
LWIP will drop the oldest package at the arp packet cache queue and return "ERR_OK"
We change it that ARP level will drop the current packet and return "ERR_MEM" to tell user that you should send the packet again latter.
When the parameter pbuf for low_level_output is a list, malloc a new pbuf of
which the length equals to the total length of pbuf and send the new pbuf to L2
New makefile component_wrapper.mk allows some variables to be set
before component.mk is evaluated. This properly fixes problems with
sdkconfig being hard to access in all phases of the build.
Including component_common.mk is no longer necessary and will print a
deprecation warning for components which use it.
LwIP will define O_NONBLOCK in sockets.h if it isn't defined yet.
If sys/fcntl.h is included after socket.h, there will be duplicate definition.
Work around by including sys/fcntl.h into lwipopts.h.
https://github.com/espressif/esp-idf/issues/75
Since the customers need more sockets in their application, support max 16 sockets,
in other words, the total socket number of UDP/TCP/RAW sockets should not exceed 16.
1. Modify comments for esp_wifi_internal_tx
2. Fix delay time error in esp32_tx_flow_ctrl which is found in code review,
modify _wait_delay init value from 0 to 1
- put contents of a few headers into c++ guard blocks
- fix off-by-one error in do_global_ctors
- remove system_init from startup code (should be called from main)
For third party components (lwip and expat), compilation flags are adjusted to silence existing warnings (i have manually checked that all warnings are benign).
In components/esp32, replaced use of WIFI_DEBUG with ESP_LOG functions.
Only remaining warning is in FreeRTOS queue.c, and it may be a useful one.
lwip: add debug code to show udp/tcp pcbs
Add code to show all tcp/udp pcbs, these kind of debug info is helpful for lwip issue debugging.
See merge request !98
