[tcp] BUS Fault occurs when running TCPEchoServ4_DHCP.js over night

[qiaojingx]

Description

Using python client to send data continuously to TCPEchoServ4_DHCP.js on FRDM-K64F over night, BUS Fault error will occurs.

Test Code

TCPEchoServ4_DHCP.js
Python client: test-tcp4-client-dhcp.py

 # !usr/bin/python
# coding:utf-8

import time
import socket
import sys

def main():
    print "Socket client creat successful"

    host = sys.argv[1]
    port = 4242
    bufSize = 1024
    addr = (host, port)
    Timeout = 300

    mySocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    mySocket.settimeout(Timeout)
    try:
        mySocket.connect(addr)
    except :
        print "Socket connect failed"

    try:
        sendData = "hello"
        mySocket.sendall(sendData)
        print "Send data: ", sendData
    except :
        print "Socket send data failed"

    try:
        recvData = mySocket.recv(bufSize)
        recvData = recvData.strip()
        print "Got data: ", recvData
    except :
        print "Socket receive data failed"

    if recvData == sendData:
        mySocket.close()
        print "Close socket"
    else :
        print "Data error"

if __name__ == "__main__" :
    i = 0
    while 1:
        try:
            i = i + 1
            print "\nTimes: ", i
            main()
            time.sleep(10)
        except KeyboardInterrupt :
            print "exit python case"
            break
        except :
            print "Error occurred"
            break

Steps to Reproduction

1. make JS=samples/TCPEchoServ4_DHCP.js BOARD=frdm_k64f
2. cp outdir/frdm_k64f/zephyr/zephyr.bin /media/<username>/MBED/
3. connect FRDM-K64F and PC to the same router
4. python test-tcp4-client-dhcp.py <IP address>

Actual Result

Expected Result

No error occurs

Test Builds

Branch	Commit Id	Target Device	Test Date	Result
master	b32969f	FRDM-K64F	Dec 28, 2017	Fail

Additional Information

[jimmy-huang]

@cuiyanx please re-test with #1816

[qiaojingx]

Verified with commit d09e4b3 + #1816，this issue is not reproduced after 4 hours.
Waiting for result over night

[qiaojingx]

Verified with commit d09e4b3 + #1816，this issue is not reproduced after running over night.