OOM for setting rlimit

[htfy96]

Current rlimit implementation is:

rlimit.preHook() // set rlimit
cmd.start() // fork and exec
rlimit.postHook() // restore rlimit

Internally Golang will start a new coroutine waiting on this thread in line 2. However, it is possible that allocation in the creation of coroutine will lead to OOM since rlimit of current process is also set.

[htfy96]

ref: https://stackoverflow.com/questions/48295074/golang-limiting-child-processs-memory-usage-with-rlimit-without-affecting-curr