Only apply TracePoint to current thread

[arkadiyt]

Hi,

While upgrading to webmock 3.4.0 I found that some of my specs started failing. The way my tests are setup, in addition to using webmock for stubbing out requests in unit tests I also perform integration tests by making unmocked http requests against a WEBRick server running in a different thread in my rspec process.

After a bit of debugging I've narrowed the issue down to the TracePoint code added in #751 not being thread safe. In particular that code will undefine any local variable called tmp whenever any line of code is run in any thread, even not in the rbuf_fill thread for which it was intended.

The end result is I would get exceptions in places like webrick/log.rb#L152:

    def log(level, data)
      tmp = Time.now.strftime(@time_format)
      tmp << " " << data  # Throws exception here
      super(level, tmp)
    end

With errors on tmp << " " like undefined method '<<' for nil:NilClass (NoMethodError) (despite tmp having been immediately defined the line before).

Or webrick/httputils.rb#L211:

    def parse_qvalues(value)
      tmp = []
      if value
        parts = value.split(/,\s*/)
        parts.each {|part|
          if m = %r{^([^\s,]+?)(?:;\s*q=(\d+(?:\.\d+)?))?$}.match(part)
            val = m[1]
            q = (m[2] or 1).to_f
            tmp.push([val, q])  # Throws nil exception for undefined tmp here

My fix is to apply the tracepoint only to the rbuf_fill thread - after applying this change locally all my tests pass without exception.

Thanks

edit: I believe the jruby-9.0.5.0 failure on travis is unrelated to my change

[bblimke]

@arkadiyt Thank you for this fix!

[arkadiyt]

@bblimke thanks for merging - would it be possible to cut a new patch release for this?

[bblimke]

@arkadiyt Done. Thank you!