On Thu, May 1, 2014 at 4:34 PM, Kees k <[email protected]> wrote: > Managed to solve this problem. The same piece of code takes now < 100 usec. > > Strange thing is still that there is a big difference when i measure the > execution time of my whole modbus reply function when measured from > javscript or in c++. > > C++ code takes only 5 ms to execute, but the additional javascript glue adds > another 2 ms on top of this. Does anyone now what the glue does? Does this > result from dynamically loading a large size *.node file? > > Async call to reply function >> >> Handle<Value> js_reply_async(const Arguments& args) { >> >> reply_t* reply = new reply_t; >> clock_gettime(CLOCK_MONOTONIC, &reply->tstart); >> ... >> uv_work_t* req = new uv_work_t(); >> req->data = reply; >> uv_queue_work(uv_default_loop(), req, reply_work, (uv_after_work_cb) >> reply_after); > > Just before performing the callback to javascript >> >> clock_gettime(CLOCK_MONOTONIC, &reply->tstop); >> reply->cb->Call(Context::GetCurrent()->Global(), 1, argv); >> reply->cb.Dispose(); >> printf("Startaddress %d offset %d ts %lu s, %lu ns\n", ((reply->req[2] >> <<8) | reply->req[3]), ((reply->req[4] <<8) | reply->req[5]), >> reply->tstop.tv_sec-reply->tstart.tv_sec, >> reply->tstop.tv_nsec-reply->tstart.tv_nsec); > > And my javascript >> >> var starttime = timers.nanotime(timers.CLOCK_MONOTONIC); >> mb.reply(self.ctx, query, len, startAddress, offset, data, >> self.settings.nrRegisters, function(error){ >> var stoptime = timers.nanotime(timers.CLOCK_MONOTONIC); >> console.log("startAddress " + startAddress + "\tlen " + len + "\tduration >> "+ ((stoptime.sec * 1000 + stoptime.nsec / 1e6) - (starttime.sec * 1000 + >> starttime.nsec / 1e6)) + " ms"); >> }
I'm not entirely sure what you mean by glue but if it's uv_queue_work() that you're referring to, that executes the work in a shared, fixed-size thread pool. That inevitably adds (variable) latency. -- -- Job Board: http://jobs.nodejs.org/ Posting guidelines: https://github.com/joyent/node/wiki/Mailing-List-Posting-Guidelines You received this message because you are subscribed to the Google Groups "nodejs" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/nodejs?hl=en?hl=en --- You received this message because you are subscribed to the Google Groups "nodejs" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
