Thanks for the detailed answer! I rewrote my test program to become tests the compressing process, but I got same result. But I got the reason. Each compressing process slice data to small chunks, and compress it in turn.
the order: data0: [ 1| 5| 9|13] data1: [ 2| 6|10|14] data2: [ 3| 7|11|15] data3: [ 4| 8|12|16] So, seemed to return after all process done. Oh in fact, them have completed at the same time really. Thanks a lot! 2012年12月6日木曜日 12時01分09秒 UTC+9 Bert Belder: > > On Thursday, December 6, 2012 3:18:42 AM UTC+1, 長島徹 wrote: >> >> Thanks for the response. >> >> Can I avoid or lessen that worker threads delay the JavaScript main >> thread? >> 4 CPU cores exists and HT supported. >> (I think ... the priority of main thread set to higher, ...?) >> > > The main thread can get pre-empted if you saturate all the cores in your > machine. (And yes, it would be possible in theory to ramp up the priority > of the main thread with pthread_setschedparam; you'll have to hack node or > create a compiled addon to do that though.) > > That however is not the "problem" that you are seeing here. Your seem to > assume that "reading and compressing a file" is executed as a single > operation in a thread pool thread. That's not how it works; node will first > read a small chunk of data in the thread pool, then compress it, then write > out the compressed data while reading in a new chunk of data in parallel, > etc. Effectively, each of your "compress-a-file" operations are broken up > in small chunks that are interleaved and partly run in parallel on the > thread pool; that's why you see them complete all at the same time. > > - Bert > -- 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 nodejs@googlegroups.com To unsubscribe from this group, send email to nodejs+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/nodejs?hl=en?hl=en
