Re: [ANNOUNCE] Native POSIX Thread Library 0.1

Mark Mielke
2002-09-23T22:53:55Z

On Mon, Sep 23, 2002 at 02:41:33PM -0700, dean gaudet wrote:
> so while this is I/O, it's certainly less efficient to have thousands of
> tasks blocked in read(2) versus having thousands of entries in <pick your
> favourite poll/select/etc. mechanism>.

In terms of kernel memory, perhaps. In terms of 'efficiency', I
wouldn't be so sure. Java uses a wack of user space storage to
represent threads regardless of whether they are green or native. The
only difference is - is Java calling poll()/select()/ioctl()
routinely? Or are the tasks sitting in an efficient kernel task queue?

Which has a better chance of being more efficient, in terms of dispatching,
(especially considering that most of the time, most java threads are idle),
and which has a better chance of being more efficient in terms of the
overhead of querying whether a task is ready to run? I lean towards the OS
on both counts.

mark

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