Re: Blocking syscalls in Tasks

["Randy Brukardt" <randy@rrsoftware.com>]

Probably because for Janus/Ada, pretty much everything you said about the 
mapping of Ada tasks to threads is wrong.

Janus/Ada still maps all tasks to one Windows thread. That was originally 
supposed to be a temporary Q&D implementation, but for a variety of reasons 
it never got replaced. Most obviously: other things needed work more 
urgently than the tasking, which is quite efficient. Depending on your 
circumstances, it might actually be faster than a threaded implementation. 
(Our ultimate goal is to have both.)

In any case, the point is that Ada doesn't say anything about the mapping of 
tasks to OS threads: you simply have to ask your vendor. And, of course 
blocking of system calls follows from that.

                     Randy.


"anon" <anon@anon.org> wrote in message 
news:eBUDk.245076$102.150485@bgtnsc05-news.ops.worldnet.att.net...
> Each and every time you speak you CUT the post down Ada!
> WHY are you trying to KILL Ada!  And I say nothing that is
> confusing except to those who hate Ada.
>
> An event thread is a blocked thread. See Microsoft Windows Documentation!
> LEARN before speaking!
>
> In <q7GdnQCVgLL7XkLVnZ2dnUVZ_h-dnZ2d@comcast.com>, tmoran@acm.org writes:
>>> Except for DOS in todays OS all Ada partitions are executed by native OS
>>> threads.
>>  This is confusing.  An Ada partition is not at all the same as an Ada
>>task, and there's no guarantee that an Ada task maps 1-1 to an OS thread.
>>
>>> Now, in a GUI system, the RC_TASK (resource task) is blocked until a 
>>> input
>>> device such as the mouse or keyboard actives the thread.
>>  MS Windows tasks do not block waiting for mouse or keyboard.  Windows
>>"event based" GUI design was based on a single thread and a polling loop.
>