[ANN] slave-0.0.1

ruby-talk
1

URIS

   http://codeforpeople.com/lib/ruby/slave/
   http://rubyforge.org/frs/?group_id=1024&release_id=5631

SYNOPSIS

   the Slave class forks a process and starts a drb server in the child using
   any object as the server. the process is detached so it is not required
   (nor possible) to wait on the child pid. a Heartbeat is set up between the
   parent and child processes so that the child will exit of the parent exits
   for any reason - preventing orphaned slaves from running indefinitely. the
   purpose of Slaves is to be able to easily set up a collection of objects
   communicating via drb protocols instead of having to use IPC.

   typical usage:

     obj = AnyClass::new

···

#
     slave = Slave::new obj # object becomes drb server in another
                                     # process

     p slave.object # handle on drb object
     p slave.uri # uri of the drb object
     p slave.socket # unix domain socket path for drb object
     p slave.psname # title shown in ps/top

     obj = slave.object

                                     #
     p obj.method # call a method on drb server in another
                                     # process

   other usage:

   set the pulse_rate used for the Heartbeat

     slave = Slave::new MyClass::new, 'pulse_rate' => 10

   same

     Slave::pulse_rate = 10
     slave = Slave::new MyClass::new

   same

     ENV['SLAVE_PULSE_RATE'] = 10
     slave = Slave::new MyClass::new

   slaves may be configured via the environment, the Slave class, or via the ctor
   for object itself. attributes which may be configured include

   * socket_creation_attempts
   * pulse_rate
   * psname
   * debug

INSTALL

   gem install slave

enjoy.

-a
--
suffering increases your inner strength. also, the wishing for suffering
makes the suffering disappear.
- h.h. the 14th dali lama

2

Ara,

I am trying to use your package on Windows. I'm running into an issue at
line 341 of slave.rb:

  @pipe.fcntl Fcntl::F_SETFD, Fcntl::FD_CLOEXEC

I'm curious what these flags mean and what their equivalent on Windows might
be (if any).

I already solved a couple of issues (well, hacked around them):

1) No fork() on windows. Solved by installing Daniel Berger's win32-process
gem
2) "drbunix" URI fails on non-unix. Solved by passing nil to
Drb.start_service (ugly hack, hoping to make it cleaner later)

Thanks for any help!

Justin

3

Ara.T.Howard wrote:

  http://codeforpeople.com/lib/ruby/slave/
...
  the Slave class forks a process and starts a drb server in the child
...
    slave = Slave::new MyClass::new, 'pulse_rate' => 10

'Master' and 'Slave' labels unacceptable.

"Based on the cultural diversity and sensitivity of Los Angeles County,
this is not an acceptable identification label."

http://www.cnn.com/2003/TECH/ptech/11/26/master.term.reut/

Enjoy,
Dave

4

hi justin-

I am trying to use your package on Windows. I'm running into an issue at
line 341 of slave.rb:

@pipe.fcntl Fcntl::F_SETFD, Fcntl::FD_CLOEXEC

I'm curious what these flags mean and what their equivalent on Windows might
be (if any).

it means that, should the parent do something like

   exec 'another_program.exe'

the pipe will be closed. it's important since pids are recycled and pipes
transfered the slave would live on for while - perhaps indefinitely.

of course it's possible that behaviour is desireable, but then a zombie would
also be created... anyhow, for hacking it's safe to comment that out.

I already solved a couple of issues (well, hacked around them):

1) No fork() on windows. Solved by installing Daniel Berger's win32-process
gem
2) "drbunix" URI fails on non-unix. Solved by passing nil to
Drb.start_service (ugly hack, hoping to make it cleaner later)

this could easily be configured - check out how the other stuff is configured
and do something like allow the ENV var 'SLAVE_DRB_PROTOCOL' to override
this... perhaps a better option might be

   Drb.start_server 'drb://localhost.localdomain:0'

note that 'nil' here doesn't work on macs for some reason...

i'm running out the door now, but i'd love to make this work on windows - just
for the challenge. maybe dan can lend a hand? :wink:

maybe we can work together and make another release that's portable. ping me
offline if your're interested.

cheers.

-a

···

On Fri, 9 Jun 2006, Justin Bailey wrote:
--
suffering increases your inner strength. also, the wishing for suffering
makes the suffering disappear.
- h.h. the 14th dali lama

5

Cloexec doesn't exist on Windows. It would be meaningless anyway, because
there's no notion of a fork. In effect, everything is cloexec.

···

On 6/8/06, ara.t.howard@noaa.gov <ara.t.howard@noaa.gov> wrote:

On Fri, 9 Jun 2006, Justin Bailey wrote:

hi justin-

> I am trying to use your package on Windows. I'm running into an issue at
> line 341 of slave.rb:
>
> @pipe.fcntl Fcntl::F_SETFD, Fcntl::FD_CLOEXEC
>
> I'm curious what these flags mean and what their equivalent on Windows
might
> be (if any).

it means that, should the parent do something like

   exec 'another_program.exe'

the pipe will be closed. it's important since pids are recycled and pipes
transfered the slave would live on for while - perhaps indefinitely.

of course it's possible that behaviour is desireable, but then a zombie
would
also be created... anyhow, for hacking it's safe to comment that out.

> I already solved a couple of issues (well, hacked around them):
>
> 1) No fork() on windows. Solved by installing Daniel
Berger's win32-process
> gem
> 2) "drbunix" URI fails on non-unix. Solved by passing nil to
> Drb.start_service (ugly hack, hoping to make it cleaner later)

this could easily be configured - check out how the other stuff is
configured
and do something like allow the ENV var 'SLAVE_DRB_PROTOCOL' to override
this... perhaps a better option might be

   Drb.start_server 'drb://localhost.localdomain:0'

note that 'nil' here doesn't work on macs for some reason...

i'm running out the door now, but i'd love to make this work on windows -
just
for the challenge. maybe dan can lend a hand? :wink:

maybe we can work together and make another release that's portable. ping
me
offline if your're interested.

cheers.

-a
--
suffering increases your inner strength. also, the wishing for suffering
makes the suffering disappear.
- h.h. the 14th dali lama

6

IPv6?

···

On Jun 8, 2006, at 5:58 PM, ara.t.howard@noaa.gov wrote:

2) "drbunix" URI fails on non-unix. Solved by passing nil to
Drb.start_service (ugly hack, hoping to make it cleaner later)

this could easily be configured - check out how the other stuff is configured
and do something like allow the ENV var 'SLAVE_DRB_PROTOCOL' to override
this... perhaps a better option might be

  Drb.start_server 'drb://localhost.localdomain:0'

note that 'nil' here doesn't work on macs for some reason...

--
Eric Hodel - drbrain@segment7.net - http://blog.segment7.net
This implementation is HODEL-HASH-9600 compliant

http://trackmap.robotcoop.com

7

everything on windows is meaningless to me :wink: care to review the code and
suggest a way to make it portable?

cheers.

-a

···

On Fri, 9 Jun 2006, Francis Cianfrocca wrote:

Cloexec doesn't exist on Windows. It would be meaningless anyway, because
there's no notion of a fork. In effect, everything is cloexec.

--
suffering increases your inner strength. also, the wishing for suffering
makes the suffering disappear.
- h.h. the 14th dali lama