Re: Roadmap for a Win32 port

I might be naive here, but would not proper threading model remove the need
for fork() altogether? On both Unix and Win32? Should not be too hard to
come up with abstraction which encapsulates POSIX, BeOS and Win32 threads...
I am not sure how universal POSIX threads are by now. Any important Unix
platforms which don't support them yet?

This has downside of letting any bug to kill the whole thing. On the bright
side, performance should be better on some platforms (note however, Apache
group still can't come up with implementation of threaded model which would
provide better performance than forked or other models). The need to deal
with possibility of 'alien' postmaster running along with orphaned backends
would also be removed since there would be only one process.

Issue of thread safety of code will come up undoubtedly and some things will
probably have to be revamped. But in long term this is probably best way if
you want to have efficient and uniform Unix AND Win32 implementations.

I am not too familiar with Win32. Speaking about POSIX threads, it would be
something like a thread pool with low & high watermarks. Main thread would
handle thread pool and hand over requests to worker threads (blocked on
condvar). How does that sound?

-- igor

----- Original Message -----
From: "Bruce Momjian" <pgman(at)candle(dot)pha(dot)pa(dot)us>
To: "PostgreSQL-development" <pgsql-hackers(at)postgresql(dot)org>
Sent: Tuesday, June 04, 2002 11:33 PM
Subject: [HACKERS] Roadmap for a Win32 port

> OK, I think I am now caught up on the Win32/cygwin discussion, and would
> like to make some remarks.
>
> First, are we doing enough to support the Win32 platform? I think the
> answer is clearly "no". There are 3-5 groups/companies working on Win32
> ports of PostgreSQL. We always said there would not be PostgreSQL forks
> if we were doing our job to meet user needs. Well, obviously, a number
> of groups see a need for a better Win32 port and we aren't meeting that
> need, so they are. I believe this is one of the few cases where groups
> are going out on their own because we are falling behind.
>
> So, there is no question in my mind we need to do more to encourage
> Win32 ports. Now, on to the details.
>
> INSTALLER
> ---------
>
> We clearly need an installer that is zero-hassle for users. We need to
> decide on a direction for this.
>
> GUI
> ---
>
> We need a slick GUI. pgadmin2 seems to be everyone's favorite, with
> pgaccess on Win32 also an option. What else do we need here?
>
> BINARY
> ------
>
> This is the big daddy. It is broken down into several sections:
>
> FORK()
>
> How do we handle fork()? Do we use the cygwin method that copies the
> whole data segment, or put the global data in shared memory and copy
> that small part manually after we create a new process?
>
> THREADING
>
> Related to fork(), do we implement an optionally threaded postmaster,
> which eliminates CreateProcess() entirely? I don't think we will have
> superior performance on Win32 without it. (This would greatly help
> Solaris as well.)
>
> IPC
>
> We can use Cygwin, MinGW, Apache, or our own code for this. Are there
> other options?
>
> ENVIRONMENT
>
> Lots of our code requires a unix shell and utilities. Will we continue
> using cygwin for this?
>
> --------------------------------------------------------------------------
-
>
> As a roadmap, it would be good to get consensus on as many of these
> items as possible so people can start working in these areas. We can
> keep a web page of decisions we have made to help rally developers to
> the project.
>
> --
> Bruce Momjian | http://candle.pha.pa.us
> pgman(at)candle(dot)pha(dot)pa(dot)us | (610) 853-3000
> + If your life is a hard drive, | 830 Blythe Avenue
> + Christ can be your backup. | Drexel Hill, Pennsylvania 19026
>
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